From patchwork Mon Apr 13 09:55:41 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gleb Natapov X-Patchwork-Id: 17912 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n3D9uDeP005985 for ; Mon, 13 Apr 2009 09:56:14 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755816AbZDMJ4N (ORCPT ); Mon, 13 Apr 2009 05:56:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755805AbZDMJ4M (ORCPT ); Mon, 13 Apr 2009 05:56:12 -0400 Received: from mx2.redhat.com ([66.187.237.31]:57753 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755541AbZDMJzu (ORCPT ); Mon, 13 Apr 2009 05:55:50 -0400 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id n3D9tnah000531; Mon, 13 Apr 2009 05:55:49 -0400 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx2.corp.redhat.com (8.13.1/8.13.1) with ESMTP id n3D9toD3026712; Mon, 13 Apr 2009 05:55:51 -0400 Received: from dhcp-1-237.tlv.redhat.com (dhcp-1-237.tlv.redhat.com [10.35.1.237]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id n3D9tm7O001888; Mon, 13 Apr 2009 05:55:48 -0400 Received: by dhcp-1-237.tlv.redhat.com (Postfix, from userid 587) id 7957413366C; Mon, 13 Apr 2009 12:55:45 +0300 (IDT) From: Gleb Natapov To: avi@redhat.com Cc: kvm@vger.kernel.org, joerg.roedel@amd.com, sheng@linux.intel.com, Gleb Natapov Subject: [PATCH 11/15] Do not report TPR write to userspace if new value bigger or equal to a previous one. Date: Mon, 13 Apr 2009 12:55:41 +0300 Message-Id: <1239616545-25199-12-git-send-email-gleb@redhat.com> In-Reply-To: <1239616545-25199-1-git-send-email-gleb@redhat.com> References: <1239616545-25199-1-git-send-email-gleb@redhat.com> X-Scanned-By: MIMEDefang 2.58 on 172.16.27.26 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Saves many exits to userspace in a case of IRQ chip in userspace. Signed-off-by: Gleb Natapov --- 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 52bd999..9a8eb14 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -1853,9 +1853,13 @@ 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 */