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| author | Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> | 2010-11-19 09:02:35 (GMT) |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-01-12 09:29:45 (GMT) |
| commit | b330aa0c7df1ece45f45566c45ea44f01e379ab0 (patch) | |
| tree | 898c047105adaf74793e2f9a9293f5082049cc9f | |
| parent | 30bfb3c4256422221cc763ff6e749ce8aca8e5c9 (diff) | |
| download | linux-b330aa0c7df1ece45f45566c45ea44f01e379ab0.tar.xz | |
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>
| -rw-r--r-- | 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 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; } |