Re: [PATCH 2/2] kvm: arm/arm64: implement kvm_arm_[halt, resume]_guest
Hi Chistoffer,
On 07/18/2015 11:18 AM, Christoffer Dall wrote:
On Mon, Jul 06, 2015 at 02:49:56PM +0200, Eric Auger wrote:
On halt, the guest is forced to exit and prevented from being
re-entered. This is synchronous.
Those two operations will be needed for IRQ forwarding setting.
Signed-off-by: Eric Auger eric.au...@linaro.org
---
RFC v1 - v2:
- add __maybe_unused
RFC:
- rename the function and this latter becomes static
- remove __KVM_HAVE_ARCH_HALT_GUEST
v4 - v5: add arm64 support
- also defines __KVM_HAVE_ARCH_HALT_GUEST for arm64
- add pause field
---
arch/arm/include/asm/kvm_host.h | 3 +++
arch/arm/kvm/arm.c| 35 ---
arch/arm64/include/asm/kvm_host.h | 3 +++
3 files changed, 38 insertions(+), 3 deletions(-)
diff --git a/arch/arm/include/asm/kvm_host.h
b/arch/arm/include/asm/kvm_host.h
index 304004d..899ae27 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -132,6 +132,9 @@ struct kvm_vcpu_arch {
/* vcpu power-off state */
bool power_off;
+/* Don't run the guest */
+bool pause;
+
/* IO related fields */
struct kvm_decode mmio_decode;
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 7537e68..46d4ef6 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -471,11 +471,39 @@ bool kvm_arch_intc_initialized(struct kvm *kvm)
return vgic_initialized(kvm);
}
+static void kvm_arm_halt_guest(struct kvm *kvm) __maybe_unused;
+static void kvm_arm_resume_guest(struct kvm *kvm) __maybe_unused;
+
+static void kvm_arm_halt_guest(struct kvm *kvm)
+{
+int i;
+struct kvm_vcpu *vcpu;
+
+kvm_for_each_vcpu(i, vcpu, kvm)
+vcpu-arch.pause = true;
+force_vm_exit(cpu_all_mask);
+}
+
+static void kvm_arm_resume_guest(struct kvm *kvm)
+{
+int i;
+struct kvm_vcpu *vcpu;
+
+kvm_for_each_vcpu(i, vcpu, kvm) {
+wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
+
+vcpu-arch.pause = false;
+wake_up_interruptible(wq);
+}
+}
+
+
static void vcpu_pause(struct kvm_vcpu *vcpu)
{
wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
-wait_event_interruptible(*wq, !vcpu-arch.power_off);
+wait_event_interruptible(*wq, ((!vcpu-arch.power_off)
+ (!vcpu-arch.pause)));
}
static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
@@ -525,7 +553,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu,
struct kvm_run *run)
update_vttbr(vcpu-kvm);
-if (vcpu-arch.power_off)
+if (vcpu-arch.power_off || vcpu-arch.pause)
vcpu_pause(vcpu);
These two changes really make me feel like kvm_arch_vcpu_runnable()
should be changed to check for both flags and all thes eplaces should
check for runnable instead.
To make the runnable function more robust, perhaps it should check:
1. The vcpu is neither paused nor powered off
2. The vcpu is not in a WFI state (vcpu-arch.wfi_request) OR there are
pending interrupts (the current check).
I did not understand what you meant by this vcpu-arch.wfi_request,
which I could not find. In case we call runnable from
kvm_vcpu_block/kvm_vcpu_check_block we sometimes are in WFI
(kvm_handle_wfx)?
Thanks
Eric
Then the logic would fit the name of the function, instead of being a
specific check only called through handle_wfx.
/*
@@ -551,7 +579,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu,
struct kvm_run *run)
run-exit_reason = KVM_EXIT_INTR;
}
-if (ret = 0 || need_new_vmid_gen(vcpu-kvm)) {
+if (ret = 0 || need_new_vmid_gen(vcpu-kvm) ||
+vcpu-arch.pause) {
so why do we need to re-check the pause flag, but not the power_off
flag? That is non-trivial for sure, so if it's correct, deserves a
comment. Also see my comment on the last patch.
local_irq_enable();
preempt_enable();
kvm_vgic_sync_hwstate(vcpu);
diff --git a/arch/arm64/include/asm/kvm_host.h
b/arch/arm64/include/asm/kvm_host.h
index 009da6b..69e3785 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -125,6 +125,9 @@ struct kvm_vcpu_arch {
/* vcpu power-off state */
bool power_off;
+/* Don't run the guest */
Probably need to be more clear about this being an implementation
requirement rather than being guest visible or related to any
architectural concept.
+bool pause;
+
/* IO related fields */
struct kvm_decode mmio_decode;
--
1.9.1
Thanks,
-Christoffer
___
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
Re: [PATCH 2/2] kvm: arm/arm64: implement kvm_arm_[halt, resume]_guest
On 07/18/2015 11:18 AM, Christoffer Dall wrote:
On Mon, Jul 06, 2015 at 02:49:56PM +0200, Eric Auger wrote:
On halt, the guest is forced to exit and prevented from being
re-entered. This is synchronous.
Those two operations will be needed for IRQ forwarding setting.
Signed-off-by: Eric Auger eric.au...@linaro.org
---
RFC v1 - v2:
- add __maybe_unused
RFC:
- rename the function and this latter becomes static
- remove __KVM_HAVE_ARCH_HALT_GUEST
v4 - v5: add arm64 support
- also defines __KVM_HAVE_ARCH_HALT_GUEST for arm64
- add pause field
---
arch/arm/include/asm/kvm_host.h | 3 +++
arch/arm/kvm/arm.c| 35 ---
arch/arm64/include/asm/kvm_host.h | 3 +++
3 files changed, 38 insertions(+), 3 deletions(-)
diff --git a/arch/arm/include/asm/kvm_host.h
b/arch/arm/include/asm/kvm_host.h
index 304004d..899ae27 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -132,6 +132,9 @@ struct kvm_vcpu_arch {
/* vcpu power-off state */
bool power_off;
+/* Don't run the guest */
+bool pause;
+
/* IO related fields */
struct kvm_decode mmio_decode;
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 7537e68..46d4ef6 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -471,11 +471,39 @@ bool kvm_arch_intc_initialized(struct kvm *kvm)
return vgic_initialized(kvm);
}
+static void kvm_arm_halt_guest(struct kvm *kvm) __maybe_unused;
+static void kvm_arm_resume_guest(struct kvm *kvm) __maybe_unused;
+
+static void kvm_arm_halt_guest(struct kvm *kvm)
+{
+int i;
+struct kvm_vcpu *vcpu;
+
+kvm_for_each_vcpu(i, vcpu, kvm)
+vcpu-arch.pause = true;
+force_vm_exit(cpu_all_mask);
+}
+
+static void kvm_arm_resume_guest(struct kvm *kvm)
+{
+int i;
+struct kvm_vcpu *vcpu;
+
+kvm_for_each_vcpu(i, vcpu, kvm) {
+wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
+
+vcpu-arch.pause = false;
+wake_up_interruptible(wq);
+}
+}
+
+
static void vcpu_pause(struct kvm_vcpu *vcpu)
{
wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
-wait_event_interruptible(*wq, !vcpu-arch.power_off);
+wait_event_interruptible(*wq, ((!vcpu-arch.power_off)
+ (!vcpu-arch.pause)));
}
static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
@@ -525,7 +553,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu,
struct kvm_run *run)
update_vttbr(vcpu-kvm);
-if (vcpu-arch.power_off)
+if (vcpu-arch.power_off || vcpu-arch.pause)
vcpu_pause(vcpu);
These two changes really make me feel like kvm_arch_vcpu_runnable()
should be changed to check for both flags and all thes eplaces should
check for runnable instead.
To make the runnable function more robust, perhaps it should check:
1. The vcpu is neither paused nor powered off
2. The vcpu is not in a WFI state (vcpu-arch.wfi_request) OR there are
pending interrupts (the current check).
Then the logic would fit the name of the function, instead of being a
specific check only called through handle_wfx.
Reading this again, I reconsider what I said in previous comment answer
and this definitively makes sense to update the runnable function. I
was/am afraid by this vcpu_block function and I need to better undertand
it - I think what I said previously is not correct - .
I will investigate that direction.
