From mboxrd@z Thu Jan 1 00:00:00 1970 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 0A897C433DF for ; Tue, 16 Jun 2020 16:13:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DAE8E2071A for ; Tue, 16 Jun 2020 16:13:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592323991; bh=yHE3Mizda/15sFcSyx9CzxSGL2SEfdk8gsWNYgqb0s4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=klTrdHcb4EIqQ7PVJsH5O/DywqvKrsLxl4PpNcEl+W/zAZpcjsCWxR+jq9fw5C9LR Vkm/Rc2bXtK41ndAPpbr8RrJ2eTN6CMHjOu1FjTxCj0Etq0dTPyOUJQSljzc+HB7Il yEPyKkVI0dr9xNptKuHMnDQdkhckSz3geiAMIvrY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731819AbgFPPng (ORCPT ); Tue, 16 Jun 2020 11:43:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:32890 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731807AbgFPPnd (ORCPT ); Tue, 16 Jun 2020 11:43:33 -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 F2A6F21475; Tue, 16 Jun 2020 15:43:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592322213; bh=yHE3Mizda/15sFcSyx9CzxSGL2SEfdk8gsWNYgqb0s4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UG82lUoKHRoFtpZVcFO2YtohXL7ly9HO2DmzhHtUhsazA6BUFmvkOm1PpYcQcgZjS McD34IP4PJBFLw+7J1zs/2s4P/ddoqGR3M9vIfaff3tJhwcjzEYz+E80Ll4ijdaK/K Kq/wGMeF/P2MPZEZ70KGIvte5LOYrJdwk/M/k5os= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Maxim Levitsky , Sean Christopherson , Paolo Bonzini Subject: [PATCH 5.7 044/163] KVM: x86: dont expose MSR_IA32_UMWAIT_CONTROL unconditionally Date: Tue, 16 Jun 2020 17:33:38 +0200 Message-Id: <20200616153108.974705115@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200616153106.849127260@linuxfoundation.org> References: <20200616153106.849127260@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Maxim Levitsky commit f4cfcd2d5aea4e96c5d483c476f3057b6b7baf6a upstream. This msr is only available when the host supports WAITPKG feature. This breaks a nested guest, if the L1 hypervisor is set to ignore unknown msrs, because the only other safety check that the kernel does is that it attempts to read the msr and rejects it if it gets an exception. Cc: stable@vger.kernel.org Fixes: 6e3ba4abce ("KVM: vmx: Emulate MSR IA32_UMWAIT_CONTROL") Signed-off-by: Maxim Levitsky Message-Id: <20200523161455.3940-3-mlevitsk@redhat.com> Reviewed-by: Sean Christopherson Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/x86.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5242,6 +5242,10 @@ static void kvm_init_msr_list(void) if (!kvm_cpu_cap_has(X86_FEATURE_RDTSCP)) continue; break; + case MSR_IA32_UMWAIT_CONTROL: + if (!kvm_cpu_cap_has(X86_FEATURE_WAITPKG)) + continue; + break; case MSR_IA32_RTIT_CTL: case MSR_IA32_RTIT_STATUS: if (!kvm_cpu_cap_has(X86_FEATURE_INTEL_PT))