Re: [PATCH] xen/x86: move domctl.o out of PV_SHIM_EXCLUSIVE

[Jan Beulich <jbeulich@xxxxxxxx>]

On 20.08.2025 05:12, Penny, Zheng wrote:
> [Public]
> 
>> -----Original Message-----
>> From: Jan Beulich <jbeulich@xxxxxxxx>
>> Sent: Monday, August 18, 2025 4:31 PM
>> To: Penny, Zheng <penny.zheng@xxxxxxx>; Oleksii Kurochko
>> <oleksii.kurochko@xxxxxxxxx>
>> Cc: Huang, Ray <Ray.Huang@xxxxxxx>; Andrew Cooper
>> <andrew.cooper3@xxxxxxxxxx>; Roger Pau Monné <roger.pau@xxxxxxxxxx>;
>> Anthony PERARD <anthony.perard@xxxxxxxxxx>; Orzel, Michal
>> <Michal.Orzel@xxxxxxx>; Julien Grall <julien@xxxxxxx>; Stefano Stabellini
>> <sstabellini@xxxxxxxxxx>; xen-devel@xxxxxxxxxxxxxxxxxxxx
>> Subject: Re: [PATCH] xen/x86: move domctl.o out of PV_SHIM_EXCLUSIVE
>>
>> On 15.08.2025 12:27, Penny Zheng wrote:
>>> In order to fix CI error of a randconfig picking both
>>> PV_SHIM_EXCLUSIVE=y and HVM=y results in hvm.c being built, but
>>> domctl.c not being built, which leaves a few functions, like
>>> domctl_lock_acquire/release() undefined, causing linking to fail.
>>> To fix that, we intend to move domctl.o out of the PV_SHIM_EXCLUSIVE
>>> Makefile /hypercall-defs section, with this adjustment, we also need
>>> to release redundant vnuma_destroy() stub definition from
>>> PV_SHIM_EXCLUSIVE guardian, to not break compilation Above change will
>>> leave dead code in the shim binary temporarily and will be fixed with
>>> the introduction of domctl-op wrapping.
>>
>> Well, "temporarily" is now getting interesting. While v1 of "Introduce
>> CONFIG_DOMCTL" was submitted in time to still be eligible for taking into 
>> 4.21,
>> that - as indicated elsewhere - is moving us further in an unwanted 
>> direction. Hence
>> I'm not sure this can even be counted as an in-time submission. Plus it 
>> looks to be
>> pretty extensive re-work in some areas.
>> Hence I'm somewhat weary as to 4.21 here. IOW question, mainly to Oleksii, is
>> whether to
>> 1) strive to complete that work in time (and hence take the patch here),
>> 2) take the patch here, accepting the size regression for the shim, or
>> 3) revert what has caused the randconfig issues, and retry the effort in
>>    4.22.
>>
>>> Fixes: 568f806cba4c ("xen/x86: remove "depends on
>>> !PV_SHIM_EXCLUSIVE"")
>>> Reported-by: Jan Beulich <jbeulich@xxxxxxxx>
>>> Signed-off-by: Penny Zheng <Penny.Zheng@xxxxxxx>
>>
>> My earlier question (when the patch still was part of a series) sadly has 
>> remained
>> unanswered: You've run this through a full round of testing this time?
> 
> Sorry, missed that, yes, it has been tested with both default defconfig and 
> allyesconfig.

I'm sorry if my request was unclear, but with "full round of testing" I in 
particular
meant a full CI pipeline, plus (given the issue that's being fixed) some extra
randconfig testing.

Jan