From patchwork Fri Jun 30 08:44:29 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 9818747 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id CB12F603D7 for ; Fri, 30 Jun 2017 08:46:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BE4B11FF0B for ; Fri, 30 Jun 2017 08:46:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B2C6127F54; Fri, 30 Jun 2017 08:46:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.4 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 28AB51FF0B for ; Fri, 30 Jun 2017 08:46:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752010AbdF3Iqb (ORCPT ); Fri, 30 Jun 2017 04:46:31 -0400 Received: from foss.arm.com ([217.140.101.70]:37210 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751676AbdF3Iqa (ORCPT ); Fri, 30 Jun 2017 04:46:30 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D074C15BE; Fri, 30 Jun 2017 01:46:19 -0700 (PDT) Received: from approximate.cambridge.arm.com (approximate.cambridge.arm.com [10.1.207.16]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8F9E03F581; Fri, 30 Jun 2017 01:46:17 -0700 (PDT) From: Marc Zyngier To: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= , Paolo Bonzini Cc: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, Alexander Graf , Andrew Jones , Catalin Marinas , Christoffer Dall , David Daney , Eric Auger , Hu Huajun , James Morse , Mark Rutland , Stefan Traby Subject: [PATCH 13/58] KVM: arm/arm64: optimize VCPU RUN Date: Fri, 30 Jun 2017 09:44:29 +0100 Message-Id: <20170630084514.6779-14-marc.zyngier@arm.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170630084514.6779-1-marc.zyngier@arm.com> References: <20170630084514.6779-1-marc.zyngier@arm.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Andrew Jones 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 Reviewed-by: Christoffer Dall Signed-off-by: Christoffer Dall --- virt/kvm/arm/arm.c | 19 +++++++++++-------- virt/kvm/arm/psci.c | 2 ++ 2 files changed, 13 insertions(+), 8 deletions(-) diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index 21a4db90073f..9379b1d75ad3 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -368,6 +368,13 @@ 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) { @@ -387,7 +394,7 @@ 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; @@ -557,7 +564,7 @@ static void vcpu_sleep(struct kvm_vcpu *vcpu) swait_event_interruptible(*wq, ((!vcpu->arch.power_off) && (!vcpu->arch.pause))); - if (vcpu->arch.pause) { + if (vcpu->arch.power_off || vcpu->arch.pause) { /* Awaken to handle a signal, request we sleep again later. */ kvm_make_request(KVM_REQ_VCPU_EXIT, vcpu); } @@ -623,9 +630,6 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) check_vcpu_requests(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 @@ -662,8 +666,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) smp_store_mb(vcpu->mode, IN_GUEST_MODE); if (ret <= 0 || need_new_vmid_gen(vcpu->kvm) || - kvm_request_pending(vcpu) || - vcpu->arch.power_off) { + kvm_request_pending(vcpu)) { vcpu->mode = OUTSIDE_GUEST_MODE; local_irq_enable(); kvm_pmu_sync_hwstate(vcpu); @@ -896,7 +899,7 @@ 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/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c index f189d0ad30d5..4a436685c552 100644 --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/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)