From patchwork Thu May 21 07:38:53 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wright X-Patchwork-Id: 25190 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n4L7dFYr015584 for ; Thu, 21 May 2009 07:39:15 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751506AbZEUHjK (ORCPT ); Thu, 21 May 2009 03:39:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751467AbZEUHjJ (ORCPT ); Thu, 21 May 2009 03:39:09 -0400 Received: from sous-sol.org ([216.99.217.87]:58930 "EHLO sequoia.sous-sol.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751221AbZEUHjI (ORCPT ); Thu, 21 May 2009 03:39:08 -0400 Received: from sequoia.sous-sol.org (sequoia.sous-sol.org [127.0.0.1]) by sequoia.sous-sol.org (8.14.2/8.14.2) with ESMTP id n4L7cr9t026572; Thu, 21 May 2009 00:38:53 -0700 Received: (from chrisw@localhost) by sequoia.sous-sol.org (8.14.2/8.14.2/Submit) id n4L7crhX026571; Thu, 21 May 2009 00:38:53 -0700 Date: Thu, 21 May 2009 00:38:53 -0700 From: Chris Wright To: Avi Kivity Cc: Chris Wright , kvm@vger.kernel.org Subject: [PATCH kvm-kmod v2] fix kvm_request_irq race Message-ID: <20090521073853.GU20823@sequoia.sous-sol.org> References: <20090521062135.GR20823@sequoia.sous-sol.org> <4A14F4AD.9060408@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4A14F4AD.9060408@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-Virus-Scanned: ClamAV version 0.93.3, clamav-milter version 0.93.3 on sequoia.sous-sol.org X-Virus-Status: Clean Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Commit "32658734: Fix request_irq() for < 2.6.19" is racy between multiple guests since ioctl is only serialized per guest. Add mutex and serialize kvm_request_irq/kvm_free_irq to avoid race. Also move all this to its own C file to keep from creating per ojbect file private mutexes. Signed-off-by: Chris Wright --- external-module-compat-comm.h | 29 +------------------------- ia64/Kbuild | 3 +- request-irq-compat.c | 44 +++++++++++++++++++++++++++++++++++++++++ x86/Kbuild | 2 +- 4 files changed, 49 insertions(+), 29 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/external-module-compat-comm.h b/external-module-compat-comm.h index f6975e0..c014b7f 100644 --- a/external-module-compat-comm.h +++ b/external-module-compat-comm.h @@ -656,33 +656,8 @@ static inline int pci_reset_function(struct pci_dev *dev) #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19) typedef irqreturn_t (*kvm_irq_handler_t)(int, void *); -static kvm_irq_handler_t kvm_irq_handlers[NR_IRQS]; - -static irqreturn_t kvm_irq_thunk(int irq, void *dev_id, struct pt_regs *regs) -{ - kvm_irq_handler_t handler = kvm_irq_handlers[irq]; - return handler(irq, dev_id); -} - -static inline int kvm_request_irq(unsigned int a, kvm_irq_handler_t handler, - unsigned long c, const char *d, void *e) -{ - int rc; - kvm_irq_handler_t old = kvm_irq_handlers[a]; - if (old) - return -EBUSY; - kvm_irq_handlers[a] = handler; - rc = request_irq(a, kvm_irq_thunk, c, d, e); - if (rc) - kvm_irq_handlers[a] = NULL; - return rc; -} - -static inline void kvm_free_irq(unsigned int irq, void *dev_id) -{ - free_irq(irq, dev_id); - kvm_irq_handlers[irq] = NULL; -} +int kvm_request_irq(unsigned int a, kvm_irq_handler_t handler, unsigned long c, const char *d, void *e); +void kvm_free_irq(unsigned int irq, void *dev_id); #else diff --git a/ia64/Kbuild b/ia64/Kbuild index 5bc6098..e2c8acc 100644 --- a/ia64/Kbuild +++ b/ia64/Kbuild @@ -1,7 +1,8 @@ obj-m := kvm.o kvm-intel.o kvm-objs := kvm_main.o ioapic.o coalesced_mmio.o kvm-ia64.o kvm_fw.o \ - irq_comm.o ../anon_inodes.o ../external-module-compat.o + irq_comm.o ../anon_inodes.o ../external-module-compat.o \ + ../request-irq-compat.o ifeq ($(CONFIG_IOMMU_API),y) kvm-objs += iommu.o diff --git a/request-irq-compat.c b/request-irq-compat.c new file mode 100644 index 0000000..51193cb --- /dev/null +++ b/request-irq-compat.c @@ -0,0 +1,44 @@ +/* + * compat for request_irq + */ + +#include +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19) + +static kvm_irq_handler_t kvm_irq_handlers[NR_IRQS]; +static DEFINE_MUTEX(kvm_irq_handlers_mutex); + +static irqreturn_t kvm_irq_thunk(int irq, void *dev_id, struct pt_regs *regs) +{ + kvm_irq_handler_t handler = kvm_irq_handlers[irq]; + return handler(irq, dev_id); +} + +int kvm_request_irq(unsigned int a, kvm_irq_handler_t handler, + unsigned long c, const char *d, void *e) +{ + int rc = -EBUSY; + kvm_irq_handler_t old; + + mutex_lock(&kvm_irq_handlers_mutex); + old = kvm_irq_handlers[a]; + if (old) + goto out; + kvm_irq_handlers[a] = handler; + rc = request_irq(a, kvm_irq_thunk, c, d, e); + if (rc) + kvm_irq_handlers[a] = NULL; +out: + mutex_unlock(&kvm_irq_handlers_mutex); + return rc; +} + +void kvm_free_irq(unsigned int irq, void *dev_id) +{ + mutex_lock(&kvm_irq_handlers_mutex); + free_irq(irq, dev_id); + kvm_irq_handlers[irq] = NULL; + mutex_unlock(&kvm_irq_handlers_mutex); +} + +#endif diff --git a/x86/Kbuild b/x86/Kbuild index d3aca00..c5b84e9 100644 --- a/x86/Kbuild +++ b/x86/Kbuild @@ -6,7 +6,7 @@ obj-m := kvm.o kvm-intel.o kvm-amd.o kvm-objs := kvm_main.o x86.o mmu.o x86_emulate.o ../anon_inodes.o irq.o i8259.o \ lapic.o ioapic.o preempt.o i8254.o coalesced_mmio.o irq_comm.o \ timer.o \ - ../external-module-compat.o + ../external-module-compat.o ../request-irq-compat.o ifeq ($(EXT_CONFIG_KVM_TRACE),y) kvm-objs += kvm_trace.o endif