From: Stefan Hajnoczi <stefanha@redhat.com>
To: Mike Christie <michael.christie@oracle.com>
Cc: target-devel@vger.kernel.org, linux-scsi@vger.kernel.org,
pbonzini@redhat.com, jasowang@redhat.com, mst@redhat.com,
sgarzare@redhat.com, virtualization@lists.linux-foundation.org
Subject: Re: vhost: multiple worker support
Date: Thu, 3 Jun 2021 15:37:37 +0100 [thread overview]
Message-ID: <YLjpMXbfJsaLrgF5@stefanha-x1.localdomain> (raw)
In-Reply-To: <20210525180600.6349-1-michael.christie@oracle.com>
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On Tue, May 25, 2021 at 01:05:51PM -0500, Mike Christie wrote:
> The following patches apply over linus's tree or mst's vhost branch
> and my cleanup patchset:
>
> https://lists.linuxfoundation.org/pipermail/virtualization/2021-May/054354.html
>
> These patches allow us to support multiple vhost workers per device. I
> ended up just doing Stefan's original idea where userspace has the
> kernel create a worker and we pass back the pid. This has the benefit
> over the workqueue and userspace thread approach where we only have
> one'ish code path in the kernel during setup to detect old tools. The
> main IO paths and device/vq setup/teardown paths all use common code.
>
> The kernel patches here allow us to then do N workers device and also
> share workers across devices.
>
> I've also included a patch for qemu so you can get an idea of how it
> works. If we are ok with the kernel code then I'll break that up into
> a patchset and send to qemu-devel.
It seems risky to allow userspace process A to "share" a vhost worker
thread with userspace process B based on a matching pid alone. Should
they have ptrace_may_access() or similar?
For example, two competing users could sabotague each other by running
lots of work items on their competitor's vhost worker thread.
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next prev parent reply other threads:[~2021-06-03 14:38 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-25 18:05 vhost: multiple worker support Mike Christie
2021-05-25 18:05 ` [PATCH 1/9] vhost: move worker thread fields to new struct Mike Christie
2021-06-03 10:16 ` Stefan Hajnoczi
2021-05-25 18:05 ` [PATCH 2/9] vhost: move vhost worker creation to kick setup Mike Christie
2021-06-03 10:28 ` Stefan Hajnoczi
2021-05-25 18:05 ` [PATCH 3/9] vhost: modify internal functions to take a vhost_worker Mike Christie
2021-06-03 10:45 ` Stefan Hajnoczi
2021-05-25 18:05 ` [PATCH 4/9] vhost: allow vhost_polls to use different vhost_workers Mike Christie
2021-06-03 13:51 ` Stefan Hajnoczi
2021-05-25 18:05 ` [PATCH 5/9] vhost-scsi: flush IO vqs then send TMF rsp Mike Christie
2021-06-03 13:54 ` Stefan Hajnoczi
2021-05-25 18:05 ` [PATCH 6/9] vhost-scsi: make SCSI cmd completion per vq Mike Christie
2021-06-03 13:57 ` Stefan Hajnoczi
2021-05-25 18:05 ` [PATCH 7/9] vhost: allow userspace to create workers Mike Christie
2021-06-03 14:30 ` Stefan Hajnoczi
2021-06-05 23:53 ` michael.christie
2021-06-07 15:19 ` Stefan Hajnoczi
2021-06-09 21:03 ` Mike Christie
2021-06-10 8:06 ` Stefan Hajnoczi
2021-06-18 2:49 ` Mike Christie
2021-06-21 13:41 ` Stefan Hajnoczi
2021-05-25 18:05 ` [PATCH 8/9] vhost: add vhost_dev pointer to vhost_work Mike Christie
2021-06-03 14:31 ` Stefan Hajnoczi
2021-05-25 18:06 ` [PATCH 9/9] vhost: support sharing workers across devs Mike Christie
2021-06-03 14:32 ` Stefan Hajnoczi
2021-06-07 2:18 ` Jason Wang
2021-06-03 10:13 ` vhost: multiple worker support Stefan Hajnoczi
2021-06-03 18:45 ` Mike Christie
2021-06-03 14:37 ` Stefan Hajnoczi [this message]
2021-06-03 22:16 ` Mike Christie
2021-06-05 22:40 ` michael.christie
2021-06-07 15:23 ` Stefan Hajnoczi
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