Re: [PATCH] KVM: VMX: remove LFENCE in vmx_spec_ctrl_restore_host()

From: Josh Poimboeuf
Date: Wed May 31 2023 - 20:56:32 EST

On Thu, Jun 01, 2023 at 01:50:48AM +0100, Andrew Cooper wrote:
> On 01/06/2023 1:42 am, Josh Poimboeuf wrote:
> > So each LFENCE has a distinct purpose. That said, there are no indirect
> > branches or unbalanced RETs between them.
> How lucky are you feeling?
> You're in C at this point, which means the compiler could have emitted a
> call to mem{cpy,cmp}() in place of a simple assignment/comparison.

But it's only unbalanced RETs we're concerned about, per Intel.