[PATCH 4.14 24/36] kvm: x86: Add AMDs EX_CFG to the list of ignored MSRs

From: Greg Kroah-Hartman
Date: Fri Dec 28 2018 - 07:20:54 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Eduardo Habkost <ehabkost@xxxxxxxxxx>

commit 0e1b869fff60c81b510c2d00602d778f8f59dd9a upstream.

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@xxxxxxxxxxxxxxx
Signed-off-by: Eduardo Habkost <ehabkost@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
arch/x86/include/asm/msr-index.h | 1 +
arch/x86/kvm/x86.c | 2 ++
2 files changed, 3 insertions(+)

--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -372,6 +372,7 @@
#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
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2227,6 +2227,7 @@ int kvm_set_msr_common(struct kvm_vcpu *
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:
@@ -2508,6 +2509,7 @@ int kvm_get_msr_common(struct kvm_vcpu *
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_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3: