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Diffstat (limited to 'virt/kvm/eventfd.c')
-rw-r--r--virt/kvm/eventfd.c134
1 files changed, 102 insertions, 32 deletions
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
index 20c3af7692c5..3c5981c87c3f 100644
--- a/virt/kvm/eventfd.c
+++ b/virt/kvm/eventfd.c
@@ -33,10 +33,13 @@
#include <linux/kernel.h>
#include <linux/srcu.h>
#include <linux/slab.h>
+#include <linux/seqlock.h>
+#include <trace/events/kvm.h>
+#include "irq.h"
#include "iodev.h"
-#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
+#ifdef CONFIG_HAVE_KVM_IRQFD
/*
* --------------------------------------------------------------------
* irqfd: Allows an fd to be used to inject an interrupt to the guest
@@ -75,7 +78,8 @@ struct _irqfd {
struct kvm *kvm;
wait_queue_t wait;
/* Update side is protected by irqfds.lock */
- struct kvm_kernel_irq_routing_entry __rcu *irq_entry;
+ 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;
@@ -223,16 +227,20 @@ irqfd_wakeup(wait_queue_t *wait, unsigned mode, int sync, void *key)
{
struct _irqfd *irqfd = container_of(wait, struct _irqfd, wait);
unsigned long flags = (unsigned long)key;
- struct kvm_kernel_irq_routing_entry *irq;
+ struct kvm_kernel_irq_routing_entry irq;
struct kvm *kvm = irqfd->kvm;
+ unsigned seq;
int idx;
if (flags & POLLIN) {
idx = srcu_read_lock(&kvm->irq_srcu);
- irq = srcu_dereference(irqfd->irq_entry, &kvm->irq_srcu);
+ do {
+ seq = read_seqcount_begin(&irqfd->irq_entry_sc);
+ irq = irqfd->irq_entry;
+ } while (read_seqcount_retry(&irqfd->irq_entry_sc, seq));
/* An event has been signaled, inject an interrupt */
- if (irq)
- kvm_set_msi(irq, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1,
+ if (irq.type == KVM_IRQ_ROUTING_MSI)
+ kvm_set_msi(&irq, kvm, KVM_USERSPACE_IRQ_SOURCE_ID, 1,
false);
else
schedule_work(&irqfd->inject);
@@ -272,34 +280,37 @@ irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh,
}
/* Must be called under irqfds.lock */
-static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd,
- struct kvm_irq_routing_table *irq_rt)
+static void irqfd_update(struct kvm *kvm, struct _irqfd *irqfd)
{
struct kvm_kernel_irq_routing_entry *e;
+ struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS];
+ int i, n_entries;
- if (irqfd->gsi >= irq_rt->nr_rt_entries) {
- rcu_assign_pointer(irqfd->irq_entry, NULL);
- return;
- }
+ n_entries = kvm_irq_map_gsi(kvm, entries, irqfd->gsi);
+
+ write_seqcount_begin(&irqfd->irq_entry_sc);
+
+ irqfd->irq_entry.type = 0;
- hlist_for_each_entry(e, &irq_rt->map[irqfd->gsi], link) {
+ e = entries;
+ for (i = 0; i < n_entries; ++i, ++e) {
/* Only fast-path MSI. */
if (e->type == KVM_IRQ_ROUTING_MSI)
- rcu_assign_pointer(irqfd->irq_entry, e);
- else
- rcu_assign_pointer(irqfd->irq_entry, NULL);
+ irqfd->irq_entry = *e;
}
+
+ write_seqcount_end(&irqfd->irq_entry_sc);
}
static int
kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
{
- struct kvm_irq_routing_table *irq_rt;
struct _irqfd *irqfd, *tmp;
struct fd f;
struct eventfd_ctx *eventfd = NULL, *resamplefd = NULL;
int ret;
unsigned int events;
+ int idx;
irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL);
if (!irqfd)
@@ -310,6 +321,7 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
INIT_LIST_HEAD(&irqfd->list);
INIT_WORK(&irqfd->inject, irqfd_inject);
INIT_WORK(&irqfd->shutdown, irqfd_shutdown);
+ seqcount_init(&irqfd->irq_entry_sc);
f = fdget(args->fd);
if (!f.file) {
