Re: [PATCH] KVM: x86: fix a typo in __try_cmpxchg_user that caused cmpxchg to be not atomic

Sean Christopherson
2022-05-12T21:27:31Z

On Thu, May 12, 2022, Paolo Bonzini wrote:
> On 5/12/22 12:14, Maxim Levitsky wrote:
> > Yes, this is the root cause of the TDP mmu leak I was doing debug of in the last week.
> > Non working cmpxchg on which TDP mmu relies makes it install two differnt shadow pages
> > under same spte.
>
> Awesome! And queued, thanks.

If you haven't done so already, can you add

Cc: stable@vger.kernel.org

Also, given that we have concrete proof that not honoring atomic accesses can have
dire consequences for the guest, what about adding a capability to turn the emul_write
path into an emulation error?