The difference between these two functions:
- virtio_notify() uses the interrupt code path (MSI or classic IRQs)
- virtio_notify_irqfd() uses guest notifiers (irqfds)
virtio_notify() can only be called with the BQL held because the
interrupt code path requires the BQL. Device models use
virtio_notify_irqfd() from IOThreads since the BQL is not held.
The two functions can be unified by pushing down the if
(qemu_in_iothread()) check from virtio-blk and virtio-scsi into core
virtio code. This is in preparation for the next commit that will add
irqfd support to virtio_notify_config() and where it's unattractive to
introduce another irqfd-only API for device model callers.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-ID: <20250922220149.498967-3-stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
1e9181dc52