On 16/10/2017 14:16, Arnd Bergmann wrote: > On Mon, Oct 16, 2017 at 2:08 PM, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: >> On 16/10/2017 10:11, Arnd Bergmann wrote: >>> Thanks! >>> >>> Since you've looked at it overall, do you have an opinion on the question >>> how to fix the PV interface to deal with the pvclock_wall_clock overflow? >> >> It has to be done separately for each hypervisor. >> >> In KVM, for example, it is probably best to abandon >> pvclock_read_wallclock altogether, and instead use the recently >> introduced KVM_HC_CLOCK_PAIRING hypercall. drivers/ptp/ptp_kvm.c is >> already using it and it's y2106 safe. > > Right, makes sense. I see that this interface is currently implemented > only for 64-bit x86 in kvm_emulate_hypercall(). Could this be extended > to x86-32 and the non-x86 architectures as well? Yes, it could be implemented for x86-32 too. The whole pvclock concept however is specific to x86. Paolo
