From: "Jürgen Groß" <jgross@suse.com>
To: Stefano Stabellini <sstabellini@kernel.org>,
Julien Grall <julien.grall@arm.com>
Cc: olekstysh@gmail.com, oleksandr_tyshchenko@epam.com,
Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>,
xen-devel@lists.xenproject.org
Subject: Re: [Xen-devel] [PATCH] xen/arm: p2m: Free the p2m entry after flushing the IOMMU TLBs
Date: Wed, 2 Oct 2019 07:07:52 +0200 [thread overview]
Message-ID: <daa146e1-c131-7cd2-aa55-678b6267d314@suse.com> (raw)
In-Reply-To: <alpine.DEB.2.21.1910011907080.26319@sstabellini-ThinkPad-T480s>
On 02.10.19 04:07, Stefano Stabellini wrote:
> + Juergen
>
> On Mon, 12 Aug 2019, Julien Grall wrote:
>> When freeing a p2m entry, all the sub-tree behind it will also be freed.
>> This may include intermediate page-tables or any l3 entry requiring to
>> drop a reference (e.g for foreign pages). As soon as pages are freed,
>> they may be re-used by Xen or another domain. Therefore it is necessary
>> to flush *all* the TLBs beforehand.
>>
>> While CPU TLBs will be flushed before freeing the pages, this is not
>> the case for IOMMU TLBs. This can be solved by moving the IOMMU TLBs
>> flush earlier in the code.
>>
>> This wasn't considered as a security issue as device passthrough on Arm
>> is not security supported.
>>
>> Signed-off-by: Julien Grall <julien.grall@arm.com>
>
> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Release-acked-by: Juergen Gross <jgross@suse.com>
Juergen
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
prev parent reply other threads:[~2019-10-02 5:08 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-12 20:27 [Xen-devel] [PATCH] xen/arm: p2m: Free the p2m entry after flushing the IOMMU TLBs Julien Grall
2019-08-13 8:03 ` Andrew Cooper
2019-08-13 8:59 ` Julien Grall
2019-08-20 15:04 ` Oleksandr
2019-10-02 2:07 ` Stefano Stabellini
2019-10-02 5:07 ` Jürgen Groß [this message]
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=daa146e1-c131-7cd2-aa55-678b6267d314@suse.com \
--to=jgross@suse.com \
--cc=Volodymyr_Babchuk@epam.com \
--cc=julien.grall@arm.com \
--cc=oleksandr_tyshchenko@epam.com \
--cc=olekstysh@gmail.com \
--cc=sstabellini@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;
as well as URLs for NNTP newsgroup(s).