Re: [PATCH RFC 1/5] x86: KVM: svm: don't pretend to advance RIP in case wrmsr_interception() results in #GP

From: Jim Mattson
Date: Thu Jun 20 2019 - 14:49:25 EST


On Thu, Jun 20, 2019 at 4:02 AM Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> wrote:
>
> svm->next_rip is only used by skip_emulated_instruction() and in case
> kvm_set_msr() fails we rightfully don't do that. Move svm->next_rip
> advancement to 'else' branch to avoid creating false impression that
> it's always advanced.
>
> By the way, rdmsr_interception() has it right already.

I think I actually prefer the current placement, because this allows
the code that's common to both kvm-amd.ko and kvm-intel.ko to be
hoisted into the vendor-agnostic kvm module. Also, this hard-coded '2'
should be going away, right?