If we populate a shadow pte due to a fault (and not speculatively due to a
pte write) then we can set the accessed bit on it, as we know it will be
set immediately on the next guest instruction. This saves a read-modify-write
operation.
Signed-off-by: Avi Kivity <[EMAIL PROTECTED]>
---
arch/x86/kvm/mmu.c | 8 +++++---
arch/x86/kvm/paging_tmpl.h | 4 ++--
2 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 072e942..a5872b3 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1020,7 +1020,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64
*shadow_pte,
unsigned pt_access, unsigned pte_access,
int user_fault, int write_fault, int dirty,
int *ptwrite, int largepage, gfn_t gfn,
- struct page *page)
+ struct page *page, bool speculative)
{
u64 spte;
int was_rmapped = 0;
@@ -1061,6 +1061,8 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64
*shadow_pte,
* demand paging).
*/
spte = PT_PRESENT_MASK | PT_DIRTY_MASK;
+ if (!speculative)
+ pte_access |= PT_ACCESSED_MASK;
if (!dirty)
pte_access &= ~ACC_WRITE_MASK;
if (!(pte_access & ACC_EXEC_MASK))
@@ -1148,13 +1150,13 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v,
int write,
if (level == 1) {
mmu_set_spte(vcpu, &table[index], ACC_ALL, ACC_ALL,
- 0, write, 1, &pt_write, 0, gfn, page);
+ 0, write, 1, &pt_write, 0, gfn, page,
false);
return pt_write;
}
if (largepage && level == 2) {
mmu_set_spte(vcpu, &table[index], ACC_ALL, ACC_ALL,
- 0, write, 1, &pt_write, 1, gfn, page);
+ 0, write, 1, &pt_write, 1, gfn, page,
false);
return pt_write;
}
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 57abbd0..e9ae5db 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -266,7 +266,7 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct
kvm_mmu_page *page,
get_page(npage);
mmu_set_spte(vcpu, spte, page->role.access, pte_access, 0, 0,
gpte & PT_DIRTY_MASK, NULL, largepage, gpte_to_gfn(gpte),
- npage);
+ npage, true);
}
/*
@@ -349,7 +349,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr,
mmu_set_spte(vcpu, shadow_ent, access, walker->pte_access & access,
user_fault, write_fault,
walker->ptes[walker->level-1] & PT_DIRTY_MASK,
- ptwrite, largepage, walker->gfn, page);
+ ptwrite, largepage, walker->gfn, page, false);
return shadow_ent;
}
--
1.5.4.5
-------------------------------------------------------------------------
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