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| author | Lan Tianyu <tianyu.lan@intel.com> | 2016-03-13 11:10:27 +0800 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-03-22 16:38:32 +0100 |
| commit | 7bfdf2177812c30928bea3fc8bc86b9dea236f65 (patch) | |
| tree | e223ff4e6069fa945c19c3e0be5d5393abf2376c | |
| parent | a30a0509165d9bc5a3107894338e6adf4be7b60f (diff) | |
| download | asoc-7bfdf2177812c30928bea3fc8bc86b9dea236f65.tar.gz | |
KVM/x86: Call smp_wmb() before increasing tlbs_dirty
Update spte before increasing tlbs_dirty to make sure no tlb flush
in lost after spte is zapped. This pairs with the barrier in the
kvm_flush_remote_tlbs().
Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/paging_tmpl.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index e0c2254211574c..1d971c7553c384 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -960,6 +960,12 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) return 0; if (FNAME(prefetch_invalid_gpte)(vcpu, sp, &sp->spt[i], gpte)) { + /* + * Update spte before increasing tlbs_dirty to make + * sure no tlb flush is lost after spte is zapped; see + * the comments in kvm_flush_remote_tlbs(). + */ + smp_wmb(); vcpu->kvm->tlbs_dirty++; continue; } @@ -975,6 +981,11 @@ static int FNAME(sync_page)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp) if (gfn != sp->gfns[i]) { drop_spte(vcpu->kvm, &sp->spt[i]); + /* + * The same as above where we are doing + * prefetch_invalid_gpte(). + */ + smp_wmb(); vcpu->kvm->tlbs_dirty++; continue; } |