Re: [Xen-devel] [PATCH 05/10] x86/cpuid: Handle leaf 0x5 in guest_cpuid()

2017-02-21 Thread Jan Beulich
>>> On 20.02.17 at 12:00, wrote: > The MONITOR flag isn't exposed to guests. The existing toolstack logic, and > pv_cpuid() in the hypervisor, zero the MONITOR leaf for queries. > > However, the MONITOR leaf is still visible in the hardware domains native > CPUID view, and Linux depends on this

[Xen-devel] [PATCH 05/10] x86/cpuid: Handle leaf 0x5 in guest_cpuid()

2017-02-20 Thread Andrew Cooper
The MONITOR flag isn't exposed to guests. The existing toolstack logic, and pv_cpuid() in the hypervisor, zero the MONITOR leaf for queries. However, the MONITOR leaf is still visible in the hardware domains native CPUID view, and Linux depends on this to set up C-state information. Leak the hos