KVM: VMX: add MSR_IA32_TSX_CTRL into msrs_to_save

Add MSR_IA32_TSX_CTRL into msrs_to_save[] to explicitly tell userspace to
save/restore the register value during migration. Missing this may cause
userspace that relies on KVM ioctl(KVM_GET_MSR_INDEX_LIST) fail to port the
value to the target VM.

In addition, there is no need to add MSR_IA32_TSX_CTRL when
ARCH_CAP_TSX_CTRL_MSR is not supported in kvm_get_arch_capabilities(). So
add the checking in kvm_probe_msr_to_save().

Fixes: c11f83e0626b ("KVM: vmx: implement MSR_IA32_TSX_CTRL disable RTM functionality")
Reported-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <20230509032348.1153070-1-mizhang@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ceb7c5e9cf9e9235a63cee5f909ba2a0ae41d5b3..c0778ca39650f42863d7e0d21464d1717b939314 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1446,7 +1446,7 @@ static const u32 msrs_to_save_base[] = {
 #endif
        MSR_IA32_TSC, MSR_IA32_CR_PAT, MSR_VM_HSAVE_PA,
        MSR_IA32_FEAT_CTL, MSR_IA32_BNDCFGS, MSR_TSC_AUX,
-       MSR_IA32_SPEC_CTRL,
+       MSR_IA32_SPEC_CTRL, MSR_IA32_TSX_CTRL,
        MSR_IA32_RTIT_CTL, MSR_IA32_RTIT_STATUS, MSR_IA32_RTIT_CR3_MATCH,
        MSR_IA32_RTIT_OUTPUT_BASE, MSR_IA32_RTIT_OUTPUT_MASK,
        MSR_IA32_RTIT_ADDR0_A, MSR_IA32_RTIT_ADDR0_B,
@@ -7155,6 +7155,10 @@ static void kvm_probe_msr_to_save(u32 msr_index)
                if (!kvm_cpu_cap_has(X86_FEATURE_XFD))
                        return;
                break;
+       case MSR_IA32_TSX_CTRL:
+               if (!(kvm_get_arch_capabilities() & ARCH_CAP_TSX_CTRL_MSR))
+                       return;
+               break;
        default:
                break;
        }