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authorMarc Zyngier <marc.zyngier@arm.com>2015-03-12 18:16:51 +0000
committerChristoffer Dall <christoffer.dall@linaro.org>2015-03-12 22:34:43 +0100
commit35307b9a5f7ebcc8d8db41c73b69c131b48ace2b (patch)
tree42cf3a7b7177139fe59d764893e0556487b5ba72 /arch/arm64
parent1d2ebaccc741a299abfafb848414b01d190f4e33 (diff)
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arm/arm64: KVM: Implement Stage-2 page aging
Until now, KVM/arm didn't care much for page aging (who was swapping anyway?), and simply provided empty hooks to the core KVM code. With server-type systems now being available, things are quite different. This patch implements very simple support for page aging, by clearing the Access flag in the Stage-2 page tables. On access fault, the current fault handling will write the PTE or PMD again, putting the Access flag back on. It should be possible to implement a much faster handling for Access faults, but that's left for a later patch. With this in place, performance in VMs is degraded much more gracefully. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/include/asm/esr.h1
-rw-r--r--arch/arm64/include/asm/kvm_arm.h1
-rw-r--r--arch/arm64/include/asm/kvm_host.h13
3 files changed, 4 insertions, 11 deletions
diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index 92bbae381598..70522450ca23 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -90,6 +90,7 @@
#define ESR_ELx_FSC (0x3F)
#define ESR_ELx_FSC_TYPE (0x3C)
#define ESR_ELx_FSC_EXTABT (0x10)
+#define ESR_ELx_FSC_ACCESS (0x08)
#define ESR_ELx_FSC_FAULT (0x04)
#define ESR_ELx_FSC_PERM (0x0C)
#define ESR_ELx_CV (UL(1) << 24)
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 94674eb7e7bb..9e5543e08955 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -187,6 +187,7 @@
/* For compatibility with fault code shared with 32-bit */
#define FSC_FAULT ESR_ELx_FSC_FAULT
+#define FSC_ACCESS ESR_ELx_FSC_ACCESS
#define FSC_PERM ESR_ELx_FSC_PERM
/* Hyp Prefetch Fault Address Register (HPFAR/HDFAR) */
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 967fb1cee300..f0f58c9beec0 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -179,19 +179,10 @@ int kvm_unmap_hva(struct kvm *kvm, unsigned long hva);
int kvm_unmap_hva_range(struct kvm *kvm,
unsigned long start, unsigned long end);
void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte);
+int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end);
+int kvm_test_age_hva(struct kvm *kvm, unsigned long hva);
/* We do not have shadow page tables, hence the empty hooks */
-static inline int kvm_age_hva(struct kvm *kvm, unsigned long start,
- unsigned long end)
-{
- return 0;
-}
-
-static inline int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
-{
- return 0;
-}
-
static inline void kvm_arch_mmu_notifier_invalidate_page(struct kvm *kvm,
unsigned long address)
{