From patchwork Thu Aug 15 07:41:23 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 11095147 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 548541398 for ; Thu, 15 Aug 2019 07:41:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3C1E028720 for ; Thu, 15 Aug 2019 07:41:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3047A28884; Thu, 15 Aug 2019 07:41:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CDB2C2023F for ; Thu, 15 Aug 2019 07:41:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730472AbfHOHlb (ORCPT ); Thu, 15 Aug 2019 03:41:31 -0400 Received: from mail-wm1-f65.google.com ([209.85.128.65]:52091 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726366AbfHOHla (ORCPT ); Thu, 15 Aug 2019 03:41:30 -0400 Received: by mail-wm1-f65.google.com with SMTP id 207so512886wma.1; Thu, 15 Aug 2019 00:41:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:from:to:cc:subject:date:message-id:in-reply-to:references; bh=203QBNRDsU40BweVYIq1zq8GgAZoiZ5+xgte91iuHBU=; b=Ng42SaxJFviZnyyCgxsk/FOSqiD/Sn01vMiC8x4tb1/goIwVrzJkro47ZoVAApjXQO cVg872uh763mngEDr0oshvojOsSdrCoPecllBRuOtSeqVV6G2nR2o8BBEd2wHbzNuL+D igeB8whp1VKXxh1tQ3w2LAd+3gGLCOApgDSnf/bcC94HTnKF6roG+rD0pRgHlc1/2Wb3 eRweOeF5Iz3SZOLXcFJu6Biia6d9fE/JmLMUmSkciSMEqO/Xt02DVRr9wzn6rdMSUj/C bNJKur64jHGFLLN44PZfuuGhwqtqrqWHo3low/lETBm7ydfrWVVbEsqRlL6Vk161l9RJ 2mfA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:from:to:cc:subject:date:message-id :in-reply-to:references; bh=203QBNRDsU40BweVYIq1zq8GgAZoiZ5+xgte91iuHBU=; b=fbx4PN9DLrryG+uHzCd59oiMSWvCB24edz4/kw+XaonHjpd/2B3M/3JhEjZ/y+qWwR BaO/x5YnylCOSAVoKEgzGgtp+1uSFYvwUaQesx3J4qCr/5qpLTvsBXkQBBq62ILyjqnU qRXjpOGNTytcXAmQZOwnHfK/RPphCb68hTNLASgNha8K9mcmEsbek9kKXg8Hndgl/RE5 XTi0rCztoCcuGx+y9mgFOoJM19iHtzqOgcfgli106rrRiCjRlf+qFujY7bK4AQUYU12W OU+hP3SPaUwaWTLBA4w9rPcvrTWg44AseGlRfVnho1r0JFxLctGRE31uC5QLQH37izxq Ug9A== X-Gm-Message-State: APjAAAXWB+xuJ0LzBq7CWswlMmgv6QDNKZ2eWTx6yxj9h3qJwue8qVQN lO/36gRlrdVFaCbZvaT6oVwmqAil X-Google-Smtp-Source: APXvYqyBizrggMLtsrNCSp7vAMF2maezD72y4g4CI0QEtyKDHYeZ6fTHFIabzDLHeTwvA098jnLIZA== X-Received: by 2002:a1c:6385:: with SMTP id x127mr1374763wmb.140.1565854888194; Thu, 15 Aug 2019 00:41:28 -0700 (PDT) Received: from 640k.localdomain.com ([93.56.166.5]) by smtp.gmail.com with ESMTPSA id m23sm809796wml.41.2019.08.15.00.41.27 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 15 Aug 2019 00:41:27 -0700 (PDT) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Konrad Rzeszutek Wilk Subject: [PATCH 2/2] KVM: x86: always expose VIRT_SSBD to guests Date: Thu, 15 Aug 2019 09:41:23 +0200 Message-Id: <1565854883-27019-3-git-send-email-pbonzini@redhat.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1565854883-27019-1-git-send-email-pbonzini@redhat.com> References: <1565854883-27019-1-git-send-email-pbonzini@redhat.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Even though it is preferrable to use SPEC_CTRL (represented by X86_FEATURE_AMD_SSBD) instead of VIRT_SPEC, VIRT_SPEC is always supported anyway because otherwise it would be impossible to migrate from old to new CPUs. Make this apparent in the result of KVM_GET_SUPPORTED_CPUID as well. Cc: Konrad Rzeszutek Wilk Reported-by: Eduardo Habkost Signed-off-by: Paolo Bonzini --- arch/x86/kvm/cpuid.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index 145ec050d45d..5865bc73bbb5 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -747,11 +747,13 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features; cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX); /* - * The preference is to use SPEC CTRL MSR instead of the - * VIRT_SPEC MSR. + * VIRT_SPEC is only implemented for AMD processors, + * but the host could set AMD_SSBD if it wanted even + * for Intel processors. */ - if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) && - !boot_cpu_has(X86_FEATURE_AMD_SSBD)) + if ((boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) || + boot_cpu_has(X86_FEATURE_AMD_SSBD)) && + boot_cpu_has(X86_FEATURE_SVM)) entry->ebx |= F(VIRT_SSBD); break; }