Re: linux-next-20180601: build error in arch/arm64/kvm/hyp/hyp-entry.S
Hi Stefan, On Fri, Jun 01, 2018 at 10:05:07PM +0200, Stefan Wahren wrote: > i can't build todays linux-next-20180601 and get the following error message: > > arch/arm64/kvm/hyp/hyp-entry.S: Assembler messages: > arch/arm64/kvm/hyp/hyp-entry.S:128: Error: constant expression required at > operand 3 -- `bfi x0,x1,#VCPU_WORKAROUND_2_FLAG_SHIFT,#1' > > Related commit: > arm64: KVM: Handle guest's ARCH_WORKAROUND_2 requests > > Toolchain: gcc-linaro-7.2.1-2017.11-x86_64_aarch64-linux-gnu > Kernel config: arm64/defconfig Thanks for reporting this. I can hit this as well. It looks like an #ifndef __ASSEMBLY__ in the wrong place in arch/arm64/include/asm/kvm_asm.h. I can't tell whether it was caused by a merge conflict resolution or just some unfortunate interaction between the security fixes going via the arm64 tree and the other arm64 KVM patches. I'll have a proper look tomorrow. -- Catalin ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
Re: [GIT PULL] KVM/ARM updates for 4.18
On 01/06/2018 17:27, Marc Zyngier wrote: > Paolo, Radim, > > This is the set of updates for KVM/ARM for v4.18. This time, lazy > context switching of the floating point registers for arm64, and the > ability to deal with multiple redistributor ranges (which allows for > larger numbers of vcpu). > > Note that some additional KVM/ARM updates will come via the arm64 tree > with the SSBD patches. This will generate three conflicts that are > pretty simple to resolve (-next has a good example of the resolution). > > Please pull, > > M. > > The following changes since commit 75bc37fefc4471e718ba8e651aa74673d4e0a9eb: > > Linux 4.17-rc4 (2018-05-06 16:57:38 -1000) > > are available in the Git repository at: > > git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git > tags/kvmarm-for-v4.18 > > for you to fetch changes up to e25028c8ded011d19f9a11164807507c94febc01: > > KVM: arm/arm64: Bump VGIC_V3_MAX_CPUS to 512 (2018-05-25 12:29:27 +0100) > > > KVM/ARM updates for 4.18 > > - Lazy context-switching of FPSIMD registers on arm64 > - Allow virtual redistributors to be part of two or more MMIO ranges Pulled, thanks. Paolo ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
[PATCH 33/33] KVM: arm/arm64: Bump VGIC_V3_MAX_CPUS to 512
From: Eric Auger Let's raise the number of supported vcpus along with vgic v3 now that HW is looming with more physical CPUs. Signed-off-by: Eric Auger Acked-by: Christoffer Dall Signed-off-by: Marc Zyngier --- include/kvm/arm_vgic.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index 08ccbe37dcda..cfdd2484cc42 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -28,7 +28,7 @@ #include -#define VGIC_V3_MAX_CPUS 255 +#define VGIC_V3_MAX_CPUS 512 #define VGIC_V2_MAX_CPUS 8 #define VGIC_NR_IRQS_LEGACY 256 #define VGIC_NR_SGIS 16 -- 2.17.1 ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
[PATCH 32/33] KVM: arm/arm64: Implement KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION
From: Eric Auger
Now all the internals are ready to handle multiple redistributor
regions, let's allow the userspace to register them.
Signed-off-by: Eric Auger
Reviewed-by: Christoffer Dall
Signed-off-by: Marc Zyngier
---
virt/kvm/arm/vgic/vgic-kvm-device.c | 40 -
virt/kvm/arm/vgic/vgic-mmio-v3.c| 4 +--
virt/kvm/arm/vgic/vgic-v3.c | 14 ++
virt/kvm/arm/vgic/vgic.h| 13 +-
4 files changed, 67 insertions(+), 4 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c
b/virt/kvm/arm/vgic/vgic-kvm-device.c
index 76ab3691f7fe..6ada2432e37c 100644
--- a/virt/kvm/arm/vgic/vgic-kvm-device.c
+++ b/virt/kvm/arm/vgic/vgic-kvm-device.c
@@ -92,7 +92,7 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64
*addr, bool write)
if (r)
break;
if (write) {
- r = vgic_v3_set_redist_base(kvm, *addr);
+ r = vgic_v3_set_redist_base(kvm, 0, *addr, 0);
goto out;
}
rdreg = list_first_entry(&vgic->rd_regions,
@@ -103,6 +103,43 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64
*addr, bool write)
addr_ptr = &rdreg->base;
break;
}
+ case KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION:
+ {
+ struct vgic_redist_region *rdreg;
+ u8 index;
+
+ r = vgic_check_type(kvm, KVM_DEV_TYPE_ARM_VGIC_V3);
+ if (r)
+ break;
+
+ index = *addr & KVM_VGIC_V3_RDIST_INDEX_MASK;
+
+ if (write) {
+ gpa_t base = *addr & KVM_VGIC_V3_RDIST_BASE_MASK;
+ u32 count = (*addr & KVM_VGIC_V3_RDIST_COUNT_MASK)
+ >> KVM_VGIC_V3_RDIST_COUNT_SHIFT;
+ u8 flags = (*addr & KVM_VGIC_V3_RDIST_FLAGS_MASK)
+ >> KVM_VGIC_V3_RDIST_FLAGS_SHIFT;
+
+ if (!count || flags)
+ r = -EINVAL;
+ else
+ r = vgic_v3_set_redist_base(kvm, index,
+ base, count);
+ goto out;
+ }
+
+ rdreg = vgic_v3_rdist_region_from_index(kvm, index);
+ if (!rdreg) {
+ r = -ENOENT;
+ goto out;
+ }
+
+ *addr = index;
+ *addr |= rdreg->base;
+ *addr |= (u64)rdreg->count << KVM_VGIC_V3_RDIST_COUNT_SHIFT;
+ goto out;
+ }
default:
r = -ENODEV;
}
@@ -674,6 +711,7 @@ static int vgic_v3_has_attr(struct kvm_device *dev,
switch (attr->attr) {
case KVM_VGIC_V3_ADDR_TYPE_DIST:
case KVM_VGIC_V3_ADDR_TYPE_REDIST:
+ case KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION:
return 0;
}
break;
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index 1c6c535585e1..287784095b5b 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -764,11 +764,11 @@ static int vgic_v3_insert_redist_region(struct kvm *kvm,
uint32_t index,
return ret;
}
-int vgic_v3_set_redist_base(struct kvm *kvm, u64 addr)
+int vgic_v3_set_redist_base(struct kvm *kvm, u32 index, u64 addr, u32 count)
{
int ret;
- ret = vgic_v3_insert_redist_region(kvm, 0, addr, 0);
+ ret = vgic_v3_insert_redist_region(kvm, index, addr, count);
if (ret)
return ret;
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index eb32b213f600..7c6d278b8aee 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -491,6 +491,20 @@ struct vgic_redist_region *vgic_v3_rdist_free_slot(struct
list_head *rd_regions)
return NULL;
}
+struct vgic_redist_region *vgic_v3_rdist_region_from_index(struct kvm *kvm,
+ u32 index)
+{
+ struct list_head *rd_regions = &kvm->arch.vgic.rd_regions;
+ struct vgic_redist_region *rdreg;
+
+ list_for_each_entry(rdreg, rd_regions, list) {
+ if (rdreg->index == index)
+ return rdreg;
+ }
+ return NULL;
+}
+
+
int vgic_v3_map_resources(struct kvm *kvm)
{
struct vgic_dist *dist = &kvm->arch.vgic;
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 1c8af4e4131c..6879cf48652a 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -96,6 +96,13 @@
/* we only support 64 kB translation table page size */
#define KVM_ITS_L1E_ADDR_MASK GENMASK_ULL(51, 16)
+#define KVM_VGIC_V3_RDIST_INDEX_MASK GENMASK_ULL(11,
[PATCH 31/33] KVM: arm/arm64: Add KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION
From: Eric Auger
This new attribute allows the userspace to set the base address
of a reditributor region, relaxing the constraint of having all
consecutive redistibutor frames contiguous.
Signed-off-by: Eric Auger
Acked-by: Christoffer Dall
Signed-off-by: Marc Zyngier
---
arch/arm/include/uapi/asm/kvm.h | 1 +
arch/arm64/include/uapi/asm/kvm.h | 1 +
2 files changed, 2 insertions(+)
diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h
index caae4843cb70..16e006f708ca 100644
--- a/arch/arm/include/uapi/asm/kvm.h
+++ b/arch/arm/include/uapi/asm/kvm.h
@@ -91,6 +91,7 @@ struct kvm_regs {
#define KVM_VGIC_V3_ADDR_TYPE_DIST 2
#define KVM_VGIC_V3_ADDR_TYPE_REDIST 3
#define KVM_VGIC_ITS_ADDR_TYPE 4
+#define KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION5
#define KVM_VGIC_V3_DIST_SIZE SZ_64K
#define KVM_VGIC_V3_REDIST_SIZE(2 * SZ_64K)
diff --git a/arch/arm64/include/uapi/asm/kvm.h
b/arch/arm64/include/uapi/asm/kvm.h
index 04b3256f8e6d..4e76630dd655 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -91,6 +91,7 @@ struct kvm_regs {
#define KVM_VGIC_V3_ADDR_TYPE_DIST 2
#define KVM_VGIC_V3_ADDR_TYPE_REDIST 3
#define KVM_VGIC_ITS_ADDR_TYPE 4
+#define KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION5
#define KVM_VGIC_V3_DIST_SIZE SZ_64K
#define KVM_VGIC_V3_REDIST_SIZE(2 * SZ_64K)
--
2.17.1
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[PATCH 30/33] KVM: arm/arm64: Check all vcpu redistributors are set on map_resources
From: Eric Auger
On vcpu first run, we eventually know the actual number of vcpus.
This is a synchronization point to check all redistributors
were assigned. On kvm_vgic_map_resources() we check both dist and
redist were set, eventually check potential base address inconsistencies.
Signed-off-by: Eric Auger
Reviewed-by: Christoffer Dall
Signed-off-by: Marc Zyngier
---
virt/kvm/arm/vgic/vgic-v3.c | 19 ++-
1 file changed, 14 insertions(+), 5 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index ce4476a08f5b..eb32b213f600 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -493,16 +493,25 @@ struct vgic_redist_region *vgic_v3_rdist_free_slot(struct
list_head *rd_regions)
int vgic_v3_map_resources(struct kvm *kvm)
{
- int ret = 0;
struct vgic_dist *dist = &kvm->arch.vgic;
- struct vgic_redist_region *rdreg =
- list_first_entry(&dist->rd_regions,
-struct vgic_redist_region, list);
+ struct kvm_vcpu *vcpu;
+ int ret = 0;
+ int c;
if (vgic_ready(kvm))
goto out;
- if (IS_VGIC_ADDR_UNDEF(dist->vgic_dist_base) || !rdreg) {
+ kvm_for_each_vcpu(c, vcpu, kvm) {
+ struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+
+ if (IS_VGIC_ADDR_UNDEF(vgic_cpu->rd_iodev.base_addr)) {
+ kvm_debug("vcpu %d redistributor base not set\n", c);
+ ret = -ENXIO;
+ goto out;
+ }
+ }
+
+ if (IS_VGIC_ADDR_UNDEF(dist->vgic_dist_base)) {
kvm_err("Need to set vgic distributor addresses first\n");
ret = -ENXIO;
goto out;
--
2.17.1
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[PATCH 29/33] KVM: arm/arm64: Check vcpu redist base before registering an iodev
From: Eric Auger As we are going to register several redist regions, vgic_register_all_redist_iodevs() may be called several times. We need to register a redist_iodev for a given vcpu only once. So let's check if the base address has already been set. Initialize this latter in kvm_vgic_vcpu_init(). Signed-off-by: Eric Auger Acked-by: Christoffer Dall Signed-off-by: Marc Zyngier --- virt/kvm/arm/vgic/vgic-init.c| 3 +++ virt/kvm/arm/vgic/vgic-mmio-v3.c | 3 +++ 2 files changed, 6 insertions(+) diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c index 272af9704952..2673efce65f3 100644 --- a/virt/kvm/arm/vgic/vgic-init.c +++ b/virt/kvm/arm/vgic/vgic-init.c @@ -199,6 +199,9 @@ int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu) int ret = 0; int i; + vgic_cpu->rd_iodev.base_addr = VGIC_ADDR_UNDEF; + vgic_cpu->sgi_iodev.base_addr = VGIC_ADDR_UNDEF; + INIT_LIST_HEAD(&vgic_cpu->ap_list_head); spin_lock_init(&vgic_cpu->ap_list_lock); diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c index 3dbc057f861b..1c6c535585e1 100644 --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c @@ -592,6 +592,9 @@ int vgic_register_redist_iodev(struct kvm_vcpu *vcpu) gpa_t rd_base, sgi_base; int ret; + if (!IS_VGIC_ADDR_UNDEF(vgic_cpu->rd_iodev.base_addr)) + return 0; + /* * We may be creating VCPUs before having set the base address for the * redistributor region, in which case we will come back to this -- 2.17.1 ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
[PATCH 28/33] KVM: arm/arm64: Remove kvm_vgic_vcpu_early_init
From: Eric Auger
kvm_vgic_vcpu_early_init gets called after kvm_vgic_cpu_init which
is confusing. The call path is as follows:
kvm_vm_ioctl_create_vcpu
|_ kvm_arch_cpu_create
|_ kvm_vcpu_init
|_ kvm_arch_vcpu_init
|_ kvm_vgic_vcpu_init
|_ kvm_arch_vcpu_postcreate
|_ kvm_vgic_vcpu_early_init
Static initialization currently done in kvm_vgic_vcpu_early_init()
can be moved to kvm_vgic_vcpu_init(). So let's move the code and
remove kvm_vgic_vcpu_early_init(). kvm_arch_vcpu_postcreate() does
nothing.
Signed-off-by: Eric Auger
Signed-off-by: Marc Zyngier
---
include/kvm/arm_vgic.h| 1 -
virt/kvm/arm/arm.c| 1 -
virt/kvm/arm/vgic/vgic-init.c | 80 ---
3 files changed, 37 insertions(+), 45 deletions(-)
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 90e489f685ae..08ccbe37dcda 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -338,7 +338,6 @@ void kvm_vgic_early_init(struct kvm *kvm);
int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu);
int kvm_vgic_create(struct kvm *kvm, u32 type);
void kvm_vgic_destroy(struct kvm *kvm);
-void kvm_vgic_vcpu_early_init(struct kvm_vcpu *vcpu);
void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu);
int kvm_vgic_map_resources(struct kvm *kvm);
int kvm_vgic_hyp_init(void);
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index 39e777155e7c..126b98fbf9ba 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -292,7 +292,6 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm,
unsigned int id)
void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
{
- kvm_vgic_vcpu_early_init(vcpu);
}
void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
index 8901b2d8fca1..272af9704952 100644
--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -44,7 +44,7 @@
*
* CPU Interface:
*
- * - kvm_vgic_vcpu_early_init(): initialization of static data that
+ * - kvm_vgic_vcpu_init(): initialization of static data that
* doesn't depend on any sizing information or emulation type. No
* allocation is allowed there.
