Re: [PATCH] KVM: x86: use positive error values for msr emulation that causes #GP

[Pankaj Gupta]

> > This looks good to me. This should solve "-EPERM" return by "__kvm_set_msr" .
> >
> > A question I have, In the case of "kvm_emulate_rdmsr()",  for "r" we
> > are injecting #GP.
> > Is there any possibility of this check to be hit and still result in #GP?
>
> When I wrote this patch series I assumed that msr reads usually don't have
> side effects so they shouldn't fail, and fixed only the msr write code path
> to deal with negative errors. Now that you put this in this light,
> I do think that you are right and I should have added code for both msr reads and writes
> especially to catch cases in which negative errors are returned by mistake
> like this one (my mistake in this case since my patch series was merged
> after the userspace msrs patch series).
>
> What do you think?
>
> I can prepare a separate patch for this, which should go to the next
> kernel version since this doesn't fix a regression.

Patch on the top should be okay. I think.

Thanks,
Pankaj