Eric
/*
@@ -551,7 +579,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu,
struct kvm_run *run)
run-exit_reason = KVM_EXIT_INTR;
}
-if (ret = 0 || need_new_vmid_gen(vcpu-kvm)) {
+if (ret = 0 || need_new_vmid_gen(vcpu-kvm) ||
+vcpu-arch.pause) {
so why do we need to re-check the pause flag, but not the power_off
flag? That is non-trivial for sure, so if it's correct, deserves a
comment. Also see my comment on the last patch.
local_irq_enable();
preempt_enable();
kvm_vgic_sync_hwstate(vcpu);
diff --git a/arch/arm64/include/asm/kvm_host.h
b/arch/arm64/include/asm/kvm_host.h
index 009da6b..69e3785 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -125,6 +125,9 @@ struct kvm_vcpu_arch {
/* vcpu power-off state */
bool power_off;
+/* Don't run the guest */
Probably need to be more clear about this being an implementation
requirement rather than being guest visible or related to any
architectural concept.
+bool pause;
+
/* IO related fields */
struct kvm_decode mmio_decode;
--
1.9.1
Thanks,
-Christoffer
___
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
Re: [PATCH 2/2] kvm: arm/arm64: implement kvm_arm_[halt, resume]_guest
On 07/07/2015 03:41 PM, Andrew Jones wrote:
On Mon, Jul 06, 2015 at 02:49:56PM +0200, Eric Auger wrote:
On halt, the guest is forced to exit and prevented from being
re-entered. This is synchronous.
Those two operations will be needed for IRQ forwarding setting.
Signed-off-by: Eric Auger eric.au...@linaro.org
---
RFC v1 - v2:
- add __maybe_unused
RFC:
- rename the function and this latter becomes static
- remove __KVM_HAVE_ARCH_HALT_GUEST
v4 - v5: add arm64 support
- also defines __KVM_HAVE_ARCH_HALT_GUEST for arm64
- add pause field
---
arch/arm/include/asm/kvm_host.h | 3 +++
arch/arm/kvm/arm.c| 35 ---
arch/arm64/include/asm/kvm_host.h | 3 +++
3 files changed, 38 insertions(+), 3 deletions(-)
diff --git a/arch/arm/include/asm/kvm_host.h
b/arch/arm/include/asm/kvm_host.h
index 304004d..899ae27 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -132,6 +132,9 @@ struct kvm_vcpu_arch {
/* vcpu power-off state */
bool power_off;
+/* Don't run the guest */
+bool pause;
+
/* IO related fields */
struct kvm_decode mmio_decode;
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 7537e68..46d4ef6 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -471,11 +471,39 @@ bool kvm_arch_intc_initialized(struct kvm *kvm)
return vgic_initialized(kvm);
}
+static void kvm_arm_halt_guest(struct kvm *kvm) __maybe_unused;
+static void kvm_arm_resume_guest(struct kvm *kvm) __maybe_unused;
+
+static void kvm_arm_halt_guest(struct kvm *kvm)
+{
+int i;
+struct kvm_vcpu *vcpu;
+
+kvm_for_each_vcpu(i, vcpu, kvm)
+vcpu-arch.pause = true;
+force_vm_exit(cpu_all_mask);
+}
+
+static void kvm_arm_resume_guest(struct kvm *kvm)
+{
+int i;
+struct kvm_vcpu *vcpu;
+
+kvm_for_each_vcpu(i, vcpu, kvm) {
+wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
+
+vcpu-arch.pause = false;
+wake_up_interruptible(wq);
+}
+}
+
+
static void vcpu_pause(struct kvm_vcpu *vcpu)
{
wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
-wait_event_interruptible(*wq, !vcpu-arch.power_off);
+wait_event_interruptible(*wq, ((!vcpu-arch.power_off)
+ (!vcpu-arch.pause)));
}
static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
@@ -525,7 +553,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu,
struct kvm_run *run)
update_vttbr(vcpu-kvm);
-if (vcpu-arch.power_off)
+if (vcpu-arch.power_off || vcpu-arch.pause)
vcpu_pause(vcpu);
/*
@@ -551,7 +579,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu,
struct kvm_run *run)
run-exit_reason = KVM_EXIT_INTR;
}
-if (ret = 0 || need_new_vmid_gen(vcpu-kvm)) {
+if (ret = 0 || need_new_vmid_gen(vcpu-kvm) ||
+vcpu-arch.pause) {
local_irq_enable();
preempt_enable();
kvm_vgic_sync_hwstate(vcpu);
diff --git a/arch/arm64/include/asm/kvm_host.h
b/arch/arm64/include/asm/kvm_host.h
index 009da6b..69e3785 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -125,6 +125,9 @@ struct kvm_vcpu_arch {
/* vcpu power-off state */
bool power_off;
+/* Don't run the guest */
+bool pause;
+
/* IO related fields */
struct kvm_decode mmio_decode;
So in the last patch, for cleanliness, maybe it would be better to
change the pause reference to a power_off reference in
kvm_arch_vcpu_ioctl_set_mpstate, and keep removing it. Or, maybe the
patch wouldn't look too bad if we just squashed this one into the
last one?
yeah I need to think again about the patch structure and/or maybe adopt
the lazy approach, putting both together.
