From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751341AbaJWFtU (ORCPT ); Thu, 23 Oct 2014 01:49:20 -0400 Received: from mga09.intel.com ([134.134.136.24]:19855 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750813AbaJWFtT (ORCPT ); Thu, 23 Oct 2014 01:49:19 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.04,773,1406617200"; d="scan'208";a="623753599" Date: Thu, 23 Oct 2014 13:49:13 +0800 From: Chao Peng To: Paolo Bonzini Cc: gleb@kernel.org, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, fenghua.yu@intel.com, bp@suse.de, qiaowei.ren@intel.com, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH] KVM: x86: Enable Intel AVX-512 for guest Message-ID: <20141023054912.GA3135@pengc-linux.bj.intel.com> Reply-To: Chao Peng References: <1413970524-12845-1-git-send-email-chao.p.peng@linux.intel.com> <5447843D.6090102@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5447843D.6090102@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 22, 2014 at 12:17:33PM +0200, Paolo Bonzini wrote: > On 10/22/2014 11:35 AM, Chao Peng wrote: > > Expose Intel AVX-512 feature bits to guest. Also add checks for > > xcr0 AVX512 related bits according to spec: > > http://download-software.intel.com/sites/default/files/managed/71/2e/319433-017.pdf > > > > Signed-off-by: Chao Peng > > The patch looks good, but you also have to patch QEMU in order to > save/restore the values of the registers. IIRC the manual already > details where the registers are in the XSAVE area, so it should be easy > to get them in and out. You can look at the MPX patches for an example. > > In the meanwhile, kernel bits are > > Reviewed-by: Paolo Bonzini > > Paolo Thanks Paolo. QEMU side patch is already sent out to QEMU list in the other thread. Also accessible from url: http://lists.nongnu.org/archive/html/qemu-devel/2014-10/msg02681.html Chao > > > --- > > arch/x86/include/asm/xsave.h | 1 + > > arch/x86/kvm/cpuid.c | 3 ++- > > arch/x86/kvm/x86.c | 6 ++++++ > > arch/x86/kvm/x86.h | 3 ++- > > 4 files changed, 11 insertions(+), 2 deletions(-) > > > > diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h > > index 7e7a79a..5fa9770 100644 > > --- a/arch/x86/include/asm/xsave.h > > +++ b/arch/x86/include/asm/xsave.h > > @@ -16,6 +16,7 @@ > > #define XSTATE_Hi16_ZMM 0x80 > > > > #define XSTATE_FPSSE (XSTATE_FP | XSTATE_SSE) > > +#define XSTATE_AVX512 (XSTATE_OPMASK | XSTATE_ZMM_Hi256 | XSTATE_Hi16_ZMM) > > /* Bit 63 of XCR0 is reserved for future expansion */ > > #define XSTATE_EXTEND_MASK (~(XSTATE_FPSSE | (1ULL << 63))) > > > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > > index 976e3a5..20d8321 100644 > > --- a/arch/x86/kvm/cpuid.c > > +++ b/arch/x86/kvm/cpuid.c > > @@ -317,7 +317,8 @@ static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, > > const u32 kvm_supported_word9_x86_features = > > F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | > > F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) | > > - F(ADX) | F(SMAP); > > + F(ADX) | F(SMAP) | F(AVX512F) | F(AVX512PF) | F(AVX512ER) | > > + F(AVX512CD); > > > > /* all calls to cpuid_count() should be made on the same cpu */ > > get_cpu(); > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > > index 5430e4b..3d77b88 100644 > > --- a/arch/x86/kvm/x86.c > > +++ b/arch/x86/kvm/x86.c > > @@ -651,6 +651,12 @@ int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr) > > if ((!(xcr0 & XSTATE_BNDREGS)) != (!(xcr0 & XSTATE_BNDCSR))) > > return 1; > > > > + if (xcr0 & XSTATE_AVX512) { > > + if (!(xcr0 & XSTATE_YMM)) > > + return 1; > > + if ((xcr0 & XSTATE_AVX512) != XSTATE_AVX512) > > + return 1; > > + } > > kvm_put_guest_xcr0(vcpu); > > vcpu->arch.xcr0 = xcr0; > > > > diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h > > index 7cb9c45..cc1d61a 100644 > > --- a/arch/x86/kvm/x86.h > > +++ b/arch/x86/kvm/x86.h > > @@ -162,7 +162,8 @@ int kvm_write_guest_virt_system(struct x86_emulate_ctxt *ctxt, > > bool kvm_mtrr_valid(struct kvm_vcpu *vcpu, u32 msr, u64 data); > > > > #define KVM_SUPPORTED_XCR0 (XSTATE_FP | XSTATE_SSE | XSTATE_YMM \ > > - | XSTATE_BNDREGS | XSTATE_BNDCSR) > > + | XSTATE_BNDREGS | XSTATE_BNDCSR \ > > + | XSTATE_AVX512) > > extern u64 host_xcr0; > > > > extern u64 kvm_supported_xcr0(void); > >