[PATCH v7 1/6] KVM: x86: Fix potential race in KVM_GET_CLOCK

[Marcelo Tosatti]

On Mon, Aug 16, 2021 at 12:11:25AM +0000, Oliver Upton wrote:
> Sean noticed that KVM_GET_CLOCK was checking kvm_arch.use_master_clock
> outside of the pvclock sync lock. This is problematic, as the clock
> value written to the user may or may not actually correspond to a stable
> TSC.
> 
> Fix the race by populating the entire kvm_clock_data structure behind
> the pvclock_gtod_sync_lock.

Oliver, 

Can you please describe the race in more detail?

Is it about host TSC going unstable VS parallel KVM_GET_CLOCK ?