From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wanpeng Li Subject: Re: KVM causes #GP on XRSTORS Date: Mon, 24 Nov 2014 10:05:53 +0800 Message-ID: <20141124020553.GA27849@kernel> References: <546F505F.9080309@redhat.com> Reply-To: Wanpeng Li Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Nadav Amit , fenghua.yu@intel.com, kvm list , Eduardo Habkost , linux-kernel@vger.kernel.org To: Paolo Bonzini Return-path: Content-Disposition: inline In-Reply-To: <546F505F.9080309@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org Hi Paolo, On Fri, Nov 21, 2014 at 03:46:55PM +0100, Paolo Bonzini wrote: > > >On 20/11/2014 17:34, Nadav Amit wrote: >> Fenghua, >> >> I got KVM (v3.17) crashing on a machine that supports XRSTORS - It appears to get a #GP when it is trying to load the guest FPU. >> One reason for the #GP is that XCOMP_BV[63] is zeroed on the guest_fpu, but I am not sure it is the only problem. >> Was KVM ever tested with XRSTORS? > >What is the content of the CPUID[EAX=13,ECX=0] and CPUID[EAX=13,ECX=1] >leaves on the host? > >Fenghua, which processors have XSAVEC, which have XGETBV with ECX=1, and >which have XSAVES? We need to expose this in QEMU, for which I can send Skylake-client supports XSAVES. >a patch later today or next week (CCing Eduardo for this). Actually I do the xsaves work in kvm/qemu recently and the patches are complete, I will start to test it before send out. Regards, Wanpeng Li > >We will also have to uncompact the XSAVE area either in KVM_GET_XSAVE or >in QEMU. It's probably not hard to do it in the kernel. > >Paolo >-- >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