From: Andrea Arcangeli <[email protected]> While looking at invlpg out of sync code with Izik I think I noticed a missing smp tlb flush here. Without this the other cpu can still write to a freed host physical page. tlb smp flush must happen if rmap_remove is called always before mmu_lock is released because the VM will take the mmu_lock before it can finally add the page to the freelist after swapout. mmu notifier makes it safe to flush the tlb after freeing the page (otherwise it would never be safe) so we can do a single flush for multiple sptes invalidated.
Signed-off-by: Andrea Arcangeli <[email protected]> --- diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index a0c11ea..855eb71 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -445,6 +445,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) gpa_t pte_gpa = -1; int level; u64 *sptep; + int need_flush = 0; spin_lock(&vcpu->kvm->mmu_lock); @@ -464,6 +465,7 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) rmap_remove(vcpu->kvm, sptep); if (is_large_pte(*sptep)) --vcpu->kvm->stat.lpages; + need_flush = 1; } set_shadow_pte(sptep, shadow_trap_nonpresent_pte); break; @@ -473,6 +475,8 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) break; } + if (need_flush) + kvm_flush_remote_tlbs(vcpu->kvm); spin_unlock(&vcpu->kvm->mmu_lock); if (pte_gpa == -1) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
