[PATCH 3.16.y-ckt 035/104] KVM: x86: trap AMD MSRs for the TSeg base and mask

[Luis Henriques]

3.16.7-ckt19 -stable review patch.  If anyone has any objections, please let me know.

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

From: Paolo Bonzini <pbonzini at redhat.com>

commit 3afb1121800128aae9f5722e50097fcf1a9d4d88 upstream.

These have roughly the same purpose as the SMRR, which we do not need
to implement in KVM.  However, Linux accesses MSR_K8_TSEG_ADDR at
boot, which causes problems when running a Xen dom0 under KVM.
Just return 0, meaning that processor protection of SMRAM is not
in effect.

Reported-by: M A Young <m.a.young at durham.ac.uk>
Acked-by: Borislav Petkov <bp at suse.de>
Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
[ luis: backported to 3.16:
  - file rename: arch/x86/include/asm/msr-index.h ->
    arch/x86/include/uapi/asm/msr-index.h
  - adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/x86/include/uapi/asm/msr-index.h | 1 +
 arch/x86/kvm/x86.c                    | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/arch/x86/include/uapi/asm/msr-index.h b/arch/x86/include/uapi/asm/msr-index.h
index fcf2b3ae1bf0..7db049a7f7ab 100644
--- a/arch/x86/include/uapi/asm/msr-index.h
+++ b/arch/x86/include/uapi/asm/msr-index.h
@@ -232,6 +232,7 @@
 /* C1E active bits in int pending message */
 #define K8_INTP_C1E_ACTIVE_MASK		0x18000000
 #define MSR_K8_TSEG_ADDR		0xc0010112
+#define MSR_K8_TSEG_MASK		0xc0010113
 #define K8_MTRRFIXRANGE_DRAM_ENABLE	0x00040000 /* MtrrFixDramEn bit    */
 #define K8_MTRRFIXRANGE_DRAM_MODIFY	0x00080000 /* MtrrFixDramModEn bit */
 #define K8_MTRR_RDMEM_WRMEM_MASK	0x18181818 /* Mask: RdMem|WrMem    */
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 27a8d4f9bce5..4977c1a93d52 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2425,6 +2425,8 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
 	case MSR_IA32_LASTINTFROMIP:
 	case MSR_IA32_LASTINTTOIP:
 	case MSR_K8_SYSCFG:
+	case MSR_K8_TSEG_ADDR:
+	case MSR_K8_TSEG_MASK:
 	case MSR_K7_HWCR:
 	case MSR_VM_HSAVE_PA:
 	case MSR_K7_EVNTSEL0: