summaryrefslogtreecommitdiffstats
path: root/arch
diff options
context:
space:
mode:
authorXiao Guangrong <xiaoguangrong@cn.fujitsu.com>2010-11-19 17:02:35 +0800
committerAvi Kivity <avi@redhat.com>2011-01-12 11:29:45 +0200
commitb330aa0c7df1ece45f45566c45ea44f01e379ab0 (patch)
tree898c047105adaf74793e2f9a9293f5082049cc9f /arch
parent30bfb3c4256422221cc763ff6e749ce8aca8e5c9 (diff)
downloadop-kernel-dev-b330aa0c7df1ece45f45566c45ea44f01e379ab0.zip
op-kernel-dev-b330aa0c7df1ece45f45566c45ea44f01e379ab0.tar.gz
KVM: MMU: don't drop spte if overwrite it from W to RO
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@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/mmu.c20
1 files changed, 9 insertions, 11 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index ab100a7..29b2ec4 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1960,7 +1960,7 @@ 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;
/*
@@ -2031,6 +2031,14 @@ 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;
}
@@ -2069,16 +2077,6 @@ 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;
}
OpenPOWER on IntegriCloud