Re: [PATCH v3 10/12] KVM: SVM: remove svm_toggle_avic_for_irq_window

From: Paolo Bonzini <pbonzini@redhat.com>
To: Maxim Levitsky <mlevitsk@redhat.com>, kvm@vger.kernel.org
Cc: Wanpeng Li <wanpengli@tencent.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Joerg Roedel <joro@8bytes.org>, Borislav Petkov <bp@alien8.de>,
	Sean Christopherson <seanjc@google.com>,
	Jim Mattson <jmattson@google.com>,
	"maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)"
	<x86@kernel.org>,
	"open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" 
	<linux-kernel@vger.kernel.org>,
	Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH v3 10/12] KVM: SVM: remove svm_toggle_avic_for_irq_window
Date: Tue, 3 Aug 2021 11:11:23 +0200	[thread overview]
Message-ID: <7b4442b6-644d-6fcb-1147-2aa220b2c8c8@redhat.com> (raw)
In-Reply-To: <20210802183329.2309921-11-mlevitsk@redhat.com>

On 02/08/21 20:33, Maxim Levitsky wrote:
> Now that kvm_request_apicv_update doesn't need to drop the kvm->srcu lock,
> we can call kvm_request_apicv_update directly.
> 
> Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
> ---
>   arch/x86/kvm/svm/avic.c | 11 -----------
>   arch/x86/kvm/svm/svm.c  |  4 ++--
>   arch/x86/kvm/svm/svm.h  |  1 -
>   3 files changed, 2 insertions(+), 14 deletions(-)
> 
> diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
> index d0acbeeab3d6..1def54c26259 100644
> --- a/arch/x86/kvm/svm/avic.c
> +++ b/arch/x86/kvm/svm/avic.c
> @@ -582,17 +582,6 @@ void avic_post_state_restore(struct kvm_vcpu *vcpu)
>   	avic_handle_ldr_update(vcpu);
>   }
>   
> -void svm_toggle_avic_for_irq_window(struct kvm_vcpu *vcpu, bool activate)
> -{
> -	if (!enable_apicv || !lapic_in_kernel(vcpu))
> -		return;
> -
> -	srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
> -	kvm_request_apicv_update(vcpu->kvm, activate,
> -				 APICV_INHIBIT_REASON_IRQWIN);
> -	vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
> -}
> -
>   void svm_set_virtual_apic_mode(struct kvm_vcpu *vcpu)
>   {
>   	return;
> diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
> index 3923d383face..c8827de49c75 100644
> --- a/arch/x86/kvm/svm/svm.c
> +++ b/arch/x86/kvm/svm/svm.c
> @@ -2994,7 +2994,7 @@ static int interrupt_window_interception(struct kvm_vcpu *vcpu)
>   	 * In this case AVIC was temporarily disabled for
>   	 * requesting the IRQ window and we have to re-enable it.
>   	 */
> -	svm_toggle_avic_for_irq_window(vcpu, true);
> +	kvm_request_apicv_update(vcpu->kvm, true, APICV_INHIBIT_REASON_IRQWIN);
>   
>   	++vcpu->stat.irq_window_exits;
>   	return 1;
> @@ -3546,7 +3546,7 @@ static void svm_enable_irq_window(struct kvm_vcpu *vcpu)
>   		 * via AVIC. In such case, we need to temporarily disable AVIC,
>   		 * and fallback to injecting IRQ via V_IRQ.
>   		 */
> -		svm_toggle_avic_for_irq_window(vcpu, false);
> +		kvm_request_apicv_update(vcpu->kvm, false, APICV_INHIBIT_REASON_IRQWIN);
>   		svm_set_vintr(svm);
>   	}
>   }
> diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
> index bd41f2a32838..aae851762b59 100644
> --- a/arch/x86/kvm/svm/svm.h
> +++ b/arch/x86/kvm/svm/svm.h
> @@ -524,7 +524,6 @@ int avic_ga_log_notifier(u32 ga_tag);
>   void avic_vm_destroy(struct kvm *kvm);
>   int avic_vm_init(struct kvm *kvm);
>   void avic_init_vmcb(struct vcpu_svm *svm);
> -void svm_toggle_avic_for_irq_window(struct kvm_vcpu *vcpu, bool activate);
>   int avic_incomplete_ipi_interception(struct kvm_vcpu *vcpu);
>   int avic_unaccelerated_access_interception(struct kvm_vcpu *vcpu);
>   int avic_init_vcpu(struct vcpu_svm *svm);
> 

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>