Commit 36ca7e0a authored by Lan Tianyu's avatar Lan Tianyu Committed by Paolo Bonzini
Browse files

KVM/x86: Replace smp_mb() with smp_store_mb/release() in the walk_shadow_page_lockless_begin/end() 



Signed-off-by: default avatarLan Tianyu <tianyu.lan@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 9753f529

arch/x86/kvm/mmu.c

+3 −4
Original line number Original line Diff line number Diff line
@@ -632,12 +632,12 @@ static void walk_shadow_page_lockless_begin(struct kvm_vcpu *vcpu) 
	 * kvm_flush_remote_tlbs() IPI to all active vcpus.

	 * kvm_flush_remote_tlbs() IPI to all active vcpus.

	 */

	 */

	local_irq_disable();

	local_irq_disable();

	vcpu->mode = READING_SHADOW_PAGE_TABLES;



	/*

	/*

	 * Make sure a following spte read is not reordered ahead of the write

	 * Make sure a following spte read is not reordered ahead of the write

	 * to vcpu->mode.

	 * 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)

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

	 * reads to sptes.  If it does, kvm_commit_zap_page() can see us

	 * OUTSIDE_GUEST_MODE and proceed to free the shadow page table.

	 * OUTSIDE_GUEST_MODE and proceed to free the shadow page table.

	 */

	 */

	smp_mb();

	smp_store_release(&vcpu->mode, OUTSIDE_GUEST_MODE);

	vcpu->mode = OUTSIDE_GUEST_MODE;

	local_irq_enable();

	local_irq_enable();

}

}