*/
@@ -67,46 +67,6 @@ void kvm_vgic_early_init(struct kvm *kvm)
spin_lock_init(&dist->lpi_list_lock);
}
-/**
- * kvm_vgic_vcpu_early_init() - Initialize static VGIC VCPU data structures
- * @vcpu: The VCPU whose VGIC data structures whould be initialized
- *
- * Only do initialization, but do not actually enable the VGIC CPU interface
- * yet.
- */
-void kvm_vgic_vcpu_early_init(struct kvm_vcpu *vcpu)
-{
- struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
- int i;
-
- INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
- spin_lock_init(&vgic_cpu->ap_list_lock);
-
- /*
-* Enable and configure all SGIs to be edge-triggered and
-* configure all PPIs as level-triggered.
-*/
- for (i = 0; i < VGIC_NR_PRIVATE_IRQS; i++) {
- struct vgic_irq *irq = &vgic_cpu->private_irqs[i];
-
- INIT_LIST_HEAD(&irq->ap_list);
- spin_lock_init(&irq->irq_lock);
- irq->intid = i;
- irq->vcpu = NULL;
- irq->target_vcpu = vcpu;
- irq->targets = 1U << vcpu->vcpu_id;
- kref_init(&irq->refcount);
- if (vgic_irq_is_sgi(i)) {
- /* SGIs */
- irq->enabled = 1;
- irq->config = VGIC_CONFIG_EDGE;
- } else {
- /* PPIs */
- irq->config = VGIC_CONFIG_LEVEL;
- }
- }
-}
-
/* CREATION */
/**
@@ -224,13 +184,47 @@ static int kvm_vgic_dist_init(struct kvm *kvm, unsigned
int nr_spis)
}
/**
- * kvm_vgic_vcpu_init() - Register VCPU-specific KVM iodevs
+ * kvm_vgic_vcpu_init() - Initialize static VGIC VCPU data
+ * structures and register VCPU-specific KVM iodevs
+ *
* @vcpu: pointer to the VCPU being created and initialized
+ *
+ * Only do initialization, but do not actually enable the
+ * VGIC CPU interface
*/
int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu)
{
- int ret = 0;
+ struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
struct vgic_dist *dist = &vcpu->kvm->arch.vgic;
+ int ret = 0;
+ int i;
+
+ INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
+ spin_lock_init(&vgic_cpu->ap_list_lock);
+
+ /*
+* Enable and configure all SGIs to be edge-triggered and
+* configure all PPIs as level-triggered.
+*/
+ for (i = 0; i < VGIC_NR_PRIVATE_IRQS; i++) {
+ struct vgic_irq *irq = &vgic_cpu->private_irqs[i];
+
+ INIT_LIST_HEAD(&irq->ap_list);
+ spin_lock_init(&irq->irq_lock);
+ irq->intid = i;
+ irq->vcpu = NULL;
+ irq->target_vcpu = vcpu;
+ irq->targets = 1U << vcpu->vcpu_id;
+ kref_init(&irq->refcount);
[PATCH 27/33] KVM: arm/arm64: Helper to register a new redistributor region
From: Eric Auger
We introduce a new helper that creates and inserts a new redistributor
region into the rdist region list. This helper both handles the case
where the redistributor region size is known at registration time
and the legacy case where it is not (eventually depending on the number
of online vcpus). Depending on pfns, we perform all the possible checks
that we can do:
- end of memory crossing
- incorrect alignment of the base address
- collision with distributor region if already defined
- collision with already registered rdist regions
- check of the new index
Rdist regions must be inserted by increasing order of indices. Indices
must be contiguous.
Signed-off-by: Eric Auger
Reviewed-by: Christoffer Dall
Signed-off-by: Marc Zyngier
---
virt/kvm/arm/vgic/vgic-mmio-v3.c | 89 ++--
virt/kvm/arm/vgic/vgic.h | 8 +++
2 files changed, 81 insertions(+), 16 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index ce5c927fad06..3dbc057f861b 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -680,14 +680,63 @@ static int vgic_register_all_redist_iodevs(struct kvm
*kvm)
return ret;
}
-int vgic_v3_set_redist_base(struct kvm *kvm, u64 addr)
+/**
+ * vgic_v3_insert_redist_region - Insert a new redistributor region
+ *
+ * Performs various checks before inserting the rdist region in the list.
+ * Those tests depend on whether the size of the rdist region is known
+ * (ie. count != 0). The list is sorted by rdist region index.
+ *
+ * @kvm: kvm handle
+ * @index: redist region index
+ * @base: base of the new rdist region
+ * @count: number of redistributors the region is made of (0 in the old style
+ * single region, whose size is induced from the number of vcpus)
+ *
+ * Return 0 on success, < 0 otherwise
+ */
+static int vgic_v3_insert_redist_region(struct kvm *kvm, uint32_t index,
+ gpa_t base, uint32_t count)
{
- struct vgic_dist *vgic = &kvm->arch.vgic;
+ struct vgic_dist *d = &kvm->arch.vgic;
struct vgic_redist_region *rdreg;
+ struct list_head *rd_regions = &d->rd_regions;
+ size_t size = count * KVM_VGIC_V3_REDIST_SIZE;
int ret;
- /* vgic_check_ioaddr makes sure we don't do this twice */
- if (!list_empty(&vgic->rd_regions))
+ /* single rdist region already set ?*/
+ if (!count && !list_empty(rd_regions))
+ return -EINVAL;
+
+ /* cross the end of memory ? */
+ if (base + size < base)
+ return -EINVAL;
+
+ if (list_empty(rd_regions)) {
+ if (index != 0)
+ return -EINVAL;
+ } else {
+ rdreg = list_last_entry(rd_regions,
+ struct vgic_redist_region, list);
+ if (index != rdreg->index + 1)
+ return -EINVAL;
+
+ /* Cannot add an explicitly sized regions after legacy region */
+ if (!rdreg->count)
+ return -EINVAL;
+ }
+
+ /*
+* For legacy single-region redistributor regions (!count),
+* check that the redistributor region does not overlap with the
+* distributor's address space.
+*/
+ if (!count && !IS_VGIC_ADDR_UNDEF(d->vgic_dist_base) &&
+ vgic_dist_overlap(kvm, base, size))
+ return -EINVAL;
+
+ /* collision with any other rdist region? */
+ if (vgic_v3_rdist_overlap(kvm, base, size))
return -EINVAL;
rdreg = kzalloc(sizeof(*rdreg), GFP_KERNEL);
@@ -696,17 +745,29 @@ int vgic_v3_set_redist_base(struct kvm *kvm, u64 addr)
rdreg->base = VGIC_ADDR_UNDEF;
- ret = vgic_check_ioaddr(kvm, &rdreg->base, addr, SZ_64K);
+ ret = vgic_check_ioaddr(kvm, &rdreg->base, base, SZ_64K);
if (ret)
- goto out;
+ goto free;
- rdreg->base = addr;
- if (!vgic_v3_check_base(kvm)) {
- ret = -EINVAL;
- goto out;
- }
+ rdreg->base = base;
+ rdreg->count = count;
+ rdreg->free_index = 0;
+ rdreg->index = index;
- list_add(&rdreg->list, &vgic->rd_regions);
+ list_add_tail(&rdreg->list, rd_regions);
+ return 0;
+free:
+ kfree(rdreg);
+ return ret;
+}
+
+int vgic_v3_set_redist_base(struct kvm *kvm, u64 addr)
+{
+ int ret;
+
+ ret = vgic_v3_insert_redist_region(kvm, 0, addr, 0);
+ if (ret)
+ return ret;
/*
* Register iodevs for each existing VCPU. Adding more VCPUs
@@ -717,10 +778,6 @@ int vgic_v3_set_redist_base(struct kvm *kvm, u64 addr)
return ret;
return 0;
-
-out:
- kfree(rdreg);
- return ret;
}
int vgic_v3_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr)
diff --git a/virt/kvm/arm/vgi
[PATCH 26/33] KVM: arm/arm64: Adapt vgic_v3_check_base to multiple rdist regions
From: Eric Auger
vgic_v3_check_base() currently only handles the case of a unique
legacy redistributor region whose size is not explicitly set but
inferred, instead, from the number of online vcpus.
We adapt it to handle the case of multiple redistributor regions
with explicitly defined size. We rely on two new helpers:
- vgic_v3_rdist_overlap() is used to detect overlap with the dist
region if defined
- vgic_v3_rd_region_size computes the size of the redist region,
would it be a legacy unique region or a new explicitly sized
region.
Signed-off-by: Eric Auger
Reviewed-by: Christoffer Dall
Signed-off-by: Marc Zyngier
---
virt/kvm/arm/vgic/vgic-v3.c | 49 -
virt/kvm/arm/vgic/vgic.h| 10
2 files changed, 42 insertions(+), 17 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 2a11fe89943a..ce4476a08f5b 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -419,6 +419,29 @@ int vgic_v3_save_pending_tables(struct kvm *kvm)
return 0;
}
+/**
+ * vgic_v3_rdist_overlap - check if a region overlaps with any
+ * existing redistributor region
+ *
+ * @kvm: kvm handle
+ * @base: base of the region
+ * @size: size of region
+ *
+ * Return: true if there is an overlap
+ */
+bool vgic_v3_rdist_overlap(struct kvm *kvm, gpa_t base, size_t size)
+{
+ struct vgic_dist *d = &kvm->arch.vgic;
+ struct vgic_redist_region *rdreg;
+
+ list_for_each_entry(rdreg, &d->rd_regions, list) {
+ if ((base + size > rdreg->base) &&
+ (base < rdreg->base + vgic_v3_rd_region_size(kvm,
rdreg)))
+ return true;
+ }
+ return false;
+}
+
/*
* Check for overlapping regions and for regions crossing the end of memory
* for base addresses which have already been set.
@@ -426,31 +449,23 @@ int vgic_v3_save_pending_tables(struct kvm *kvm)
bool vgic_v3_check_base(struct kvm *kvm)
{
struct vgic_dist *d = &kvm->arch.vgic;
- gpa_t redist_size = KVM_VGIC_V3_REDIST_SIZE;
- struct vgic_redist_region *rdreg =
- list_first_entry(&d->rd_regions,
-struct vgic_redist_region, list);
-
- redist_size *= atomic_read(&kvm->online_vcpus);
+ struct vgic_redist_region *rdreg;
if (!IS_VGIC_ADDR_UNDEF(d->vgic_dist_base) &&
d->vgic_dist_base + KVM_VGIC_V3_DIST_SIZE < d->vgic_dist_base)
return false;
- if (rdreg && (rdreg->base + redist_size < rdreg->base))
- return false;
-
- /* Both base addresses must be set to check if they overlap */
- if (IS_VGIC_ADDR_UNDEF(d->vgic_dist_base) || !rdreg)
- return true;
-
- if (d->vgic_dist_base + KVM_VGIC_V3_DIST_SIZE <= rdreg->base)
- return true;
+ list_for_each_entry(rdreg, &d->rd_regions, list) {
+ if (rdreg->base + vgic_v3_rd_region_size(kvm, rdreg) <
+ rdreg->base)
+ return false;
+ }
- if (rdreg->base + redist_size <= d->vgic_dist_base)
+ if (IS_VGIC_ADDR_UNDEF(d->vgic_dist_base))
return true;
- return false;
+ return !vgic_v3_rdist_overlap(kvm, d->vgic_dist_base,
+ KVM_VGIC_V3_DIST_SIZE);
}
/**
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index fddd57ff6529..e9f192660097 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -276,6 +276,16 @@ vgic_v3_redist_region_full(struct vgic_redist_region
*region)
struct vgic_redist_region *vgic_v3_rdist_free_slot(struct list_head *rdregs);
+static inline size_t
+vgic_v3_rd_region_size(struct kvm *kvm, struct vgic_redist_region *rdreg)
+{
+ if (!rdreg->count)
+ return atomic_read(&kvm->online_vcpus) *
KVM_VGIC_V3_REDIST_SIZE;
+ else
+ return rdreg->count * KVM_VGIC_V3_REDIST_SIZE;
+}
+bool vgic_v3_rdist_overlap(struct kvm *kvm, gpa_t base, size_t size);
+
int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
u32 devid, u32 eventid, struct vgic_irq **irq);
struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
--
2.17.1
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[PATCH 25/33] KVM: arm/arm64: Revisit Redistributor TYPER last bit computation
From: Eric Auger
The TYPER of an redistributor reflects whether the rdist is
the last one of the redistributor region. Let's compare the TYPER
GPA against the address of the last occupied slot within the
redistributor region.
Signed-off-by: Eric Auger
Reviewed-by: Christoffer Dall
Signed-off-by: Marc Zyngier
---
virt/kvm/arm/vgic/vgic-mmio-v3.c | 7 ++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index 49ca176e2e08..ce5c927fad06 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -184,12 +184,17 @@ static unsigned long vgic_mmio_read_v3r_typer(struct
kvm_vcpu *vcpu,
gpa_t addr, unsigned int len)
{
unsigned long mpidr = kvm_vcpu_get_mpidr_aff(vcpu);
+ struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
+ struct vgic_redist_region *rdreg = vgic_cpu->rdreg;
int target_vcpu_id = vcpu->vcpu_id;
+ gpa_t last_rdist_typer = rdreg->base + GICR_TYPER +
+ (rdreg->free_index - 1) * KVM_VGIC_V3_REDIST_SIZE;
u64 value;
value = (u64)(mpidr & GENMASK(23, 0)) << 32;
value |= ((target_vcpu_id & 0x) << 8);
- if (target_vcpu_id == atomic_read(&vcpu->kvm->online_vcpus) - 1)
+
+ if (addr == last_rdist_typer)
value |= GICR_TYPER_LAST;
if (vgic_has_its(vcpu->kvm))
value |= GICR_TYPER_PLPIS;
--
2.17.1
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[PATCH 23/33] KVM: arm/arm64: Replace the single rdist region by a list
From: Eric Auger
At the moment KVM supports a single rdist region. We want to
support several separate rdist regions so let's introduce a list
of them. This patch currently only cares about a single
entry in this list as the functionality to register several redist
regions is not yet there. So this only translates the existing code
into something functionally similar using that new data struct.
The redistributor region handle is stored in the vgic_cpu structure
to allow later computation of the TYPER last bit.
