#include <linux/msi.h>
#include <linux/pci.h>
#include <linux/file.h>
-#include <linux/poll.h>
#include <linux/vfio.h>
#include <linux/wait.h>
-#include <linux/workqueue.h>
#include <linux/slab.h>
#include "vfio_pci_private.h"
-/*
- * IRQfd - generic
- */
-struct virqfd {
- void *opaque;
- struct eventfd_ctx *eventfd;
- int (*handler)(void *, void *);
- void (*thread)(void *, void *);
- void *data;
- struct work_struct inject;
- wait_queue_t wait;
- poll_table pt;
- struct work_struct shutdown;
- struct virqfd **pvirqfd;
-};
-
-static struct workqueue_struct *vfio_irqfd_cleanup_wq;
-DEFINE_SPINLOCK(virqfd_lock);
-
-int __init vfio_virqfd_init(void)
-{
- vfio_irqfd_cleanup_wq =
- create_singlethread_workqueue("vfio-irqfd-cleanup");
- if (!vfio_irqfd_cleanup_wq)
- return -ENOMEM;
-
- return 0;
-}
-
-void vfio_virqfd_exit(void)
-{
- destroy_workqueue(vfio_irqfd_cleanup_wq);
-}
-
-static void virqfd_deactivate(struct virqfd *virqfd)
-{
- queue_work(vfio_irqfd_cleanup_wq, &virqfd->shutdown);
-}
-
-static int virqfd_wakeup(wait_queue_t *wait, unsigned mode, int sync, void *key)
-{
- struct virqfd *virqfd = container_of(wait, struct virqfd, wait);
- unsigned long flags = (unsigned long)key;
-
- if (flags & POLLIN) {
- /* An event has been signaled, call function */
- if ((!virqfd->handler ||
- virqfd->handler(virqfd->opaque, virqfd->data)) &&
- virqfd->thread)
- schedule_work(&virqfd->inject);
- }
-
- if (flags & POLLHUP) {
- unsigned long flags;
- spin_lock_irqsave(&virqfd_lock, flags);
-
- /*
- * The eventfd is closing, if the virqfd has not yet been
- * queued for release, as determined by testing whether the
- * virqfd pointer to it is still valid, queue it now. As
- * with kvm irqfds, we know we won't race against the virqfd
- * going away because we hold the lock to get here.
- */
- if (*(virqfd->pvirqfd) == virqfd) {
- *(virqfd->pvirqfd) = NULL;
- virqfd_deactivate(virqfd);
- }
-
- spin_unlock_irqrestore(&virqfd_lock, flags);
- }
-
- return 0;
-}
-
-static void virqfd_ptable_queue_proc(struct file *file,
- wait_queue_head_t *wqh, poll_table *pt)
-{
- struct virqfd *virqfd = container_of(pt, struct virqfd, pt);
- add_wait_queue(wqh, &virqfd->wait);
-}
-
-static void virqfd_shutdown(struct work_struct *work)
-{
- struct virqfd *virqfd = container_of(work, struct virqfd, shutdown);
- u64 cnt;
-
- eventfd_ctx_remove_wait_queue(virqfd->eventfd, &virqfd->wait, &cnt);
- flush_work(&virqfd->inject);
- eventfd_ctx_put(virqfd->eventfd);
-
- kfree(virqfd);
-}
-
-static void virqfd_inject(struct work_struct *work)
-{
- struct virqfd *virqfd = container_of(work, struct virqfd, inject);
- if (virqfd->thread)
- virqfd->thread(virqfd->opaque, virqfd->data);
-}
-
-int vfio_virqfd_enable(void *opaque,
- int (*handler)(void *, void *),
- void (*thread)(void *, void *),
- void *data, struct virqfd **pvirqfd, int fd)
-{
- struct fd irqfd;
- struct eventfd_ctx *ctx;
- struct virqfd *virqfd;
- int ret = 0;
- unsigned int events;
-
- virqfd = kzalloc(sizeof(*virqfd), GFP_KERNEL);
- if (!virqfd)
- return -ENOMEM;
-
- virqfd->pvirqfd = pvirqfd;
- virqfd->opaque = opaque;
- virqfd->handler = handler;
- virqfd->thread = thread;
- virqfd->data = data;
-
- INIT_WORK(&virqfd->shutdown, virqfd_shutdown);
- INIT_WORK(&virqfd->inject, virqfd_inject);
-
- irqfd = fdget(fd);
- if (!irqfd.file) {
- ret = -EBADF;
- goto err_fd;
- }
-
- ctx = eventfd_ctx_fileget(irqfd.file);
- if (IS_ERR(ctx)) {
- ret = PTR_ERR(ctx);
- goto err_ctx;
- }
-
- virqfd->eventfd = ctx;
-
- /*
- * virqfds can be released by closing the eventfd or directly
- * through ioctl. These are both done through a workqueue, so
- * we update the pointer to the virqfd under lock to avoid
- * pushing multiple jobs to release the same virqfd.
- */
- spin_lock_irq(&virqfd_lock);
-
- if (*pvirqfd) {
- spin_unlock_irq(&virqfd_lock);
- ret = -EBUSY;
- goto err_busy;
- }
- *pvirqfd = virqfd;
-
- spin_unlock_irq(&virqfd_lock);
-
- /*
- * Install our own custom wake-up handling so we are notified via
- * a callback whenever someone signals the underlying eventfd.
- */
- init_waitqueue_func_entry(&virqfd->wait, virqfd_wakeup);
- init_poll_funcptr(&virqfd->pt, virqfd_ptable_queue_proc);
-
- events = irqfd.file->f_op->poll(irqfd.file, &virqfd->pt);
-
- /*
- * Check if there was an event already pending on the eventfd
- * before we registered and trigger it as if we didn't miss it.
- */
- if (events & POLLIN) {
- if ((!handler || handler(opaque, data)) && thread)
- schedule_work(&virqfd->inject);
- }
-
- /*
- * Do not drop the file until the irqfd is fully initialized,
- * otherwise we might race against the POLLHUP.
- */
- fdput(irqfd);
-
- return 0;
-err_busy:
- eventfd_ctx_put(ctx);
-err_ctx:
- fdput(irqfd);
-err_fd:
- kfree(virqfd);
-
- return ret;
-}
-EXPORT_SYMBOL_GPL(vfio_virqfd_enable);
-
-void vfio_virqfd_disable(struct virqfd **pvirqfd)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&virqfd_lock, flags);
-
- if (*pvirqfd) {
- virqfd_deactivate(*pvirqfd);
- *pvirqfd = NULL;
- }
-
- spin_unlock_irqrestore(&virqfd_lock, flags);
-
- /*
- * Block until we know all outstanding shutdown jobs have completed.
- * Even if we don't queue the job, flush the wq to be sure it's
- * been released.
- */
- flush_workqueue(vfio_irqfd_cleanup_wq);
-}
-EXPORT_SYMBOL_GPL(vfio_virqfd_disable);
-
/*
* INTx
*/
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