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 guest. So add the checking in kvm_probe_msr_to_save(). Fixes: b07a5c53d42a ("KVM: vmx: use MSR_IA32_TSX_CTRL to hard-disable TSX on guest that lack it") Reported-by: Jim Mattson <jmattson@xxxxxxxxxx> Signed-off-by: Mingwei Zhang <mizhang@xxxxxxxxxx> --- arch/x86/kvm/x86.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 237c483b1230..c8accbd6c861 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1431,7 +1431,7 @@ 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, @@ -7077,6 +7077,10 @@ 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; } -- 2.40.1.521.gf1e218fcd8-goog