> On Nov 25, 2014, at 12:36, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: > > > > On 25/11/2014 11:13, Wanpeng Li wrote: >> Hi Paolo, >> On Mon, Nov 24, 2014 at 05:43:32PM +0100, Paolo Bonzini wrote: >>> The first patch ensures that XSAVES is not exposed in the guest until >>> we emulate MSR_IA32_XSS. The second exports XSAVE data in the correct >>> format. >>> >>> I tested these on a non-XSAVES system so they should not be completely >>> broken, but I need some help. I am not even sure which XSAVE states >>> are _not_ enabled, and thus compacted, in Linux. >>> >>> Note that these patches do not add support for XSAVES in the guest yet, >>> since MSR_IA32_XSS is not emulated. >>> >>> If they fix the bug Nadav reported, I'll add Reported-by and commit. >> >> I test this patchset w/ your "KVM: x86: export get_xsave_addr" patch on >> Skylake and guest hang during boot. The guest screen show "Probing EDD >> (edd=off to disable)... ok", and no more dump. > > Anything in dmesg? Can you try this patch on top? > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index 373b0ab9a32e..ca26681455c2 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -6955,6 +6955,9 @@ int fx_init(struct kvm_vcpu *vcpu) > return err; > > fpu_finit(&vcpu->arch.guest_fpu); > + if (cpu_has_xsaves) > + vcpu->arch.guest_fpu.state->xsave.xsave_hdr.xcomp_bv = > + host_xcr0 | XSTATE_COMPACTION_ENABLED; > > /* > * Ensure guest xcr0 is valid for loading > The second version works for me (w/qemu v2.1.0; Linux 3.13 guest). I did not need to apply this patch on top. [although I am not sure whether relying on userspace to call KVM_SET_XSAVE early enough is a good practice]. One disclaimer: Since I got limited time with the machine, I executed a slightly modified kernel/qemu, and not the latest version. Anyhow, I don’t think these differences can have any impact. Regards, Nadav -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
