On 26.01.2022 09:44, Andrew Cooper wrote: > This bug existed in early in 2018 between MSR_SPEC_CTRL arriving in microcode, > and SSBD arriving a few months later. It went unnoticed presumably because > everyone was busy rebooting everything. > > The same bug will reappear when adding PSFD support. > > Clamp the guest MSR_SPEC_CTRL value to that permitted by CPUID on migrate. > The guest is already playing with reserved bits at this point, and clamping > the value will prevent a migration to a less capable host from failing. > > Signed-off-by: Andrew Cooper <[email protected]>
Reviewed-by: Jan Beulich <[email protected]>
