[PATCH 2/2] x86, kvm: Add MSR_AMD64_BU_CFG2 to the list of ignored MSRs

[Borislav Petkov]

From: Borislav Petkov <bp@xxxxxxx>

The "x86, AMD: Enable WC+ memory type on family 10 processors" patch
currently in -tip added a workaround for AMD F10h CPUs which #GPs my
guest when booted in kvm. This is because it accesses MSR_AMD64_BU_CFG2
which is not currently ignored by kvm. Do that because this MSR is only
baremetal-relevant anyway. While at it, move the ignored MSRs at the
beginning of kvm_set_msr_common so that we exit then and there.

Acked-by: Gleb Natapov <gleb@xxxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: Andre Przywara <andre@xxxxxxxxx>
Cc: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
---
 arch/x86/kvm/x86.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c243b81e3c74..37040079cd6b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1881,6 +1881,14 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 	u64 data = msr_info->data;
 
 	switch (msr) {
+	case MSR_AMD64_NB_CFG:
+	case MSR_IA32_UCODE_REV:
+	case MSR_IA32_UCODE_WRITE:
+	case MSR_VM_HSAVE_PA:
+	case MSR_AMD64_PATCH_LOADER:
+	case MSR_AMD64_BU_CFG2:
+		break;
+
 	case MSR_EFER:
 		return set_efer(vcpu, data);
 	case MSR_K7_HWCR:
@@ -1900,8 +1908,6 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 			return 1;
 		}
 		break;
-	case MSR_AMD64_NB_CFG:
-		break;
 	case MSR_IA32_DEBUGCTLMSR:
 		if (!data) {
 			/* We support the non-activated case already */
@@ -1914,11 +1920,6 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 		vcpu_unimpl(vcpu, "%s: MSR_IA32_DEBUGCTLMSR 0x%llx, nop\n",
 			    __func__, data);
 		break;
-	case MSR_IA32_UCODE_REV:
-	case MSR_IA32_UCODE_WRITE:
-	case MSR_VM_HSAVE_PA:
-	case MSR_AMD64_PATCH_LOADER:
-		break;
 	case 0x200 ... 0x2ff:
 		return set_msr_mtrr(vcpu, msr, data);
 	case MSR_IA32_APICBASE:
@@ -2253,6 +2254,7 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
 	case MSR_K8_INT_PENDING_MSG:
 	case MSR_AMD64_NB_CFG:
 	case MSR_FAM10H_MMIO_CONF_BASE:
+	case MSR_AMD64_BU_CFG2:
 		data = 0;
 		break;
 	case MSR_P6_PERFCTR0:
-- 
1.8.1.3.535.ga923c31

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