Re: [v3 1/5] arm64: kvm: add a cpu tear-down function
On 04/08/2015 10:02 PM, Mark Rutland wrote: + /* We're now in idmap, disable MMU */ +1: mrs x0, sctlr_el2 + and x1, x0, #SCTLR_EL2_EE + orr x0, x0, x1 // preserve endianness of EL2 + ldr x1, =SCTLR_EL2_FLAGS + eor x1, x1, xzr + bic x0, x0, x1 // Clear SCTL_M and etc + msr sctlr_el2, x0 + isb This can instead be: 1: mrs x0, sctlr_el2 ldr x1, =SCTLR_EL2_FLAGS bic x0, x0, x1 msr sctlr_el2, x0 isb As SCTLR_EL2_FLAGS doesn't contain the EE bit. Oops. I will fix it. Thanks, -Takahiro AKASHI Mark. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [v3 1/5] arm64: kvm: add a cpu tear-down function
> + /* We're now in idmap, disable MMU */ > +1: mrs x0, sctlr_el2 > + and x1, x0, #SCTLR_EL2_EE > + orr x0, x0, x1 // preserve endianness of EL2 > + ldr x1, =SCTLR_EL2_FLAGS > + eor x1, x1, xzr > + bic x0, x0, x1 // Clear SCTL_M and etc > + msr sctlr_el2, x0 > + isb This can instead be: 1: mrs x0, sctlr_el2 ldr x1, =SCTLR_EL2_FLAGS bic x0, x0, x1 msr sctlr_el2, x0 isb As SCTLR_EL2_FLAGS doesn't contain the EE bit. Mark. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [v3 1/5] arm64: kvm: add a cpu tear-down function
+ /* We're now in idmap, disable MMU */ +1: mrs x0, sctlr_el2 + and x1, x0, #SCTLR_EL2_EE + orr x0, x0, x1 // preserve endianness of EL2 + ldr x1, =SCTLR_EL2_FLAGS + eor x1, x1, xzr + bic x0, x0, x1 // Clear SCTL_M and etc + msr sctlr_el2, x0 + isb This can instead be: 1: mrs x0, sctlr_el2 ldr x1, =SCTLR_EL2_FLAGS bic x0, x0, x1 msr sctlr_el2, x0 isb As SCTLR_EL2_FLAGS doesn't contain the EE bit. Mark. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [v3 1/5] arm64: kvm: add a cpu tear-down function
On 04/08/2015 10:02 PM, Mark Rutland wrote: + /* We're now in idmap, disable MMU */ +1: mrs x0, sctlr_el2 + and x1, x0, #SCTLR_EL2_EE + orr x0, x0, x1 // preserve endianness of EL2 + ldr x1, =SCTLR_EL2_FLAGS + eor x1, x1, xzr + bic x0, x0, x1 // Clear SCTL_M and etc + msr sctlr_el2, x0 + isb This can instead be: 1: mrs x0, sctlr_el2 ldr x1, =SCTLR_EL2_FLAGS bic x0, x0, x1 msr sctlr_el2, x0 isb As SCTLR_EL2_FLAGS doesn't contain the EE bit. Oops. I will fix it. Thanks, -Takahiro AKASHI Mark. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[v3 1/5] arm64: kvm: add a cpu tear-down function
Cpu must be put back into its initial state, at least, in the
following cases in order to shutdown the system and/or re-initialize cpus
later on:
1) kexec/kdump
2) cpu hotplug (offline)
3) removing kvm as a module
To address those issues in later patches, this patch adds a tear-down
function, kvm_cpu_reset(), that disables D-cache & MMU and restore a vector
table to the initial stub at EL2.
