From patchwork Wed Apr 22 09:56:38 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 227325 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A359C5518C for ; Wed, 22 Apr 2020 10:06:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3F4932075A for ; Wed, 22 Apr 2020 10:06:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549978; bh=idgshFs3pJ4wddZ6Cds1FGvsSASdv3dtQQDtPhm/v8E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VjxOLOPj8lmouImQ50ABoTl4jX670Hu0F5RuNzQpTR3dfqQ2LHzqupy2J93f1G7TG TqW5UBI7XSs06qJXjwAPSO/aaWW6gUZnOXcLVE7frHZiNeHJ2HjQXBgpTuUGsVcUB1 WTkwXJM6lx8la5C9YHzwLTKClkFb0phYIMQjsdvk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727056AbgDVKGN (ORCPT ); Wed, 22 Apr 2020 06:06:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:57986 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728317AbgDVKGM (ORCPT ); Wed, 22 Apr 2020 06:06:12 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 790712075A; Wed, 22 Apr 2020 10:06:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587549971; bh=idgshFs3pJ4wddZ6Cds1FGvsSASdv3dtQQDtPhm/v8E=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=E/eI5zgEj/E0PEuxqN3sSpPuUICoS1PSdLjZiKLZX4+Gz0omzKdi0uQyvOXOvkqbC yW2TKwJqFxspFC6DiMp5xtkviD56obCT4dwMqdn/o2TJSOGukuz46tj6bnLs2yAEgI uIX2hr6zIYhHE8/iPrAPcc+ZiiBcdr3GQhnUQDvQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jim Mattson , Jacob Xu , Peter Shier , Paolo Bonzini , Eric Biggers , Ben Hutchings , Sasha Levin Subject: [PATCH 4.9 081/125] kvm: x86: Host feature SSBD doesnt imply guest feature SPEC_CTRL_SSBD Date: Wed, 22 Apr 2020 11:56:38 +0200 Message-Id: <20200422095046.158101353@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095032.909124119@linuxfoundation.org> References: <20200422095032.909124119@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Jim Mattson commit 396d2e878f92ec108e4293f1c77ea3bc90b414ff upstream. The host reports support for the synthetic feature X86_FEATURE_SSBD when any of the three following hardware features are set: CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] CPUID.80000008H:EBX.AMD_SSBD[bit 24] CPUID.80000008H:EBX.VIRT_SSBD[bit 25] Either of the first two hardware features implies the existence of the IA32_SPEC_CTRL MSR, but CPUID.80000008H:EBX.VIRT_SSBD[bit 25] does not. Therefore, CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] should only be set in the guest if CPUID.(EAX=7,ECX=0):EDX.SSBD[bit 31] or CPUID.80000008H:EBX.AMD_SSBD[bit 24] is set on the host. Fixes: 0c54914d0c52a ("KVM: x86: use Intel speculation bugs and features as derived in generic x86 code") Signed-off-by: Jim Mattson Reviewed-by: Jacob Xu Reviewed-by: Peter Shier Cc: Paolo Bonzini Reported-by: Eric Biggers Signed-off-by: Paolo Bonzini [bwh: Backported to 4.x: adjust indentation] Signed-off-by: Ben Hutchings Signed-off-by: Sasha Levin --- arch/x86/kvm/cpuid.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c index c57dab0884fed..63c3ff9e74d42 100644 --- a/arch/x86/kvm/cpuid.c +++ b/arch/x86/kvm/cpuid.c @@ -479,7 +479,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, entry->edx |= F(SPEC_CTRL); if (boot_cpu_has(X86_FEATURE_STIBP)) entry->edx |= F(INTEL_STIBP); - if (boot_cpu_has(X86_FEATURE_SSBD)) + if (boot_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD) || + boot_cpu_has(X86_FEATURE_AMD_SSBD)) entry->edx |= F(SPEC_CTRL_SSBD); /* * We emulate ARCH_CAPABILITIES in software even