From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: [PATCH v2 2/3] KVM: Optimize vcpu->requests slow path slightly Date: Sun, 20 May 2012 16:49:27 +0300 Message-ID: <1337521768-14182-3-git-send-email-avi@redhat.com> References: <1337521768-14182-1-git-send-email-avi@redhat.com> To: Marcelo Tosatti , kvm@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:26122 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755310Ab2ETNtf (ORCPT ); Sun, 20 May 2012 09:49:35 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q4KDnZYU002580 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Sun, 20 May 2012 09:49:35 -0400 In-Reply-To: <1337521768-14182-1-git-send-email-avi@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Instead of using a atomic operation per active request, use just one to get all requests at once, then check them with local ops. This probably isn't any faster, since simultaneous requests are rare, but it does reduce code size. Signed-off-by: Avi Kivity --- arch/x86/kvm/x86.c | 33 ++++++++++++++++++--------------- 1 file changed, 18 insertions(+), 15 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 953e692..c0209eb 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5232,55 +5232,58 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) bool req_int_win = !irqchip_in_kernel(vcpu->kvm) && vcpu->run->request_interrupt_window; bool req_immediate_exit = 0; + ulong reqs; if (unlikely(req_int_win)) kvm_make_request(KVM_REQ_EVENT, vcpu); if (vcpu->requests) { - if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu)) + reqs = xchg(&vcpu->requests, 0UL); + + if (test_bit(KVM_REQ_MMU_RELOAD, &reqs)) kvm_mmu_unload(vcpu); - if (kvm_check_request(KVM_REQ_MIGRATE_TIMER, vcpu)) + if (test_bit(KVM_REQ_MIGRATE_TIMER, &reqs)) __kvm_migrate_timers(vcpu); - if (kvm_check_request(KVM_REQ_CLOCK_UPDATE, vcpu)) { + if (test_bit(KVM_REQ_CLOCK_UPDATE, &reqs)) { r = kvm_guest_time_update(vcpu); if (unlikely(r)) goto out; } - if (kvm_check_request(KVM_REQ_MMU_SYNC, vcpu)) + if (test_bit(KVM_REQ_MMU_SYNC, &reqs)) kvm_mmu_sync_roots(vcpu); - if (kvm_check_request(KVM_REQ_TLB_FLUSH, vcpu)) + if (test_bit(KVM_REQ_TLB_FLUSH, &reqs)) kvm_x86_ops->tlb_flush(vcpu); - if (kvm_check_request(KVM_REQ_REPORT_TPR_ACCESS, vcpu)) { + if (test_bit(KVM_REQ_REPORT_TPR_ACCESS, &reqs)) { vcpu->run->exit_reason = KVM_EXIT_TPR_ACCESS; r = 0; goto out; } - if (kvm_check_request(KVM_REQ_TRIPLE_FAULT, vcpu)) { + if (test_bit(KVM_REQ_TRIPLE_FAULT, &reqs)) { vcpu->run->exit_reason = KVM_EXIT_SHUTDOWN; r = 0; goto out; } - if (kvm_check_request(KVM_REQ_DEACTIVATE_FPU, vcpu)) { + if (test_bit(KVM_REQ_DEACTIVATE_FPU, &reqs)) { vcpu->fpu_active = 0; kvm_x86_ops->fpu_deactivate(vcpu); } - if (kvm_check_request(KVM_REQ_APF_HALT, vcpu)) { + if (test_bit(KVM_REQ_APF_HALT, &reqs)) { /* Page is swapped out. Do synthetic halt */ vcpu->arch.apf.halted = true; r = 1; goto out; } - if (kvm_check_request(KVM_REQ_STEAL_UPDATE, vcpu)) + if (test_bit(KVM_REQ_STEAL_UPDATE, &reqs)) record_steal_time(vcpu); - if (kvm_check_request(KVM_REQ_NMI, vcpu)) + if (test_bit(KVM_REQ_NMI, &reqs)) process_nmi(vcpu); req_immediate_exit = - kvm_check_request(KVM_REQ_IMMEDIATE_EXIT, vcpu); - if (kvm_check_request(KVM_REQ_PMU, vcpu)) + test_bit(KVM_REQ_IMMEDIATE_EXIT, &reqs); + if (test_bit(KVM_REQ_PMU, &reqs)) kvm_handle_pmu_event(vcpu); - if (kvm_check_request(KVM_REQ_PMI, vcpu)) + if (test_bit(KVM_REQ_PMI, &reqs)) kvm_deliver_pmi(vcpu); - if (kvm_check_request(KVM_REQ_EVENT, vcpu)) { + if (test_bit(KVM_REQ_EVENT, &reqs)) { inject_pending_event(vcpu); /* enable NMI/IRQ window open exits if needed */ -- 1.7.10.1