#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>
#include <linux/srcu.h>
#include <linux/slab.h>
#include <linux/seqlock.h>
+#include <linux/irqbypass.h>
#include <trace/events/kvm.h>
#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) {
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,
}
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);
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;
/*
/*
* It is now safe to release the object's resources
*/
+#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
+ irq_bypass_unregister_consumer(&irqfd->consumer);
+#endif
eventfd_ctx_put(irqfd->eventfd);
kfree(irqfd);
}
/* 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;
}
* 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));
queue_work(irqfd_cleanup_wq, &irqfd->shutdown);
}
+int __attribute__((weak)) kvm_arch_set_irq_inatomic(
+ struct kvm_kernel_irq_routing_entry *irq,
+ struct kvm *kvm, int irq_source_id,
+ int level,
+ bool line_status)
+{
+ return -EWOULDBLOCK;
+}
+
/*
* Called with wqh->lock held and interrupts disabled
*/
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;
irq = irqfd->irq_entry;
} while (read_seqcount_retry(&irqfd->irq_entry_sc, seq));
/* An event has been signaled, inject an interrupt */
- if (irq.type == KVM_IRQ_ROUTING_MSI)
- kvm_set_msi(&irq, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1,
- false);
- else
+ if (kvm_arch_set_irq_inatomic(&irq, kvm,
+ KVM_USERSPACE_IRQ_SOURCE_ID, 1,
+ false) == -EWOULDBLOCK)
schedule_work(&irqfd->inject);
srcu_read_unlock(&kvm->irq_srcu, idx);
}
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];
- int i, n_entries;
+ int n_entries;
n_entries = kvm_irq_map_gsi(kvm, entries, irqfd->gsi);
write_seqcount_begin(&irqfd->irq_entry_sc);
- irqfd->irq_entry.type = 0;
-
e = entries;
- for (i = 0; i < n_entries; ++i, ++e) {
- /* Only fast-path MSI. */
- if (e->type == KVM_IRQ_ROUTING_MSI)
- irqfd->irq_entry = *e;
- }
+ if (n_entries == 1)
+ irqfd->irq_entry = *e;
+ else
+ irqfd->irq_entry.type = 0;
write_seqcount_end(&irqfd->irq_entry_sc);
}
+#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
+void __attribute__((weak)) kvm_arch_irq_bypass_stop(
+ struct irq_bypass_consumer *cons)
+{
+}
+
+void __attribute__((weak)) kvm_arch_irq_bypass_start(
+ struct irq_bypass_consumer *cons)
+{
+}
+
+int __attribute__((weak)) kvm_arch_update_irqfd_routing(
+ struct kvm *kvm, unsigned int host_irq,
+ uint32_t guest_irq, bool set)
+{
+ return 0;
+}
+#endif
+
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;
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)) {
* we might race against the POLLHUP
*/
fdput(f);
+#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
+ irqfd->consumer.token = (void *)irqfd->eventfd;
+ irqfd->consumer.add_producer = kvm_arch_irq_bypass_add_producer;
+ irqfd->consumer.del_producer = kvm_arch_irq_bypass_del_producer;
+ irqfd->consumer.stop = kvm_arch_irq_bypass_stop;
+ irqfd->consumer.start = kvm_arch_irq_bypass_start;
+ ret = irq_bypass_register_consumer(&irqfd->consumer);
+ if (ret)
+ pr_info("irq bypass consumer (token %p) registration fails: %d\n",
+ irqfd->consumer.token, ret);
+#endif
return 0;
}
EXPORT_SYMBOL_GPL(kvm_irq_has_notifier);
-void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
+void kvm_notify_acked_gsi(struct kvm *kvm, int gsi)
{
struct kvm_irq_ack_notifier *kian;
+
+ hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,
+ link)
+ if (kian->gsi == gsi)
+ kian->irq_acked(kian);
+}
+
+void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
+{
int gsi, idx;
trace_kvm_ack_irq(irqchip, pin);
idx = srcu_read_lock(&kvm->irq_srcu);
gsi = kvm_irq_map_chip_pin(kvm, irqchip, pin);
if (gsi != -1)
- hlist_for_each_entry_rcu(kian, &kvm->irq_ack_notifier_list,
- link)
- if (kian->gsi == gsi)
- kian->irq_acked(kian);
+ kvm_notify_acked_gsi(kvm, gsi);
srcu_read_unlock(&kvm->irq_srcu, idx);
}
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);
void
kvm_irqfd_release(struct kvm *kvm)
{
- struct _irqfd *irqfd, *tmp;
+ struct kvm_kernel_irqfd *irqfd, *tmp;
spin_lock_irq(&kvm->irqfds.lock);
*/
void kvm_irq_routing_update(struct kvm *kvm)
{
- struct _irqfd *irqfd;
+ struct kvm_kernel_irqfd *irqfd;
