struct kvm_guest_debug_arch arch;
};
+enum {
+ kvm_ioeventfd_flag_nr_datamatch,
+ kvm_ioeventfd_flag_nr_pio,
+ kvm_ioeventfd_flag_nr_deassign,
+ kvm_ioeventfd_flag_nr_max,
+};
+
+#define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch)
+#define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio)
+#define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign)
+
+#define KVM_IOEVENTFD_VALID_FLAG_MASK ((1 << kvm_ioeventfd_flag_nr_max) - 1)
+
+struct kvm_ioeventfd {
+ __u64 datamatch;
+ __u64 addr; /* legal pio/mmio address */
+ __u32 len; /* 1, 2, 4, or 8 bytes */
+ __s32 fd;
+ __u32 flags;
+ __u8 pad[36];
+};
+
#define KVM_TRC_SHIFT 16
/*
* kvm trace categories
#ifdef __KVM_HAVE_PIT_STATE2
#define KVM_CAP_PIT_STATE2 35
#endif
+#define KVM_CAP_IOEVENTFD 36
#ifdef KVM_CAP_IRQ_ROUTING
#define KVM_IRQFD _IOW(KVMIO, 0x76, struct kvm_irqfd)
#define KVM_CREATE_PIT2 _IOW(KVMIO, 0x77, struct kvm_pit_config)
#define KVM_SET_BOOT_CPU_ID _IO(KVMIO, 0x78)
+#define KVM_IOEVENTFD _IOW(KVMIO, 0x79, struct kvm_ioeventfd)
/*
* ioctls for vcpu fds
*/
#include <linux/kvm_host.h>
+#include <linux/kvm.h>
#include <linux/workqueue.h>
#include <linux/syscalls.h>
#include <linux/wait.h>
#include <linux/file.h>
#include <linux/list.h>
#include <linux/eventfd.h>
+#include <linux/kernel.h>
+
+#include "iodev.h"
/*
* --------------------------------------------------------------------
}
void
-kvm_irqfd_init(struct kvm *kvm)
+kvm_eventfd_init(struct kvm *kvm)
{
spin_lock_init(&kvm->irqfds.lock);
INIT_LIST_HEAD(&kvm->irqfds.items);
+ INIT_LIST_HEAD(&kvm->ioeventfds);
}
/*
module_init(irqfd_module_init);
module_exit(irqfd_module_exit);
+
+/*
+ * --------------------------------------------------------------------
+ * ioeventfd: translate a PIO/MMIO memory write to an eventfd signal.
+ *
+ * userspace can register a PIO/MMIO address with an eventfd for receiving
+ * notification when the memory has been touched.
+ * --------------------------------------------------------------------
+ */
+
+struct _ioeventfd {
+ struct list_head list;
+ u64 addr;
+ int length;
+ struct eventfd_ctx *eventfd;
+ u64 datamatch;
+ struct kvm_io_device dev;
+ bool wildcard;
+};
+
+static inline struct _ioeventfd *
+to_ioeventfd(struct kvm_io_device *dev)
+{
+ return container_of(dev, struct _ioeventfd, dev);
+}
+
+static void
+ioeventfd_release(struct _ioeventfd *p)
+{
+ eventfd_ctx_put(p->eventfd);
+ list_del(&p->list);
+ kfree(p);
+}
+
+static bool
+ioeventfd_in_range(struct _ioeventfd *p, gpa_t addr, int len, const void *val)
+{
+ u64 _val;
+
+ if (!(addr == p->addr && len == p->length))
+ /* address-range must be precise for a hit */
+ return false;
+
+ if (p->wildcard)
+ /* all else equal, wildcard is always a hit */
+ return true;
+
+ /* otherwise, we have to actually compare the data */
+
+ BUG_ON(!IS_ALIGNED((unsigned long)val, len));
+
+ switch (len) {
+ case 1:
+ _val = *(u8 *)val;
+ break;
+ case 2:
+ _val = *(u16 *)val;
+ break;
+ case 4:
+ _val = *(u32 *)val;
+ break;
+ case 8:
+ _val = *(u64 *)val;
+ break;
+ default:
+ return false;
+ }
+
+ return _val == p->datamatch ? true : false;
+}
+
+/* MMIO/PIO writes trigger an event if the addr/val match */
+static int
+ioeventfd_write(struct kvm_io_device *this, gpa_t addr, int len,
+ const void *val)
+{
+ struct _ioeventfd *p = to_ioeventfd(this);
+
+ if (!ioeventfd_in_range(p, addr, len, val))
+ return -EOPNOTSUPP;
+
+ eventfd_signal(p->eventfd, 1);
+ return 0;
+}
+
+/*
+ * This function is called as KVM is completely shutting down. We do not
+ * need to worry about locking just nuke anything we have as quickly as possible
+ */
+static void
+ioeventfd_destructor(struct kvm_io_device *this)
+{
+ struct _ioeventfd *p = to_ioeventfd(this);
+
+ ioeventfd_release(p);
+}
+
+static const struct kvm_io_device_ops ioeventfd_ops = {
+ .write = ioeventfd_write,
+ .destructor = ioeventfd_destructor,
+};
+
+/* assumes kvm->slots_lock held */
+static bool
+ioeventfd_check_collision(struct kvm *kvm, struct _ioeventfd *p)
+{
+ struct _ioeventfd *_p;
+
+ list_for_each_entry(_p, &kvm->ioeventfds, list)
+ if (_p->addr == p->addr && _p->length == p->length &&
+ (_p->wildcard || p->wildcard ||
+ _p->datamatch == p->datamatch))
+ return true;
+
+ return false;
+}
+
+static int
+kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
+{
+ int pio = args->flags & KVM_IOEVENTFD_FLAG_PIO;
+ struct kvm_io_bus *bus = pio ? &kvm->pio_bus : &kvm->mmio_bus;
+ struct _ioeventfd *p;
+ struct eventfd_ctx *eventfd;
+ int ret;
+
+ /* must be natural-word sized */
+ switch (args->len) {
+ 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;
+
+ eventfd = eventfd_ctx_fdget(args->fd);
+ if (IS_ERR(eventfd))
+ return PTR_ERR(eventfd);
+
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (!p) {
+ ret = -ENOMEM;
+ goto fail;
+ }
+
+ INIT_LIST_HEAD(&p->list);
+ p->addr = args->addr;
+ p->length = args->len;
+ p->eventfd = eventfd;
+
+ /* The datamatch feature is optional, otherwise this is a wildcard */
+ if (args->flags & KVM_IOEVENTFD_FLAG_DATAMATCH)
+ p->datamatch = args->datamatch;
+ else
+ p->wildcard = true;
+
+ down_write(&kvm->slots_lock);
+
+ /* Verify that there isnt a match already */
+ if (ioeventfd_check_collision(kvm, p)) {
+ ret = -EEXIST;
+ goto unlock_fail;
+ }
+
+ kvm_iodevice_init(&p->dev, &ioeventfd_ops);
+
+ ret = __kvm_io_bus_register_dev(bus, &p->dev);
+ if (ret < 0)
+ goto unlock_fail;
+
+ list_add_tail(&p->list, &kvm->ioeventfds);
+
+ up_write(&kvm->slots_lock);
+
+ return 0;
+
+unlock_fail:
+ up_write(&kvm->slots_lock);
+
+fail:
+ kfree(p);
+ eventfd_ctx_put(eventfd);
+
+ return ret;
+}
+
+static int
+kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
+{
+ int pio = args->flags & KVM_IOEVENTFD_FLAG_PIO;
+ struct kvm_io_bus *bus = pio ? &kvm->pio_bus : &kvm->mmio_bus;
+ struct _ioeventfd *p, *tmp;
+ struct eventfd_ctx *eventfd;
+ int ret = -ENOENT;
+
+ eventfd = eventfd_ctx_fdget(args->fd);
+ if (IS_ERR(eventfd))
+ return PTR_ERR(eventfd);
+
+ down_write(&kvm->slots_lock);
+
+ list_for_each_entry_safe(p, tmp, &kvm->ioeventfds, list) {
+ bool wildcard = !(args->flags & KVM_IOEVENTFD_FLAG_DATAMATCH);
+
+ if (p->eventfd != eventfd ||
+ p->addr != args->addr ||
+ p->length != args->len ||
+ p->wildcard != wildcard)
+ continue;
+
+ if (!p->wildcard && p->datamatch != args->datamatch)
+ continue;
+
+ __kvm_io_bus_unregister_dev(bus, &p->dev);
+ ioeventfd_release(p);
+ ret = 0;
+ break;
+ }
+
+ up_write(&kvm->slots_lock);
+
+ eventfd_ctx_put(eventfd);
+
+ return ret;
+}
+
+int
+kvm_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
+{
+ if (args->flags & KVM_IOEVENTFD_FLAG_DEASSIGN)
+ return kvm_deassign_ioeventfd(kvm, args);
+
+ return kvm_assign_ioeventfd(kvm, args);
+}
projects / linux.git / commitdiff