On 5/5/2023 2:18 AM, Mingwei Zhang wrote:
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")
I wonder it's the fix for this commit.
Apart from this,
Reviewed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
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;
}
