On Fri, 2026-05-15 at 12:19 -0700, Sean Christopherson wrote:
> When resuming timekeeping after suspend, restore clocksources prior to
> reading the persistent clock.  Paravirt clocks, e.g. kvmclock, tie the
> validity of a PV persistent clock to a clocksource, i.e. reading the PV
> persistent clock will return garbage if the underlying PV clocksource
> hasn't been enabled.  The flaw has gone unnoticed because kvmclock is a
> mess and uses its own suspend/resume hooks instead of the clocksource
> suspend/resume hooks, which happens to work by sheer dumb luck (the
> kvmclock resume hook runs before timekeeping_resume()).
> 
> Note, there is no evidence that any clocksource supported by the kernel
> depends on a persistent clock.
> 
> Reviewed-by: Thomas Gleixner <[email protected]>
> Signed-off-by: Sean Christopherson <[email protected]>

Reviewed-by: David Woodhouse <[email protected]>

Attachment: smime.p7s
Description: S/MIME cryptographic signature

Reply via email to