LXR linux/include/linux/kvm

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 *
   4 * irqfd: Allows an fd to be used to inject an interrupt to the guest
   5 * Credit goes to Avi Kivity for the original idea.
   6 */
   7
   8#ifndef __LINUX_KVM_IRQFD_H
   9#define __LINUX_KVM_IRQFD_H
  10
  11#include <linux/kvm_host.h>
  12#include <linux/poll.h>
  13
  14/*
  15 * Resampling irqfds are a special variety of irqfds used to emulate
  16 * level triggered interrupts.  The interrupt is asserted on eventfd
  17 * trigger.  On acknowledgment through the irq ack notifier, the
  18 * interrupt is de-asserted and userspace is notified through the
  19 * resamplefd.  All resamplers on the same gsi are de-asserted
  20 * together, so we don't need to track the state of each individual
  21 * user.  We can also therefore share the same irq source ID.
  22 */
  23struct kvm_kernel_irqfd_resampler {
  24        struct kvm *kvm;
  25        /*
  26         * List of resampling struct _irqfd objects sharing this gsi.
  27         * RCU list modified under kvm->irqfds.resampler_lock
  28         */
  29        struct list_head list;
  30        struct kvm_irq_ack_notifier notifier;
  31        /*
  32         * Entry in list of kvm->irqfd.resampler_list.  Use for sharing
  33         * resamplers among irqfds on the same gsi.
  34         * Accessed and modified under kvm->irqfds.resampler_lock
  35         */
  36        struct list_head link;
  37};
  38
  39struct kvm_kernel_irqfd {
  40        /* Used for MSI fast-path */
  41        struct kvm *kvm;
  42        wait_queue_entry_t wait;
  43        /* Update side is protected by irqfds.lock */
  44        struct kvm_kernel_irq_routing_entry irq_entry;
  45        seqcount_t irq_entry_sc;
  46        /* Used for level IRQ fast-path */
  47        int gsi;
  48        struct work_struct inject;
  49        /* The resampler used by this irqfd (resampler-only) */
  50        struct kvm_kernel_irqfd_resampler *resampler;
  51        /* Eventfd notified on resample (resampler-only) */
  52        struct eventfd_ctx *resamplefd;
  53        /* Entry in list of irqfds for a resampler (resampler-only) */
  54        struct list_head resampler_link;
  55        /* Used for setup/shutdown */
  56        struct eventfd_ctx *eventfd;
  57        struct list_head list;
  58        poll_table pt;
  59        struct work_struct shutdown;
  60        struct irq_bypass_consumer consumer;
  61        struct irq_bypass_producer *producer;
  62};
  63
  64#endif /* __LINUX_KVM_IRQFD_H */
  65