1 /* 2 * This program is free software; you can redistribute it and/or modify 3 * it under the terms of the GNU General Public License as published by 4 * the Free Software Foundation; either version 2 of the License. 5 * 6 * This program is distributed in the hope that it will be useful, 7 * but WITHOUT ANY WARRANTY; without even the implied warranty of 8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 9 * GNU General Public License for more details. 10 * 11 * irqfd: Allows an fd to be used to inject an interrupt to the guest 12 * Credit goes to Avi Kivity for the original idea. 13 */ 14 15 #ifndef __LINUX_KVM_IRQFD_H 16 #define __LINUX_KVM_IRQFD_H 17 18 #include <linux/kvm_host.h> 19 #include <linux/poll.h> 20 21 /* 22 * Resampling irqfds are a special variety of irqfds used to emulate 23 * level triggered interrupts. The interrupt is asserted on eventfd 24 * trigger. On acknowledgment through the irq ack notifier, the 25 * interrupt is de-asserted and userspace is notified through the 26 * resamplefd. All resamplers on the same gsi are de-asserted 27 * together, so we don't need to track the state of each individual 28 * user. We can also therefore share the same irq source ID. 29 */ 30 struct kvm_kernel_irqfd_resampler { 31 struct kvm *kvm; 32 /* 33 * List of resampling struct _irqfd objects sharing this gsi. 34 * RCU list modified under kvm->irqfds.resampler_lock 35 */ 36 struct list_head list; 37 struct kvm_irq_ack_notifier notifier; 38 /* 39 * Entry in list of kvm->irqfd.resampler_list. Use for sharing 40 * resamplers among irqfds on the same gsi. 41 * Accessed and modified under kvm->irqfds.resampler_lock 42 */ 43 struct list_head link; 44 }; 45 46 struct kvm_kernel_irqfd { 47 /* Used for MSI fast-path */ 48 struct kvm *kvm; 49 wait_queue_t wait; 50 /* Update side is protected by irqfds.lock */ 51 struct kvm_kernel_irq_routing_entry irq_entry; 52 seqcount_t irq_entry_sc; 53 /* Used for level IRQ fast-path */ 54 int gsi; 55 struct work_struct inject; 56 /* The resampler used by this irqfd (resampler-only) */ 57 struct kvm_kernel_irqfd_resampler *resampler; 58 /* Eventfd notified on resample (resampler-only) */ 59 struct eventfd_ctx *resamplefd; 60 /* Entry in list of irqfds for a resampler (resampler-only) */ 61 struct list_head resampler_link; 62 /* Used for setup/shutdown */ 63 struct eventfd_ctx *eventfd; 64 struct list_head list; 65 poll_table pt; 66 struct work_struct shutdown; 67 struct irq_bypass_consumer consumer; 68 struct irq_bypass_producer *producer; 69 }; 70 71 #endif /* __LINUX_KVM_IRQFD_H */ 72