On Wed, Oct 12, 2022 at 09:59:04AM +0000, Huang, Kai wrote:
> On Wed, 2022-10-12 at 04:26 -0400, Yang Zhong wrote:
> > The previous patch wrongly replaced FEAT_XSAVE_XCR0_{LO|HI} with
> > FEAT_XSAVE_XSS_{LO|HI} in CPUID(EAX=12,ECX=1):ECX, which made SGX
> ^
>
> Nit: both ECX and EDX are wrongly set, but not only ECX.
>
Yes, I will change to CPUID(EAX=12,ECX=1):{ECX,EDX}, thanks!
> > enclave only supported SSE and x87 feature(xfrm=0x3).
>
> Is this true? Perhaps I am missing something, but it seems env-
> >features[FEAT_XSAVE_XCR0_LO] only includes LBR bit, which is bit 15.
We printed the XFRM value from SGX SDK to find this issue.
>
> /* Calculate XSAVE components based on the configured CPU feature flags */
> static void x86_cpu_enable_xsave_components(X86CPU *cpu)
> {
> ...
> env->features[FEAT_XSAVE_XSS_LO] = mask & CPUID_XSTATE_XSS_MASK;
> ...
> }
>
> /* CPUID feature bits available in XSS */
> #define CPUID_XSTATE_XSS_MASK (XSTATE_ARCH_LBR_MASK)
>
> >
> > Fixes: 301e90675c3f ("target/i386: Enable support for XSAVES based
> > features")
> >
> > Signed-off-by: Yang Zhong <[email protected]>
> > ---
> > target/i386/cpu.c | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> > index ad623d91e4..19aaed877b 100644
> > --- a/target/i386/cpu.c
> > +++ b/target/i386/cpu.c
> > @@ -5584,8 +5584,8 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index,
> > uint32_t count,
> > } else {
> > *eax &= env->features[FEAT_SGX_12_1_EAX];
> > *ebx &= 0; /* ebx reserve */
> > - *ecx &= env->features[FEAT_XSAVE_XSS_LO];
> > - *edx &= env->features[FEAT_XSAVE_XSS_HI];
> > + *ecx &= env->features[FEAT_XSAVE_XCR0_LO];
> > + *edx &= env->features[FEAT_XSAVE_XCR0_HI];
> >
> > /* FP and SSE are always allowed regardless of XSAVE/XCR0. */
> > *ecx |= XSTATE_FP_MASK | XSTATE_SSE_MASK;
>
> The code looks good:
>
> Reviewed-by: Kai Huang <[email protected]>
>
