Re: [PATCH v6 00/51] x86: Try to wrangle PV clocks vs. TSC

On Thu, Aug 06, 2026, Sean Christopherson wrote:

The primary goal of this series to fix flaws with SNP and TDX guests where a
PV clock provided by the untrusted hypervisor is used instead of the secure
TSC that is controlled by trusted firmware.

The secondary goal is modernize running under KVM.  Currently, KVM guests will
use TSC for clocksource, but not sched_clock.  And Linux-as-a-KVM-guest doesn't
support paravirt enumeration of the TSC/APIC frequencies, even though QEMU
provides that information by default.

The tertiary goal is to clean up the PV clock code to deduplicate logic across
hypervisors, and to hopefully make it all easier to maintain going forward.

The quaternary goal is to clean up the TSC calibration code, which was made
stupidly hard to follow by hypervisor code mixing in with the native
calibration routines, instead of being implemented as a pure alternative.

Note, the VMware and Xen changes still probably should get acks from those
maintainers, as my understanding of what they're trying to do may be flawed.

This (thankfully) still applies cleanly.  What can I do to help move this forward?