On 02/25/2016 10:15 AM, Takuya Yoshikawa wrote:
On 2016/02/24 22:17, Paolo Bonzini wrote:Move the call to kvm_mmu_flush_or_zap outside the loop. Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- arch/x86/kvm/mmu.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 725316df32ec..6d47b5c43246 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2029,24 +2029,27 @@ static void mmu_sync_children(struct kvm_vcpu *vcpu, struct mmu_page_path parents; struct kvm_mmu_pages pages; LIST_HEAD(invalid_list); + bool flush = false; while (mmu_unsync_walk(parent, &pages)) { bool protected = false; - bool flush = false; for_each_sp(pages, sp, parents, i) protected |= rmap_write_protect(vcpu, sp->gfn); - if (protected) + if (protected) { kvm_flush_remote_tlbs(vcpu->kvm); + flush = false; + } for_each_sp(pages, sp, parents, i) { flush |= kvm_sync_page(vcpu, sp, &invalid_list); mmu_pages_clear_parents(&parents); } - kvm_mmu_flush_or_zap(vcpu, &invalid_list, false, flush); cond_resched_lock(&vcpu->kvm->mmu_lock);This may release the mmu_lock before committing the zapping. Is it safe? If so, we may want to see the reason in the changelog.
It is unsafe indeed, please do not do it.
