xen: do not map the same GSI twice in PVHVM guests.
PV on HVM guests map GSIs into event channels. At restore time the
event channels are resumed by restore_pirqs.
Device drivers might try to register the same GSI again through ACPI at
restore time, but the GSI has already been mapped and bound by
restore_pirqs. This patch detects these situations and avoids
mapping the same GSI multiple times.
Without this patch we get:
(XEN) irq.c:2235: dom4: pirq 23 or emuirq 28 already mapped
and waste a pirq.
CC: stable@kernel.org
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/include/xen/events.h b/include/xen/events.h
index 0f77370..04399b2 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -103,6 +103,9 @@
/* Return the pirq allocated to the irq. */
int xen_pirq_from_irq(unsigned irq);
+/* Return the irq allocated to the gsi */
+int xen_irq_from_gsi(unsigned gsi);
+
/* Determine whether to ignore this IRQ if it is passed to a guest. */
int xen_test_irq_shared(int irq);