KVM: ignore AMDs HWCR register access to set the FFDIS bit (8f1589d9) · Commits · 戴 / test

Linux tries to disable the flush filter on all AMD K8 CPUs. Since KVM does not handle the needed MSR, the injected #GP will panic the Linux kernel. Ignore setting of the HWCR.FFDIS bit in this MSR to let Linux boot with an AMD K8 family guest CPU. Signed-off-by:

Andre Przywara <andre.przywara@amd.com> Signed-off-by:

Avi Kivity <avi@redhat.com>

arch/x86/kvm/svm.c

+0 −1

Original line number	Diff line number	Diff line
		@@ -2137,7 +2137,6 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 data)
		break;
		case MSR_VM_CR:
		case MSR_VM_IGNNE:
		case MSR_K7_HWCR:
		pr_unimpl(vcpu, "unimplemented wrmsr: 0x%x data 0x%llx\n", ecx, data);
		break;
		default:

arch/x86/kvm/x86.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -833,6 +833,14 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 data)
		case MSR_EFER:
		set_efer(vcpu, data);
		break;
		case MSR_K7_HWCR:
		data &= ~(u64)0x40; /* ignore flush filter disable */
		if (data != 0) {
		pr_unimpl(vcpu, "unimplemented HWCR wrmsr: 0x%llx\n",
		data);
		return 1;
		}
		break;
		case MSR_IA32_DEBUGCTLMSR:
		if (!data) {
		/* We support the non-activated case already */

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