On Fri, Feb 25, 2022, David Woodhouse wrote: > On Fri, 2022-02-25 at 13:10 +0100, Paolo Bonzini wrote: > > > > Queued, but I'd rather have a subject that calls out that max_tsc_khz > > needs a replacement at vCPU creation time. In fact, the real change > > (and bug, and fix) is in kvm_arch_vcpu_create(), while the subject > > mentions only the change in kvm_timer_init(). > > In > https://lore.kernel.org/kvm/e7be32b06676c7ebf415d9deea5faf50aa8c0785.camel@xxxxxxxxxxxxx/T/ > last night I was coming round to the idea that we might want a KVM-wide > default frequency which is settable from userspace and is used instead > of max_tsc_khz anyway. > > I also have questions about the use case for the above patch.... if > this is a clean boot and you're just starting to host guests, surely we > can wait for the time it takes for the TSC synchronization to complete? KVM is built into the kernel in their case, the vmx_init() => kvm_init() gets automatically called during boot. The VMs aren't started until well after synchronization has completed, but KVM has already snapshotted the "bad" value.