Signed-off-by: Eric Auger
Reviewed-by: Christoffer Dall
Signed-off-by: Marc Zyngier
---
include/kvm/arm_vgic.h | 14 ---
virt/kvm/arm/vgic/vgic-init.c | 16 ++--
virt/kvm/arm/vgic/vgic-kvm-device.c | 13 --
virt/kvm/arm/vgic/vgic-mmio-v3.c| 38 +++--
virt/kvm/arm/vgic/vgic-v3.c | 20 +--
5 files changed, 77 insertions(+), 24 deletions(-)
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index e7efe12a81bd..90e489f685ae 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -201,6 +201,14 @@ struct vgic_its {
struct vgic_state_iter;
+struct vgic_redist_region {
+ u32 index;
+ gpa_t base;
+ u32 count; /* number of redistributors or 0 if single region */
+ u32 free_index; /* index of the next free redistributor */
+ struct list_head list;
+};
+
struct vgic_dist {
boolin_kernel;
boolready;
@@ -220,10 +228,7 @@ struct vgic_dist {
/* either a GICv2 CPU interface */
gpa_t vgic_cpu_base;
/* or a number of GICv3 redistributor regions */
- struct {
- gpa_t vgic_redist_base;
- gpa_t vgic_redist_free_offset;
- };
+ struct list_head rd_regions;
};
/* distributor enabled */
@@ -311,6 +316,7 @@ struct vgic_cpu {
*/
struct vgic_io_device rd_iodev;
struct vgic_io_device sgi_iodev;
+ struct vgic_redist_region *rdreg;
/* Contains the attributes and gpa of the LPI pending tables. */
u64 pendbaser;
diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
index 9a5aed7eecfd..8901b2d8fca1 100644
--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -167,8 +167,11 @@ int kvm_vgic_create(struct kvm *kvm, u32 type)
kvm->arch.vgic.vgic_model = type;
kvm->arch.vgic.vgic_dist_base = VGIC_ADDR_UNDEF;
- kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
- kvm->arch.vgic.vgic_redist_base = VGIC_ADDR_UNDEF;
+
+ if (type == KVM_DEV_TYPE_ARM_VGIC_V2)
+ kvm->arch.vgic.vgic_cpu_base = VGIC_ADDR_UNDEF;
+ else
+ INIT_LIST_HEAD(&kvm->arch.vgic.rd_regions);
out_unlock:
for (; vcpu_lock_idx >= 0; vcpu_lock_idx--) {
@@ -303,6 +306,7 @@ int vgic_init(struct kvm *kvm)
static void kvm_vgic_dist_destroy(struct kvm *kvm)
{
struct vgic_dist *dist = &kvm->arch.vgic;
+ struct vgic_redist_region *rdreg, *next;
dist->ready = false;
dist->initialized = false;
@@ -311,6 +315,14 @@ static void kvm_vgic_dist_destroy(struct kvm *kvm)
dist->spis = NULL;
dist->nr_spis = 0;
+ if (kvm->arch.vgic.vgic_model == KVM_DEV_TYPE_ARM_VGIC_V3) {
+ list_for_each_entry_safe(rdreg, next, &dist->rd_regions, list) {
+ list_del(&rdreg->list);
+ kfree(rdreg);
+ }
+ INIT_LIST_HEAD(&dist->rd_regions);
+ }
+
if (vgic_supports_direct_msis(kvm))
vgic_v4_teardown(kvm);
}
diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c
b/virt/kvm/arm/vgic/vgic-kvm-device.c
index 10ae6f394b71..76ab3691f7fe 100644
--- a/virt/kvm/arm/vgic/vgic-kvm-device.c
+++ b/virt/kvm/arm/vgic/vgic-kvm-device.c
@@ -66,6 +66,7 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64
*addr, bool write)
int r = 0;
struct vgic_dist *vgic = &kvm->arch.vgic;
phys_addr_t *addr_ptr, alignment;
+ u64 undef_value = VGIC_ADDR_UNDEF;
mutex_lock(&kvm->lock);
switch (type) {
@@ -84,7 +85,9 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64
*addr, bool write)
addr_ptr = &vgic->vgic_dist_base;
alignment = SZ_64K;
break;
- case KVM_VGIC_V3_ADDR_TYPE_REDIST:
+ case KVM_VGIC_V3_ADDR_TYPE_REDIST: {
+ struct vgic_redist_region *rdreg;
+
r = vgic_check_type(kvm, KVM_DEV_TYPE_ARM_VGIC_V3);
if (r)
break;
@@ -92,8 +95,14 @@ int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64
*addr, bool write)
r = vgic_v3_set_redist_base(kvm, *addr);
goto out;
[PATCH 24/33] KVM: arm/arm64: Helper to locate free rdist index
From: Eric Auger
We introduce vgic_v3_rdist_free_slot to help identifying
where we can place a new 2x64KB redistributor.
Signed-off-by: Eric Auger
Reviewed-by: Christoffer Dall
Signed-off-by: Marc Zyngier
---
virt/kvm/arm/vgic/vgic-mmio-v3.c | 3 +--
virt/kvm/arm/vgic/vgic-v3.c | 23 +++
virt/kvm/arm/vgic/vgic.h | 11 +++
3 files changed, 35 insertions(+), 2 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index d1aab183a1cc..49ca176e2e08 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -593,8 +593,7 @@ int vgic_register_redist_iodev(struct kvm_vcpu *vcpu)
* function for all VCPUs when the base address is set. Just return
* without doing any work for now.
*/
- rdreg = list_first_entry(&vgic->rd_regions,
-struct vgic_redist_region, list);
+ rdreg = vgic_v3_rdist_free_slot(&vgic->rd_regions);
if (!rdreg)
return 0;
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 56e6e903d998..2a11fe89943a 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -453,6 +453,29 @@ bool vgic_v3_check_base(struct kvm *kvm)
return false;
}
+/**
+ * vgic_v3_rdist_free_slot - Look up registered rdist regions and identify one
+ * which has free space to put a new rdist region.
+ *
+ * @rd_regions: redistributor region list head
+ *
+ * A redistributor regions maps n redistributors, n = region size / (2 x 64kB).
+ * Stride between redistributors is 0 and regions are filled in the index
order.
+ *
+ * Return: the redist region handle, if any, that has space to map a new rdist
+ * region.
+ */
+struct vgic_redist_region *vgic_v3_rdist_free_slot(struct list_head
*rd_regions)
+{
+ struct vgic_redist_region *rdreg;
+
+ list_for_each_entry(rdreg, rd_regions, list) {
+ if (!vgic_v3_redist_region_full(rdreg))
+ return rdreg;
+ }
+ return NULL;
+}
+
int vgic_v3_map_resources(struct kvm *kvm)
{
int ret = 0;
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 32c25d42c93f..fddd57ff6529 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -265,6 +265,17 @@ static inline int vgic_v3_max_apr_idx(struct kvm_vcpu
*vcpu)
}
}
+static inline bool
+vgic_v3_redist_region_full(struct vgic_redist_region *region)
+{
+ if (!region->count)
+ return false;
+
+ return (region->free_index >= region->count);
+}
+
+struct vgic_redist_region *vgic_v3_rdist_free_slot(struct list_head *rdregs);
+
int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its,
u32 devid, u32 eventid, struct vgic_irq **irq);
struct vgic_its *vgic_msi_to_its(struct kvm *kvm, struct kvm_msi *msi);
--
2.17.1
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[PATCH 22/33] KVM: arm/arm64: Document KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION
From: Eric Auger We introduce a new KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION attribute in KVM_DEV_ARM_VGIC_GRP_ADDR group. It allows userspace to provide the base address and size of a redistributor region Compared to KVM_VGIC_V3_ADDR_TYPE_REDIST, this new attribute allows to declare several separate redistributor regions. So the whole redist space does not need to be contiguous anymore. Signed-off-by: Eric Auger Reviewed-by: Peter Maydell Acked-by: Christoffer Dall Signed-off-by: Marc Zyngier --- .../virtual/kvm/devices/arm-vgic-v3.txt | 30 +-- 1 file changed, 28 insertions(+), 2 deletions(-) diff --git a/Documentation/virtual/kvm/devices/arm-vgic-v3.txt b/Documentation/virtual/kvm/devices/arm-vgic-v3.txt index 9293b45abdb9..2408ab720ef7 100644 --- a/Documentation/virtual/kvm/devices/arm-vgic-v3.txt +++ b/Documentation/virtual/kvm/devices/arm-vgic-v3.txt @@ -27,16 +27,42 @@ Groups: VCPU and all of the redistributor pages are contiguous. Only valid for KVM_DEV_TYPE_ARM_VGIC_V3. This address needs to be 64K aligned. + +KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION (rw, 64-bit) + The attribute data pointed to by kvm_device_attr.addr is a __u64 value: + bits: | 63 52 | 51 16 | 15 - 12 |11 - 0 + values: | count | base | flags | index + - index encodes the unique redistributor region index + - flags: reserved for future use, currently 0 + - base field encodes bits [51:16] of the guest physical base address +of the first redistributor in the region. + - count encodes the number of redistributors in the region. Must be +greater than 0. + There are two 64K pages for each redistributor in the region and + redistributors are laid out contiguously within the region. Regions + are filled with redistributors in the index order. The sum of all + region count fields must be greater than or equal to the number of + VCPUs. Redistributor regions must be registered in the incremental + index order, starting from index 0. + The characteristics of a specific redistributor region can be read + by presetting the index field in the attr data. + Only valid for KVM_DEV_TYPE_ARM_VGIC_V3. + + It is invalid to mix calls with KVM_VGIC_V3_ADDR_TYPE_REDIST and + KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION attributes. + Errors: -E2BIG: Address outside of addressable IPA range --EINVAL: Incorrectly aligned address +-EINVAL: Incorrectly aligned address, bad redistributor region + count/index, mixed redistributor region attribute usage -EEXIST: Address already configured +-ENOENT: Attempt to read the characteristics of a non existing + redistributor region -ENXIO: The group or attribute is unknown/unsupported for this device or hardware support is missing. -EFAULT: Invalid user pointer for attr->addr. - KVM_DEV_ARM_VGIC_GRP_DIST_REGS KVM_DEV_ARM_VGIC_GRP_REDIST_REGS Attributes: -- 2.17.1 ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
[PATCH 21/33] KVM: arm/arm64: Set dist->spis to NULL after kfree
From: Eric Auger
in case kvm_vgic_map_resources() fails, typically if the vgic
distributor is not defined, __kvm_vgic_destroy will be called
several times. Indeed kvm_vgic_map_resources() is called on
first vcpu run. As a result dist->spis is freeed more than once
and on the second time it causes a "kernel BUG at mm/slub.c:3912!"
Set dist->spis to NULL to avoid the crash.
Fixes: ad275b8bb1e6 ("KVM: arm/arm64: vgic-new: vgic_init: implement
vgic_init")
Signed-off-by: Eric Auger
Reviewed-by: Marc Zyngier
Reviewed-by: Christoffer Dall
Signed-off-by: Marc Zyngier
---
virt/kvm/arm/vgic/vgic-init.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c
index e07156c30323..9a5aed7eecfd 100644
--- a/virt/kvm/arm/vgic/vgic-init.c
+++ b/virt/kvm/arm/vgic/vgic-init.c
@@ -308,6 +308,7 @@ static void kvm_vgic_dist_destroy(struct kvm *kvm)
dist->initialized = false;
kfree(dist->spis);
+ dist->spis = NULL;
dist->nr_spis = 0;
if (vgic_supports_direct_msis(kvm))
--
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[PATCH 20/33] KVM: arm64: Invoke FPSIMD context switch trap from C
From: Dave Martin
The conversion of the FPSIMD context switch trap code to C has added
some overhead to calling it, due to the need to save registers that
the procedure call standard defines as caller-saved.
So, perhaps it is no longer worth invoking this trap handler quite
so early.
Instead, we can invoke it from fixup_guest_exit(), with little
likelihood of increasing the overhead much further.
As a convenience, this patch gives __hyp_switch_fpsimd() the same
return semantics fixup_guest_exit(). For now there is no
possibility of a spurious FPSIMD trap, so the function always
returns true, but this allows it to be tail-called with a single
return statement.
Signed-off-by: Dave Martin
Reviewed-by: Marc Zyngier
Reviewed-by: Christoffer Dall
Reviewed-by: Alex Bennée
Signed-off-by: Marc Zyngier
---
arch/arm64/kvm/hyp/entry.S | 30 --
arch/arm64/kvm/hyp/hyp-entry.S | 19 ---
arch/arm64/kvm/hyp/switch.c| 15 +--
3 files changed, 13 insertions(+), 51 deletions(-)
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S
index 40f349bc1079..fad1e164fe48 100644
--- a/arch/arm64/kvm/hyp/entry.S
+++ b/arch/arm64/kvm/hyp/entry.S
@@ -166,33 +166,3 @@ abort_guest_exit_end:
orr x0, x0, x5
1: ret
ENDPROC(__guest_exit)
-
-ENTRY(__fpsimd_guest_restore)
- // x0: esr
- // x1: vcpu
- // x2-x29,lr: vcpu regs
- // vcpu x0-x1 on the stack
- stp x2, x3, [sp, #-144]!
- stp x4, x5, [sp, #16]
- stp x6, x7, [sp, #32]
- stp x8, x9, [sp, #48]
- stp x10, x11, [sp, #64]
- stp x12, x13, [sp, #80]
- stp x14, x15, [sp, #96]
- stp x16, x17, [sp, #112]
- stp x18, lr, [sp, #128]
-
- bl __hyp_switch_fpsimd
-
- ldp x4, x5, [sp, #16]
- ldp x6, x7, [sp, #32]
- ldp x8, x9, [sp, #48]
- ldp x10, x11, [sp, #64]
- ldp x12, x13, [sp, #80]
- ldp x14, x15, [sp, #96]
- ldp x16, x17, [sp, #112]
- ldp x18, lr, [sp, #128]
- ldp x0, x1, [sp, #144]
- ldp x2, x3, [sp], #160
- eret
-ENDPROC(__fpsimd_guest_restore)
diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S
index bffece27b5c1..753b9d213651 100644
--- a/arch/arm64/kvm/hyp/hyp-entry.S
+++ b/arch/arm64/kvm/hyp/hyp-entry.S
@@ -113,25 +113,6 @@ el1_hvc_guest:
el1_trap:
get_vcpu_ptrx1, x0
-
- mrs x0, esr_el2
- lsr x0, x0, #ESR_ELx_EC_SHIFT
- /*
-* x0: ESR_EC
-* x1: vcpu pointer
-*/
-
- /*
-* We trap the first access to the FP/SIMD to save the host context
-* and restore the guest context lazily.
-* If FP/SIMD is not implemented, handle the trap and inject an
-* undefined instruction exception to the guest.
