From 474d1f4678a679a98eaf53801e7f95c61ae9daa7 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Mon, 21 May 2012 16:54:10 +0100 Subject: [PATCH] xen: do not map the same GSI twice in PVHVM guests. commit 68c2c39a76b094e9b2773e5846424ea674bf2c46 upstream. 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. Signed-off-by: Stefano Stabellini Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Greg Kroah-Hartman --- arch/x86/pci/xen.c | 4 ++++ drivers/xen/events.c | 5 +++-- include/xen/events.h | 3 +++ 3 files changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/x86/pci/xen.c b/arch/x86/pci/xen.c index 7415aa9..56ab749 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 0a8a17c..6908e4c 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 0f77370..04399b2 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); -- 2.7.4