LXR linux/include/linux/kvm

   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 */
  30struct 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
  46struct 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