Re: [RFC XEN PATCH v8 5/5] domctl: Add XEN_DOMCTL_gsi_permission to grant gsi

[Jan Beulich <jbeulich@xxxxxxxx>]

On 04.06.2024 08:01, Chen, Jiqian wrote:
> On 2024/6/4 13:55, Jan Beulich wrote:
>> On 04.06.2024 05:04, Chen, Jiqian wrote:
>>> On 2024/5/30 23:51, Jan Beulich wrote:
>>>> On 30.05.2024 13:19, Chen, Jiqian wrote:
>>>>> I dump all mpc_config_intsrc of array mp_irqs, it shows:
>>>>> (XEN) find_irq_entry type 3 irqtype 0 irqflag 0 srcbus 0 srcbusirq 0 
>>>>> dstapic 33 dstirq 2
>>>>> (XEN) find_irq_entry type 3 irqtype 0 irqflag 15 srcbus 0 srcbusirq 9 
>>>>> dstapic 33 dstirq 9
>>>>> (XEN) find_irq_entry type 3 irqtype 0 irqflag 0 srcbus 0 srcbusirq 1 
>>>>> dstapic 33 dstirq 1
>>>>> (XEN) find_irq_entry type 3 irqtype 0 irqflag 0 srcbus 0 srcbusirq 3 
>>>>> dstapic 33 dstirq 3
>>>>> (XEN) find_irq_entry type 3 irqtype 0 irqflag 0 srcbus 0 srcbusirq 4 
>>>>> dstapic 33 dstirq 4
>>>>> (XEN) find_irq_entry type 3 irqtype 0 irqflag 0 srcbus 0 srcbusirq 5 
>>>>> dstapic 33 dstirq 5
>>>>> (XEN) find_irq_entry type 3 irqtype 0 irqflag 0 srcbus 0 srcbusirq 6 
>>>>> dstapic 33 dstirq 6
>>>>> (XEN) find_irq_entry type 3 irqtype 0 irqflag 0 srcbus 0 srcbusirq 7 
>>>>> dstapic 33 dstirq 7
>>>>> (XEN) find_irq_entry type 3 irqtype 0 irqflag 0 srcbus 0 srcbusirq 8 
>>>>> dstapic 33 dstirq 8
>>>>> (XEN) find_irq_entry type 3 irqtype 0 irqflag 0 srcbus 0 srcbusirq 10 
>>>>> dstapic 33 dstirq 10
>>>>> (XEN) find_irq_entry type 3 irqtype 0 irqflag 0 srcbus 0 srcbusirq 11 
>>>>> dstapic 33 dstirq 11
>>>>> (XEN) find_irq_entry type 3 irqtype 0 irqflag 0 srcbus 0 srcbusirq 12 
>>>>> dstapic 33 dstirq 12
>>>>> (XEN) find_irq_entry type 3 irqtype 0 irqflag 0 srcbus 0 srcbusirq 13 
>>>>> dstapic 33 dstirq 13
>>>>> (XEN) find_irq_entry type 3 irqtype 0 irqflag 0 srcbus 0 srcbusirq 14 
>>>>> dstapic 33 dstirq 14
>>>>> (XEN) find_irq_entry type 3 irqtype 0 irqflag 0 srcbus 0 srcbusirq 15 
>>>>> dstapic 33 dstirq 15
>>>>>
>>>>> It seems only Legacy irq and gsi[0:15] has a mapping in mp_irqs.
>>>>> Other gsi can be considered 1:1 mapping with irq? Or are there other 
>>>>> places reflect the mapping between irq and gsi?
>>>>
>>>> It may be uncommon to have overrides for higher GSIs, but I don't think 
>>>> ACPI
>>>> disallows that.
>>> Do you suggest me to add overrides for higher GSIs into array mp_irqs?
>>
>> Why "add"? That's what mp_override_legacy_irq() already does, isn't it?
> No. mp_override_legacy_irq only overrides for gsi < 16, but not for gsi >= 
> 16(I dump all mappings from array mp_irqs).

I assume you mean you observe so ...

> In my environment, gsi of my dGPU is 24.

... on one specific system? The function is invoked from
acpi_parse_int_src_ovr(), and I can't spot any restriction to
IRQs less than 16 there.

Jan