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KVM: create kvm_irqfd.h
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Move _irqfd_resampler and _irqfd struct declarations in a new
public header: kvm_irqfd.h. They are respectively renamed into
kvm_kernel_irqfd_resampler and kvm_kernel_irqfd. Those datatypes
will be used by architecture specific code, in the context of
IRQ bypass manager integration.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Feng Wu <feng.wu@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Eric Auger authored and bonzini committed Oct 1, 2015
1 parent 37d9fe4 commit 166c977
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Showing 2 changed files with 92 additions and 72 deletions.
69 changes: 69 additions & 0 deletions include/linux/kvm_irqfd.h
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Original file line number Diff line number Diff line change
@@ -0,0 +1,69 @@
/*
* 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.
*
* 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_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;
};

#endif /* __LINUX_KVM_IRQFD_H */
95 changes: 23 additions & 72 deletions virt/kvm/eventfd.c
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Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,7 @@

#include <linux/kvm_host.h>
#include <linux/kvm.h>
#include <linux/kvm_irqfd.h>
#include <linux/workqueue.h>
#include <linux/syscalls.h>
#include <linux/wait.h>
Expand All @@ -39,68 +40,14 @@
#include <kvm/iodev.h>

#ifdef CONFIG_HAVE_KVM_IRQFD
/*
* --------------------------------------------------------------------
* irqfd: Allows an fd to be used to inject an interrupt to the guest
*
* Credit goes to Avi Kivity for the original idea.
* --------------------------------------------------------------------
*/

/*
* Resampling irqfds are a special variety of irqfds used to emulate
* level triggered interrupts. The interrupt is asserted on eventfd
* trigger. On acknowledgement 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 _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 _irqfd {
/* Used for MSI fast-path */
struct kvm *kvm;
wait_queue_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 _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;
};

static struct workqueue_struct *irqfd_cleanup_wq;

static void
irqfd_inject(struct work_struct *work)
{
struct _irqfd *irqfd = container_of(work, struct _irqfd, inject);
struct kvm_kernel_irqfd *irqfd =
container_of(work, struct kvm_kernel_irqfd, inject);
struct kvm *kvm = irqfd->kvm;

if (!irqfd->resampler) {
Expand All @@ -121,12 +68,13 @@ irqfd_inject(struct work_struct *work)
static void
irqfd_resampler_ack(struct kvm_irq_ack_notifier *kian)
{
struct _irqfd_resampler *resampler;
struct kvm_kernel_irqfd_resampler *resampler;
struct kvm *kvm;
struct _irqfd *irqfd;
struct kvm_kernel_irqfd *irqfd;
int idx;

resampler = container_of(kian, struct _irqfd_resampler, notifier);
resampler = container_of(kian,
struct kvm_kernel_irqfd_resampler, notifier);
kvm = resampler->kvm;

kvm_set_irq(kvm, KVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID,
Expand All @@ -141,9 +89,9 @@ irqfd_resampler_ack(struct kvm_irq_ack_notifier *kian)
}

static void
irqfd_resampler_shutdown(struct _irqfd *irqfd)
irqfd_resampler_shutdown(struct kvm_kernel_irqfd *irqfd)
{
struct _irqfd_resampler *resampler = irqfd->resampler;
struct kvm_kernel_irqfd_resampler *resampler = irqfd->resampler;
struct kvm *kvm = resampler->kvm;

mutex_lock(&kvm->irqfds.resampler_lock);
Expand All @@ -168,7 +116,8 @@ irqfd_resampler_shutdown(struct _irqfd *irqfd)
static void
irqfd_shutdown(struct work_struct *work)
{
struct _irqfd *irqfd = container_of(work, struct _irqfd, shutdown);
struct kvm_kernel_irqfd *irqfd =
container_of(work, struct kvm_kernel_irqfd, shutdown);
u64 cnt;

/*
Expand Down Expand Up @@ -198,7 +147,7 @@ irqfd_shutdown(struct work_struct *work)

/* assumes kvm->irqfds.lock is held */
static bool
irqfd_is_active(struct _irqfd *irqfd)
irqfd_is_active(struct kvm_kernel_irqfd *irqfd)
{
return list_empty(&irqfd->list) ? false : true;
}
Expand All @@ -209,7 +158,7 @@ irqfd_is_active(struct _irqfd *irqfd)
* assumes kvm->irqfds.lock is held
*/
static void
irqfd_deactivate(struct _irqfd *irqfd)
irqfd_deactivate(struct kvm_kernel_irqfd *irqfd)
{
BUG_ON(!irqfd_is_active(irqfd));

Expand All @@ -224,7 +173,8 @@ irqfd_deactivate(struct _irqfd *irqfd)
static int
irqfd_wakeup(wait_queue_t *wait, unsigned mode, int sync, void *key)
{
struct _irqfd *irqfd = container_of(wait, struct _irqfd, wait);
struct kvm_kernel_irqfd *irqfd =
container_of(wait, struct kvm_kernel_irqfd, wait);
unsigned long flags = (unsigned long)key;
struct kvm_kernel_irq_routing_entry irq;
struct kvm *kvm = irqfd->kvm;
Expand Down Expand Up @@ -274,12 +224,13 @@ static void
irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh,
poll_table *pt)
{
struct _irqfd *irqfd = container_of(pt, struct _irqfd, pt);
struct kvm_kernel_irqfd *irqfd =
container_of(pt, struct kvm_kernel_irqfd, pt);
add_wait_queue(wqh, &irqfd->wait);
}

/* Must be called under irqfds.lock */
static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd)
static void irqfd_update(struct kvm *kvm, struct kvm_kernel_irqfd *irqfd)
{
struct kvm_kernel_irq_routing_entry *e;
struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS];
Expand All @@ -304,7 +255,7 @@ static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd)
static int
kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
{
struct _irqfd *irqfd, *tmp;
struct kvm_kernel_irqfd *irqfd, *tmp;
struct fd f;
struct eventfd_ctx *eventfd = NULL, *resamplefd = NULL;
int ret;
Expand Down Expand Up @@ -340,7 +291,7 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
irqfd->eventfd = eventfd;

if (args->flags & KVM_IRQFD_FLAG_RESAMPLE) {
struct _irqfd_resampler *resampler;
struct kvm_kernel_irqfd_resampler *resampler;

resamplefd = eventfd_ctx_fdget(args->resamplefd);
if (IS_ERR(resamplefd)) {
Expand Down Expand Up @@ -525,7 +476,7 @@ kvm_eventfd_init(struct kvm *kvm)
static int
kvm_irqfd_deassign(struct kvm *kvm, struct kvm_irqfd *args)
{
struct _irqfd *irqfd, *tmp;
struct kvm_kernel_irqfd *irqfd, *tmp;
struct eventfd_ctx *eventfd;

eventfd = eventfd_ctx_fdget(args->fd);
Expand Down Expand Up @@ -581,7 +532,7 @@ kvm_irqfd(struct kvm *kvm, struct kvm_irqfd *args)
void
kvm_irqfd_release(struct kvm *kvm)
{
struct _irqfd *irqfd, *tmp;
struct kvm_kernel_irqfd *irqfd, *tmp;

spin_lock_irq(&kvm->irqfds.lock);

Expand All @@ -604,7 +555,7 @@ kvm_irqfd_release(struct kvm *kvm)
*/
void kvm_irq_routing_update(struct kvm *kvm)
{
struct _irqfd *irqfd;
struct kvm_kernel_irqfd *irqfd;

spin_lock_irq(&kvm->irqfds.lock);

Expand Down

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