Re: [PATCH v2 1/4] KVM: x86: INIT and reset sequences are different

[Bandan Das <bsd@redhat.com>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> On 02/04/2015 04:17, Bandan Das wrote:
>>> > x86 architecture defines differences between the reset and INIT sequences.
>>> > INIT does not initialize the FPU (including MMX, XMM, YMM, etc.), TSC, PMU,
>>> > MSRs (in general), MTRRs machine-check, APIC ID, APIC arbitration ID and BSP.
>>> >
>>> > EFER is supposed NOT to be reset according to the SDM, but leaving the LMA and
>>> > LME untouched causes failed VM-entry.  Therefore we reset EFER (although it is
>>> > unclear whether the rest of EFER bits should be reset).
>> Thanks! This was actually in my todo list. #INIT and #RESET are actually separate pins
>> on the processor. So, shouldn't we differentiate between the two too by having
>> (*vcpu_init) and (*vcpu_reset) separate ?
>
> I think a bool argument is good enough.  QEMU has different functions,
> and init ends up doing save/reset/restore which is pretty ugly.

Right, I meant that init could just be a wrapper so that it atleast shows up in
a backtrace - could be helpful for debugging.

> Paolo
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