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 <[email protected]>
Signed-off-by: Mingwei Zhang <[email protected]>
---
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
On Thu, May 4, 2023 at 11:18 AM Mingwei Zhang <[email protected]> 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")
> Reported-by: Jim Mattson <[email protected]>
> Signed-off-by: Mingwei Zhang <[email protected]>
Reviewed-by: Jim Mattson <[email protected]>
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 <[email protected]>
> Reported-by: Jim Mattson <[email protected]>
> Signed-off-by: Mingwei Zhang <[email protected]>
> ---
> 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;
> }
On Sun, May 7, 2023 at 6:54 PM Xiaoyao Li <[email protected]> wrote:
>
> 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 <[email protected]>
I concur.
How about:
Fixes: ea732b38b341 ("KVM: vmx: implement MSR_IA32_TSX_CTRL disable
RTM functionality")
Reviewed-by: Jim Mattson <[email protected]>
On Mon, May 8, 2023 at 10:28 AM Jim Mattson <[email protected]> wrote:
>
> On Sun, May 7, 2023 at 6:54 PM Xiaoyao Li <[email protected]> wrote:
> >
> > 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 <[email protected]>
>
> I concur.
>
> How about:
>
> Fixes: ea732b38b341 ("KVM: vmx: implement MSR_IA32_TSX_CTRL disable
> RTM functionality")
>
> Reviewed-by: Jim Mattson <[email protected]>
Will send a v3 with the update of the "Fixes"