Re: Ping: [PATCH 2/2] x86/vpic: also execute dpci callback for non-specific EOI

[Jan Beulich <jbeulich@xxxxxxxx>]

On 29.09.2020 12:27, Roger Pau Monné wrote:
> On Mon, Sep 21, 2020 at 12:05:51PM +0200, Jan Beulich wrote:
>> On 21.08.2020 09:45, Jan Beulich wrote:
>>> On 20.08.2020 18:28, Andrew Cooper wrote:
>>>> On 20/08/2020 16:34, Roger Pau Monne wrote:
>>>>> Currently the dpci EOI callback is only executed for specific EOIs.
>>>>> This is wrong as non-specific EOIs will also clear the ISR bit and
>>>>> thus end the interrupt. Re-arrange the code a bit so that the common
>>>>> EOI handling path can be shared between all EOI modes.
>>>>>
>>>>> Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
>>>>> ---
>>>>>  xen/arch/x86/hvm/vpic.c | 10 +++++-----
>>>>>  1 file changed, 5 insertions(+), 5 deletions(-)
>>>>>
>>>>> diff --git a/xen/arch/x86/hvm/vpic.c b/xen/arch/x86/hvm/vpic.c
>>>>> index feb1db2ee3..3cf12581e9 100644
>>>>> --- a/xen/arch/x86/hvm/vpic.c
>>>>> +++ b/xen/arch/x86/hvm/vpic.c
>>>>> @@ -249,15 +249,15 @@ static void vpic_ioport_write(
>>>>>                  if ( priority == VPIC_PRIO_NONE )
>>>>>                      break;
>>>>>                  pin = (priority + vpic->priority_add) & 7;
>>>>> -                vpic->isr &= ~(1 << pin);
>>>>> -                if ( cmd == 5 )
>>>>> -                    vpic->priority_add = (pin + 1) & 7;
>>>>> -                break;
>>>>> +                goto common_eoi;
>>>>> +
>>>>>              case 3: /* Specific EOI                */
>>>>>              case 7: /* Specific EOI & Rotate       */
>>>>>                  pin = val & 7;
>>>>
>>>> You'll need a /* Fallthrough */ here to keep various things happy.
>>>
>>> Are you sure? There's ...
>>>
>>>> Otherwise, Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
>>>>
>>>> Can fix on commit if you're happy.
>>>>
>>>>> +
>>>>> +            common_eoi:
>>>
>>> ... an ordinary label here, not a case one.
>>
>> I would have wanted to commit this, but it's still not clear to me
>> whether the adjustment you ask for is really needed.
> 
> Was about to send a further series I have on top of this and saw this
> is still on my patch queue. I'm happy with either way, but I would
> like to get this committed if possible (as I think from a technical
> PoV we all agree it's correct).

Hmm, did you mean to send this _to_ Andrew, with me on _cc_? There's
nothing I can do without his further input.

Jan