From 721eecbf4fe995ca94a9edec0c9843b1cc0eaaf3 Mon Sep 17 00:00:00 2001 From: Gregory Haskins Date: Wed, 20 May 2009 10:30:49 -0400 Subject: KVM: irqfd KVM provides a complete virtual system environment for guests, including support for injecting interrupts modeled after the real exception/interrupt facilities present on the native platform (such as the IDT on x86). Virtual interrupts can come from a variety of sources (emulated devices, pass-through devices, etc) but all must be injected to the guest via the KVM infrastructure. This patch adds a new mechanism to inject a specific interrupt to a guest using a decoupled eventfd mechnanism: Any legal signal on the irqfd (using eventfd semantics from either userspace or kernel) will translate into an injected interrupt in the guest at the next available interrupt window. Signed-off-by: Gregory Haskins Signed-off-by: Avi Kivity --- include/linux/kvm.h | 11 +++++++++++ include/linux/kvm_host.h | 24 ++++++++++++++++++++++++ 2 files changed, 35 insertions(+) (limited to 'include') diff --git a/include/linux/kvm.h b/include/linux/kvm.h index 7b17141c47c..8f53f24e527 100644 --- a/include/linux/kvm.h +++ b/include/linux/kvm.h @@ -418,6 +418,7 @@ struct kvm_trace_rec { #ifdef __KVM_HAVE_MCE #define KVM_CAP_MCE 31 #endif +#define KVM_CAP_IRQFD 32 #ifdef KVM_CAP_IRQ_ROUTING @@ -470,6 +471,15 @@ struct kvm_x86_mce { }; #endif +#define KVM_IRQFD_FLAG_DEASSIGN (1 << 0) + +struct kvm_irqfd { + __u32 fd; + __u32 gsi; + __u32 flags; + __u8 pad[20]; +}; + /* * ioctls for VM fds */ @@ -514,6 +524,7 @@ struct kvm_x86_mce { #define KVM_ASSIGN_SET_MSIX_ENTRY \ _IOW(KVMIO, 0x74, struct kvm_assigned_msix_entry) #define KVM_DEASSIGN_DEV_IRQ _IOW(KVMIO, 0x75, struct kvm_assigned_irq) +#define KVM_IRQFD _IOW(KVMIO, 0x76, struct kvm_irqfd) /* * ioctls for vcpu fds diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 3060bdc35ff..7724dcb6ff7 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -136,6 +136,12 @@ struct kvm { struct list_head vm_list; struct kvm_io_bus mmio_bus; struct kvm_io_bus pio_bus; +#ifdef CONFIG_HAVE_KVM_EVENTFD + struct { + spinlock_t lock; + struct list_head items; + } irqfds; +#endif struct kvm_vm_stat stat; struct kvm_arch arch; atomic_t users_count; @@ -525,4 +531,22 @@ static inline void kvm_free_irq_routing(struct kvm *kvm) {} #endif +#ifdef CONFIG_HAVE_KVM_EVENTFD + +void kvm_irqfd_init(struct kvm *kvm); +int kvm_irqfd(struct kvm *kvm, int fd, int gsi, int flags); +void kvm_irqfd_release(struct kvm *kvm); + +#else + +static inline void kvm_irqfd_init(struct kvm *kvm) {} +static inline int kvm_irqfd(struct kvm *kvm, int fd, int gsi, int flags) +{ + return -EINVAL; +} + +static inline void kvm_irqfd_release(struct kvm *kvm) {} + +#endif /* CONFIG_HAVE_KVM_EVENTFD */ + #endif -- cgit v1.2.3