[PATCH] Call mask notifiers from pic.

[PATCH] Call mask notifiers from pic.

[Gleb Natapov]

If pit delivers interrupt while pic is masking it OS will never do EOI
and ack notifier will not be called so when pit will be unmasked no pit
interrupts will be delivered any more. Calling mask notifiers solves this
issue.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 819b748..80d98cd 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -363,10 +363,18 @@ static void pic_ioport_write(void *opaque, u32 addr, u32 val)
 		}
 	} else
 		switch (s->init_state) {
-		case 0:		/* normal mode */
+		case 0: { /* normal mode */
+			u8 imr_diff = s->imr ^ val;
 			s->imr = val;
+			for (irq = 0; irq < PIC_NUM_PINS/2; irq++)
+				if (imr_diff & (1 << irq))
+					kvm_fire_mask_notifiers(
+						s->pics_state->kvm,
+						SELECT_PIC(irq), irq,
+						!!(s->imr & (1 << irq)));
 			pic_update_irq(s->pics_state);
 			break;
+		}
 		case 1:
 			s->irq_base = val & 0xf8;
 			s->init_state = 2;
--
			Gleb.

Re: [PATCH] Call mask notifiers from pic.

[Marcelo Tosatti]

On Wed, Jul 14, 2010 at 07:28:31PM +0300, Gleb Natapov wrote:
> If pit delivers interrupt while pic is masking it OS will never do EOI
> and ack notifier will not be called so when pit will be unmasked no pit
> interrupts will be delivered any more. Calling mask notifiers solves this
> issue.
> 
> Signed-off-by: Gleb Natapov <gleb@redhat.com>
> diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
> index 819b748..80d98cd 100644
> --- a/arch/x86/kvm/i8259.c
> +++ b/arch/x86/kvm/i8259.c
> @@ -363,10 +363,18 @@ static void pic_ioport_write(void *opaque, u32 addr, u32 val)
>  		}
>  	} else
>  		switch (s->init_state) {
> -		case 0:		/* normal mode */
> +		case 0: { /* normal mode */
> +			u8 imr_diff = s->imr ^ val;
>  			s->imr = val;
> +			for (irq = 0; irq < PIC_NUM_PINS/2; irq++)
> +				if (imr_diff & (1 << irq))
> +					kvm_fire_mask_notifiers(
> +						s->pics_state->kvm,
> +						SELECT_PIC(irq), irq,
> +						!!(s->imr & (1 << irq)));

irqchip/pin parameters are wrong for PIC_SLAVE.