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Commit efa67e0d authored by Chris Lalancette's avatar Chris Lalancette Committed by Avi Kivity
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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: default avatarChris Lalancette <clalance@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent 65267ea1

arch/x86/kvm/vmx.c

+12 −0
Original line number Diff line number Diff line
@@ -920,6 +920,18 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, u32 msr_index, u64 data) 
		break;

	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);