On Thu, Jan 22, 2026 at 12:41:31PM +0100, Carlos López wrote:
> While unhooking from the irqfd waitqueue, clear the internal eventfd
> counter by using eventfd_ctx_remove_wait_queue() instead of
> remove_wait_queue(), preventing potential spurious interrupts. This
> removes the need to store a pointer into the workqueue, as the eventfd
> already keeps track of it.
>
> This mimicks what other similar subsystems do on their equivalent paths
> with their irqfds (KVM, Xen, ACRN support, etc).
>
> Signed-off-by: Carlos López <[email protected]>
This looks like a good change to me. I've queued it to hyperv-next.
Thanks!
Also CC our kernel folks just in case I missed something.
Wei
> ---
> drivers/hv/mshv_eventfd.c | 5 ++---
> drivers/hv/mshv_eventfd.h | 1 -
> 2 files changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/hv/mshv_eventfd.c b/drivers/hv/mshv_eventfd.c
> index d93a18f09c76..4432063e963d 100644
> --- a/drivers/hv/mshv_eventfd.c
> +++ b/drivers/hv/mshv_eventfd.c
> @@ -247,12 +247,13 @@ static void mshv_irqfd_shutdown(struct work_struct
> *work)
> {
> struct mshv_irqfd *irqfd =
> container_of(work, struct mshv_irqfd, irqfd_shutdown);
> + u64 cnt;
>
> /*
> * Synchronize with the wait-queue and unhook ourselves to prevent
> * further events.
> */
> - remove_wait_queue(irqfd->irqfd_wqh, &irqfd->irqfd_wait);
> + eventfd_ctx_remove_wait_queue(irqfd->irqfd_eventfd_ctx,
> &irqfd->irqfd_wait, &cnt);
>
> if (irqfd->irqfd_resampler) {
> mshv_irqfd_resampler_shutdown(irqfd);
> @@ -371,8 +372,6 @@ static void mshv_irqfd_queue_proc(struct file *file,
> wait_queue_head_t *wqh,
> struct mshv_irqfd *irqfd =
> container_of(polltbl, struct mshv_irqfd, irqfd_polltbl);
>
> - irqfd->irqfd_wqh = wqh;
> -
> /*
> * TODO: Ensure there isn't already an exclusive, priority waiter, e.g.
> * that the irqfd isn't already bound to another partition. Only the
> diff --git a/drivers/hv/mshv_eventfd.h b/drivers/hv/mshv_eventfd.h
> index 332e7670a344..464c6b81ab33 100644
> --- a/drivers/hv/mshv_eventfd.h
> +++ b/drivers/hv/mshv_eventfd.h
> @@ -32,7 +32,6 @@ struct mshv_irqfd {
> struct mshv_lapic_irq irqfd_lapic_irq;
> struct hlist_node irqfd_hnode;
> poll_table irqfd_polltbl;
> - wait_queue_head_t *irqfd_wqh;
> wait_queue_entry_t irqfd_wait;
> struct work_struct irqfd_shutdown;
> struct mshv_irqfd_resampler *irqfd_resampler;
>
> base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
> --
> 2.51.0
>
