On 05.06.2025 12:15, Oleksii Kurochko wrote:
>
> On 6/5/25 11:42 AM, Jan Beulich wrote:
>> On 05.06.2025 11:13, Oleksii Kurochko wrote:
>>> On 6/5/25 8:50 AM, Jan Beulich wrote:
>>>> On 04.06.2025 17:36, Oleksii Kurochko wrote:
>>>>> On 6/2/25 12:21 PM, Jan Beulich wrote:
>>>>>> On 26.05.2025 20:44, Oleksii Kurochko wrote:
>>>>>>> On 5/22/25 4:46 PM, Jan Beulich wrote:
>>>>>>>> On 21.05.2025 18:03, Oleksii Kurochko wrote:
>>>>>>>>> + /* Check MMIO register sets */
>>>>>>>>> + for ( unsigned int i = 0; i < nr_mmios; i++ )
>>>>>>>>> + {
>>>>>>>>> + if ( !alloc_cpumask_var(&imsic_cfg.mmios[i].cpus) )
>>>>>>>>> + {
>>>>>>>>> + rc = -ENOMEM;
>>>>>>>>> + goto imsic_init_err;
>>>>>>>>> + }
>>>>>>>>> +
>>>>>>>>> + rc = dt_device_get_address(node, i,
>>>>>>>>> &imsic_cfg.mmios[i].base_addr,
>>>>>>>>> + &imsic_cfg.mmios[i].size);
>>>>>>>>> + if ( rc )
>>>>>>>>> + {
>>>>>>>>> + printk(XENLOG_ERR "%s: unable to parse MMIO regset %u\n",
>>>>>>>>> + node->name, i);
>>>>>>>>> + goto imsic_init_err;
>>>>>>>>> + }
>>>>>>>>> +
>>>>>>>>> + base_addr = imsic_cfg.mmios[i].base_addr;
>>>>>>>>> + base_addr &= ~(BIT(imsic_cfg.guest_index_bits +
>>>>>>>>> + imsic_cfg.hart_index_bits +
>>>>>>>>> + IMSIC_MMIO_PAGE_SHIFT, UL) - 1);
>>>>>>>>> + base_addr &= ~((BIT(imsic_cfg.group_index_bits, UL) - 1) <<
>>>>>>>>> + imsic_cfg.group_index_shift);
>>>>>>>>> + if ( base_addr != imsic_cfg.base_addr )
>>>>>>>>> + {
>>>>>>>>> + rc = -EINVAL;
>>>>>>>>> + printk(XENLOG_ERR "%s: address mismatch for regset %u\n",
>>>>>>>>> + node->name, i);
>>>>>>>>> + goto imsic_init_err;
>>>>>>>>> + }
>>>>>>>> Maybe just for my own understanding: There's no similar check for the
>>>>>>>> sizes to match / be consistent wanted / needed?
>>>>>>> If you are speaking about imsic_cfg.mmios[i].size then it depends fully
>>>>>>> on h/w will
>>>>>>> provide, IMO.
>>>>>>> So I don't what is possible range for imsic_cfg.mmios[i].size.
>>>>>> Well, all I can say is that's it feels odd that you sanity check
>>>>>> base_addr
>>>>>> but permit effectively any size.
>>>>> Okay, I think I have two ideas how to check the size:
>>>>> 1. Based on guest bits from IMSIC's DT node. QEMU calculates a size as:
>>>>> for (socket = 0; socket < socket_count; socket++) {
>>>>> imsic_addr = base_addr + socket * VIRT_IMSIC_GROUP_MAX_SIZE;
>>>>> imsic_size = IMSIC_HART_SIZE(imsic_guest_bits) *
>>>>> s->soc[socket].num_harts;
>>>>> ...
>>>>> where:
>>>>> #define IMSIC_MMIO_PAGE_SHIFT 12
>>>>> #define IMSIC_MMIO_PAGE_SZ (1UL <<
>>>>> IMSIC_MMIO_PAGE_SHIFT)
>>>>>
>>>>> #define IMSIC_HART_NUM_GUESTS(__guest_bits) \
>>>>> (1U << (__guest_bits))
>>>>> #define IMSIC_HART_SIZE(__guest_bits) \
>>>>> (IMSIC_HART_NUM_GUESTS(__guest_bits) * IMSIC_MMIO_PAGE_SZ)
>>>>>
>>>>> 2. Just take a theoretical maximum for S-mode IMSIC's node:
>>>>> 16,384 * 64 1(S-mode interrupt file) + 63(max guest interrupt
>>>>> files)) * 4 KiB
>>>>> Where,
>>>>> 16,384 - maximum possible amount of harts according to AIA spec
>>>>> 64 - a maximum amount of possible interrupt file for S-mode IMSIC
>>>>> node:
>>>>> 1 - S interupt file + 63 guest interrupt files.
>>>>> 4 Kib - a maximum size of one interrupt file.
>>>>>
>>>>> Which option is preferred?
>>>> I would have said 2, if your outline used "actual" rather than "maximum"
>>>> values.
>>> In option 2 maximum possible values are used. If we want to use "actual"
>>> values then
>>> the option 1 should be used.
>> Actually I was wrong with request "actual" uniformly. It's only the hart
>> count where
>> I meant to ask for that. For interrupts we should allow the maximum possible
>> unless
>> we already know their count.
>
> Do you mean 'interrupt file' here?
Yes, I do. Sorry for getting the terminology wrong.
Jan
> If yes, then an amount of them shouldn't be bigger
> then 1 + BIT(guest_bits).
>
> ~ Oleksii
>
