[PATCH v4 10/12] KVM: x86: never write to memory from kvm_vcpu_check_block()

[Jim Mattson]

On Thu, Dec 7, 2023 at 8:21 AM Sean Christopherson <seanjc at google.com> wrote:
> Doh.  We got the less obvious cases and missed the obvious one.
>
> Ugh, and we also missed a related mess in kvm_guest_apic_has_interrupt().  That
> thing should really be folded into vmx_has_nested_events().
>
> Good gravy.  And vmx_interrupt_blocked() does the wrong thing because that
> specifically checks if L1 interrupts are blocked.
>
> Compile tested only, and definitely needs to be chunked into multiple patches,
> but I think something like this mess?

The proposed patch does not fix the problem. In fact, it messes things
up so much that I don't get any test results back.

Google has an internal K-U-T test that demonstrates the problem. I
will post it soon.