Signed-off-by: AKASHI Takahiro
---
arch/arm/kvm/arm.c| 15 +++
arch/arm/kvm/mmu.c|5 +
arch/arm64/include/asm/kvm_asm.h |1 +
arch/arm64/include/asm/kvm_host.h | 11 +++
arch/arm64/include/asm/kvm_mmu.h |7 +++
arch/arm64/include/asm/virt.h | 11 +++
arch/arm64/kvm/hyp-init.S | 35 +++
arch/arm64/kvm/hyp.S | 16 +---
8 files changed, 98 insertions(+), 3 deletions(-)
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 5560f74..39df694 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -897,6 +897,21 @@ static void cpu_init_hyp_mode(void *dummy)
__cpu_init_hyp_mode(boot_pgd_ptr, pgd_ptr, hyp_stack_ptr, vector_ptr);
}
+static void kvm_cpu_reset(void *dummy)
+{
+ phys_addr_t boot_pgd_ptr;
+ phys_addr_t phys_idmap_start;
+
+ if (__hyp_get_vectors() == hyp_default_vectors)
+ return;
+
+ boot_pgd_ptr = kvm_mmu_get_boot_httbr();
+ phys_idmap_start = kvm_get_idmap_start();
+ __cpu_reset_hyp_mode(boot_pgd_ptr, phys_idmap_start,
+hyp_default_vectors,
+kvm_virt_to_trampoline(__kvm_hyp_reset));
+}
+
static int hyp_init_cpu_notify(struct notifier_block *self,
unsigned long action, void *cpu)
{
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 3e6859b..3631a37 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -1490,6 +1490,11 @@ phys_addr_t kvm_get_idmap_vector(void)
return hyp_idmap_vector;
}
+phys_addr_t kvm_get_idmap_start(void)
+{
+ return hyp_idmap_start;
+}
+
int kvm_mmu_init(void)
{
int err;
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 4f7310f..f1c16e2 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -118,6 +118,7 @@ struct kvm_vcpu;
extern char __kvm_hyp_init[];
extern char __kvm_hyp_init_end[];
+extern char __kvm_hyp_reset[];
extern char __kvm_hyp_vector[];
diff --git a/arch/arm64/include/asm/kvm_host.h
b/arch/arm64/include/asm/kvm_host.h
index 8ac3c70..6a8da9c 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -199,6 +199,8 @@ struct kvm_vcpu *kvm_arm_get_running_vcpu(void);
struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void);
u64 kvm_call_hyp(void *hypfn, ...);
+void kvm_call_reset(phys_addr_t boot_pgd_ptr, phys_addr_t phys_idmap_start,
+ unsigned long stub_vector_ptr, unsigned long reset_func);
void force_vm_exit(const cpumask_t *mask);
void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot);
@@ -223,6 +225,15 @@ static inline void __cpu_init_hyp_mode(phys_addr_t
boot_pgd_ptr,
hyp_stack_ptr, vector_ptr);
}
+static inline void __cpu_reset_hyp_mode(phys_addr_t boot_pgd_ptr,
+ phys_addr_t phys_idmap_start,
+ unsigned long stub_vector_ptr,
+ unsigned long reset_func)
+{
+ kvm_call_reset(boot_pgd_ptr, phys_idmap_start, stub_vector_ptr,
+ reset_func);
+}
+
struct vgic_sr_vectors {
void*save_vgic;
void*restore_vgic;
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 6458b53..facfd6d 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -96,6 +96,7 @@ void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu);
phys_addr_t kvm_mmu_get_httbr(void);
phys_addr_t kvm_mmu_get_boot_httbr(void);
phys_addr_t kvm_get_idmap_vector(void);
+phys_addr_t kvm_get_idmap_start(void);
int kvm_mmu_init(void);
void kvm_clear_hyp_idmap(void);
@@ -305,5 +306,11 @@ static inline void __kvm_flush_dcache_pud(pud_t pud)
void kvm_set_way_flush(struct kvm_vcpu *vcpu);
void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled);
+extern char __hyp_idmap_text_start[];
+#define kvm_virt_to_trampoline(x) \
+ (TRAMPOLINE_VA \
+ + ((unsigned long)(x) \
+ - ((unsigned long)__hyp_idmap_text_start & PAGE_MASK)))
+
#endif /* __ASSEMBLY__ */
#endif /* __ARM64_KVM_MMU_H__ */
diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
index 3070096..7fcd087 100644
--- a/arch/arm64/include/asm/virt.h
+++ b/arch/arm64/include/asm/virt.h
@@ -61,6 +61,17 @@
#define BOOT_CPU_MODE_EL1 (0xe11)
#define
[v3 1/5] arm64: kvm: add a cpu tear-down function
Cpu must be put back into its initial state, at least, in the
following cases in order to shutdown the system and/or re-initialize cpus
later on:
1) kexec/kdump
2) cpu hotplug (offline)
3) removing kvm as a module
To address those issues in later patches, this patch adds a tear-down
function, kvm_cpu_reset(), that disables D-cache MMU and restore a vector
table to the initial stub at EL2.