-*/
-alternative_if_not ARM64_HAS_NO_FPSIMD
- cmp x0, #ESR_ELx_EC_FP_ASIMD
- b.eq__fpsimd_guest_restore
-alternative_else_nop_endif
-
mov x0, #ARM_EXCEPTION_TRAP
b __guest_exit
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 4fbee9502162..2d45bd719a5d 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -328,8 +328,7 @@ static bool __hyp_text __skip_instr(struct kvm_vcpu *vcpu)
}
}
-void __hyp_text __hyp_switch_fpsimd(u64 esr __always_unused,
- struct kvm_vcpu *vcpu)
+static bool __hyp_text __hyp_switch_fpsimd(struct kvm_vcpu *vcpu)
{
struct user_fpsimd_state *host_fpsimd = vcpu->arch.host_fpsimd_state;
@@ -369,6 +368,8 @@ void __hyp_text __hyp_switch_fpsimd(u64 esr __always_unused,
fpexc32_el2);
vcpu->arch.flags |= KVM_ARM64_FP_ENABLED;
+
+ return true;
}
/*
@@ -390,6 +391,16 @@ static bool __hyp_text fixup_guest_exit(struct kvm_vcpu
*vcpu, u64 *exit_code)
if (*exit_code != ARM_EXCEPTION_TRAP)
goto exit;
+ /*
+* We trap the first access to the FP/SIMD to save the host context
+* and restore the guest context lazily.
+* If FP/SIMD is not implemented, handle the trap and inject an
+* undefined instruction exception to the guest.
+*/
+ if (system_supports_fpsimd() &&
+ kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_FP_ASIMD)
+ return __hyp_switch_fpsimd(vcpu);
+
if (!__populate_fault_info(vcpu))
return true;
--
2.17.1
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[PATCH 18/33] KVM: arm64: Remove redundant *exit_code changes in fpsimd_guest_exit()
From: Dave Martin
In fixup_guest_exit(), there are a couple of cases where after
checking what the exit code was, we assign it explicitly with the
value it already had.
Assuming this is not indicative of a bug, these assignments are not
needed.
This patch removes the redundant assignments, and simplifies some
if-nesting that becomes trivial as a result.
No functional change.
Signed-off-by: Dave Martin
Reviewed-by: Alex Bennée
Acked-by: Marc Zyngier
Acked-by: Christoffer Dall
Signed-off-by: Marc Zyngier
---
arch/arm64/kvm/hyp/switch.c | 16
1 file changed, 4 insertions(+), 12 deletions(-)
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index a6a8c7d9157d..18d0faa8c806 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -403,12 +403,8 @@ static bool __hyp_text fixup_guest_exit(struct kvm_vcpu
*vcpu, u64 *exit_code)
if (valid) {
int ret = __vgic_v2_perform_cpuif_access(vcpu);
- if (ret == 1) {
- if (__skip_instr(vcpu))
- return true;
- else
- *exit_code = ARM_EXCEPTION_TRAP;
- }
+ if (ret == 1 && __skip_instr(vcpu))
+ return true;
if (ret == -1) {
/* Promote an illegal access to an
@@ -430,12 +426,8 @@ static bool __hyp_text fixup_guest_exit(struct kvm_vcpu
*vcpu, u64 *exit_code)
kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_CP15_32)) {
int ret = __vgic_v3_perform_cpuif_access(vcpu);
- if (ret == 1) {
- if (__skip_instr(vcpu))
- return true;
- else
- *exit_code = ARM_EXCEPTION_TRAP;
- }
+ if (ret == 1 && __skip_instr(vcpu))
+ return true;
}
/* Return to the host kernel and handle the exit */
--
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[PATCH 16/33] KVM: arm64: Save host SVE context as appropriate
From: Dave Martin
This patch adds SVE context saving to the hyp FPSIMD context switch
path. This means that it is no longer necessary to save the host
SVE state in advance of entering the guest, when in use.
In order to avoid adding pointless complexity to the code, VHE is
assumed if SVE is in use. VHE is an architectural prerequisite for
SVE, so there is no good reason to turn CONFIG_ARM64_VHE off in
kernels that support both SVE and KVM.
Historically, software models exist that can expose the
architecturally invalid configuration of SVE without VHE, so if
this situation is detected at kvm_init() time then KVM will be
disabled.
Signed-off-by: Dave Martin
Reviewed-by: Alex Bennée
Acked-by: Catalin Marinas
Signed-off-by: Marc Zyngier
---
arch/arm/include/asm/kvm_host.h | 1 +
arch/arm64/Kconfig| 7 +++
arch/arm64/include/asm/kvm_host.h | 13 +
arch/arm64/kvm/fpsimd.c | 1 -
arch/arm64/kvm/hyp/switch.c | 20 +++-
virt/kvm/arm/arm.c| 7 +++
6 files changed, 47 insertions(+), 2 deletions(-)
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index ac870b2cd5d1..3b85bbb4b23e 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -280,6 +280,7 @@ void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot);
struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);
+static inline bool kvm_arch_check_sve_has_vhe(void) { return true; }
static inline void kvm_arch_hardware_unsetup(void) {}
static inline void kvm_arch_sync_events(struct kvm *kvm) {}
static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index eb2cf4938f6d..b0d3820081c8 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1130,6 +1130,7 @@ endmenu
config ARM64_SVE
bool "ARM Scalable Vector Extension support"
default y
+ depends on !KVM || ARM64_VHE
help
The Scalable Vector Extension (SVE) is an extension to the AArch64
execution state which complements and extends the SIMD functionality
@@ -1155,6 +1156,12 @@ config ARM64_SVE
booting the kernel. If unsure and you are not observing these
symptoms, you should assume that it is safe to say Y.
+ CPUs that support SVE are architecturally required to support the
+ Virtualization Host Extensions (VHE), so the kernel makes no
+ provision for supporting SVE alongside KVM without VHE enabled.
+ Thus, you will need to enable CONFIG_ARM64_VHE if you want to support
+ KVM in the same kernel image.
+
config ARM64_MODULE_PLTS
bool
select HAVE_MOD_ARCH_SPECIFIC
diff --git a/arch/arm64/include/asm/kvm_host.h
b/arch/arm64/include/asm/kvm_host.h
index b3fe7301bdbe..fda9289f3b9c 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -405,6 +405,19 @@ static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr,
kvm_call_hyp(__kvm_set_tpidr_el2, tpidr_el2);
}
+static inline bool kvm_arch_check_sve_has_vhe(void)
+{
+ /*
+* The Arm architecture specifies that implementation of SVE
+* requires VHE also to be implemented. The KVM code for arm64
+* relies on this when SVE is present:
+*/
+ if (system_supports_sve())
+ return has_vhe();
+ else
+ return true;
+}
+
static inline void kvm_arch_hardware_unsetup(void) {}
static inline void kvm_arch_sync_events(struct kvm *kvm) {}
static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c
index 365933a98a7c..dc6ecfa5a2d2 100644
--- a/arch/arm64/kvm/fpsimd.c
+++ b/arch/arm64/kvm/fpsimd.c
@@ -59,7 +59,6 @@ int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu)
*/
void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu)
{
- BUG_ON(system_supports_sve());
BUG_ON(!current->mm);
vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED | KVM_ARM64_HOST_SVE_IN_USE);
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 118f3002b9ce..a6a8c7d9157d 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -21,6 +21,7 @@
#include
+#include
#include
#include
#include
@@ -28,6 +29,7 @@
#include
#include
#include
+#include
#include
/* Check whether the FP regs were dirtied while in the host-side run loop: */
@@ -329,6 +331,8 @@ static bool __hyp_text __skip_instr(struct kvm_vcpu *vcpu)
void __hyp_text __hyp_switch_fpsimd(u64 esr __always_unused,
struct kvm_vcpu *vcpu)
{
+ struct user_fpsimd_state *host_fpsimd = vcpu->arch.host_fpsimd_state;
+
if (has_vhe())
write_sysreg(read_sysreg(cpacr_el1) | CPACR_EL1_FPEN,
cpacr_el1);
@@ -339,7 +343,21 @@ void __hyp_text __hy
[PATCH 19/33] KVM: arm64: Fold redundant exit code checks out of fixup_guest_exit()
From: Dave Martin
The entire tail of fixup_guest_exit() is contained in if statements
of the form if (x && *exit_code == ARM_EXCEPTION_TRAP). As a result,
we can check just once and bail out of the function early, allowing
the remaining if conditions to be simplified.
The only awkward case is where *exit_code is changed to
ARM_EXCEPTION_EL1_SERROR in the case of an illegal GICv2 CPU
interface access: in that case, the GICv3 trap handling code is
skipped using a goto. This avoids pointlessly evaluating the
static branch check for the GICv3 case, even though we can't have
vgic_v2_cpuif_trap and vgic_v3_cpuif_trap true simultaneously
unless we have a GICv3 and GICv2 on the host: that sounds stupid,
but I haven't satisfied myself that it can't happen.
No functional change.
Signed-off-by: Dave Martin
Reviewed-by: Marc Zyngier
Reviewed-by: Alex Bennée
Acked-by: Christoffer Dall
Signed-off-by: Marc Zyngier
---
arch/arm64/kvm/hyp/switch.c | 12
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 18d0faa8c806..4fbee9502162 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -387,11 +387,13 @@ static bool __hyp_text fixup_guest_exit(struct kvm_vcpu
*vcpu, u64 *exit_code)
* same PC once the SError has been injected, and replay the
* trapping instruction.
*/
- if (*exit_code == ARM_EXCEPTION_TRAP && !__populate_fault_info(vcpu))
+ if (*exit_code != ARM_EXCEPTION_TRAP)
+ goto exit;
+
+ if (!__populate_fault_info(vcpu))
return true;
- if (static_branch_unlikely(&vgic_v2_cpuif_trap) &&
- *exit_code == ARM_EXCEPTION_TRAP) {
+ if (static_branch_unlikely(&vgic_v2_cpuif_trap)) {
bool valid;
valid = kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_DABT_LOW &&
@@ -417,11 +419,12 @@ static bool __hyp_text fixup_guest_exit(struct kvm_vcpu
*vcpu, u64 *exit_code)
*vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS;
*exit_code = ARM_EXCEPTION_EL1_SERROR;
}
+
+ goto exit;
}
}
if (static_branch_unlikely(&vgic_v3_cpuif_trap) &&
- *exit_code == ARM_EXCEPTION_TRAP &&
(kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_SYS64 ||
kvm_vcpu_trap_get_class(vcpu) == ESR_ELx_EC_CP15_32)) {
int ret = __vgic_v3_perform_cpuif_access(vcpu);
@@ -430,6 +433,7 @@ static bool __hyp_text fixup_guest_exit(struct kvm_vcpu
*vcpu, u64 *exit_code)
return true;
}
+exit:
/* Return to the host kernel and handle the exit */
return false;
}
--
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[PATCH 15/33] arm64/sve: Move sve_pffr() to fpsimd.h and make inline
From: Dave Martin
In order to make sve_save_state()/sve_load_state() more easily
reusable and to get rid of a potential branch on context switch
critical paths, this patch makes sve_pffr() inline and moves it to
fpsimd.h.
must be included in fpsimd.h in order to make
this work, and this creates an #include cycle that is tricky to
avoid without modifying core code, due to the way the PR_SVE_*()
prctl helpers are included in the core prctl implementation.
Instead of breaking the cycle, this patch defers inclusion of
in until the point where it is
actually needed: i.e., immediately before the prctl definitions.
No functional change.
Signed-off-by: Dave Martin
Reviewed-by: Alex Bennée
Acked-by: Catalin Marinas
Acked-by: Marc Zyngier
Signed-off-by: Marc Zyngier
---
arch/arm64/include/asm/fpsimd.h| 13 +
arch/arm64/include/asm/processor.h | 12 +++-
arch/arm64/kernel/fpsimd.c | 12
3 files changed, 24 insertions(+), 13 deletions(-)
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h
index fb60b22b8bbf..fa92747a49c8 100644
--- a/arch/arm64/include/asm/fpsimd.h
+++ b/arch/arm64/include/asm/fpsimd.h
@@ -18,6 +18,8 @@
#include
#include
+#include
+#include
#ifndef __ASSEMBLY__
@@ -61,6 +63,17 @@ extern void sve_flush_cpu_state(void);
/* Maximum VL that SVE VL-agnostic software can transparently support */
#define SVE_VL_ARCH_MAX 0x100
+/* Offset of FFR in the SVE register dump */
+static inline size_t sve_ffr_offset(int vl)
+{
+ return SVE_SIG_FFR_OFFSET(sve_vq_from_vl(vl)) - SVE_SIG_REGS_OFFSET;
+}
+
+static inline void *sve_pffr(struct thread_struct *thread)
+{
+ return (char *)thread->sve_state + sve_ffr_offset(thread->sve_vl);
+}
+
extern void sve_save_state(void *state, u32 *pfpsr);
extern void sve_load_state(void const *state, u32 const *pfpsr,
unsigned long vq_minus_1);
diff --git a/arch/arm64/include/asm/processor.h
b/arch/arm64/include/asm/processor.h
index 9231b8762ca6..c99e657fdd57 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -40,7 +40,6 @@
#include
#include
-#include
#include
#include
#include
@@ -247,6 +246,17 @@ void cpu_enable_pan(const struct arm64_cpu_capabilities
*__unused);
void cpu_enable_cache_maint_trap(const struct arm64_cpu_capabilities
*__unused);
void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused);
+/*
+ * Not at the top of the file due to a direct #include cycle between
+ * and . Deferring this #include
+ * ensures that contents of processor.h are visible to fpsimd.h even if
+ * processor.h is included first.
+ *
+ * These prctl helpers are the only things in this file that require
+ * fpsimd.h. The core code expects them to be in this header.
+ */
+#include
+
/* Userspace interface for PR_SVE_{SET,GET}_VL prctl()s: */
#define SVE_SET_VL(arg)sve_set_current_vl(arg)
#define SVE_GET_VL() sve_get_current_vl()
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 842b2ad08bec..e60c3a28380f 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -161,18 +161,6 @@ static void sve_free(struct task_struct *task)
__sve_free(task);
}
-
-/* Offset of FFR in the SVE register dump */
-static size_t sve_ffr_offset(int vl)
-{
- return SVE_SIG_FFR_OFFSET(sve_vq_from_vl(vl)) - SVE_SIG_REGS_OFFSET;
-}
-
-static void *sve_pffr(struct thread_struct *thread)
-{
- return (char *)thread->sve_state + sve_ffr_offset(thread->sve_vl);
-}
-
static void change_cpacr(u64 val, u64 mask)
{
u64 cpacr = read_sysreg(CPACR_EL1);
--
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[PATCH 17/33] KVM: arm64: Remove eager host SVE state saving
From: Dave Martin
Now that the host SVE context can be saved on demand from Hyp,
there is no longer any need to save this state in advance before
entering the guest.
This patch removes the relevant call to
kvm_fpsimd_flush_cpu_state().
Since the problem that function was intended to solve now no longer
exists, the function and its dependencies are also deleted.
