diff mbox series

[v2] KVM: apic: reuse smp_wmb() in kvm_make_request()

Message ID 1581088927-3269-1-git-send-email-linmiaohe@huawei.com (mailing list archive)
State New, archived
Headers show
Series [v2] KVM: apic: reuse smp_wmb() in kvm_make_request() | expand

Commit Message

Miaohe Lin Feb. 7, 2020, 3:22 p.m. UTC 
From: Miaohe Lin <linmiaohe@huawei.com>

kvm_make_request() provides smp_wmb() so pending_events changes are
guaranteed to be visible.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
v1->v2:
Collected Vitaly's R-b
Use Vitaly's alternative wording
Drop unnecessary comment as suggested by Sean Christopherson
---
 arch/x86/kvm/lapic.c | 3 ---
 1 file changed, 3 deletions(-)

Comments

Sean Christopherson Feb. 7, 2020, 3:40 p.m. UTC | #1 
On Fri, Feb 07, 2020 at 11:22:07PM +0800, linmiaohe wrote:
> From: Miaohe Lin <linmiaohe@huawei.com>
> 
> kvm_make_request() provides smp_wmb() so pending_events changes are
> guaranteed to be visible.
> 
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---

Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Paolo Bonzini Feb. 12, 2020, 11:55 a.m. UTC | #2 
On 07/02/20 16:22, linmiaohe wrote:
> From: Miaohe Lin <linmiaohe@huawei.com>
> 
> kvm_make_request() provides smp_wmb() so pending_events changes are
> guaranteed to be visible.
> 
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
> v1->v2:
> Collected Vitaly's R-b
> Use Vitaly's alternative wording
> Drop unnecessary comment as suggested by Sean Christopherson
> ---
>  arch/x86/kvm/lapic.c | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index eafc631d305c..afcd30d44cbb 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -1080,9 +1080,6 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
>  			result = 1;
>  			/* assumes that there are only KVM_APIC_INIT/SIPI */
>  			apic->pending_events = (1UL << KVM_APIC_INIT);
> -			/* make sure pending_events is visible before sending
> -			 * the request */
> -			smp_wmb();
>  			kvm_make_request(KVM_REQ_EVENT, vcpu);
>  			kvm_vcpu_kick(vcpu);
>  		}
> 


Queued, thanks.

Paolo
diff mbox series

Patch

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index eafc631d305c..afcd30d44cbb 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1080,9 +1080,6 @@  static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
 			result = 1;
 			/* assumes that there are only KVM_APIC_INIT/SIPI */
 			apic->pending_events = (1UL << KVM_APIC_INIT);
-			/* make sure pending_events is visible before sending
-			 * the request */
-			smp_wmb();
 			kvm_make_request(KVM_REQ_EVENT, vcpu);
 			kvm_vcpu_kick(vcpu);
 		}