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KVM: x86: Call mask notifiers from pic.

PATCH Applied Gleb Natapov 2 participants 2 messages Jul 15, 2010 – Jul 16, 2010

Subsystems (3)
x86 KVM KVM x86
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Gleb Natapov

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#0 lore raw

PATCH v2 1/1 KVM: x86: Call mask notifiers from pic.

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 <[email protected]>

---
Changelog:
v1->v2
Properly handle slave pic.

arch/x86/kvm/i8259.c +11 -1
index 819b748..8d10c06 100644
@@ -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.

Applied
#1 lore raw
Quoted 6 lines · 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 <[email protected]>

Applied, thanks.