On 09/07/2015 10:17, Richard Henderson wrote:
> +
> + /* ??? This variable is somewhat silly. Methinks KVM should be
> + using XCR0 to store into the XSTATE_BV field. Either that or
> + there's more missing information, e.g. the AVX bits. */
> + env->xstate_bv = XSTATE_FP;
> + if (env->features[FEAT_1_EDX] & CPUID_SSE) {
> + env->xstate_bv |= XSTATE_SSE;
> + }
> + if (env->features[FEAT_7_0_EBX] & CPUID_7_0_EBX_MPX) {
> + env->xstate_bv |= XSTATE_BNDREGS | XSTATE_BNDCSR;
> + }
xstate_bv != xcr0 if the kernel is using XSAVEOPT and some of the values
were in the initial state. Legacy state is never optimized, hence the
value of env->xstate_bv after reset. So I think this hunk is wrong,
while the other is correct.
Paolo
