Bits 11:2 must be zero and the linear addess in bits 63:12 must be
canonical. Otherwise, WRMSR(BNDCFGS) should raise #GP.
Fixes: 0dd376e709975779 ("KVM: x86: add MSR_IA32_BNDCFGS to msrs_to_save")
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
---
arch/x86/include/asm/msr-index.h | 2 ++
arch/x86/kvm/vmx.c | 3 +++
2 files changed, 5 insertions(+)
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 673f9ac50f6d..dbf266b0d14a 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -420,6 +420,8 @@
#define MSR_IA32_TSC_ADJUST 0x0000003b
#define MSR_IA32_BNDCFGS 0x00000d90
+#define MSR_IA32_BNDCFGS_RSVD 0x00000ffc
+
#define MSR_IA32_XSS 0x00000da0
#define FEATURE_CONTROL_LOCKED (1<<0)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 846c60c74258..04d428cd1d9d 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3279,6 +3279,9 @@ static int vmx_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
case MSR_IA32_BNDCFGS:
if (!guest_cpuid_has_mpx(vcpu))
return 1;
+ if (is_noncanonical_address(data & PAGE_MASK) ||
+ (data & MSR_IA32_BNDCFGS_RSVD))
+ return 1;
vmcs_write64(GUEST_BNDCFGS, data);
break;
case MSR_IA32_TSC:
--
2.13.0.219.gdb65acc882-goog