Signed-off-by: Dave Martin
Reviewed-by: Alex Bennée
Acked-by: Christoffer Dall
Acked-by: Marc Zyngier
Acked-by: Catalin Marinas
Signed-off-by: Marc Zyngier
---
arch/arm/include/asm/kvm_host.h | 3 ---
arch/arm64/include/asm/kvm_host.h | 10 --
arch/arm64/kernel/fpsimd.c| 21 -
virt/kvm/arm/arm.c| 3 ---
4 files changed, 37 deletions(-)
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 3b85bbb4b23e..f079a2039c8a 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -312,9 +312,6 @@ static inline void kvm_arch_vcpu_load_fp(struct kvm_vcpu
*vcpu) {}
static inline void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu) {}
-/* All host FP/SIMD state is restored on guest exit, so nothing to save: */
-static inline void kvm_fpsimd_flush_cpu_state(void) {}
-
static inline void kvm_arm_vhe_guest_enter(void) {}
static inline void kvm_arm_vhe_guest_exit(void) {}
diff --git a/arch/arm64/include/asm/kvm_host.h
b/arch/arm64/include/asm/kvm_host.h
index fda9289f3b9c..a4ca202ff3f2 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -457,16 +457,6 @@ static inline int kvm_arch_vcpu_run_pid_change(struct
kvm_vcpu *vcpu)
}
#endif
-/*
- * All host FP/SIMD state is restored on guest exit, so nothing needs
- * doing here except in the SVE case:
-*/
-static inline void kvm_fpsimd_flush_cpu_state(void)
-{
- if (system_supports_sve())
- sve_flush_cpu_state();
-}
-
static inline void kvm_arm_vhe_guest_enter(void)
{
local_daif_mask();
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index e60c3a28380f..7074c4cd0e0e 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -120,7 +120,6 @@
*/
struct fpsimd_last_state_struct {
struct user_fpsimd_state *st;
- bool sve_in_use;
};
static DEFINE_PER_CPU(struct fpsimd_last_state_struct, fpsimd_last_state);
@@ -1008,7 +1007,6 @@ void fpsimd_bind_task_to_cpu(void)
this_cpu_ptr(&fpsimd_last_state);
last->st = ¤t->thread.uw.fpsimd_state;
- last->sve_in_use = test_thread_flag(TIF_SVE);
current->thread.fpsimd_cpu = smp_processor_id();
if (system_supports_sve()) {
@@ -1030,7 +1028,6 @@ void fpsimd_bind_state_to_cpu(struct user_fpsimd_state
*st)
WARN_ON(!in_softirq() && !irqs_disabled());
last->st = st;
- last->sve_in_use = false;
}
/*
@@ -1091,24 +1088,6 @@ void fpsimd_flush_cpu_state(void)
set_thread_flag(TIF_FOREIGN_FPSTATE);
}
-/*
- * Invalidate any task SVE state currently held in this CPU's regs.
- *
- * This is used to prevent the kernel from trying to reuse SVE register data
- * that is detroyed by KVM guest enter/exit. This function should go away when
- * KVM SVE support is implemented. Don't use it for anything else.
- */
-#ifdef CONFIG_ARM64_SVE
-void sve_flush_cpu_state(void)
-{
- struct fpsimd_last_state_struct const *last =
- this_cpu_ptr(&fpsimd_last_state);
-
- if (last->st && last->sve_in_use)
- fpsimd_flush_cpu_state();
-}
-#endif /* CONFIG_ARM64_SVE */
-
#ifdef CONFIG_KERNEL_MODE_NEON
DEFINE_PER_CPU(bool, kernel_neon_busy);
diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c
index ce7c6f36471b..39e777155e7c 100644
--- a/virt/kvm/arm/arm.c
+++ b/virt/kvm/arm/arm.c
@@ -682,9 +682,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct
kvm_run *run)
*/
preempt_disable();
- /* Flush FP/SIMD state that can't survive guest entry/exit */
- kvm_fpsimd_flush_cpu_state();
-
kvm_pmu_flush_hwstate(vcpu);
local_irq_disable();
--
2.17.1
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[PATCH 14/33] arm64/sve: Switch sve_pffr() argument from task to thread
From: Dave Martin
sve_pffr(), which is used to derive the base address used for
low-level SVE save/restore routines, currently takes the relevant
task_struct as an argument.
The only accessed fields are actually part of thread_struct, so
this patch changes the argument type accordingly. This is done in
preparation for moving this function to a header, where we do not
want to have to include due to the consequent
circular #include problems.
No functional change.
Signed-off-by: Dave Martin
Reviewed-by: Alex Bennée
Acked-by: Catalin Marinas
Acked-by: Marc Zyngier
Signed-off-by: Marc Zyngier
---
arch/arm64/kernel/fpsimd.c | 10 +-
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 6c01ee2062c4..842b2ad08bec 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -44,6 +44,7 @@
#include
#include
#include
+#include
#include
#include
#include
@@ -167,10 +168,9 @@ static size_t sve_ffr_offset(int vl)
return SVE_SIG_FFR_OFFSET(sve_vq_from_vl(vl)) - SVE_SIG_REGS_OFFSET;
}
-static void *sve_pffr(struct task_struct *task)
+static void *sve_pffr(struct thread_struct *thread)
{
- return (char *)task->thread.sve_state +
- sve_ffr_offset(task->thread.sve_vl);
+ return (char *)thread->sve_state + sve_ffr_offset(thread->sve_vl);
}
static void change_cpacr(u64 val, u64 mask)
@@ -253,7 +253,7 @@ static void task_fpsimd_load(void)
WARN_ON(!in_softirq() && !irqs_disabled());
if (system_supports_sve() && test_thread_flag(TIF_SVE))
- sve_load_state(sve_pffr(current),
+ sve_load_state(sve_pffr(¤t->thread),
¤t->thread.uw.fpsimd_state.fpsr,
sve_vq_from_vl(current->thread.sve_vl) - 1);
else
@@ -285,7 +285,7 @@ void fpsimd_save(void)
return;
}
- sve_save_state(sve_pffr(current), &st->fpsr);
+ sve_save_state(sve_pffr(¤t->thread), &st->fpsr);
} else
fpsimd_save_state(st);
}
--
2.17.1
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[PATCH 13/33] arm64/sve: Move read_zcr_features() out of cpufeature.h
From: Dave Martin
Having read_zcr_features() inline in cpufeature.h results in that
header requiring #includes which make it hard to include
elsewhere without triggering header inclusion
cycles.
This is not a hot-path function and arguably should not be in
cpufeature.h in the first place, so this patch moves it to
fpsimd.c, compiled conditionally if CONFIG_ARM64_SVE=y.
This allows some SVE-related #includes to be dropped from
cpufeature.h, which will ease future maintenance.
A couple of missing #includes of are exposed by this
change under arch/arm64/. This patch adds the missing #includes as
necessary.
No functional change.
Signed-off-by: Dave Martin
Reviewed-by: Alex Bennée
Acked-by: Catalin Marinas
Acked-by: Marc Zyngier
Signed-off-by: Marc Zyngier
---
arch/arm64/include/asm/cpufeature.h | 29 -
arch/arm64/include/asm/fpsimd.h | 2 ++
arch/arm64/include/asm/processor.h | 1 +
arch/arm64/kernel/fpsimd.c | 28
arch/arm64/kernel/ptrace.c | 1 +
5 files changed, 32 insertions(+), 29 deletions(-)
diff --git a/arch/arm64/include/asm/cpufeature.h
b/arch/arm64/include/asm/cpufeature.h
index 09b0f2a80c8f..0a6b7133195e 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -11,9 +11,7 @@
#include
#include
-#include
#include
-#include
#include
/*
@@ -510,33 +508,6 @@ static inline bool system_supports_sve(void)
cpus_have_const_cap(ARM64_SVE);
}
-/*
- * Read the pseudo-ZCR used by cpufeatures to identify the supported SVE
- * vector length.
- *
- * Use only if SVE is present.
- * This function clobbers the SVE vector length.
- */
-static inline u64 read_zcr_features(void)
-{
- u64 zcr;
- unsigned int vq_max;
-
- /*
-* Set the maximum possible VL, and write zeroes to all other
-* bits to see if they stick.
-*/
- sve_kernel_enable(NULL);
- write_sysreg_s(ZCR_ELx_LEN_MASK, SYS_ZCR_EL1);
-
- zcr = read_sysreg_s(SYS_ZCR_EL1);
- zcr &= ~(u64)ZCR_ELx_LEN_MASK; /* find sticky 1s outside LEN field */
- vq_max = sve_vq_from_vl(sve_get_vl());
- zcr |= vq_max - 1; /* set LEN field to maximum effective value */
-
- return zcr;
-}
-
#endif /* __ASSEMBLY__ */
#endif
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h
index 3e00f701cb9c..fb60b22b8bbf 100644
--- a/arch/arm64/include/asm/fpsimd.h
+++ b/arch/arm64/include/asm/fpsimd.h
@@ -69,6 +69,8 @@ extern unsigned int sve_get_vl(void);
struct arm64_cpu_capabilities;
extern void sve_kernel_enable(const struct arm64_cpu_capabilities *__unused);
+extern u64 read_zcr_features(void);
+
extern int __ro_after_init sve_max_vl;
#ifdef CONFIG_ARM64_SVE
diff --git a/arch/arm64/include/asm/processor.h
b/arch/arm64/include/asm/processor.h
index 36d64f83cdfb..9231b8762ca6 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -40,6 +40,7 @@
#include
#include
+#include
#include
#include
#include
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 794dd990da82..6c01ee2062c4 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -37,6 +37,7 @@
#include
#include
#include
+#include
#include
#include
@@ -755,6 +756,33 @@ void sve_kernel_enable(const struct arm64_cpu_capabilities
*__always_unused p)
isb();
}
+/*
+ * Read the pseudo-ZCR used by cpufeatures to identify the supported SVE
+ * vector length.
+ *
+ * Use only if SVE is present.
+ * This function clobbers the SVE vector length.
+ */
+u64 read_zcr_features(void)
+{
+ u64 zcr;
+ unsigned int vq_max;
+
+ /*
+* Set the maximum possible VL, and write zeroes to all other
+* bits to see if they stick.
+*/
+ sve_kernel_enable(NULL);
+ write_sysreg_s(ZCR_ELx_LEN_MASK, SYS_ZCR_EL1);
+
+ zcr = read_sysreg_s(SYS_ZCR_EL1);
+ zcr &= ~(u64)ZCR_ELx_LEN_MASK; /* find sticky 1s outside LEN field */
+ vq_max = sve_vq_from_vl(sve_get_vl());
+ zcr |= vq_max - 1; /* set LEN field to maximum effective value */
+
+ return zcr;
+}
+
void __init sve_setup(void)
{
u64 zcr;
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 7ff81fed46e1..78889c4546d7 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -44,6 +44,7 @@
#include
#include
#include
+#include
#include
#include
#include
--
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[PATCH 12/33] KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing
From: Dave Martin
This patch refactors KVM to align the host and guest FPSIMD
save/restore logic with each other for arm64. This reduces the
number of redundant save/restore operations that must occur, and
reduces the common-case IRQ blackout time during guest exit storms
by saving the host state lazily and optimising away the need to
restore the host state before returning to the run loop.
Four hooks are defined in order to enable this:
* kvm_arch_vcpu_run_map_fp():
Called on PID change to map necessary bits of current to Hyp.
* kvm_arch_vcpu_load_fp():
Set up FP/SIMD for entering the KVM run loop (parse as
"vcpu_load fp").
* kvm_arch_vcpu_ctxsync_fp():
Get FP/SIMD into a safe state for re-enabling interrupts after a
guest exit back to the run loop.
For arm64 specifically, this involves updating the host kernel's
FPSIMD context tracking metadata so that kernel-mode NEON use
will cause the vcpu's FPSIMD state to be saved back correctly
into the vcpu struct. This must be done before re-enabling
interrupts because kernel-mode NEON may be used by softirqs.
* kvm_arch_vcpu_put_fp():
Save guest FP/SIMD state back to memory and dissociate from the
CPU ("vcpu_put fp").
Also, the arm64 FPSIMD context switch code is updated to enable it
to save back FPSIMD state for a vcpu, not just current. A few
helpers drive this:
* fpsimd_bind_state_to_cpu(struct user_fpsimd_state *fp):
mark this CPU as having context fp (which may belong to a vcpu)
currently loaded in its registers. This is the non-task
equivalent of the static function fpsimd_bind_to_cpu() in
fpsimd.c.
* task_fpsimd_save():
exported to allow KVM to save the guest's FPSIMD state back to
memory on exit from the run loop.
* fpsimd_flush_state():
invalidate any context's FPSIMD state that is currently loaded.
Used to disassociate the vcpu from the CPU regs on run loop exit.
These changes allow the run loop to enable interrupts (and thus
softirqs that may use kernel-mode NEON) without having to save the
guest's FPSIMD state eagerly.
Some new vcpu_arch fields are added to make all this work. Because
host FPSIMD state can now be saved back directly into current's
thread_struct as appropriate, host_cpu_context is no longer used
for preserving the FPSIMD state. However, it is still needed for
preserving other things such as the host's system registers. To
avoid ABI churn, the redundant storage space in host_cpu_context is
not removed for now.
arch/arm is not addressed by this patch and continues to use its
current save/restore logic. It could provide implementations of
the helpers later if desired.
Signed-off-by: Dave Martin
Reviewed-by: Marc Zyngier
Reviewed-by: Christoffer Dall
Reviewed-by: Alex Bennée
Acked-by: Catalin Marinas
Signed-off-by: Marc Zyngier
---
arch/arm/include/asm/kvm_host.h | 8 +++
arch/arm64/include/asm/fpsimd.h | 6 ++
arch/arm64/include/asm/kvm_host.h | 21 ++
arch/arm64/kernel/fpsimd.c| 19 +++--
arch/arm64/kvm/Kconfig| 1 +
arch/arm64/kvm/Makefile | 2 +-
arch/arm64/kvm/fpsimd.c | 111 ++
arch/arm64/kvm/hyp/switch.c | 51 +++---
virt/kvm/arm/arm.c| 4 ++
9 files changed, 192 insertions(+), 31 deletions(-)
create mode 100644 arch/arm64/kvm/fpsimd.c
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index c7c28c885a19..ac870b2cd5d1 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -303,6 +303,14 @@ int kvm_arm_vcpu_arch_get_attr(struct kvm_vcpu *vcpu,
int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr);
+/*
+ * VFP/NEON switching is all done by the hyp switch code, so no need to
+ * coordinate with host context handling for this state:
+ */
+static inline void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu) {}
+
/* All host FP/SIMD state is restored on guest exit, so nothing to save: */
static inline void kvm_fpsimd_flush_cpu_state(void) {}
diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h
index aa7162ae93e3..3e00f701cb9c 100644
--- a/arch/arm64/include/asm/fpsimd.h
+++ b/arch/arm64/include/asm/fpsimd.h
@@ -41,6 +41,8 @@ struct task_struct;
extern void fpsimd_save_state(struct user_fpsimd_state *state);
extern void fpsimd_load_state(struct user_fpsimd_state *state);
+extern void fpsimd_save(void);
+
extern void fpsimd_thread_switch(struct task_struct *next);
extern void fpsimd_flush_thread(void);
@@ -49,7 +51,11 @@ extern void fpsimd_preserve_current_state(void);
extern void fpsimd_restore_current_state(void);
extern void fpsimd_update_current_state(struct user_fpsimd_state const *state);
+extern void fpsimd_bind_task_to_cpu(v
[PATCH 11/33] KVM: arm64: Repurpose vcpu_arch.debug_flags for general-purpose flags
From: Dave Martin
In struct vcpu_arch, the debug_flags field is used to store
debug-related flags about the vcpu state.
