Messages in this thread Patch in this message | | | From | Lan Tianyu <> | Subject | [PATCH 4/7] KVM/x86: Call smp_wmb() before increasing tlbs_dirty | Date | Sun, 13 Mar 2016 11:10:27 +0800 |
| |
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> --- arch/x86/kvm/paging_tmpl.h | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index e159a81..d34475e 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -949,6 +949,12 @@ 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 in lost after spte is zapped, see the + * comments in kvm_flush_remote_tlbs(). + */ + smp_wmb(); vcpu->kvm->tlbs_dirty++; continue; } @@ -964,6 +970,11 @@ 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; } -- 1.8.4.rc0.1.g8f6a3e5.dirty
| |