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Date:   Wed, 14 Jun 2023 10:20:44 -0400
From:   "Michael S. Tsirkin" <mst@redhat.com>
To:     "Eric W. Biederman" <ebiederm@xmission.com>
Cc:     Mike Christie <michael.christie@oracle.com>,
        Oleg Nesterov <oleg@redhat.com>, linux@leemhuis.info,
        nicolas.dichtel@6wind.com, axboe@kernel.dk,
        torvalds@linux-foundation.org, linux-kernel@vger.kernel.org,
        virtualization@lists.linux-foundation.org, sgarzare@redhat.com,
        jasowang@redhat.com, stefanha@redhat.com, brauner@kernel.org
Subject: Re: Can vhost translate to io_uring?
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On Wed, Jun 14, 2023 at 01:02:58AM -0500, Eric W. Biederman wrote:
> 
> I am sad my idea for simplifying things did not work out.
> 
> 
> Let's try an even bigger idea to reduce maintenance and simplify things.
> 
> Could vhost depend on io_uring?
> 
> Could vhost just be a translation layer of existing vhost requests to
> io_uring requests?

I expect that's going to have a measureable performance impact.

> At a quick glance it looks like io_uring already supports the
> functionality that vhost supports (which I think is networking and
> scsi).
> 
> If vhost could become a translation layer that would allow removing
> the vhost worker and PF_USER_WORKER could be removed completely,
> leaving only PF_IO_WORKER.
> 
> 
> I suggest this because a significant vhost change is needed because in
> the long term the hacks in exec and coredump are not a good idea.  Which
> means something like my failed "[PATCH v3] fork, vhost: Use CLONE_THREAD
> to fix freezer/ps regression".
> 
> If we have to go to all of the trouble of reworking things it why can't
> we just make io_uring do all of the work?
> 
> Eric