Re: [PATCH]: Fix MSR_K7_EVNTSEL{0,3} for SVM

Chris Lalancette
2008-04-25T13:06:56Z

Avi Kivity wrote:
>
> Hmm, looking back at the dump:
>
>> 1811: 8d 86 00 00 ff 3f lea 0x3fff0000(%rsi),%eax
>> 1817: 83 f8 03 cmp $0x3,%eax
>> 181a: 0f 87 e2 01 00 00 ja 1a02 <svm_set_msr+0x27f>
>
> So while gcc is using %rsi, it loads the result back into %eax, which
> has the effect of dropping back into 32-bits. So looks like gcc was
> right here. Sorry for spreading confusion and apologies to gcc.
>

OK. Well, then I can't explain why we are unconditionally calling
kvm_set_msr_common(), regardless of whether data == 0 or not. Avi, you said it
works for you; what version of gcc are you using, and can you send me your
objdump -Sr? I'd like to compare the assembly output with what 4.3.0 is
spitting out.

Chris Lalancette