Documentation update for KVM_CAP_MEMORY_FAULT_INFO > KVM_CAP_MEMORY_FAULT_INFO > ------------------------------------------- Old: > -The presence of this capability indicates that KVM_RUN may annotate EFAULTs > -returned by KVM_RUN in response to failed vCPU guest memory accesses which > -userspace may be able to resolve. New: > +The presence of this capability indicates that KVM_RUN may fill > +kvm_run.memory_fault in response to failed guest memory accesses in a vCPU > +context. On Wed, Jun 14, 2023 at 10:35 AM Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > (B) is the trickiest to defend against in the kernel, but as I mentioned in earlier > versions of this series, userspace needs to guard against a vCPU getting stuck in > an infinite fault anyways, so I'm not _that_ concerned with figuring out a way to > address this in the kernel. KVM's documentation should strongly encourage userspace > to take action if KVM repeatedly exits with the same info over and over, but beyond > that I think anything else is nice to have, not mandatory. In response to that, I've added the following bit as well: +Note: Userspaces which attempt to resolve memory faults so that they can retry +KVM_RUN are encouraged to guard against repeatedly receiving the same +error/annotated fault.
