linux-stable/include/linux/kvm_irqfd.h
Thomas Gleixner 2504ba9f59 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 235
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license this
  program is distributed in the hope that it will be useful but
  without any warranty without even the implied warranty of
  merchantability or fitness for a particular purpose see the gnu
  general public license for more details

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 53 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.904365654@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:07 +02:00

64 lines
2 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
*
* irqfd: Allows an fd to be used to inject an interrupt to the guest
* Credit goes to Avi Kivity for the original idea.
*/
#ifndef __LINUX_KVM_IRQFD_H
#define __LINUX_KVM_IRQFD_H
#include <linux/kvm_host.h>
#include <linux/poll.h>
/*
* Resampling irqfds are a special variety of irqfds used to emulate
* level triggered interrupts. The interrupt is asserted on eventfd
* trigger. On acknowledgment through the irq ack notifier, the
* interrupt is de-asserted and userspace is notified through the
* resamplefd. All resamplers on the same gsi are de-asserted
* together, so we don't need to track the state of each individual
* user. We can also therefore share the same irq source ID.
*/
struct kvm_kernel_irqfd_resampler {
struct kvm *kvm;
/*
* List of resampling struct _irqfd objects sharing this gsi.
* RCU list modified under kvm->irqfds.resampler_lock
*/
struct list_head list;
struct kvm_irq_ack_notifier notifier;
/*
* Entry in list of kvm->irqfd.resampler_list. Use for sharing
* resamplers among irqfds on the same gsi.
* Accessed and modified under kvm->irqfds.resampler_lock
*/
struct list_head link;
};
struct kvm_kernel_irqfd {
/* Used for MSI fast-path */
struct kvm *kvm;
wait_queue_entry_t wait;
/* Update side is protected by irqfds.lock */
struct kvm_kernel_irq_routing_entry irq_entry;
seqcount_t irq_entry_sc;
/* Used for level IRQ fast-path */
int gsi;
struct work_struct inject;
/* The resampler used by this irqfd (resampler-only) */
struct kvm_kernel_irqfd_resampler *resampler;
/* Eventfd notified on resample (resampler-only) */
struct eventfd_ctx *resamplefd;
/* Entry in list of irqfds for a resampler (resampler-only) */
struct list_head resampler_link;
/* Used for setup/shutdown */
struct eventfd_ctx *eventfd;
struct list_head list;
poll_table pt;
struct work_struct shutdown;
struct irq_bypass_consumer consumer;
struct irq_bypass_producer *producer;
};
#endif /* __LINUX_KVM_IRQFD_H */