From patchwork Mon Dec 30 20:56:29 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhihui Zhang X-Patchwork-Id: 3420851 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 3353EC02DC for ; Mon, 30 Dec 2013 20:56:45 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 4A25B200F3 for ; Mon, 30 Dec 2013 20:56:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 77CAE200F2 for ; Mon, 30 Dec 2013 20:56:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932242Ab3L3U4k (ORCPT ); Mon, 30 Dec 2013 15:56:40 -0500 Received: from mail-qe0-f52.google.com ([209.85.128.52]:44114 "EHLO mail-qe0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932127Ab3L3U4j (ORCPT ); Mon, 30 Dec 2013 15:56:39 -0500 Received: by mail-qe0-f52.google.com with SMTP id ne12so11973434qeb.11 for ; Mon, 30 Dec 2013 12:56:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=2CSBuKjnWufXuvX5yaQXWAX7MYtnptOTgplM42ehF44=; b=ef92u6vcKMhtreIsy93a9+mHhZ4rN29xqBiNZoxVnV6dTWhCKDQqppcEnLUSAybdHA n5xa1ot/5UETuq1fuvGbRJbDFdOVD+ioTplCdN/TXrQvbY25lqPy+qndqhkcxyI/4R7B dPGuQjGE1Ihskl1ZWSluIdKmFC0vPg8Sml4O2ClbmYwprJy7YwIGpqqdBr1EjQMThzuk ZHBrshqajdscquDTeaRtuTqNmJg9Ki+xdqS7Rm4NgDG3nWdlyJ+z9rxK2c4gc7ZvBtXR 7E+EuTz42WewW7tPJHuAW+m+U2eCAvz3oSZ0mUtn+8RQlZOf/9veEWJbUgB8bpvYV+Cc /a0A== X-Received: by 10.49.131.5 with SMTP id oi5mr114529438qeb.38.1388436997776; Mon, 30 Dec 2013 12:56:37 -0800 (PST) Received: from localhost.localdomain (c-67-165-51-178.hsd1.wv.comcast.net. [67.165.51.178]) by mx.google.com with ESMTPSA id j9sm60495186qeo.18.2013.12.30.12.56.37 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 30 Dec 2013 12:56:37 -0800 (PST) From: Zhihui Zhang To: gleb@redhat.com, pbonzini@redhat.com, hpa@zytor.com Cc: kvm@vger.kernel.org Subject: [PATCH] Check use I/O bitmap first before unconditional I/O exit Date: Mon, 30 Dec 2013 15:56:29 -0500 Message-Id: <1388436989-8597-1-git-send-email-zzhsuny@gmail.com> X-Mailer: git-send-email 1.8.1.2 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED, FREEMAIL_FROM, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP According to Table C-1 of Intel SDM 3C, a VM exit happens on an I/O instruction when "use I/O bitmaps" VM-execution control was 0 _and_ the "unconditional I/O exiting" VM-execution control was 1. So we can't just check "unconditional I/O exiting" alone. This patch was improved by suggestion from Jan Kiszka. Signed-off-by: Zhihui Zhang Reviewed-by: Jan Kiszka --- arch/x86/kvm/vmx.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index b2fe1c2..45617db 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -6460,11 +6460,8 @@ static bool nested_vmx_exit_handled_io(struct kvm_vcpu *vcpu, int size; u8 b; - if (nested_cpu_has(vmcs12, CPU_BASED_UNCOND_IO_EXITING)) - return 1; - if (!nested_cpu_has(vmcs12, CPU_BASED_USE_IO_BITMAPS)) - return 0; + return nested_cpu_has(vmcs12, CPU_BASED_UNCOND_IO_EXITING); exit_qualification = vmcs_readl(EXIT_QUALIFICATION);