From: Alex Williamson <alex.williamson@redhat.com>
To: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Steven Sistare <steven.sistare@oracle.com>,
"Tian, Kevin" <kevin.tian@intel.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: [PATCH] vfio/type1: Cleanup remaining vaddr removal/update fragments
Date: Mon, 12 Dec 2022 08:58:23 -0700 [thread overview]
Message-ID: <20221212085823.5d760656.alex.williamson@redhat.com> (raw)
In-Reply-To: <Y5cqAk1/6ayzmTjg@ziepe.ca>
On Mon, 12 Dec 2022 09:17:54 -0400
Jason Gunthorpe <jgg@ziepe.ca> wrote:
> On Sat, Dec 10, 2022 at 09:14:06AM -0500, Steven Sistare wrote:
>
> > Thank you for your thoughtful response. Rather than debate the degree of
> > of vulnerability, I propose an alternate solution. The technical crux of
> > the matter is support for mediated devices.
>
> I'm not sure I'm convinced about that. It is easy to make problematic
> situations with mdevs, but that doesn't mean other cases don't exist
> too eg what happens if userspace suspends and then immediately does
> something to trigger a domain attachment? Doesn't it still deadlock
> the kernel?
The opportunity for that to deadlock isn't obvious to me, a replay
would be stalled waiting for invalid vaddrs, but this is essentially
the user deadlocking themselves. There's also code there to handle the
process getting killed while waiting, making it interruptible. Thanks,
Alex
next prev parent reply other threads:[~2022-12-12 15:59 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-07 21:45 [PATCH] vfio/type1: Cleanup remaining vaddr removal/update fragments Alex Williamson
2022-12-07 23:21 ` Jason Gunthorpe
2022-12-08 7:56 ` Tian, Kevin
2022-12-08 16:40 ` Alex Williamson
2022-12-09 18:40 ` Steven Sistare
2022-12-09 19:42 ` Alex Williamson
2022-12-09 19:52 ` Steven Sistare
2022-12-09 21:01 ` Alex Williamson
2022-12-10 14:14 ` Steven Sistare
2022-12-12 13:17 ` Jason Gunthorpe
2022-12-12 13:54 ` Steven Sistare
2022-12-12 15:58 ` Alex Williamson [this message]
2022-12-12 20:59 ` Steven Sistare
2022-12-12 21:26 ` Alex Williamson
2022-12-12 23:08 ` Jason Gunthorpe
2022-12-12 23:29 ` Alex Williamson
2022-12-12 23:35 ` Jason Gunthorpe
2022-12-13 0:04 ` Alex Williamson
2022-12-13 0:11 ` Jason Gunthorpe
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