Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752433AbaBXLNW (ORCPT ); Mon, 24 Feb 2014 06:13:22 -0500 Received: from mx1.redhat.com ([209.132.183.28]:32497 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751545AbaBXLNU (ORCPT ); Mon, 24 Feb 2014 06:13:20 -0500 Message-ID: <530B2949.4030000@redhat.com> Date: Mon, 24 Feb 2014 12:13:13 +0100 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.2.0 MIME-Version: 1.0 To: "Liu, Jinsong" , "'kvm@vger.kernel.org'" , "'linux-kernel@vger.kernel.org'" , "'qemu-devel@nongnu.org'" CC: "'gleb@redhat.com'" , "'hpa@zytor.com'" Subject: Re: [PATCH v5 3/3] KVM: x86: Enable Intel MPX for guest References: In-Reply-To: X-Enigmail-Version: 1.6 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Il 24/02/2014 11:58, Liu, Jinsong ha scritto: > @@ -599,6 +599,9 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr) > u64 old_xcr0 = vcpu->arch.xcr0; > u64 valid_bits; > > + if (!kvm_x86_ops->mpx_supported || !kvm_x86_ops->mpx_supported()) > + xcr0 &= ~(XSTATE_BNDREGS | XSTATE_BNDCSR); > + > /* Only support XCR_XFEATURE_ENABLED_MASK(xcr0) now */ > if (index != XCR_XFEATURE_ENABLED_MASK) > return 1; This hunk is incorrect, and I can simply drop it when applying. If MPX is not supported, it should not be in the 0Dh CPUID leaf and thus in vcpu->arch.guest_supported_xcr0. This however relies on userspace passing a "sensible" value of CPUID. I'll send a patch to strengthen the computation of guest_supported_xcr0. Thanks! Paolo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/