Re: [PATCH 6/6] docs: deprecate virtio-crypto

On 19/08/2026 11.22, Alex Bennée wrote:
> We have outstanding guest exploitable bugs in the code which is fairly
> complex and needs some serious love to clean it up. As off-CPU
> cryptography acceleration seems to be waning in popularity lets just
> deprecate the sub-system with a view to removing it in a couple of
> cycles.
> 
> Link: https://gitlab.com/qemu-project/qemu/-/work_items/3625
> Signed-off-by: Alex Bennée <[email protected]>
> Cc: Gonglei <[email protected]>
> ---
>   docs/about/deprecated.rst | 14 ++++++++++++++
>   1 file changed, 14 insertions(+)
> 
> diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
> index 0c656a968fc..3c22981fc8a 100644
> --- a/docs/about/deprecated.rst
> +++ b/docs/about/deprecated.rst
> @@ -276,6 +276,20 @@ future release. Where no 'dh-params.pem' file is provided, the DH
>   parameters will be automatically negotiated in accordance with
>   RFC7919.
>   
> +Devices
> +-------
> +
> +``virtio-crypto`` (since 11.2)
> +''''''''''''''''''''''''''''''
> +
> +The ``virtio-crypto`` device emulation is quite complex code with a
> +number of known flaws. It has never been migratable so is unlikely to
> +be used in any serious virtualization setting. With most modern
> +systems supporting on-CPU cryptography acceleration via their
> +ISAs sets the need for off-CPU acceleration is also reduced. Add to
> +that the kernel has recently removed the ability to use off-CPU
> +acceleration suggests the time for this sort of off-load has passed.
Reviewed-by: Thomas Huth <[email protected]>