From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wanpeng Li Subject: Re: [PATCH 6/9] KVM: cpuid: mask more bits in leaf 0xd and subleaves Date: Fri, 5 Dec 2014 09:20:05 +0800 Message-ID: <20141205012005.GB2683@kernel> References: <1417708634-24333-1-git-send-email-pbonzini@redhat.com> <1417708634-24333-7-git-send-email-pbonzini@redhat.com> <20141205003446.GA6967@kernel> Reply-To: Wanpeng Li Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, rkrcmar@redhat.com To: Paolo Bonzini Return-path: Content-Disposition: inline In-Reply-To: <20141205003446.GA6967@kernel> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Fri, Dec 05, 2014 at 08:34:47AM +0800, Wanpeng Li wrote: >Hi Paolo, >On Thu, Dec 04, 2014 at 04:57:11PM +0100, Paolo Bonzini wrote: >>- EAX=3D0Dh, ECX=3D1: output registers ECX/EDX are reserved. >> >>- EAX=3D0Dh, ECX>1: output register ECX bit 0 is clear for all the CP= UID >>leaves we support, because variable "supported" comes from XCR0 and n= ot >>XSS. Bits above 0 are reserved, so ECX is overall zero. Output regi= ster >>EDX is reserved. >> >>Source: Intel Architecture Instruction Set Extensions Programming >>Reference, ref. number 319433-022 >> >>Reviewed-by: Radim Kr=C4=8Dm=C3=A1=C5=99 >>Signed-off-by: Paolo Bonzini >>--- >> arch/x86/kvm/cpuid.c | 10 ++++++++-- >> 1 file changed, 8 insertions(+), 2 deletions(-) >> > >Do you miss this in your patch? > >+ /* cpuid 0xD.1.eax */ >+ const u32 kvm_supported_word10_x86_features =3D >+ F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1); >+ > >In addition, there is bisect issue if this is added in this patch. >(4/9 will take advantage of kvm_supported_word10_x86_features) Also due to "kvm: x86: mask out XSAVES". Regards, Wanpeng Li > >Regards, >Wanpeng Li=20 > >>diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c >>index 2f7bc2de9915..644bfe828ce1 100644 >>--- a/arch/x86/kvm/cpuid.c >>+++ b/arch/x86/kvm/cpuid.c >>@@ -482,8 +482,14 @@ static inline int __do_cpuid_ent(struct kvm_cpui= d_entry2 *entry, u32 function, >> entry[i].ebx =3D >> xstate_required_size(supported, >> true); >>- } else if (entry[i].eax =3D=3D 0 || !(supported & mask)) >>- continue; >>+ } else { >>+ if (entry[i].eax =3D=3D 0 || !(supported & mask)) >>+ continue; >>+ if (WARN_ON_ONCE(entry[i].ecx & 1)) >>+ continue; >>+ } >>+ entry[i].ecx =3D 0; >>+ entry[i].edx =3D 0; >> entry[i].flags |=3D >> KVM_CPUID_FLAG_SIGNIFCANT_INDEX; >> ++*nent; >>--=20 >>1.8.3.1 >> >-- >To unsubscribe from this list: send the line "unsubscribe kvm" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html