From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Dongli Zhang <dongli.zhang@oracle.com>,
"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Cc: John Sobecki <john.sobecki@oracle.com>,
Joe Jin <joe.jin@oracle.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
<stable@vger.kernel.org>
Subject: Re: [Xen-devel] [PATCH] xen-swiotlb: use actually allocated size on check physical contiguous
Date: Wed, 5 Sep 2018 00:36:09 +0100 [thread overview]
Message-ID: <717bd7ec-229d-02dc-e696-7ede026dbe92@citrix.com> (raw)
In-Reply-To: <f3befca2-fc65-81b8-c9ed-311de7967958@oracle.com>
On 05/09/18 00:14, Dongli Zhang wrote:
> Below module would help people reproduce the issue to understand the symptom:
>
> https://github.com/finallyjustice/patchset/blob/master/xen-swiotlb-panic.c
>
> In addition, on the xen hypervisor side, the memory_exchange() in xen hypervisor
> does not check if the the pfn of input mfn belong to the same extent are
> continuous in guest domain. As a result, the wrong page is stolen from guest domain.
>
> Can we assume it is fine to not check if pfn of mfn are continuous in xen
> hypervisor?
The purpose of the memory_exchange hypercall is to exchange any
arbitrary set of guest frames with an equivalently sized set frames with
different properties.
The practical use is for PV guests to be able to create a DMA buffer
which is physically continuous. Xen does not, and indeed should not,
care about the properties of the input frame list.
~Andrew
next prev parent reply other threads:[~2018-09-04 23:36 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-04 18:16 Joe Jin
2018-09-04 19:13 ` Greg KH
2018-09-04 23:14 ` [Xen-devel] " Dongli Zhang
2018-09-04 23:36 ` Andrew Cooper [this message]
2018-09-07 22:47 ` Joe Jin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=717bd7ec-229d-02dc-e696-7ede026dbe92@citrix.com \
--to=andrew.cooper3@citrix.com \
--cc=dongli.zhang@oracle.com \
--cc=joe.jin@oracle.com \
--cc=john.sobecki@oracle.com \
--cc=linux-kernel@vger.kernel.org \
--cc=stable@vger.kernel.org \
--cc=xen-devel@lists.xenproject.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome