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

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

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.

Otherwise, Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

Can fix on commit if you're happy.

> +
> +            common_eoi:
>                  vpic->isr &= ~(1 << pin);
> -                if ( cmd == 7 )
> +                if ( cmd == 7 || cmd == 5 )
>                      vpic->priority_add = (pin + 1) & 7;
>                  /* Release lock and EOI the physical interrupt (if any). */
>                  vpic_update_int_output(vpic);