KVM: x86: trap AMD MSRs for the TSeg base and mask

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@durham.ac.uk>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@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@canonical.com>

diff --git a/arch/x86/include/uapi/asm/msr-index.h b/arch/x86/include/uapi/asm/msr-index.h
index fcf2b3ae1bf0208d9e6b153dc81c6b0ed60f8352..7db049a7f7abb4dad661b5f0011c438dd790526d 100644 (file)
--- 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 27a8d4f9bce5aa768c44931a9bd84642c40e8529..4977c1a93d52d8a07704e61d4c411f5bf5ce6c1c 100644 (file)
--- 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: