On 12/01/2021 04:17, Igor Druzhinin wrote: > TLFS 7.8.1 stipulates that "a virtual processor index must be less than > the maximum number of virtual processors per partition" that "can be obtained > through CPUID leaf 0x40000005". Furthermore, "Requirements for Implementing > the Microsoft Hypervisor Interface" defines that starting from Windows Server > 2012, which allowed more than 64 CPUs to be brought up, this leaf can now > contain a value -1 basically assuming the hypervisor has no restriction while > 0 (that we currently expose) means the default restriction is still present. > > Along with the previous changes exposing ExProcessorMasks this allows a recent > Windows VM with Viridian extension enabled to have more than 64 vCPUs without > going into BSOD in some cases. > > Since we didn't expose the leaf before and to keep CPUID data consistent for > incoming streams from previous Xen versions - let's keep it behind an option. > > Signed-off-by: Igor Druzhinin <igor.druzhi...@citrix.com> > ---
ping? Paul? Igor
