This is a note to let you know that I've just added the patch titled
xen: do not map the same GSI twice in PVHVM guests.
to the 3.3-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
xen-do-not-map-the-same-gsi-twice-in-pvhvm-guests.patch
and it can be found in the queue-3.3 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.
>From 68c2c39a76b094e9b2773e5846424ea674bf2c46 Mon Sep 17 00:00:00 2001
From: Stefano Stabellini <stefano.stabell...@eu.citrix.com>
Date: Mon, 21 May 2012 16:54:10 +0100
Subject: xen: do not map the same GSI twice in PVHVM guests.
From: Stefano Stabellini <stefano.stabell...@eu.citrix.com>
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 <stefano.stabell...@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
arch/x86/pci/xen.c | 4 ++++
drivers/xen/events.c | 5 +++--
include/xen/events.h | 3 +++
3 files changed, 10 insertions(+), 2 deletions(-)
--- a/arch/x86/pci/xen.c
+++ b/arch/x86/pci/xen.c
@@ -64,6 +64,10 @@ static int xen_register_pirq(u32 gsi, in
int shareable = 0;
char *name;
+ irq = xen_irq_from_gsi(gsi);
+ if (irq > 0)
+ return irq;
+
if (set_pirq)
pirq = gsi;
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -604,7 +604,7 @@ static void disable_pirq(struct irq_data
disable_dynirq(data);
}
-static int find_irq_by_gsi(unsigned gsi)
+int xen_irq_from_gsi(unsigned gsi)
{
struct irq_info *info;
@@ -618,6 +618,7 @@ 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
@@ -637,7 +638,7 @@ int xen_bind_pirq_gsi_to_irq(unsigned gs
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);
--- 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);
Patches currently in stable-queue which might be from
stefano.stabell...@eu.citrix.com are
queue-3.3/xen-do-not-map-the-same-gsi-twice-in-pvhvm-guests.patch
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