[PATCH v4 3/5] KVM: create kvm_irqfd.h

From: Eric Auger
Date: Mon Aug 03 2015 - 13:22:06 EST


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@xxxxxxxxxx>
---
include/linux/kvm_irqfd.h | 69 ++++++++++++++++++++++++++++++++++
virt/kvm/eventfd.c | 95 ++++++++++++-----------------------------------
2 files changed, 92 insertions(+), 72 deletions(-)
create mode 100644 include/linux/kvm_irqfd.h

diff --git a/include/linux/kvm_irqfd.h b/include/linux/kvm_irqfd.h
new file mode 100644
index 0000000..f926b39
--- /dev/null
+++ b/include/linux/kvm_irqfd.h
@@ -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 */
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index 9ff4193..647ffb8 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -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>
@@ -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) {
@@ -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,
@@ -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);
@@ -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;

/*
@@ -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;
}
@@ -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));

@@ -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;
@@ -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];
@@ -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;
@@ -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)) {
@@ -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);
@@ -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);

@@ -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);

--
1.9.1

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