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authorStefano Stabellini <stefano.stabellini@eu.citrix.com>2012-05-21 16:54:10 +0100
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-05-21 14:11:36 -0400
commit68c2c39a76b094e9b2773e5846424ea674bf2c46 (patch)
treeb3959303806a6228adbbab234c474e16c81738ba
parent201a52bea928687b7557728b176ac4f8a37d5cbd (diff)
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>
-rw-r--r--arch/x86/pci/xen.c4
-rw-r--r--drivers/xen/events.c5
-rw-r--r--include/xen/events.h3
3 files changed, 10 insertions, 2 deletions
diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c
index 7415aa927913..56ab74989cf1 100644
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -64,6 +64,10 @@ static int xen_register_pirq(u32 gsi, int gsi_override, int triggering,
int shareable = 0;
char *name;
+ irq = xen_irq_from_gsi(gsi);
+ if (irq > 0)
+ return irq;
+
if (set_pirq)
pirq = gsi;
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 4b33acd8ed4e..faae2f910ad2 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -611,7 +611,7 @@ static void disable_pirq(struct irq_data *data)
disable_dynirq(data);
}
-static int find_irq_by_gsi(unsigned gsi)
+int xen_irq_from_gsi(unsigned gsi)
{
struct irq_info *info;
@@ -625,6 +625,7 @@ static int find_irq_by_gsi(unsigned gsi)
return -1;
}
+EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
/*
* Do not make any assumptions regarding the relationship between the
@@ -644,7 +645,7 @@ int xen_bind_pirq_gsi_to_irq(unsigned gsi,
mutex_lock(&irq_mapping_update_lock);
- irq = find_irq_by_gsi(gsi);
+ irq = xen_irq_from_gsi(gsi);
if (irq != -1) {
printk(KERN_INFO "xen_map_pirq_gsi: returning irq %d for gsi %u\n",
irq, gsi);
diff --git a/include/xen/events.h b/include/xen/events.h
index 0f773708e02c..04399b28e821 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -103,6 +103,9 @@ int xen_irq_from_pirq(unsigned pirq);
/* 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);