In current code, the accessed bit is always set when page fault occurred,
do not need to set it on pte write path

Signed-off-by: Xiao Guangrong <xiaoguangr...@cn.fujitsu.com>
---
 arch/x86/include/asm/kvm_host.h |    1 -
 arch/x86/kvm/mmu.c              |   22 +---------------------
 2 files changed, 1 insertions(+), 22 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 27a25df..58ea3a7 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -356,7 +356,6 @@ struct kvm_vcpu_arch {
        gfn_t last_pt_write_gfn;
        int   last_pt_write_count;
        u64  *last_pte_updated;
-       gfn_t last_pte_gfn;
 
        struct fpu guest_fpu;
        u64 xcr0;
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 26aae11..7ec2a6a 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2206,11 +2206,6 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
        if (set_mmio_spte(sptep, gfn, pfn, pte_access))
                return 0;
 
-       /*
-        * We don't set the accessed bit, since we sometimes want to see
-        * whether the guest actually used the pte (in order to detect
-        * demand paging).
-        */
        spte = PT_PRESENT_MASK;
        if (!speculative)
                spte |= shadow_accessed_mask;
@@ -2361,10 +2356,8 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 
*sptep,
                }
        }
        kvm_release_pfn_clean(pfn);
-       if (speculative) {
+       if (speculative)
                vcpu->arch.last_pte_updated = sptep;
-               vcpu->arch.last_pte_gfn = gfn;
-       }
 }
 
 static void nonpaging_new_cr3(struct kvm_vcpu *vcpu)
@@ -3532,18 +3525,6 @@ static bool last_updated_pte_accessed(struct kvm_vcpu 
*vcpu)
        return !!(spte && (*spte & shadow_accessed_mask));
 }
 
-static void kvm_mmu_access_page(struct kvm_vcpu *vcpu, gfn_t gfn)
-{
-       u64 *spte = vcpu->arch.last_pte_updated;
-
-       if (spte
-           && vcpu->arch.last_pte_gfn == gfn
-           && shadow_accessed_mask
-           && !(*spte & shadow_accessed_mask)
-           && is_shadow_present_pte(*spte))
-               set_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
-}
-
 void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
                       const u8 *new, int bytes,
                       bool guest_initiated)
@@ -3614,7 +3595,6 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
        ++vcpu->kvm->stat.mmu_pte_write;
        trace_kvm_mmu_audit(vcpu, AUDIT_PRE_PTE_WRITE);
        if (guest_initiated) {
-               kvm_mmu_access_page(vcpu, gfn);
                if (gfn == vcpu->arch.last_pt_write_gfn
                    && !last_updated_pte_accessed(vcpu)) {
                        ++vcpu->arch.last_pt_write_count;
-- 
1.7.5.4

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