kvm: x86: Add AMD's EX_CFG to the list of ignored MSRs

Some guests OSes (including Windows 10) write to MSR 0xc001102c
on some cases (possibly while trying to apply a CPU errata).
Make KVM ignore reads and writes to that MSR, so the guest won't
crash.

The MSR is documented as "Execution Unit Configuration (EX_CFG)",
at AMD's "BIOS and Kernel Developer's Guide (BKDG) for AMD Family
15h Models 00h-0Fh Processors".

Cc: stable@vger.kernel.org
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index c8f73efb4eceb82391bf908f1f8f292586be5925..9e39cc8bd989855cc2ca8c349c335fe36d029b37 100644 (file)
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -390,6 +390,7 @@
 #define MSR_F15H_NB_PERF_CTR           0xc0010241
 #define MSR_F15H_PTSC                  0xc0010280
 #define MSR_F15H_IC_CFG                        0xc0011021
+#define MSR_F15H_EX_CFG                        0xc001102c
 
 /* Fam 10h MSRs */
 #define MSR_FAM10H_MMIO_CONF_BASE      0xc0010058

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 477563e7ccbdc87b6b2fc9313b1e9b3246ab87f6..f049ecfac7bb8a8cd7780efd9b40fbbdf8a7d089 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2426,6 +2426,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
        case MSR_AMD64_PATCH_LOADER:
        case MSR_AMD64_BU_CFG2:
        case MSR_AMD64_DC_CFG:
+       case MSR_F15H_EX_CFG:
                break;
 
        case MSR_IA32_UCODE_REV:
@@ -2721,6 +2722,7 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
        case MSR_AMD64_BU_CFG2:
        case MSR_IA32_PERF_CTL:
        case MSR_AMD64_DC_CFG:
+       case MSR_F15H_EX_CFG:
                msr_info->data = 0;
                break;
        case MSR_F15H_PERF_CTL0 ... MSR_F15H_PERF_CTR5: