KVM: x86: Control guest reads of MSR_PLATFORM_INFO

Add KVM_CAP_MSR_PLATFORM_INFO so that userspace can disable guest access
to reads of MSR_PLATFORM_INFO.

Disabling access to reads of this MSR gives userspace the control to "expose"
this platform-dependent information to guests in a clear way. As it exists
today, guests that read this MSR would get unpopulated information if userspace
hadn't already set it (and prior to this patch series, only the CPUID faulting
information could have been populated). This existing interface could be
confusing if guests don't handle the potential for incorrect/incomplete
information gracefully (e.g. zero reported for base frequency).

Signed-off-by: Drew Schmitt <dasch@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Drew Schmitt 2018-08-20 10:32:15 -07:00 committed by Paolo Bonzini
parent d84f1cff90
commit 6fbbde9a19
4 changed files with 22 additions and 0 deletions

View file

@ -952,6 +952,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_S390_HPAGE_1M 156
#define KVM_CAP_NESTED_STATE 157
#define KVM_CAP_ARM_INJECT_SERROR_ESR 158
#define KVM_CAP_MSR_PLATFORM_INFO 159
#ifdef KVM_CAP_IRQ_ROUTING