Re: [PATCH v6 05/36] KVM: x86: Add KVM_[GS]ET_CLOCK_GUEST for accurate KVM clock migration
Sean Christopherson <[email protected]>
| Newsgroups | gmane.linux.documentation,gmane.comp.emulators.kvm.devel,gmane.linux.kernel,gmane.comp.emulators.xen.devel |
|---|---|
| Message-ID | <[email protected]> |
On Sat, Jul 25, 2026, David Woodhouse wrote: > On Fri, 2026-07-24 at 14:17 -0700, Sean Christopherson wrote: > > On Fri, Jul 03, 2026, David Woodhouse wrote: > > > +4.145 KVM_GET_CLOCK_GUEST > > > +---------------------------- > > > + > > > +:Capability: none > > > > Why not add a CAP? The check in the subsequent selftest is quite gross. > > Because nobody would ever use it in practice anyway. Yes, the selftest will. > Even if the ioctl is present, you *still* have to try it and fall back to the > old method because there are ways that a *guest* can force master clock mode > off. That's totally fine, but userspace, especially for selftests, needs a way to know the ioctl exists and _should_ work.