Since we are about to add some more flags related to FPSIMD and
SVE, it makes sense to add them to the existing flags field rather
than adding new fields. Since there is only one debug_flags flag
defined so far, there is plenty of free space for expansion.
In preparation for adding more flags, this patch renames the
debug_flags field to simply "flags", and updates comments
appropriately.
The flag definitions are also moved to , since
their presence in was for purely historical
reasons: these definitions are not used from asm any more, and not
very likely to be as more Hyp asm is migrated to C.
KVM_ARM64_DEBUG_DIRTY_SHIFT has not been used since commit
1ea66d27e7b0 ("arm64: KVM: Move away from the assembly version of
the world switch"), so this patch gets rid of that too.
No functional change.
Signed-off-by: Dave Martin
Reviewed-by: Marc Zyngier
Reviewed-by: Alex Bennée
Acked-by: Christoffer Dall
[maz: fixed minor conflict]
Signed-off-by: Marc Zyngier
---
arch/arm64/include/asm/kvm_asm.h | 3 ---
arch/arm64/include/asm/kvm_host.h | 7 +--
arch/arm64/kvm/debug.c| 8
arch/arm64/kvm/hyp/debug-sr.c | 6 +++---
arch/arm64/kvm/hyp/sysreg-sr.c| 4 ++--
arch/arm64/kvm/sys_regs.c | 9 -
6 files changed, 18 insertions(+), 19 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index a9ceeec5a76f..821a7032c0f7 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -30,9 +30,6 @@
/* The hyp-stub will return this for any kvm_call_hyp() call */
#define ARM_EXCEPTION_HYP_GONE HVC_STUB_ERR
-#define KVM_ARM64_DEBUG_DIRTY_SHIFT0
-#define KVM_ARM64_DEBUG_DIRTY (1 << KVM_ARM64_DEBUG_DIRTY_SHIFT)
-
#ifndef __ASSEMBLY__
#include
diff --git a/arch/arm64/include/asm/kvm_host.h
b/arch/arm64/include/asm/kvm_host.h
index 469de8acd06f..146c16794d32 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -216,8 +216,8 @@ struct kvm_vcpu_arch {
/* Exception Information */
struct kvm_vcpu_fault_info fault;
- /* Guest debug state */
- u64 debug_flags;
+ /* Miscellaneous vcpu state flags */
+ u64 flags;
/*
* We maintain more than a single set of debug registers to support
@@ -293,6 +293,9 @@ struct kvm_vcpu_arch {
bool sysregs_loaded_on_cpu;
};
+/* vcpu_arch flags field values: */
+#define KVM_ARM64_DEBUG_DIRTY (1 << 0)
+
#define vcpu_gp_regs(v)(&(v)->arch.ctxt.gp_regs)
/*
diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
index a1f4ebdfe6d3..00d422336a45 100644
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c
@@ -103,7 +103,7 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu)
*
* Additionally, KVM only traps guest accesses to the debug registers if
* the guest is not actively using them (see the KVM_ARM64_DEBUG_DIRTY
- * flag on vcpu->arch.debug_flags). Since the guest must not interfere
+ * flag on vcpu->arch.flags). Since the guest must not interfere
* with the hardware state when debugging the guest, we must ensure that
* trapping is enabled whenever we are debugging the guest using the
* debug registers.
@@ -111,7 +111,7 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu)
void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
{
- bool trap_debug = !(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY);
+ bool trap_debug = !(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY);
unsigned long mdscr;
trace_kvm_arm_setup_debug(vcpu, vcpu->guest_debug);
@@ -184,7 +184,7 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
vcpu_write_sys_reg(vcpu, mdscr, MDSCR_EL1);
vcpu->arch.debug_ptr = &vcpu->arch.external_debug_state;
- vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
+ vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;
trap_debug = true;
trace_kvm_arm_set_regset("BKPTS", get_num_brps(),
@@ -206,7 +206,7 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
/* If KDE or MDE are set, perform a full save/restore cycle. */
if (vcpu_read_sys_reg(vcpu, MDSCR_EL1) & (DBG_MDSCR_KDE |
DBG_MDSCR_MDE))
- vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
+ vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;
trace_kvm_arm_set_dreg32("MDCR_EL2", vcpu->arch.mdcr_el2);
trace_kvm_arm_set_dreg32("MDSCR_EL1", vcpu_read_sys_reg(vcpu,
MDSCR_EL1));
diff --git a/arch/arm64/kvm/hyp/debug-sr.c b/arch/arm64/kvm/hyp/debug-sr.c
index 3e717f66f011..50009766e5e5 100644
--- a/arch/arm64/kvm/hyp/debug-sr.c
+++ b/arch/arm64/kvm/hyp/debug-sr.c
@@ -163,7 +163,7 @@ void __hyp_text __debug_switch_to_guest(struct kvm_vcpu
*v
[PATCH 09/33] arm64: fpsimd: Eliminate task->mm checks
From: Dave Martin
Currently the FPSIMD handling code uses the condition task->mm ==
NULL as a hint that task has no FPSIMD register context.
The ->mm check is only there to filter out tasks that cannot
possibly have FPSIMD context loaded, for optimisation purposes.
Also, TIF_FOREIGN_FPSTATE must always be checked anyway before
saving FPSIMD context back to memory. For these reasons, the ->mm
checks are not useful, providing that TIF_FOREIGN_FPSTATE is
maintained in a consistent way for all threads.
The context switch logic is already deliberately optimised to defer
reloads of the regs until ret_to_user (or sigreturn as a special
case), and save them only if they have been previously loaded.
These paths are the only places where the wrong_task and wrong_cpu
conditions can be made false, by calling fpsimd_bind_task_to_cpu().
Kernel threads by definition never reach these paths. As a result,
the wrong_task and wrong_cpu tests in fpsimd_thread_switch() will
always yield true for kernel threads.
This patch removes the redundant checks and special-case code,
ensuring that TIF_FOREIGN_FPSTATE is set whenever a kernel thread
is scheduled in, and ensures that this flag is set for the init
task. The fpsimd_flush_task_state() call already present in
copy_thread() ensures the same for any new task.
With TIF_FOREIGN_FPSTATE always set for kernel threads, this patch
ensures that no extra context save work is added for kernel
threads, and eliminates the redundant context saving that may
currently occur for kernel threads that have acquired an mm via
use_mm().
Signed-off-by: Dave Martin
Reviewed-by: Catalin Marinas
Reviewed-by: Alex Bennée
Reviewed-by: Christoffer Dall
Cc: Catalin Marinas
Cc: Will Deacon
Cc: Ard Biesheuvel
Signed-off-by: Marc Zyngier
---
arch/arm64/include/asm/processor.h | 4 ++-
arch/arm64/kernel/fpsimd.c | 40 --
2 files changed, 19 insertions(+), 25 deletions(-)
diff --git a/arch/arm64/include/asm/processor.h
b/arch/arm64/include/asm/processor.h
index 767598932549..36d64f83cdfb 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -156,7 +156,9 @@ static inline void arch_thread_struct_whitelist(unsigned
long *offset,
/* Sync TPIDR_EL0 back to thread_struct for current */
void tls_preserve_current_state(void);
-#define INIT_THREAD { }
+#define INIT_THREAD { \
+ .fpsimd_cpu = NR_CPUS, \
+}
static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
{
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 2d9a9e8ed826..d736b6c412ef 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -892,31 +892,25 @@ asmlinkage void do_fpsimd_exc(unsigned int esr, struct
pt_regs *regs)
void fpsimd_thread_switch(struct task_struct *next)
{
+ bool wrong_task, wrong_cpu;
+
if (!system_supports_fpsimd())
return;
+
+ /* Save unsaved fpsimd state, if any: */
+ fpsimd_save();
+
/*
-* Save the current FPSIMD state to memory, but only if whatever is in
-* the registers is in fact the most recent userland FPSIMD state of
-* 'current'.
+* Fix up TIF_FOREIGN_FPSTATE to correctly describe next's
+* state. For kernel threads, FPSIMD registers are never loaded
+* and wrong_task and wrong_cpu will always be true.
*/
- if (current->mm)
- fpsimd_save();
-
- if (next->mm) {
- /*
-* If we are switching to a task whose most recent userland
-* FPSIMD state is already in the registers of *this* cpu,
-* we can skip loading the state from memory. Otherwise, set
-* the TIF_FOREIGN_FPSTATE flag so the state will be loaded
-* upon the next return to userland.
-*/
- bool wrong_task = __this_cpu_read(fpsimd_last_state.st) !=
+ wrong_task = __this_cpu_read(fpsimd_last_state.st) !=
&next->thread.uw.fpsimd_state;
- bool wrong_cpu = next->thread.fpsimd_cpu != smp_processor_id();
+ wrong_cpu = next->thread.fpsimd_cpu != smp_processor_id();
- update_tsk_thread_flag(next, TIF_FOREIGN_FPSTATE,
- wrong_task || wrong_cpu);
- }
+ update_tsk_thread_flag(next, TIF_FOREIGN_FPSTATE,
+ wrong_task || wrong_cpu);
}
void fpsimd_flush_thread(void)
@@ -1121,9 +1115,8 @@ void kernel_neon_begin(void)
__this_cpu_write(kernel_neon_busy, true);
- /* Save unsaved task fpsimd state, if any: */
- if (current->mm)
- fpsimd_save();
+ /* Save unsaved fpsimd state, if any: */
+ fpsimd_save();
/* Invalidate any task state remaining in the fpsimd regs: */
fpsimd_flush_cpu_state();
@@ -
[PATCH 10/33] arm64/sve: Refactor user SVE trap maintenance for external use
From: Dave Martin
In preparation for optimising the way KVM manages switching the
guest and host FPSIMD state, it is necessary to provide a means for
code outside arch/arm64/kernel/fpsimd.c to restore the user trap
configuration for SVE correctly for the current task.
Rather than requiring external code to duplicate the maintenance
explicitly, this patch moves the trap maintenenace to
fpsimd_bind_to_cpu(), since it is logically part of the work of
associating the current task with the cpu.
Because fpsimd_bind_to_cpu() is rather a cryptic name to publish
alongside fpsimd_bind_state_to_cpu(), the former function is
renamed to fpsimd_bind_task_to_cpu() to make its purpose more
explicit.
This patch makes appropriate changes to ensure that
fpsimd_bind_task_to_cpu() is always called alongside
task_fpsimd_load(), so that the trap maintenance continues to be
done in every situation where it was done prior to this patch.
As a side-effect, the metadata updates done by
fpsimd_bind_task_to_cpu() now change from conditional to
unconditional in the "already bound" case of sigreturn. This is
harmless, and a couple of extra stores on this slow path will not
impact performance. I consider this a reasonable price to pay for
a slightly cleaner interface.
Signed-off-by: Dave Martin
Reviewed-by: Alex Bennée
Acked-by: Marc Zyngier
Acked-by: Catalin Marinas
Signed-off-by: Marc Zyngier
---
arch/arm64/kernel/fpsimd.c | 30 +++---
1 file changed, 15 insertions(+), 15 deletions(-)
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index d736b6c412ef..d5f659f476a8 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -257,16 +257,6 @@ static void task_fpsimd_load(void)
sve_vq_from_vl(current->thread.sve_vl) - 1);
else
fpsimd_load_state(¤t->thread.uw.fpsimd_state);
-
- if (system_supports_sve()) {
- /* Toggle SVE trapping for userspace if needed */
- if (test_thread_flag(TIF_SVE))
- sve_user_enable();
- else
- sve_user_disable();
-
- /* Serialised by exception return to user */
- }
}
/*
@@ -278,7 +268,7 @@ static void task_fpsimd_load(void)
static void fpsimd_save(void)
{
struct user_fpsimd_state *st = __this_cpu_read(fpsimd_last_state.st);
- /* set by fpsimd_bind_to_cpu() */
+ /* set by fpsimd_bind_task_to_cpu() */
WARN_ON(!in_softirq() && !irqs_disabled());
@@ -996,7 +986,7 @@ void fpsimd_signal_preserve_current_state(void)
* Associate current's FPSIMD context with this cpu
* Preemption must be disabled when calling this function.
*/
-static void fpsimd_bind_to_cpu(void)
+static void fpsimd_bind_task_to_cpu(void)
{
struct fpsimd_last_state_struct *last =
this_cpu_ptr(&fpsimd_last_state);
@@ -1004,6 +994,16 @@ static void fpsimd_bind_to_cpu(void)
last->st = ¤t->thread.uw.fpsimd_state;
last->sve_in_use = test_thread_flag(TIF_SVE);
current->thread.fpsimd_cpu = smp_processor_id();
+
+ if (system_supports_sve()) {
+ /* Toggle SVE trapping for userspace if needed */
+ if (test_thread_flag(TIF_SVE))
+ sve_user_enable();
+ else
+ sve_user_disable();
+
+ /* Serialised by exception return to user */
+ }
}
/*
@@ -1020,7 +1020,7 @@ void fpsimd_restore_current_state(void)
if (test_and_clear_thread_flag(TIF_FOREIGN_FPSTATE)) {
task_fpsimd_load();
- fpsimd_bind_to_cpu();
+ fpsimd_bind_task_to_cpu();
}
local_bh_enable();
@@ -1043,9 +1043,9 @@ void fpsimd_update_current_state(struct user_fpsimd_state
const *state)
fpsimd_to_sve(current);
task_fpsimd_load();
+ fpsimd_bind_task_to_cpu();
- if (test_and_clear_thread_flag(TIF_FOREIGN_FPSTATE))
- fpsimd_bind_to_cpu();
+ clear_thread_flag(TIF_FOREIGN_FPSTATE);
local_bh_enable();
}
--
2.17.1
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[PATCH 08/33] arm64: fpsimd: Avoid FPSIMD context leakage for the init task
From: Dave Martin
The init task is started with thread_flags equal to 0, which means
that TIF_FOREIGN_FPSTATE is initially clear.
It is theoretically possible (if unlikely) that the init task could
reach userspace without ever being scheduled out. If this occurs,
data left in the FPSIMD registers by the kernel could be exposed.
This patch fixes this anomaly by ensuring that the init task's
initial TIF_FOREIGN_FPSTATE is set.
