Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932499Ab2E0BMS (ORCPT ); Sat, 26 May 2012 21:12:18 -0400 Received: from mail-pb0-f46.google.com ([209.85.160.46]:38960 "EHLO mail-pb0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756267Ab2E0BMI (ORCPT ); Sat, 26 May 2012 21:12:08 -0400 Message-Id: <20120527010433.917442192@linuxfoundation.org> User-Agent: quilt/0.60-19.1 Date: Sun, 27 May 2012 10:05:35 +0900 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Stefano Stabellini , Konrad Rzeszutek Wilk Subject: [ 72/94] xen: do not map the same GSI twice in PVHVM guests. In-Reply-To: <20120527010332.GA11170@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2626 Lines: 90 3.3-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stefano Stabellini 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(-) --- 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/