[Bug 218267] [Sapphire Rapids][Upstream]Boot up multiple Windows VMs hang

bugzilla-daemon
2025-01-27T18:32:22Z

--- Comment #12 from Sean Christopherson (seanjc@google.com) ---
I'm not terribly concerned about the complexity, I'm more concerned about the
efficacy of a software workaround, and to a lesser extent the risk of doing
more harm than good (this seems unlikely though). E.g. if an exit that _can_
occur during vectoring collides with the bug, then KVM will inject a spurious
fault into the guest. And if our list of "impossible" exits is wrong, KVM
could incorrectly suppress an exception.

I suppose we could mitigate the efficacy concerns by emitting a pr_err_once()
to suggest a ucode update if the erratum is hit.