Signed-off-by: Dave Martin
Fixes: 005f78cd8849 ("arm64: defer reloading a task's FPSIMD state to userland
resume")
Reviewed-by: Catalin Marinas
Reviewed-by: Alex Bennée
Cc: Will Deacon
Cc: Ard Biesheuvel
Signed-off-by: Marc Zyngier
---
arch/arm64/include/asm/thread_info.h | 13 +++--
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/include/asm/thread_info.h
b/arch/arm64/include/asm/thread_info.h
index 740aa03c5f0d..af271f9a6c9f 100644
--- a/arch/arm64/include/asm/thread_info.h
+++ b/arch/arm64/include/asm/thread_info.h
@@ -45,12 +45,6 @@ struct thread_info {
int preempt_count; /* 0 => preemptable, <0 => bug
*/
};
-#define INIT_THREAD_INFO(tsk) \
-{ \
- .preempt_count = INIT_PREEMPT_COUNT, \
- .addr_limit = KERNEL_DS,\
-}
-
#define thread_saved_pc(tsk) \
((unsigned long)(tsk->thread.cpu_context.pc))
#define thread_saved_sp(tsk) \
@@ -117,5 +111,12 @@ void arch_release_task_struct(struct task_struct *tsk);
_TIF_SYSCALL_TRACEPOINT | _TIF_SECCOMP | \
_TIF_NOHZ)
+#define INIT_THREAD_INFO(tsk) \
+{ \
+ .flags = _TIF_FOREIGN_FPSTATE, \
+ .preempt_count = INIT_PREEMPT_COUNT, \
+ .addr_limit = KERNEL_DS,\
+}
+
#endif /* __KERNEL__ */
#endif /* __ASM_THREAD_INFO_H */
--
2.17.1
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[PATCH 07/33] arm64: fpsimd: Generalise context saving for non-task contexts
From: Dave Martin
In preparation for allowing non-task (i.e., KVM vcpu) FPSIMD
contexts to be handled by the fpsimd common code, this patch adapts
task_fpsimd_save() to save back the currently loaded context,
removing the explicit dependency on current.
The relevant storage to write back to in memory is now found by
examining the fpsimd_last_state percpu struct.
fpsimd_save() does nothing unless TIF_FOREIGN_FPSTATE is clear, and
fpsimd_last_state is updated under local_bh_disable() or
local_irq_disable() everywhere that TIF_FOREIGN_FPSTATE is cleared:
thus, fpsimd_save() will write back to the correct storage for the
loaded context.
No functional change.
Signed-off-by: Dave Martin
Reviewed-by: Alex Bennée
Acked-by: Marc Zyngier
Acked-by: Catalin Marinas
Signed-off-by: Marc Zyngier
---
arch/arm64/kernel/fpsimd.c | 26 ++
1 file changed, 14 insertions(+), 12 deletions(-)
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 9d853732f9f4..2d9a9e8ed826 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -270,13 +270,16 @@ static void task_fpsimd_load(void)
}
/*
- * Ensure current's FPSIMD/SVE storage in thread_struct is up to date
- * with respect to the CPU registers.
+ * Ensure FPSIMD/SVE storage in memory for the loaded context is up to
+ * date with respect to the CPU registers.
*
* Softirqs (and preemption) must be disabled.
*/
-static void task_fpsimd_save(void)
+static void fpsimd_save(void)
{
+ struct user_fpsimd_state *st = __this_cpu_read(fpsimd_last_state.st);
+ /* set by fpsimd_bind_to_cpu() */
+
WARN_ON(!in_softirq() && !irqs_disabled());
if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) {
@@ -291,10 +294,9 @@ static void task_fpsimd_save(void)
return;
}
- sve_save_state(sve_pffr(current),
- ¤t->thread.uw.fpsimd_state.fpsr);
+ sve_save_state(sve_pffr(current), &st->fpsr);
} else
- fpsimd_save_state(¤t->thread.uw.fpsimd_state);
+ fpsimd_save_state(st);
}
}
@@ -598,7 +600,7 @@ int sve_set_vector_length(struct task_struct *task,
if (task == current) {
local_bh_disable();
- task_fpsimd_save();
+ fpsimd_save();
set_thread_flag(TIF_FOREIGN_FPSTATE);
}
@@ -837,7 +839,7 @@ asmlinkage void do_sve_acc(unsigned int esr, struct pt_regs
*regs)
local_bh_disable();
- task_fpsimd_save();
+ fpsimd_save();
fpsimd_to_sve(current);
/* Force ret_to_user to reload the registers: */
@@ -898,7 +900,7 @@ void fpsimd_thread_switch(struct task_struct *next)
* 'current'.
*/
if (current->mm)
- task_fpsimd_save();
+ fpsimd_save();
if (next->mm) {
/*
@@ -980,7 +982,7 @@ void fpsimd_preserve_current_state(void)
return;
local_bh_disable();
- task_fpsimd_save();
+ fpsimd_save();
local_bh_enable();
}
@@ -1121,7 +1123,7 @@ void kernel_neon_begin(void)
/* Save unsaved task fpsimd state, if any: */
if (current->mm)
- task_fpsimd_save();
+ fpsimd_save();
/* Invalidate any task state remaining in the fpsimd regs: */
fpsimd_flush_cpu_state();
@@ -1244,7 +1246,7 @@ static int fpsimd_cpu_pm_notifier(struct notifier_block
*self,
switch (cmd) {
case CPU_PM_ENTER:
if (current->mm)
- task_fpsimd_save();
+ fpsimd_save();
fpsimd_flush_cpu_state();
break;
case CPU_PM_EXIT:
--
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[PATCH 06/33] KVM: arm64: Convert lazy FPSIMD context switch trap to C
From: Dave Martin
To make the lazy FPSIMD context switch trap code easier to hack on,
this patch converts it to C.
This is not amazingly efficient, but the trap should typically only
be taken once per host context switch.
Signed-off-by: Dave Martin
Reviewed-by: Marc Zyngier
Reviewed-by: Alex Bennée
Signed-off-by: Marc Zyngier
---
arch/arm64/kvm/hyp/entry.S | 57 ++---
arch/arm64/kvm/hyp/switch.c | 24
2 files changed, 46 insertions(+), 35 deletions(-)
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S
index e41a161d313a..40f349bc1079 100644
--- a/arch/arm64/kvm/hyp/entry.S
+++ b/arch/arm64/kvm/hyp/entry.S
@@ -172,40 +172,27 @@ ENTRY(__fpsimd_guest_restore)
// x1: vcpu
// x2-x29,lr: vcpu regs
// vcpu x0-x1 on the stack
- stp x2, x3, [sp, #-16]!
- stp x4, lr, [sp, #-16]!
-
-alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
- mrs x2, cptr_el2
- bic x2, x2, #CPTR_EL2_TFP
- msr cptr_el2, x2
-alternative_else
- mrs x2, cpacr_el1
- orr x2, x2, #CPACR_EL1_FPEN
- msr cpacr_el1, x2
-alternative_endif
- isb
-
- mov x3, x1
-
- ldr x0, [x3, #VCPU_HOST_CONTEXT]
- kern_hyp_va x0
- add x0, x0, #CPU_GP_REG_OFFSET(CPU_FP_REGS)
- bl __fpsimd_save_state
-
- add x2, x3, #VCPU_CONTEXT
- add x0, x2, #CPU_GP_REG_OFFSET(CPU_FP_REGS)
- bl __fpsimd_restore_state
-
- // Skip restoring fpexc32 for AArch64 guests
- mrs x1, hcr_el2
- tbnzx1, #HCR_RW_SHIFT, 1f
- ldr x4, [x3, #VCPU_FPEXC32_EL2]
- msr fpexc32_el2, x4
-1:
- ldp x4, lr, [sp], #16
- ldp x2, x3, [sp], #16
- ldp x0, x1, [sp], #16
-
+ stp x2, x3, [sp, #-144]!
+ stp x4, x5, [sp, #16]
+ stp x6, x7, [sp, #32]
+ stp x8, x9, [sp, #48]
+ stp x10, x11, [sp, #64]
+ stp x12, x13, [sp, #80]
+ stp x14, x15, [sp, #96]
+ stp x16, x17, [sp, #112]
+ stp x18, lr, [sp, #128]
+
+ bl __hyp_switch_fpsimd
+
+ ldp x4, x5, [sp, #16]
+ ldp x6, x7, [sp, #32]
+ ldp x8, x9, [sp, #48]
+ ldp x10, x11, [sp, #64]
+ ldp x12, x13, [sp, #80]
+ ldp x14, x15, [sp, #96]
+ ldp x16, x17, [sp, #112]
+ ldp x18, lr, [sp, #128]
+ ldp x0, x1, [sp, #144]
+ ldp x2, x3, [sp], #160
eret
ENDPROC(__fpsimd_guest_restore)
diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index d9645236e474..c0796c4d93a5 100644
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -318,6 +318,30 @@ static bool __hyp_text __skip_instr(struct kvm_vcpu *vcpu)
}
}
+void __hyp_text __hyp_switch_fpsimd(u64 esr __always_unused,
+ struct kvm_vcpu *vcpu)
+{
+ kvm_cpu_context_t *host_ctxt;
+
+ if (has_vhe())
+ write_sysreg(read_sysreg(cpacr_el1) | CPACR_EL1_FPEN,
+cpacr_el1);
+ else
+ write_sysreg(read_sysreg(cptr_el2) & ~(u64)CPTR_EL2_TFP,
+cptr_el2);
+
+ isb();
+
+ host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
+ __fpsimd_save_state(&host_ctxt->gp_regs.fp_regs);
+ __fpsimd_restore_state(&vcpu->arch.ctxt.gp_regs.fp_regs);
+
+ /* Skip restoring fpexc32 for AArch64 guests */
+ if (!(read_sysreg(hcr_el2) & HCR_RW))
+ write_sysreg(vcpu->arch.ctxt.sys_regs[FPEXC32_EL2],
+fpexc32_el2);
+}
+
/*
* Return true when we were able to fixup the guest exit and should return to
* the guest, false when we should restore the host state and return to the
--
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[PATCH 05/33] KVM: arm/arm64: Introduce kvm_arch_vcpu_run_pid_change
From: Christoffer Dall
KVM/ARM differs from other architectures in having to maintain an
additional virtual address space from that of the host and the
guest, because we split the execution of KVM across both EL1 and
EL2.
This results in a need to explicitly map data structures into EL2
(hyp) which are accessed from the hyp code. As we are about to be
more clever with our FPSIMD handling on arm64, which stores data in
the task struct and uses thread_info flags, we will have to map
parts of the currently executing task struct into the EL2 virtual
address space.
However, we don't want to do this on every KVM_RUN, because it is a
fairly expensive operation to walk the page tables, and the common
execution mode is to map a single thread to a VCPU. By introducing
a hook that architectures can select with
HAVE_KVM_VCPU_RUN_PID_CHANGE, we do not introduce overhead for
other architectures, but have a simple way to only map the data we
need when required for arm64.
This patch introduces the framework only, and wires it up in the
arm/arm64 KVM common code.
No functional change.
Signed-off-by: Christoffer Dall
Signed-off-by: Dave Martin
Reviewed-by: Marc Zyngier
Reviewed-by: Alex Bennée
Signed-off-by: Marc Zyngier
---
include/linux/kvm_host.h | 9 +
virt/kvm/Kconfig | 3 +++
virt/kvm/kvm_main.c | 7 ++-
3 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 6930c63126c7..4268ace60bf1 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1276,4 +1276,13 @@ static inline long kvm_arch_vcpu_async_ioctl(struct file
*filp,
void kvm_arch_mmu_notifier_invalidate_range(struct kvm *kvm,
unsigned long start, unsigned long end);
+#ifdef CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE
+int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu);
+#else
+static inline int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu)
+{
+ return 0;
+}
+#endif /* CONFIG_HAVE_KVM_VCPU_RUN_PID_CHANGE */
+
#endif
diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index cca7e065a075..72143cfaf6ec 100644
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -54,3 +54,6 @@ config HAVE_KVM_IRQ_BYPASS
config HAVE_KVM_VCPU_ASYNC_IOCTL
bool
+
+config HAVE_KVM_VCPU_RUN_PID_CHANGE
+ bool
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index c7b2e927f699..c32e2407713d 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -2550,8 +2550,13 @@ static long kvm_vcpu_ioctl(struct file *filp,
oldpid = rcu_access_pointer(vcpu->pid);
if (unlikely(oldpid != current->pids[PIDTYPE_PID].pid)) {
/* The thread running this VCPU changed. */
- struct pid *newpid = get_task_pid(current, PIDTYPE_PID);
+ struct pid *newpid;
+ r = kvm_arch_vcpu_run_pid_change(vcpu);
+ if (r)
+ break;
+
+ newpid = get_task_pid(current, PIDTYPE_PID);
rcu_assign_pointer(vcpu->pid, newpid);
if (oldpid)
synchronize_rcu();
--
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[PATCH 04/33] arm64: Use update{,_tsk}_thread_flag()
From: Dave Martin This patch uses the new update_thread_flag() helpers to simplify a couple of if () set; else clear; constructs. No functional change. Signed-off-by: Dave Martin Reviewed-by: Alex Bennée Acked-by: Marc Zyngier Acked-by: Catalin Marinas Cc: Will Deacon Signed-off-by: Marc Zyngier --- arch/arm64/kernel/fpsimd.c | 18 -- 1 file changed, 8 insertions(+), 10 deletions(-) diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c index 12e1c967c7b5..9d853732f9f4 100644 --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -618,10 +618,8 @@ int sve_set_vector_length(struct task_struct *task, task->thread.sve_vl = vl; out: - if (flags & PR_SVE_VL_INHERIT) - set_tsk_thread_flag(task, TIF_SVE_VL_INHERIT); - else - clear_tsk_thread_flag(task, TIF_SVE_VL_INHERIT); + update_tsk_thread_flag(task, TIF_SVE_VL_INHERIT, + flags & PR_SVE_VL_INHERIT); return 0; } @@ -910,12 +908,12 @@ void fpsimd_thread_switch(struct task_struct *next) * the TIF_FOREIGN_FPSTATE flag so the state will be loaded * upon the next return to userland. */ - if (__this_cpu_read(fpsimd_last_state.st) == - &next->thread.uw.fpsimd_state - && next->thread.fpsimd_cpu == smp_processor_id()) - clear_tsk_thread_flag(next, TIF_FOREIGN_FPSTATE); - else - set_tsk_thread_flag(next, TIF_FOREIGN_FPSTATE); + bool wrong_task = __this_cpu_read(fpsimd_last_state.st) != + &next->thread.uw.fpsimd_state; + bool wrong_cpu = next->thread.fpsimd_cpu != smp_processor_id(); + + update_tsk_thread_flag(next, TIF_FOREIGN_FPSTATE, + wrong_task || wrong_cpu); } } -- 2.17.1 ___ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
[PATCH 03/33] thread_info: Add update_thread_flag() helpers
From: Dave Martin
There are a number of bits of code sprinkled around the kernel to
set a thread flag if a certain condition is true, and clear it
otherwise.