Thanks again
Eric
drew
___
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
Re: [PATCH 2/2] kvm: arm/arm64: implement kvm_arm_[halt, resume]_guest
On Mon, Jul 06, 2015 at 02:49:56PM +0200, Eric Auger wrote:
On halt, the guest is forced to exit and prevented from being
re-entered. This is synchronous.
Those two operations will be needed for IRQ forwarding setting.
Signed-off-by: Eric Auger eric.au...@linaro.org
---
RFC v1 - v2:
- add __maybe_unused
RFC:
- rename the function and this latter becomes static
- remove __KVM_HAVE_ARCH_HALT_GUEST
v4 - v5: add arm64 support
- also defines __KVM_HAVE_ARCH_HALT_GUEST for arm64
- add pause field
---
arch/arm/include/asm/kvm_host.h | 3 +++
arch/arm/kvm/arm.c| 35 ---
arch/arm64/include/asm/kvm_host.h | 3 +++
3 files changed, 38 insertions(+), 3 deletions(-)
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 304004d..899ae27 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -132,6 +132,9 @@ struct kvm_vcpu_arch {
/* vcpu power-off state */
bool power_off;
+ /* Don't run the guest */
+ bool pause;
+
/* IO related fields */
struct kvm_decode mmio_decode;
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 7537e68..46d4ef6 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -471,11 +471,39 @@ bool kvm_arch_intc_initialized(struct kvm *kvm)
return vgic_initialized(kvm);
}
+static void kvm_arm_halt_guest(struct kvm *kvm) __maybe_unused;
+static void kvm_arm_resume_guest(struct kvm *kvm) __maybe_unused;
+
+static void kvm_arm_halt_guest(struct kvm *kvm)
+{
+ int i;
+ struct kvm_vcpu *vcpu;
+
+ kvm_for_each_vcpu(i, vcpu, kvm)
+ vcpu-arch.pause = true;
+ force_vm_exit(cpu_all_mask);
+}
+
+static void kvm_arm_resume_guest(struct kvm *kvm)
+{
+ int i;
+ struct kvm_vcpu *vcpu;
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
+
+ vcpu-arch.pause = false;
+ wake_up_interruptible(wq);
+ }
+}
+
+
static void vcpu_pause(struct kvm_vcpu *vcpu)
{
wait_queue_head_t *wq = kvm_arch_vcpu_wq(vcpu);
- wait_event_interruptible(*wq, !vcpu-arch.power_off);
+ wait_event_interruptible(*wq, ((!vcpu-arch.power_off)
+(!vcpu-arch.pause)));
}
static int kvm_vcpu_initialized(struct kvm_vcpu *vcpu)
@@ -525,7 +553,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct
kvm_run *run)
update_vttbr(vcpu-kvm);
- if (vcpu-arch.power_off)
+ if (vcpu-arch.power_off || vcpu-arch.pause)
vcpu_pause(vcpu);
/*
@@ -551,7 +579,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct
kvm_run *run)
run-exit_reason = KVM_EXIT_INTR;
}
- if (ret = 0 || need_new_vmid_gen(vcpu-kvm)) {
+ if (ret = 0 || need_new_vmid_gen(vcpu-kvm) ||
+ vcpu-arch.pause) {
local_irq_enable();
preempt_enable();
kvm_vgic_sync_hwstate(vcpu);
diff --git a/arch/arm64/include/asm/kvm_host.h
b/arch/arm64/include/asm/kvm_host.h
index 009da6b..69e3785 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -125,6 +125,9 @@ struct kvm_vcpu_arch {
/* vcpu power-off state */
bool power_off;
+ /* Don't run the guest */
+ bool pause;
+
/* IO related fields */
struct kvm_decode mmio_decode;
So in the last patch, for cleanliness, maybe it would be better to
change the pause reference to a power_off reference in
kvm_arch_vcpu_ioctl_set_mpstate, and keep removing it. Or, maybe the
patch wouldn't look too bad if we just squashed this one into the
last one?
drew
___
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
