Re: [PATCH RFC 04/15] net/vhost-user: add memory isolation

Hanna Czenczek <[email protected]> Mon, 3 Aug 2026 14:27:01 +0200
Newsgroups dev.linux.lists.virtio-fs,org.nongnu.qemu-devel
Message-ID <[email protected]>
On 24.07.26 00:30, Connor Kite wrote:
> Add a memory-isolation property to NetdevPassOptions and
> NetDevVhostUserOptions in net.json.  This property will
> be used for vhost-user devices to disable access to guest
> memory from devices.
>
> It will be passed into vhost_user_init() in a future patch.
>
> Signed-off-by: Connor Kite <[email protected]>
> ---
>   net/passt.c      |  7 +++++++
>   net/vhost-user.c |  4 ++++
>   qapi/net.json    | 15 +++++++++++----
>   3 files changed, 22 insertions(+), 4 deletions(-)

[...]

> diff --git a/qapi/net.json b/qapi/net.json
> index 1a6382825c..4588c7014b 100644
> --- a/qapi/net.json
> +++ b/qapi/net.json
> @@ -213,6 +213,9 @@
>   #
>   # @param: parameter to pass to passt command
>   #
> +# @memory-isolation: enable memory isolation.  Only has effect if
> +#     using vhost-user.  (default: false)
> +#
>   # Since: 10.1
>   ##
>   { 'struct': 'NetdevPasstOptions',
> @@ -250,7 +253,8 @@
>       '*ipv6':               'bool',
>       '*tcp-ports':          ['PasstPortForward'],
>       '*udp-ports':          ['PasstPortForward'],
> -    '*param':              ['PasstParameter'] },
> +    '*param':              ['PasstParameter'],
> +    '*memory-isolation':   'bool'},
>       'if': 'CONFIG_PASST' }

I have a gut feeling there ought to be a better way to add an option the 
only works for vhost-user, but maybe not. I certainly don’t have a 
constructive suggestions. :)

(Apart from that, my only comments would be the QAPI “since” field 
missing, as Markus noted on the previous patch, and the patch ordering 
Stefan has noted.)

Hanna