Re: [PATCH v2] Revert "tap: setting error appropriately when calling net_init_tap_one()"

[Jason Wang]

On Thu, Sep 21, 2023 at 5:48 PM Akihiko Odaki <akihiko.odaki@daynix.com> wrote:
>
> This reverts commit 46d4d36d0bf2b24b205f2f604f0905db80264eef.
>
> The reverted commit changed to emit warnings instead of errors when
> vhost is requested but vhost initialization fails if vhostforce option
> is not set.
>
> However, vhostforce is not meant to change the error handling. It was
> once introduced as an option to commit 5430a28fe4 ("vhost: force vhost
> off for non-MSI guests") to force enabling vhost for non-MSI guests,
> which will have worse performance with vhost. It was deprecated with
> commit 1e7398a140 ("vhost: enable vhost without without MSI-X") and
> changed to behave identical with the vhost option for compatibility.
>
> Worse, commit bf769f742c ("virtio: del net client if net_init_tap_one
> failed") changed to delete the client when vhost fails even when the
> failure only results in a warning. The leads to an assertion failure
> for the -netdev command line option.
>
> The reverted commit was intended to ensure that the vhost initialization
> failure won't result in a corrupted netdev. This problem should have
> been fixed by deleting netdev when the initialization fails instead of
> ignoring the failure by converting it into a warning. Fortunately,
> commit bf769f742c ("virtio: del net client if net_init_tap_one failed"),
> mentioned earlier, implements this behavior.
>
> Restore the correct semantics and fix the assertion failure for the
> -netdev command line option by reverting the problematic commit.
>
> Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
> ---
> V1 -> V2: Corrected the message.
>

Queued.

Thanks