Re: NetBSD dom0 PVH: hardware interrupts stalls

[Jan Beulich <jbeulich@suse.com>]

On 18.11.2020 11:14, Manuel Bouyer wrote:
> On Wed, Nov 18, 2020 at 10:43:27AM +0100, Jan Beulich wrote:
>> On 18.11.2020 10:28, Manuel Bouyer wrote:
>>> On Wed, Nov 18, 2020 at 10:16:17AM +0100, Jan Beulich wrote:
>>>> On 17.11.2020 17:40, Manuel Bouyer wrote:
>>>>> On Tue, Nov 17, 2020 at 04:58:07PM +0100, Roger Pau Monné wrote:
>>>>>> [...]
>>>>>>
>>>>>> I have attached a patch below that will dump the vIO-APIC info as part
>>>>>> of the 'i' debug key output, can you paste the whole output of the 'i'
>>>>>> debug key when the system stalls?
>>>>>
>>>>> see attached file. Note that the kernel did unstall while 'i' output was
>>>>> being printed, so it is mixed with some NetBSD kernel output.
>>>>
>>>> Could you try to run Xen's serial port without use of any IRQ
>>>> (i.e. in "polling" mode), in an attempt to avoid this unstalling
>>>> (which is likely to render the resulting output at least in part
>>>> meaningless)?
>>>
>>> It there a boot line option for that ?
>>
>> Yes, com<N>= has a field for this:
>>
>> ### com1
>> ### com2
>>> `= <baud>[/<base-baud>][,[DPS][,[<io-base>|pci|amt][,[<irq>|msi][,[<port-bdf>][,[<bridge-bdf>]]]]]]`
>>
>> with
>>
>> * `<irq>` is the IRQ number to use, or `0` to use the UART in poll
>>   mode only, or `msi` to set up a Message Signaled Interrupt.
> 
> thanks.
> This marginally changes the boot behavior (the kenrel hangs a little bit
> earlier) but switching the console input to Xen is enough to get some
> interrupt, and hitting 'i' causes again the boot to complete.

That's unfortunate for the purposes here, but thanks for trying.

Jan