KVM: x86: Emulate MSR_EBC_FREQUENCY_ID (7b914098) · Commits · 戴 / test

Some operating systems store data about the host processor at the time of installation, and when booted on a more uptodate cpu tries to read MSR_EBC_FREQUENCY_ID. This has been found with XP. Signed-off-by:

Jes Sorensen <Jes.Sorensen@redhat.com> Reviewed-by:

Juan Quintela <quintela@redhat.com> Signed-off-by:

Marcelo Tosatti <mtosatti@redhat.com>

arch/x86/kvm/x86.c

+14 −0

Original line number	Diff line number	Diff line
		@@ -1651,6 +1651,20 @@ int kvm_get_msr_common(struct kvm_vcpu vcpu, u32 msr, u64 pdata)
		case 0xcd: /* fsb frequency */
		data = 3;
		break;
		/*
		* MSR_EBC_FREQUENCY_ID
		* Conservative value valid for even the basic CPU models.
		* Models 0,1: 000 in bits 23:21 indicating a bus speed of
		* 100MHz, model 2 000 in bits 18:16 indicating 100MHz,
		* and 266MHz for model 3, or 4. Set Core Clock
		* Frequency to System Bus Frequency Ratio to 1 (bits
		* 31:24) even though these are only valid for CPU
		* models > 2, however guests may end up dividing or
		* multiplying by zero otherwise.
		*/
		case MSR_EBC_FREQUENCY_ID:
		data = 1 << 24;
		break;
		case MSR_IA32_APICBASE:
		data = kvm_get_apic_base(vcpu);
		break;

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