Signed-off-by: AKASHI Takahiro takahiro.aka...@linaro.org
---
arch/arm/kvm/arm.c| 15 +++
arch/arm/kvm/mmu.c|5 +
arch/arm64/include/asm/kvm_asm.h |1 +
arch/arm64/include/asm/kvm_host.h | 11 +++
arch/arm64/include/asm/kvm_mmu.h |7 +++
arch/arm64/include/asm/virt.h | 11 +++
arch/arm64/kvm/hyp-init.S | 35 +++
arch/arm64/kvm/hyp.S | 16 +---
8 files changed, 98 insertions(+), 3 deletions(-)
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 5560f74..39df694 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -897,6 +897,21 @@ static void cpu_init_hyp_mode(void *dummy)
__cpu_init_hyp_mode(boot_pgd_ptr, pgd_ptr, hyp_stack_ptr, vector_ptr);
}
+static void kvm_cpu_reset(void *dummy)
+{
+ phys_addr_t boot_pgd_ptr;
+ phys_addr_t phys_idmap_start;
+
+ if (__hyp_get_vectors() == hyp_default_vectors)
+ return;
+
+ boot_pgd_ptr = kvm_mmu_get_boot_httbr();
+ phys_idmap_start = kvm_get_idmap_start();
+ __cpu_reset_hyp_mode(boot_pgd_ptr, phys_idmap_start,
+hyp_default_vectors,
+kvm_virt_to_trampoline(__kvm_hyp_reset));
+}
+
static int hyp_init_cpu_notify(struct notifier_block *self,
unsigned long action, void *cpu)
{
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 3e6859b..3631a37 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -1490,6 +1490,11 @@ phys_addr_t kvm_get_idmap_vector(void)
return hyp_idmap_vector;
}
+phys_addr_t kvm_get_idmap_start(void)
+{
+ return hyp_idmap_start;
+}
+
int kvm_mmu_init(void)
{
int err;
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 4f7310f..f1c16e2 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -118,6 +118,7 @@ struct kvm_vcpu;
extern char __kvm_hyp_init[];
extern char __kvm_hyp_init_end[];
+extern char __kvm_hyp_reset[];
extern char __kvm_hyp_vector[];
diff --git a/arch/arm64/include/asm/kvm_host.h
b/arch/arm64/include/asm/kvm_host.h
index 8ac3c70..6a8da9c 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -199,6 +199,8 @@ struct kvm_vcpu *kvm_arm_get_running_vcpu(void);
struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void);
u64 kvm_call_hyp(void *hypfn, ...);
+void kvm_call_reset(phys_addr_t boot_pgd_ptr, phys_addr_t phys_idmap_start,
+ unsigned long stub_vector_ptr, unsigned long reset_func);
void force_vm_exit(const cpumask_t *mask);
void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot);
@@ -223,6 +225,15 @@ static inline void __cpu_init_hyp_mode(phys_addr_t
boot_pgd_ptr,
hyp_stack_ptr, vector_ptr);
}
+static inline void __cpu_reset_hyp_mode(phys_addr_t boot_pgd_ptr,
+ phys_addr_t phys_idmap_start,
+ unsigned long stub_vector_ptr,
+ unsigned long reset_func)
+{
+ kvm_call_reset(boot_pgd_ptr, phys_idmap_start, stub_vector_ptr,
+ reset_func);
+}
+
struct vgic_sr_vectors {
void*save_vgic;
void*restore_vgic;
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 6458b53..facfd6d 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -96,6 +96,7 @@ void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu);
phys_addr_t kvm_mmu_get_httbr(void);
phys_addr_t kvm_mmu_get_boot_httbr(void);
phys_addr_t kvm_get_idmap_vector(void);
+phys_addr_t kvm_get_idmap_start(void);
int kvm_mmu_init(void);
void kvm_clear_hyp_idmap(void);
@@ -305,5 +306,11 @@ static inline void __kvm_flush_dcache_pud(pud_t pud)
void kvm_set_way_flush(struct kvm_vcpu *vcpu);
void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled);
+extern char __hyp_idmap_text_start[];
+#define kvm_virt_to_trampoline(x) \
+ (TRAMPOLINE_VA \
+ + ((unsigned long)(x) \
+ - ((unsigned long)__hyp_idmap_text_start PAGE_MASK)))
+
#endif /* __ASSEMBLY__ */
#endif /* __ARM64_KVM_MMU_H__ */
diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h
index 3070096..7fcd087 100644
--- a/arch/arm64/include/asm/virt.h
+++ b/arch/arm64/include/asm/virt.h
@@ -61,6 +61,17 @@
#define
