Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932283AbaLDN4E (ORCPT ); Thu, 4 Dec 2014 08:56:04 -0500 Received: from mail-wi0-f177.google.com ([209.85.212.177]:54158 "EHLO mail-wi0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932117AbaLDN4D (ORCPT ); Thu, 4 Dec 2014 08:56:03 -0500 Message-ID: <548067ED.2020309@redhat.com> Date: Thu, 04 Dec 2014 14:55:57 +0100 From: Paolo Bonzini User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 Newsgroups: gmane.linux.kernel,gmane.comp.emulators.kvm.devel To: Wanpeng Li CC: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/4] kvm: cpuid: fix the size of xsaves area References: <1417681468-7165-1-git-send-email-wanpeng.li@linux.intel.com> <1417681468-7165-2-git-send-email-wanpeng.li@linux.intel.com> In-Reply-To: <1417681468-7165-2-git-send-email-wanpeng.li@linux.intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/12/2014 09:24, Wanpeng Li wrote: > The section of CPUID(EAX=0xd, ECX=1) in the spec which commit > f5c2290cd01e (KVM: cpuid: mask more bits in leaf 0xd and subleaves) > mentioned is older than SDM. > > EBX: Bits 31-00: The size in bytes of the XSAVE area containing all > states enabled by XCR0|IA32_XSS. > > The the value of EBX should represent the size of XCR0 related XSAVE > area since IA32_XSS is not used currently. > > Signed-off-by: Wanpeng Li > --- > arch/x86/kvm/cpuid.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index 646e6e8..70f0fa1 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -477,7 +477,10 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, > do_cpuid_1_ent(&entry[i], function, idx); > if (idx == 1) { > entry[i].eax &= kvm_supported_word10_x86_features; > - entry[i].ebx = 0; > + if (entry[i].eax & F(XSAVES)) > + entry[i].ebx = xstate_required_size(supported, true); > + else > + entry[i].ebx = xstate_required_size(supported, false); On machines without XSAVES, this value is zero though. Paolo > } else { > if (entry[i].eax == 0 || !(supported & mask)) > continue; > -- 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/