From patchwork Tue Feb 16 10:35:36 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Avi Kivity X-Patchwork-Id: 79594 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter.kernel.org (8.14.3/8.14.3) with ESMTP id o1GAcxCU017958 for ; Tue, 16 Feb 2010 10:38:59 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932866Ab0BPKhO (ORCPT ); Tue, 16 Feb 2010 05:37:14 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59022 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932826Ab0BPKfl (ORCPT ); Tue, 16 Feb 2010 05:35:41 -0500 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 (8.13.8/8.13.8) with ESMTP id o1GAZedw003588 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 16 Feb 2010 05:35:41 -0500 Received: from cleopatra.tlv.redhat.com (cleopatra.tlv.redhat.com [10.35.255.11]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o1GAZcME001100; Tue, 16 Feb 2010 05:35:40 -0500 Received: from localhost.localdomain (file.tlv.redhat.com [10.35.255.8]) by cleopatra.tlv.redhat.com (Postfix) with ESMTP id 38BD3250AF6; Tue, 16 Feb 2010 12:35:37 +0200 (IST) From: Avi Kivity To: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Subject: [PATCH 38/38] KVM: Remove redundant reading of rax on OUT instructions Date: Tue, 16 Feb 2010 12:35:36 +0200 Message-Id: <1266316536-28936-39-git-send-email-avi@redhat.com> In-Reply-To: <1266316536-28936-1-git-send-email-avi@redhat.com> References: <1266316536-28936-1-git-send-email-avi@redhat.com> X-Scanned-By: MIMEDefang 2.67 on 10.5.11.12 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Tue, 16 Feb 2010 10:39:00 +0000 (UTC) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index c91007f..bd3161c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -3551,8 +3551,10 @@ int kvm_emulate_pio(struct kvm_vcpu *vcpu, int in, int size, unsigned port) trace_kvm_pio(vcpu->run->io.direction == KVM_EXIT_IO_OUT, port, size, 1); - val = kvm_register_read(vcpu, VCPU_REGS_RAX); - memcpy(vcpu->arch.pio_data, &val, 4); + if (!vcpu->arch.pio.in) { + val = kvm_register_read(vcpu, VCPU_REGS_RAX); + memcpy(vcpu->arch.pio_data, &val, 4); + } if (!kernel_pio(vcpu, vcpu->arch.pio_data)) { complete_pio(vcpu);