Re: [PATCH] crypto: virtio: Convert from tasklet to BH workqueue

[Herbert Xu]

On Sat, Feb 07, 2026 at 01:20:01PM -0500, Pat Somaru wrote:
> The only generic interface to execute asynchronously in the BH context
> is tasklet; however, it's marked deprecated and has some design flaws
> such as the execution code accessing the tasklet item after the
> execution is complete which can lead to subtle use-after-free in certain
> usage scenarios and less-developed flush and cancel mechanisms.
> 
> To replace tasklets, BH workqueue support was recently added. A BH
> workqueue behaves similarly to regular workqueues except that the queued
> work items are executed in the BH context.
> 
> Convert virtio_crypto_core.c from tasklet to BH workqueue.
> 
> Semantically, this is an equivalent conversion and there shouldn't be
> any user-visible behavior changes. The BH workqueue implementation uses
> the same softirq infrastructure, and performance-critical networking
> conversions have shown no measurable performance impact.
> 
> Signed-off-by: Pat Somaru <patso@xxxxxxxxxxxxxx>
> ---
>  Hi, I'm working on converting tasklet usages to the BH WQ API.
> 
>  The virtio-crypto driver uses a tasklet per data queue to process
>  completed crypto operations in BH context. This converts that tasklet
>  to use the BH workqueue infrastructure.
> 
>  This patch was tested by:
>     - Building with allmodconfig: no new warnings (compared to v6.18)
>     - Building with allyesconfig: no new warnings (compared to v6.18)
>     - Booting defconfig kernel via vng and running `uname -a`:
>     Linux virtme-ng 6.18.0-virtme #1 SMP PREEMPT_DYNAMIC 0 x86_64 GNU/Linux
> 
>  Maintainers can apply this directly to the crypto subsystem tree or ack
>  it for the workqueue tree to carry.
> 
>  drivers/crypto/virtio/virtio_crypto_common.h |  3 ++-
>  drivers/crypto/virtio/virtio_crypto_core.c   | 11 +++++------
>  2 files changed, 7 insertions(+), 7 deletions(-)

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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