We just need flush tlb if overwrite a writable spte with a read-only
one.
And we should move this operation to set_spte() for sync_page path
Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxxxxx>
---
arch/x86/kvm/mmu.c | 20 +++++++++-----------
1 files changed, 9 insertions(+), 11 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index e008ae7..9bad960 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1966,7 +1966,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
gfn_t gfn, pfn_t pfn, bool speculative,
bool can_unsync, bool reset_host_protection)
{
- u64 spte;
+ u64 spte, entry = *sptep;
int ret = 0;
/*
@@ -2039,6 +2039,14 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
set_pte:
update_spte(sptep, spte);
+ /*
+ * If we overwrite a writable spte with a read-only one we
+ * should flush remote TLBs. Otherwise rmap_write_protect
+ * will find a read-only spte, even though the writable spte
+ * might be cached on a CPU's TLB.
+ */
+ if (is_writable_pte(entry) && !is_writable_pte(*sptep))
+ kvm_flush_remote_tlbs(vcpu->kvm);
done:
return ret;
}
@@ -2077,16 +2085,6 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
spte_to_pfn(*sptep), pfn);
drop_spte(vcpu->kvm, sptep, shadow_trap_nonpresent_pte);
kvm_flush_remote_tlbs(vcpu->kvm);
- /*
- * If we overwrite a writable spte with a read-only one,
- * drop it and flush remote TLBs. Otherwise rmap_write_protect
- * will find a read-only spte, even though the writable spte
- * might be cached on a CPU's TLB.
- */
- } else if (is_writable_pte(*sptep) &&
- (!(pte_access & ACC_WRITE_MASK) || !dirty)) {
- drop_spte(vcpu->kvm, sptep, shadow_trap_nonpresent_pte);
- kvm_flush_remote_tlbs(vcpu->kvm);
} else
was_rmapped = 1;
}
--
1.7.0.4
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
