linux-kernel - [PATCH 4.14 24/36] kvm: x86: Add AMDs EX

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Date:   Fri, 28 Dec 2018 12:52:40 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Eduardo Habkost <ehabkost@...hat.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Subject: [PATCH 4.14 24/36] kvm: x86: Add AMDs EX_CFG to the list of ignored MSRs

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

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

From: Eduardo Habkost <ehabkost@...hat.com>

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@...r.kernel.org
Signed-off-by: Eduardo Habkost <ehabkost@...hat.com>
Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 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: