Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1356596 > unrolled thread

[PATCH 2/7] KVM/x86: Replace smp_mb() with smp_store_mb/release() in the walk_shadow_page_lockless_begin/end()

Back to article view | Back to linux.kernel

This discussion starts older than the indexed window; earlier articles aren't shown. The article labeled Started by below is the oldest one visible, not the original post.

Contents

  [PATCH 2/7] KVM/x86: Replace smp_mb() with smp_store_mb/release() in the walk_shadow_page_lockless_begin/end() Lan Tianyu <tianyu.lan@intel.com> - 2016-03-13 04:30 +0100

#1356596 — [PATCH 2/7] KVM/x86: Replace smp_mb() with smp_store_mb/release() in the walk_shadow_page_lockless_begin/end()

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
---
 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 5e795af..d1ee68c 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();
 }
 
-- 
1.8.4.rc0.1.g8f6a3e5.dirty

[toc] | [standalone]

Back to top | Article view | linux.kernel

csiph-web