Re: [PATCH v3 15/28] xen/domctl: wrap domain_kill() with CONFIG_MGMT_HYPERCALLS

[Jan Beulich <jbeulich@xxxxxxxx>]

On 12.11.2025 09:58, Penny, Zheng wrote:
> [Public]
> 
>> -----Original Message-----
>> From: Jan Beulich <jbeulich@xxxxxxxx>
>> Sent: Thursday, October 30, 2025 8:44 PM
>> To: Penny, Zheng <penny.zheng@xxxxxxx>
>> Cc: Huang, Ray <Ray.Huang@xxxxxxx>; oleksii.kurochko@xxxxxxxxx; Stefano
>> Stabellini <sstabellini@xxxxxxxxxx>; Julien Grall <julien@xxxxxxx>; Bertrand
>> Marquis <bertrand.marquis@xxxxxxx>; Orzel, Michal <Michal.Orzel@xxxxxxx>;
>> Volodymyr Babchuk <Volodymyr_Babchuk@xxxxxxxx>; Andrew Cooper
>> <andrew.cooper3@xxxxxxxxxx>; Anthony PERARD <anthony.perard@xxxxxxxxxx>;
>> Roger Pau Monné <roger.pau@xxxxxxxxxx>; Shawn Anastasio
>> <sanastasio@xxxxxxxxxxxxxxxxxxxxx>; Alistair Francis 
>> <alistair.francis@xxxxxxx>;
>> Bob Eshleman <bobbyeshleman@xxxxxxxxx>; Connor Davis
>> <connojdavis@xxxxxxxxx>; Tamas K Lengyel <tamas@xxxxxxxxxxxxx>; xen-
>> devel@xxxxxxxxxxxxxxxxxxxx
>> Subject: Re: [PATCH v3 15/28] xen/domctl: wrap domain_kill() with
>> CONFIG_MGMT_HYPERCALLS
>>
>> On 13.10.2025 12:15, Penny Zheng wrote:
>>> --- a/xen/arch/x86/mm/mem_sharing.c
>>> +++ b/xen/arch/x86/mm/mem_sharing.c
>>> @@ -1396,6 +1396,7 @@ int __mem_sharing_unshare_page(struct domain *d,
>>>      return rc;
>>>  }
>>>
>>> +#ifdef CONFIG_MGMT_HYPERCALLS
>>>  int relinquish_shared_pages(struct domain *d)  {
>>>      int rc = 0;
>>> @@ -1452,6 +1453,7 @@ int relinquish_shared_pages(struct domain *d)
>>>      p2m_unlock(p2m);
>>>      return rc;
>>>  }
>>> +#endif /* CONFIG_MGMT_HYPERCALLS */
>>>
>>>  static int range_share(struct domain *d, struct domain *cd,
>>>                         struct mem_sharing_op_range *range)
>>
>> Is this necessary? Shouldn't MEM_SHARING as a whole become dependent upon
>> MGMT_HYPERCALLS, then also covering XENMEM_sharing_op? (The same will
>> already implicitly happen for MEM_PAGING, due to its VM_EVENT dependency.)
>>
> 
> Yes, Since I didn't see VM_EVENT dependency for MEM_SHARING. I'm not 100% 
> sure that whether memory sharing feature is dependent on VM_EVENT. Also as I 
> roughly look through the codes in mm/mem_sharing.c, maybe only 
> mem_sharing_notify_enomem() utilizes vm event subsystem.

Right, a little while ago (iirc in the context of your work) Tamas said the 
same.
But I didn't ask about VM_EVENT; I asked about MGMT_HYPERCALLS.

Jan