From 36ca7e0a577aa61f648953886958e50398732d63 Mon Sep 17 00:00:00 2001 From: Lan Tianyu Date: Sun, 13 Mar 2016 11:10:25 +0800 Subject: [PATCH] KVM/x86: Replace smp_mb() with smp_store_mb/release() in the walk_shadow_page_lockless_begin/end() Signed-off-by: Lan Tianyu Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index fc8ab1f..6bdfbc2 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -632,12 +632,12 @@ static void walk_shadow_page_lockless_begin(struct kvm_vcpu *vcpu) * kvm_flush_remote_tlbs() IPI to all active vcpus. */ local_irq_disable(); - vcpu->mode = READING_SHADOW_PAGE_TABLES; + /* * Make sure a following spte read is not reordered ahead of the write * to vcpu->mode. */ - smp_mb(); + smp_store_mb(vcpu->mode, READING_SHADOW_PAGE_TABLES); } static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu) @@ -647,8 +647,7 @@ static void walk_shadow_page_lockless_end(struct kvm_vcpu *vcpu) * reads to sptes. If it does, kvm_commit_zap_page() can see us * OUTSIDE_GUEST_MODE and proceed to free the shadow page table. */ - smp_mb(); - vcpu->mode = OUTSIDE_GUEST_MODE; + smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE); local_irq_enable(); } -- 2.7.4