Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754008AbdGSLPV (ORCPT ); Wed, 19 Jul 2017 07:15:21 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:48416 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753983AbdGSLPS (ORCPT ); Wed, 19 Jul 2017 07:15:18 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Haozhong Zhang , Paolo Bonzini Subject: [PATCH 4.4 57/57] kvm: vmx: allow host to access guest MSR_IA32_BNDCFGS Date: Wed, 19 Jul 2017 13:13:03 +0200 Message-Id: <20170719111252.259593849@linuxfoundation.org> X-Mailer: git-send-email 2.13.3 In-Reply-To: <20170719111249.973558472@linuxfoundation.org> References: <20170719111249.973558472@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1447 Lines: 43 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Haozhong Zhang commit 691bd4340bef49cf7e5855d06cf24444b5bf2d85 upstream. It's easier for host applications, such as QEMU, if they can always access guest MSR_IA32_BNDCFGS in VMCS, even though MPX is disabled in guest cpuid. Signed-off-by: Haozhong Zhang Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/vmx.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -2812,7 +2812,8 @@ static int vmx_get_msr(struct kvm_vcpu * msr_info->data = vmcs_readl(GUEST_SYSENTER_ESP); break; case MSR_IA32_BNDCFGS: - if (!kvm_mpx_supported() || !guest_cpuid_has_mpx(vcpu)) + if (!kvm_mpx_supported() || + (!msr_info->host_initiated && !guest_cpuid_has_mpx(vcpu))) return 1; msr_info->data = vmcs_read64(GUEST_BNDCFGS); break; @@ -2889,7 +2890,8 @@ static int vmx_set_msr(struct kvm_vcpu * vmcs_writel(GUEST_SYSENTER_ESP, data); break; case MSR_IA32_BNDCFGS: - if (!kvm_mpx_supported() || !guest_cpuid_has_mpx(vcpu)) + if (!kvm_mpx_supported() || + (!msr_info->host_initiated && !guest_cpuid_has_mpx(vcpu))) return 1; if (is_noncanonical_address(data & PAGE_MASK) || (data & MSR_IA32_BNDCFGS_RSVD))