@@ -392,9 +404,9 @@ kvm_irqfd_assign(struct kvm *kvm, struct kvm_irqfd *args)
goto fail;
}
- irq_rt = rcu_dereference_protected(kvm->irq_routing,
- lockdep_is_held(&kvm->irqfds.lock));
- irqfd_update(kvm, irqfd, irq_rt);
+ idx = srcu_read_lock(&kvm->irq_srcu);
+ irqfd_update(kvm, irqfd);
+ srcu_read_unlock(&kvm->irq_srcu, idx);
list_add_tail(&irqfd->list, &kvm->irqfds.items);
@@ -433,12 +445,73 @@ out:
kfree(irqfd);
return ret;
}
+
+bool kvm_irq_has_notifier(struct kvm *kvm, unsigned irqchip, unsigned pin)
+{
+ struct kvm_irq_ack_notifier *kian;
+ int gsi, idx;
+
+ 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) {
+ srcu_read_unlock(&kvm->irq_srcu, idx);
+ return true;
+ }
+
+ srcu_read_unlock(&kvm->irq_srcu, idx);
+
+ return false;
+}
+EXPORT_SYMBOL_GPL(kvm_irq_has_notifier);
+
+void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
+{
+ struct kvm_irq_ack_notifier *kian;
+ 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);
+ srcu_read_unlock(&kvm->irq_srcu, idx);
+}
+
+void kvm_register_irq_ack_notifier(struct kvm *kvm,
+ struct kvm_irq_ack_notifier *kian)
+{
+ mutex_lock(&kvm->irq_lock);
+ hlist_add_head_rcu(&kian->link, &kvm->irq_ack_notifier_list);
+ mutex_unlock(&kvm->irq_lock);
+#ifdef __KVM_HAVE_IOAPIC
+ kvm_vcpu_request_scan_ioapic(kvm);
+#endif
+}
+
+void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
+ struct kvm_irq_ack_notifier *kian)
+{
+ mutex_lock(&kvm->irq_lock);
+ hlist_del_init_rcu(&kian->link);
+ mutex_unlock(&kvm->irq_lock);
+ synchronize_srcu(&kvm->irq_srcu);
+#ifdef __KVM_HAVE_IOAPIC
+ kvm_vcpu_request_scan_ioapic(kvm);
+#endif
+}
#endif
void
kvm_eventfd_init(struct kvm *kvm)
{
-#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
+#ifdef CONFIG_HAVE_KVM_IRQFD
spin_lock_init(&kvm->irqfds.lock);
INIT_LIST_HEAD(&kvm->irqfds.items);
INIT_LIST_HEAD(&kvm->irqfds.resampler_list);
@@ -447,7 +520,7 @@ kvm_eventfd_init(struct kvm *kvm)
INIT_LIST_HEAD(&kvm->ioeventfds);
}
-#ifdef CONFIG_HAVE_KVM_IRQ_ROUTING
+#ifdef CONFIG_HAVE_KVM_IRQFD
/*
* shutdown any irqfd's that match fd+gsi
*/
@@ -466,14 +539,14 @@ kvm_irqfd_deassign(struct kvm *kvm, struct kvm_irqfd *args)
list_for_each_entry_safe(irqfd, tmp, &kvm->irqfds.items, list) {
if (irqfd->eventfd == eventfd && irqfd->gsi == args->gsi) {
/*
- * This rcu_assign_pointer is needed for when
+ * This clearing of irq_entry.type is needed for when
* another thread calls kvm_irq_routing_update before
* we flush workqueue below (we synchronize with
* kvm_irq_routing_update using irqfds.lock).
- * It is paired with synchronize_srcu done by caller
- * of that function.
*/
- rcu_assign_pointer(irqfd->irq_entry, NULL);
+ write_seqcount_begin(&irqfd->irq_entry_sc);
+ irqfd->irq_entry.type = 0;
+ write_seqcount_end(&irqfd->irq_entry_sc);
irqfd_deactivate(irqfd);
}
}
@@ -528,20 +601,17 @@ kvm_irqfd_release(struct kvm *kvm)
}
/*
- * Change irq_routing and irqfd.
+ * Take note of a change in irq routing.
* Caller must invoke synchronize_srcu(&kvm->irq_srcu) afterwards.
*/
-void kvm_irq_routing_update(struct kvm *kvm,
- struct kvm_irq_routing_table *irq_rt)
+void kvm_irq_routing_update(struct kvm *kvm)
{
struct _irqfd *irqfd;
spin_lock_irq(&kvm->irqfds.lock);
- rcu_assign_pointer(kvm->irq_routing, irq_rt);
-
list_for_each_entry(irqfd, &kvm->irqfds.items, list)
- irqfd_update(kvm, irqfd, irq_rt);
+ irqfd_update(kvm, irqfd);
spin_unlock_irq(&kvm->irqfds.lock);
}
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-07-21 02:06:02 +0200