To help make those call sites terser and less cumbersome, this
patch adds a new family of thread flag manipulators
update*_thread_flag([...,] flag, cond)
which do the equivalent of:
if (cond)
set*_thread_flag([...,] flag);
else
clear*_thread_flag([...,] flag);
Signed-off-by: Dave Martin
Reviewed-by: Alex Bennée
Acked-by: Steven Rostedt (VMware)
Acked-by: Marc Zyngier
Acked-by: Catalin Marinas
Acked-by: Peter Zijlstra (Intel)
Cc: Ingo Molnar
Cc: Oleg Nesterov
Signed-off-by: Marc Zyngier
---
include/linux/sched.h | 6 ++
include/linux/thread_info.h | 11 +++
2 files changed, 17 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index b3d697f3b573..c2c305199721 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1578,6 +1578,12 @@ static inline void clear_tsk_thread_flag(struct
task_struct *tsk, int flag)
clear_ti_thread_flag(task_thread_info(tsk), flag);
}
+static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
+ bool value)
+{
+ update_ti_thread_flag(task_thread_info(tsk), flag, value);
+}
+
static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int
flag)
{
return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index cf2862bd134a..8d8821b3689a 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -60,6 +60,15 @@ static inline void clear_ti_thread_flag(struct thread_info
*ti, int flag)
clear_bit(flag, (unsigned long *)&ti->flags);
}
+static inline void update_ti_thread_flag(struct thread_info *ti, int flag,
+bool value)
+{
+ if (value)
+ set_ti_thread_flag(ti, flag);
+ else
+ clear_ti_thread_flag(ti, flag);
+}
+
static inline int test_and_set_ti_thread_flag(struct thread_info *ti, int flag)
{
return test_and_set_bit(flag, (unsigned long *)&ti->flags);
@@ -79,6 +88,8 @@ static inline int test_ti_thread_flag(struct thread_info *ti,
int flag)
set_ti_thread_flag(current_thread_info(), flag)
#define clear_thread_flag(flag) \
clear_ti_thread_flag(current_thread_info(), flag)
+#define update_thread_flag(flag, value) \
+ update_ti_thread_flag(current_thread_info(), flag, value)
#define test_and_set_thread_flag(flag) \
test_and_set_ti_thread_flag(current_thread_info(), flag)
#define test_and_clear_thread_flag(flag) \
--
2.17.1
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[PATCH 02/33] arm64: fpsimd: Fix TIF_FOREIGN_FPSTATE after invalidating cpu regs
From: Dave Martin
fpsimd_last_state.st is set to NULL as a way of indicating that
current's FPSIMD registers are no longer loaded in the cpu. In
particular, this is done when the kernel temporarily uses or
clobbers the FPSIMD registers for its own purposes, as in CPU PM or
kernel-mode NEON, resulting in them being populated with garbage
data not belonging to a task.
Commit 17eed27b02da ("arm64/sve: KVM: Prevent guests from using
SVE") factors this operation out as a new helper
fpsimd_flush_cpu_state() to make it clearer what is being done
here, and on SVE systems this helper is now used, via
kvm_fpsimd_flush_cpu_state(), to invalidate the registers after KVM
has run a vcpu. The reason for this is that KVM does not yet
understand how to restore the full host SVE registers itself after
loading the guest FPSIMD context into them.
This exposes a particular problem: if fpsimd_last_state.st is set
to NULL without also setting TIF_FOREIGN_FPSTATE, the kernel may
continue to think that current's FPSIMD registers are live even
though they have actually been clobbered.
Prior to the aforementioned commit, the only path where
fpsimd_last_state.st is set to NULL without setting
TIF_FOREIGN_FPSTATE is when kernel_neon_begin() is called by a
kernel thread (where current->mm can be NULL). This does not
matter, because the only harm is that at context-switch time
fpsimd_thread_switch() may unnecessarily save the FPSIMD registers
back to current's thread_struct (even though kernel threads are not
considered to have any FPSIMD context of their own and the
registers will never be reloaded).
Note that although CPU_PM_ENTER lacks the TIF_FOREIGN_FPSTATE
setting, every CPU passing through that path must subsequently pass
through CPU_PM_EXIT before it can re-enter the kernel proper.
CPU_PM_EXIT sets the flag.
The sve_flush_cpu_state() function added by commit 17eed27b02da
also lacks the proper maintenance of TIF_FOREIGN_FPSTATE. This may
cause the bits of a host task's SVE registers that do not alias the
FPSIMD register file to spontaneously appear zeroed if a KVM vcpu
runs in the same task in the meantime. Although this effect is
hidden by the fact that the non-FPSIMD bits of the SVE registers
are zeroed by a syscall anyway, it is doubtless a bad idea to rely
on these different code paths interacting correctly under future
maintenance.
This patch makes TIF_FOREIGN_FPSTATE an unconditional side-effect
of fpsimd_flush_cpu_state(), and removes the set_thread_flag()
calls that become redundant as a result. This ensures that
TIF_FOREIGN_FPSTATE cannot remain clear if the FPSIMD state in the
FPSIMD registers is invalid.
Signed-off-by: Dave Martin
Reviewed-by: Christoffer Dall
Reviewed-by: Alex Bennée
Reviewed-by: Catalin Marinas
Cc: Will Deacon
Cc: Ard Biesheuvel
Signed-off-by: Marc Zyngier
---
arch/arm64/kernel/fpsimd.c | 7 ++-
1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 87a35364e750..12e1c967c7b5 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -1067,6 +1067,7 @@ void fpsimd_flush_task_state(struct task_struct *t)
static inline void fpsimd_flush_cpu_state(void)
{
__this_cpu_write(fpsimd_last_state.st, NULL);
+ set_thread_flag(TIF_FOREIGN_FPSTATE);
}
/*
@@ -1121,10 +1122,8 @@ void kernel_neon_begin(void)
__this_cpu_write(kernel_neon_busy, true);
/* Save unsaved task fpsimd state, if any: */
- if (current->mm) {
+ if (current->mm)
task_fpsimd_save();
- set_thread_flag(TIF_FOREIGN_FPSTATE);
- }
/* Invalidate any task state remaining in the fpsimd regs: */
fpsimd_flush_cpu_state();
@@ -1251,8 +1250,6 @@ static int fpsimd_cpu_pm_notifier(struct notifier_block
*self,
fpsimd_flush_cpu_state();
break;
case CPU_PM_EXIT:
- if (current->mm)
- set_thread_flag(TIF_FOREIGN_FPSTATE);
break;
case CPU_PM_ENTER_FAILED:
default:
--
2.17.1
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[PATCH 01/33] arm64: KVM: Use lm_alias() for kvm_ksym_ref()
From: Mark Rutland
For historical reasons, we open-code lm_alias() in kvm_ksym_ref().
Let's use lm_alias() to avoid duplication and make things clearer.
As we have to pull this from (which is not safe for
inclusion in assembly), we may as well move the kvm_ksym_ref()
definition into the existing !__ASSEMBLY__ block.
Signed-off-by: Mark Rutland
Cc: Christoffer Dall
Cc: Marc Zyngier
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Marc Zyngier
---
arch/arm64/include/asm/kvm_asm.h | 7 +--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index f6648a3e4152..a9ceeec5a76f 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -33,16 +33,19 @@
#define KVM_ARM64_DEBUG_DIRTY_SHIFT0
#define KVM_ARM64_DEBUG_DIRTY (1 << KVM_ARM64_DEBUG_DIRTY_SHIFT)
+#ifndef __ASSEMBLY__
+
+#include
+
/* Translate a kernel address of @sym into its equivalent linear mapping */
#define kvm_ksym_ref(sym) \
({ \
void *val = &sym; \
if (!is_kernel_in_hyp_mode()) \
- val = phys_to_virt((u64)&sym - kimage_voffset); \
+ val = lm_alias(&sym); \
val;\
})
-#ifndef __ASSEMBLY__
struct kvm;
struct kvm_vcpu;
--
2.17.1
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[GIT PULL] KVM/ARM updates for 4.18
Paolo, Radim,
This is the set of updates for KVM/ARM for v4.18. This time, lazy
context switching of the floating point registers for arm64, and the
ability to deal with multiple redistributor ranges (which allows for
larger numbers of vcpu).
Note that some additional KVM/ARM updates will come via the arm64 tree
with the SSBD patches. This will generate three conflicts that are
pretty simple to resolve (-next has a good example of the resolution).
Please pull,
M.
The following changes since commit 75bc37fefc4471e718ba8e651aa74673d4e0a9eb:
Linux 4.17-rc4 (2018-05-06 16:57:38 -1000)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git
tags/kvmarm-for-v4.18
for you to fetch changes up to e25028c8ded011d19f9a11164807507c94febc01:
KVM: arm/arm64: Bump VGIC_V3_MAX_CPUS to 512 (2018-05-25 12:29:27 +0100)
KVM/ARM updates for 4.18
- Lazy context-switching of FPSIMD registers on arm64
- Allow virtual redistributors to be part of two or more MMIO ranges
Christoffer Dall (1):
KVM: arm/arm64: Introduce kvm_arch_vcpu_run_pid_change
Dave Martin (18):
arm64: fpsimd: Fix TIF_FOREIGN_FPSTATE after invalidating cpu regs
thread_info: Add update_thread_flag() helpers
arm64: Use update{,_tsk}_thread_flag()
KVM: arm64: Convert lazy FPSIMD context switch trap to C
arm64: fpsimd: Generalise context saving for non-task contexts
arm64: fpsimd: Avoid FPSIMD context leakage for the init task
arm64: fpsimd: Eliminate task->mm checks
arm64/sve: Refactor user SVE trap maintenance for external use
KVM: arm64: Repurpose vcpu_arch.debug_flags for general-purpose flags
KVM: arm64: Optimise FPSIMD handling to reduce guest/host thrashing
arm64/sve: Move read_zcr_features() out of cpufeature.h
arm64/sve: Switch sve_pffr() argument from task to thread
arm64/sve: Move sve_pffr() to fpsimd.h and make inline
KVM: arm64: Save host SVE context as appropriate
KVM: arm64: Remove eager host SVE state saving
KVM: arm64: Remove redundant *exit_code changes in fpsimd_guest_exit()
KVM: arm64: Fold redundant exit code checks out of fixup_guest_exit()
KVM: arm64: Invoke FPSIMD context switch trap from C
Eric Auger (13):
KVM: arm/arm64: Set dist->spis to NULL after kfree
KVM: arm/arm64: Document KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION
KVM: arm/arm64: Replace the single rdist region by a list
KVM: arm/arm64: Helper to locate free rdist index
KVM: arm/arm64: Revisit Redistributor TYPER last bit computation
KVM: arm/arm64: Adapt vgic_v3_check_base to multiple rdist regions
KVM: arm/arm64: Helper to register a new redistributor region
KVM: arm/arm64: Remove kvm_vgic_vcpu_early_init
KVM: arm/arm64: Check vcpu redist base before registering an iodev
KVM: arm/arm64: Check all vcpu redistributors are set on map_resources
KVM: arm/arm64: Add KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION
KVM: arm/arm64: Implement KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION
KVM: arm/arm64: Bump VGIC_V3_MAX_CPUS to 512
Mark Rutland (1):
arm64: KVM: Use lm_alias() for kvm_ksym_ref()
Documentation/virtual/kvm/devices/arm-vgic-v3.txt | 30 +++-
arch/arm/include/asm/kvm_host.h | 10 +-
arch/arm/include/uapi/asm/kvm.h | 1 +
arch/arm64/Kconfig| 7 +
arch/arm64/include/asm/cpufeature.h | 29
arch/arm64/include/asm/fpsimd.h | 21 +++
arch/arm64/include/asm/kvm_asm.h | 8 +-
arch/arm64/include/asm/kvm_host.h | 45 --
arch/arm64/include/asm/processor.h| 15 +-
arch/arm64/include/asm/thread_info.h | 13 +-
arch/arm64/include/uapi/asm/kvm.h | 1 +
arch/arm64/kernel/fpsimd.c| 177 +++---
arch/arm64/kernel/ptrace.c| 1 +
arch/arm64/kvm/Kconfig| 1 +
arch/arm64/kvm/Makefile | 2 +-
arch/arm64/kvm/debug.c| 8 +-
arch/arm64/kvm/fpsimd.c | 110 ++
arch/arm64/kvm/hyp/debug-sr.c | 6 +-
arch/arm64/kvm/hyp/entry.S| 43 --
arch/arm64/kvm/hyp/hyp-entry.S| 19 ---
arch/arm64/kvm/hyp/switch.c | 124 ++-
arch/arm64/kvm/hyp/sysreg-sr.c| 4 +-
arch/arm64/kvm/sys_regs.c | 9 +-
include/kvm/arm_vgic.h| 17 ++-
include/linux/kvm_host.h | 9 ++
include/linux/sched.h | 6 +
include/linux/thread_info.h
[PATCH] KVM: arm/arm64: drop resource size check for GICV window
When booting a 64 KB pages kernel on a ACPI GICv3 system that
implements support for v2 emulation, the following warning is
produced
GICV size 0x2000 not a multiple of page size 0x1
and support for v2 emulation is disabled, preventing GICv2 VMs
from being able to run on such hosts.
The reason is that vgic_v3_probe() performs a sanity check on the
size of the window (it should be a multiple of the page size),
while the ACPI MADT parsing code hardcodes the size of the window
to 8 KB. This makes sense, considering that ACPI does not bother
to describe the size in the first place, under the assumption that
platforms implementing ACPI will follow the architecture and not
put anything else in the same 64 KB window.
So let's just drop the sanity check altogether, and assume that
the window is at least 64 KB in size.
Fixes: 909777324588 ("KVM: arm/arm64: vgic-new: vgic_init: implement
kvm_vgic_hyp_init")
Signed-off-by: Ard Biesheuvel
---
virt/kvm/arm/vgic/vgic-v3.c | 5 -
1 file changed, 5 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index bdcf8e7a6161..72fc688c3e9d 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -552,11 +552,6 @@ int vgic_v3_probe(const struct gic_kvm_info *info)
pr_warn("GICV physical address 0x%llx not page aligned\n",
(unsigned long long)info->vcpu.start);
kvm_vgic_global_state.vcpu_base = 0;
- } else if (!PAGE_ALIGNED(resource_size(&info->vcpu))) {
- pr_warn("GICV size 0x%llx not a multiple of page size 0x%lx\n",
- (unsigned long long)resource_size(&info->vcpu),
- PAGE_SIZE);
- kvm_vgic_global_state.vcpu_base = 0;
} else {
kvm_vgic_global_state.vcpu_base = info->vcpu.start;
kvm_vgic_global_state.can_emulate_gicv2 = true;
--
2.17.0
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