Re: [PATCH v6 9/9] OvmfPkg/SmmControl2Dxe: negotiate CPU hot-unplug

["Laszlo Ersek" <lersek@redhat.com>]

On 02/01/21 18:40, Laszlo Ersek wrote:
> On 02/01/21 18:37, Laszlo Ersek wrote:
>> On 01/29/21 01:59, Ankur Arora wrote:
>>> As part of the negotiation treat ICH9_LPC_SMI_F_CPU_HOT_UNPLUG as a
>>> subfeature of feature flag ICH9_LPC_SMI_F_CPU_HOTPLUG, so enable it
>>> only if the other is also being negotiated.
>>>
>>> Cc: Laszlo Ersek <lersek@redhat.com>
>>> Cc: Jordan Justen <jordan.l.justen@intel.com>
>>> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
>>> Cc: Igor Mammedov <imammedo@redhat.com>
>>> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
>>> Cc: Aaron Young <aaron.young@oracle.com>
>>> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3132
>>> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
>>> ---
>>>  OvmfPkg/SmmControl2Dxe/SmiFeatures.c | 25 ++++++++++++++++++++++---
>>>  1 file changed, 22 insertions(+), 3 deletions(-)

[...]

>>> @@ -120,8 +128,18 @@ NegotiateSmiFeatures (
>>>      // For now, we only support hotplug with SEV disabled.
>>>      //
>>>      RequestedFeaturesMask |= ICH9_LPC_SMI_F_CPU_HOTPLUG;
>>> +    RequestedFeaturesMask |= ICH9_LPC_SMI_F_CPU_HOT_UNPLUG;
>>>    }
>>>    mSmiFeatures &= RequestedFeaturesMask;
>>> +
>>> +  if (!(mSmiFeatures & ICH9_LPC_SMI_F_CPU_HOTPLUG) &&
>>> +      (mSmiFeatures & ICH9_LPC_SMI_F_CPU_HOT_UNPLUG)) {
>>> +    DEBUG ((DEBUG_WARN, "%a CPU host-features %Lx, requested mask %Lx\n",
>>> +      __FUNCTION__, mSmiFeatures, RequestedFeaturesMask));
>>> +
>>> +    mSmiFeatures &= ~ICH9_LPC_SMI_F_CPU_HOT_UNPLUG;
>>> +  }
>>> +
>>>    QemuFwCfgSelectItem (mRequestedFeaturesItem);
>>>    QemuFwCfgWriteBytes (sizeof mSmiFeatures, &mSmiFeatures);
>>>  
>>
>> (6) Please drop this hunk. We don't try to be smarter than QEMU, in
>> general, whenever we perform feature negotiation.

(8) ... Please refresh the commit message accordingly.

> ... obviously: don't drop the part where you set the new bit! :) Sorry,
> "hunk" was not the correct term.

Thanks!
Laszlo