From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Jones Subject: [PATCH v3 07/10] KVM: arm/arm64: optimize VCPU RUN Date: Wed, 3 May 2017 18:06:32 +0200 Message-ID: <20170503160635.21669-8-drjones@redhat.com> References: <20170503160635.21669-1-drjones@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 3279040B58 for ; Wed, 3 May 2017 12:03:51 -0400 (EDT) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id elnW4c7BAil0 for ; Wed, 3 May 2017 12:03:50 -0400 (EDT) Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id 561F440C57 for ; Wed, 3 May 2017 12:03:50 -0400 (EDT) In-Reply-To: <20170503160635.21669-1-drjones@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: marc.zyngier@arm.com, cdall@linaro.org, pbonzini@redhat.com List-Id: kvmarm@lists.cs.columbia.edu We can make a small optimization by not checking the state of the power_off field on each run. This is done by treating power_off like pause, only checking it when we get the EXIT VCPU request. When a VCPU powers off another VCPU the EXIT request is already made, so we just need to make sure the request is also made on self power off. kvm_vcpu_kick() isn't necessary for these cases, as the VCPU would just be kicking itself, but we add it anyway as a self kick doesn't cost much, and it makes the code more future-proof. Signed-off-by: Andrew Jones --- arch/arm/kvm/arm.c | 16 ++++++++++------ arch/arm/kvm/psci.c | 2 ++ 2 files changed, 12 insertions(+), 6 deletions(-) diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 26d9d4d72853..24bbc7671d89 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -371,6 +371,13 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) kvm_timer_vcpu_put(vcpu); } +static void vcpu_power_off(struct kvm_vcpu *vcpu) +{ + vcpu->arch.power_off = true; + kvm_make_request(KVM_REQ_VCPU_EXIT, vcpu); + kvm_vcpu_kick(vcpu); +} + int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu, struct kvm_mp_state *mp_state) { @@ -390,7 +397,7 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, vcpu->arch.power_off = false; break; case KVM_MP_STATE_STOPPED: - vcpu->arch.power_off = true; + vcpu_power_off(vcpu); break; default: return -EINVAL; @@ -626,14 +633,11 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) if (kvm_request_pending(vcpu)) { if (kvm_check_request(KVM_REQ_VCPU_EXIT, vcpu)) { - if (vcpu->arch.pause) + if (vcpu->arch.power_off || vcpu->arch.pause) vcpu_sleep(vcpu); } } - if (vcpu->arch.power_off) - vcpu_sleep(vcpu); - /* * Preparing the interrupts to be injected also * involves poking the GIC, which must be done in a @@ -903,7 +907,7 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu, * Handle the "start in power-off" case. */ if (test_bit(KVM_ARM_VCPU_POWER_OFF, vcpu->arch.features)) - vcpu->arch.power_off = true; + vcpu_power_off(vcpu); else vcpu->arch.power_off = false; diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index f189d0ad30d5..4a436685c552 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -65,6 +65,8 @@ static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu) static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu) { vcpu->arch.power_off = true; + kvm_make_request(KVM_REQ_VCPU_EXIT, vcpu); + kvm_vcpu_kick(vcpu); } static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) -- 2.9.3