CVS commit: src/sys/dev/pci

["Taylor R Campbell" <riastradh%netbsd.org@localhost>]

Module Name:    src
Committed By:   riastradh
Date:           Fri May 22 14:38:51 UTC 2026

Modified Files:
        src/sys/dev/pci: ld_virtio.c

Log Message:
ld@virtio: Guard virtio_dequeue by virtio_vq_is_enqueued.

After triggering the DMA operation, or any previous virtio_dequeue,
virtio_vq_is_enqueued issues the necessary bus_dmamap_sync for
virtio_dequeue to observe any potential (new) result.

Normally this happens inside virtio(4) (in virtio_vq_intr) between
interrupt delivery and calling the virtqueue's done callback.  But
polling mode I/O operations (and dump operations) don't take that
path, so it is necessary to call virtio_vq_is_enqueued explicitly.

PR kern/60182: ld@virtio sometimes hangs up


To generate a diff of this commit:
cvs rdiff -u -r1.47 -r1.48 src/sys/dev/pci/ld_virtio.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.