spin_lock_irq(&kvm->irqfds.lock);
- list_for_each_entry(irqfd, &kvm->irqfds.items, list)
+ list_for_each_entry(irqfd, &kvm->irqfds.items, list) {
irqfd_update(kvm, irqfd);
+#ifdef CONFIG_HAVE_KVM_IRQ_BYPASS
+ if (irqfd->producer) {
+ int ret = kvm_arch_update_irqfd_routing(
+ irqfd->kvm, irqfd->producer->irq,
+ irqfd->gsi, 1);
+ WARN_ON(ret);
+ }
+#endif
+ }
+
spin_unlock_irq(&kvm->irqfds.lock);
}
return KVM_MMIO_BUS;
}
-static int
-kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
+static int kvm_assign_ioeventfd_idx(struct kvm *kvm,
+ enum kvm_bus bus_idx,
+ struct kvm_ioeventfd *args)
{
- enum kvm_bus bus_idx;
- struct _ioeventfd *p;
- struct eventfd_ctx *eventfd;
- int ret;
- bus_idx = ioeventfd_bus_from_flags(args->flags);
- /* must be natural-word sized, or 0 to ignore length */
- switch (args->len) {
- case 0:
- case 1:
- case 2:
- case 4:
- case 8:
- break;
- default:
- return -EINVAL;
- }
-
- /* check for range overflow */
- if (args->addr + args->len < args->addr)
- return -EINVAL;
-
- /* check for extra flags that we don't understand */
- if (args->flags & ~KVM_IOEVENTFD_VALID_FLAG_MASK)
- return -EINVAL;
-
- /* ioeventfd with no length can't be combined with DATAMATCH */
- if (!args->len &&
- args->flags & (KVM_IOEVENTFD_FLAG_PIO |
- KVM_IOEVENTFD_FLAG_DATAMATCH))
- return -EINVAL;
+ struct eventfd_ctx *eventfd;
+ struct _ioeventfd *p;
+ int ret;
eventfd = eventfd_ctx_fdget(args->fd);
if (IS_ERR(eventfd))
if (ret < 0)
goto unlock_fail;
- /* When length is ignored, MMIO is also put on a separate bus, for
- * faster lookups.
- */
- if (!args->len && !(args->flags & KVM_IOEVENTFD_FLAG_PIO)) {
- ret = kvm_io_bus_register_dev(kvm, KVM_FAST_MMIO_BUS,
- p->addr, 0, &p->dev);
- if (ret < 0)
- goto register_fail;
- }
-
kvm->buses[bus_idx]->ioeventfd_count++;
list_add_tail(&p->list, &kvm->ioeventfds);
return 0;
-register_fail:
- kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev);
unlock_fail:
mutex_unlock(&kvm->slots_lock);
}
static int
-kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
+kvm_deassign_ioeventfd_idx(struct kvm *kvm, enum kvm_bus bus_idx,
+ struct kvm_ioeventfd *args)
{
- enum kvm_bus bus_idx;
struct _ioeventfd *p, *tmp;
struct eventfd_ctx *eventfd;
int ret = -ENOENT;
- bus_idx = ioeventfd_bus_from_flags(args->flags);
eventfd = eventfd_ctx_fdget(args->fd);
if (IS_ERR(eventfd))
return PTR_ERR(eventfd);
continue;
kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev);
- if (!p->length) {
- kvm_io_bus_unregister_dev(kvm, KVM_FAST_MMIO_BUS,
- &p->dev);
- }
kvm->buses[bus_idx]->ioeventfd_count--;
ioeventfd_release(p);
ret = 0;
return ret;
}
+static int kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
+{
+ enum kvm_bus bus_idx = ioeventfd_bus_from_flags(args->flags);
+ int ret = kvm_deassign_ioeventfd_idx(kvm, bus_idx, args);
+
+ if (!args->len && bus_idx == KVM_MMIO_BUS)
+ kvm_deassign_ioeventfd_idx(kvm, KVM_FAST_MMIO_BUS, args);
+
+ return ret;
+}
+
+static int
+kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
+{
+ enum kvm_bus bus_idx;
+ int ret;
+
+ bus_idx = ioeventfd_bus_from_flags(args->flags);
+ /* must be natural-word sized, or 0 to ignore length */
+ switch (args->len) {
+ case 0:
+ case 1:
+ case 2:
+ case 4:
+ case 8:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* check for range overflow */
+ if (args->addr + args->len < args->addr)
+ return -EINVAL;
+
+ /* check for extra flags that we don't understand */
+ if (args->flags & ~KVM_IOEVENTFD_VALID_FLAG_MASK)
+ return -EINVAL;
+
+ /* ioeventfd with no length can't be combined with DATAMATCH */
+ if (!args->len && (args->flags & KVM_IOEVENTFD_FLAG_DATAMATCH))
+ return -EINVAL;
+
+ ret = kvm_assign_ioeventfd_idx(kvm, bus_idx, args);
+ if (ret)
+ goto fail;
+
+ /* When length is ignored, MMIO is also put on a separate bus, for
+ * faster lookups.
+ */
+ if (!args->len && bus_idx == KVM_MMIO_BUS) {
+ ret = kvm_assign_ioeventfd_idx(kvm, KVM_FAST_MMIO_BUS, args);
+ if (ret < 0)
+ goto fast_fail;
+ }
+
+ return 0;
+
+fast_fail:
+ kvm_deassign_ioeventfd_idx(kvm, bus_idx, args);
+fail:
+ return ret;
+}
+
int
kvm_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
{
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