[PATCH v2] KVM: x86: Call mask notifiers from pic.

[PATCH v2] KVM: x86: 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>
---
Changelog:
 v1->v2
	Properly handle slave pic.

diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 819b748..8d10c06 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -363,10 +363,20 @@ 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,
+				off = (s == &s->pics_state->pics[0]) ? 0 : 8;
 			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 + off),
+						irq + off,
+						!!(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 v2] KVM: x86: Call mask notifiers from pic.

[Marcelo Tosatti]

On Thu, Jul 15, 2010 at 12:24:37PM +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>

Applied, thanks.