On 12.10.2021 09:24, Dongli Zhang wrote: > The guest may access the pv vcpu_time_info immediately after > VCPUOP_register_vcpu_info. This is to borrow the idea of > VCPUOP_register_vcpu_time_memory_area, where the > force_update_vcpu_system_time() is called immediately when the new memory > area is registered. > > Otherwise, we may observe clock drift at the VM side if the VM accesses > the clocksource immediately after VCPUOP_register_vcpu_info(). > > Cc: Joe Jin <[email protected]> > Signed-off-by: Dongli Zhang <[email protected]>
While I agree with the change in principle, ... > --- a/xen/common/domain.c > +++ b/xen/common/domain.c > @@ -1695,6 +1695,8 @@ long do_vcpu_op(int cmd, unsigned int vcpuid, > XEN_GUEST_HANDLE_PARAM(void) arg) > rc = map_vcpu_info(v, info.mfn, info.offset); > domain_unlock(d); > > + force_update_vcpu_system_time(v); ... I'm afraid you're breaking the Arm build here. Arm will first need to gain this function. Jan
