From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756105AbZEXPu5 (ORCPT ); Sun, 24 May 2009 11:50:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755000AbZEXPuf (ORCPT ); Sun, 24 May 2009 11:50:35 -0400 Received: from mx2.redhat.com ([66.187.237.31]:41820 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752613AbZEXPub (ORCPT ); Sun, 24 May 2009 11:50:31 -0400 From: Avi Kivity To: linux-kernel@vger.kernel.org Cc: kvm@vger.kernel.org Subject: [PATCH 04/45] KVM: Do not report TPR write to userspace if new value bigger or equal to a previous one. Date: Sun, 24 May 2009 18:49:49 +0300 Message-Id: <1243180230-2480-5-git-send-email-avi@redhat.com> In-Reply-To: <1243180230-2480-1-git-send-email-avi@redhat.com> References: <1243180230-2480-1-git-send-email-avi@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Gleb Natapov Saves many exits to userspace in a case of IRQ chip in userspace. Signed-off-by: Gleb Natapov Signed-off-by: Avi Kivity --- arch/x86/kvm/svm.c | 4 ++++ arch/x86/kvm/vmx.c | 19 ++++++++++++------- 2 files changed, 16 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 143818e..e283a63 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1862,9 +1862,13 @@ static int emulate_on_interception(struct vcpu_svm *svm, static int cr8_write_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run) { + u8 cr8_prev = kvm_get_cr8(&svm->vcpu); + /* instruction emulation calls kvm_set_cr8() */ emulate_instruction(&svm->vcpu, NULL, 0, 0, 0); if (irqchip_in_kernel(svm->vcpu.kvm)) return 1; + if (cr8_prev <= kvm_get_cr8(&svm->vcpu)) + return 1; kvm_run->exit_reason = KVM_EXIT_SET_TPR; return 0; } diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 9162b4c..51f804c 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2724,13 +2724,18 @@ static int handle_cr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) kvm_set_cr4(vcpu, kvm_register_read(vcpu, reg)); skip_emulated_instruction(vcpu); return 1; - case 8: - kvm_set_cr8(vcpu, kvm_register_read(vcpu, reg)); - skip_emulated_instruction(vcpu); - if (irqchip_in_kernel(vcpu->kvm)) - return 1; - kvm_run->exit_reason = KVM_EXIT_SET_TPR; - return 0; + case 8: { + u8 cr8_prev = kvm_get_cr8(vcpu); + u8 cr8 = kvm_register_read(vcpu, reg); + kvm_set_cr8(vcpu, cr8); + skip_emulated_instruction(vcpu); + if (irqchip_in_kernel(vcpu->kvm)) + return 1; + if (cr8_prev <= cr8) + return 1; + kvm_run->exit_reason = KVM_EXIT_SET_TPR; + return 0; + } }; break; case 2: /* clts */ -- 1.6.0.6