KVM: VMX: Fake emulate Intel perfctr MSRs
Older linux guests (in this case, 2.6.9) can attempt to
access the performance counter MSRs without a fixup section, and injecting
a GPF kills the guest. Work around by allowing the guest to write those MSRs.
Tested by me on RHEL-4 i386 and x86_64 guests, as well as F-9 guests.
Signed-off-by: Chris Lalancette <clalance@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 6a3a403..d493a97 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -921,6 +921,18 @@
case MSR_IA32_TIME_STAMP_COUNTER:
guest_write_tsc(data);
break;
+ case MSR_P6_PERFCTR0:
+ case MSR_P6_PERFCTR1:
+ case MSR_P6_EVNTSEL0:
+ case MSR_P6_EVNTSEL1:
+ /*
+ * Just discard all writes to the performance counters; this
+ * should keep both older linux and windows 64-bit guests
+ * happy
+ */
+ pr_unimpl(vcpu, "unimplemented perfctr wrmsr: 0x%x data 0x%llx\n", msr_index, data);
+
+ break;
default:
vmx_load_host_state(vmx);
msr = find_msr_entry(vmx, msr_index);