Messages in this thread | | | Date | Wed, 2 Jan 2019 10:54:53 -0800 | From | Sean Christopherson <> | Subject | Re: [PATCH v1 7/8] kvm:cpuid Fix xsaves area size calculation for CPUID.(EAX=0xD,ECX=1). |
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On Wed, Dec 26, 2018 at 04:15:31PM +0800, Yang Weijiang wrote: > According to latest Software Development Manual vol.2/3.2, > for CPUID.(EAX=0xD,ECX=1), it should report xsaves area size > containing all states enabled by XCR0|IA32_MSR_XSS. > > Signed-off-by: Zhang Yi Z <yi.z.zhang@linux.intel.com> > Signed-off-by: Yang Weijiang <weijiang.yang@intel.com> > --- > arch/x86/kvm/cpuid.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c > index 5bac31e58955..55c282f71f93 100644 > --- a/arch/x86/kvm/cpuid.c > +++ b/arch/x86/kvm/cpuid.c > @@ -121,7 +121,8 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu) > > best = kvm_find_cpuid_entry(vcpu, 0xD, 1); > if (best && (best->eax & (F(XSAVES) | F(XSAVEC)))) > - best->ebx = xstate_required_size(vcpu->arch.xcr0, true); > + best->ebx = xstate_required_size(vcpu->arch.xcr0 | > + best->ecx | ((u64)best->edx << 32), true);
Passing the CPUID bits is wrong, it needs to be the guest's IA32_MSR_XSS. The CPUID bits enumerate what is legal to enable, not what features are actually enabled by software.
> > /* > * The existing code assumes virtual address is 48-bit or 57-bit in the > -- > 2.17.1 >
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