From: Chris Wright <[email protected]> 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 <[email protected]> Signed-off-by: Avi Kivity <[email protected]> diff --git a/external-module-compat-comm.h b/external-module-compat-comm.h index f6975e0..a27774d 100644 --- a/external-module-compat-comm.h +++ b/external-module-compat-comm.h @@ -656,33 +656,9 @@ 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 ($(CONFIG_IOMMU_API),y) kvm-objs += iommu.o diff --git a/request-irq-compat.c b/request-irq-compat.c new file mode 100644 index 0000000..51193cb --- /dev/null +++ b/request-irq-compat.c @@ -0,0 +1,44 @@ +/* + * compat for request_irq + */ + +#include <linux/interrupt.h> +#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,19) + +static kvm_irq_handler_t kvm_irq_handlers[NR_IRQS]; +static DEFINE_MUTEX(kvm_irq_handlers_mutex); + +static irqreturn_t kvm_irq_thunk(int irq, void *dev_id, struct pt_regs *regs) +{ + kvm_irq_handler_t handler = kvm_irq_handlers[irq]; + return handler(irq, dev_id); +} + +int kvm_request_irq(unsigned int a, kvm_irq_handler_t handler, + unsigned long c, const char *d, void *e) +{ + int rc = -EBUSY; + kvm_irq_handler_t old; + + mutex_lock(&kvm_irq_handlers_mutex); + old = kvm_irq_handlers[a]; + if (old) + goto out; + kvm_irq_handlers[a] = handler; + rc = request_irq(a, kvm_irq_thunk, c, d, e); + if (rc) + kvm_irq_handlers[a] = NULL; +out: + mutex_unlock(&kvm_irq_handlers_mutex); + return rc; +} + +void kvm_free_irq(unsigned int irq, void *dev_id) +{ + mutex_lock(&kvm_irq_handlers_mutex); + free_irq(irq, dev_id); + kvm_irq_handlers[irq] = NULL; + mutex_unlock(&kvm_irq_handlers_mutex); +} + +#endif diff --git a/x86/Kbuild b/x86/Kbuild index 19b5f20..e304c79 100644 --- a/x86/Kbuild +++ b/x86/Kbuild @@ -6,7 +6,7 @@ obj-m := kvm.o kvm-intel.o kvm-amd.o kvm-objs := kvm_main.o x86.o mmu.o x86_emulate.o ../anon_inodes.o irq.o i8259.o \ lapic.o ioapic.o preempt.o i8254.o coalesced_mmio.o irq_comm.o \ timer.o eventfd.o \ - ../external-module-compat.o + ../external-module-compat.o ../request-irq-compat.o ifeq ($(EXT_CONFIG_KVM_TRACE),y) kvm-objs += kvm_trace.o endif -- To unsubscribe from this list: send the line "unsubscribe kvm-commits" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
