From: "Jan Beulich" <JBeulich@suse.com>
To: Andrey Grodzovsky <andrey2805@gmail.com>
Cc: jw@quattru.com, xen-devel@lists.xen.org
Subject: Re: Issues with PCI-Passtrough (VT-d) in HVM with Xen 4.6
Date: Wed, 15 Jun 2016 07:14:18 -0600 [thread overview]
Message-ID: <576170CA02000078000F5556@prv-mh.provo.novell.com> (raw)
In-Reply-To: <CAJphD_o27ySbiwkmdbYsW-HkkEct0nwEKEfa-xTs79dbVmPn9A@mail.gmail.com>
>>> On 15.06.16 at 12:45, <andrey2805@gmail.com> wrote:
> In reply to -
> http://lists.xen.org/archives/html/xen-devel/2016-06/msg00622.html
>
> HI, I am working with Jurgen on the issue, as per Jan's request I tried to
> write explicitly only latency timer to be written -
> bool force_write = false;
> if ((dev_data->permissive || xen_pcibk_permissive) &&
> offset == PCI_CACHE_LINE_SIZE && size == 4)
> force_write = true;
> ...
>
> if ((force_write || !handled) && !err) {...}
>
> But then it exposed another issue, the command register field seems not to
> be restored also
> because I think the bits which are to be restored are not
> in PCI_COMMAND_GUEST mask.
Please be more precise: Which bits in particular are not getting
set back to the needed values (I would guess the memory
and/or I/O decode ones, which we specifically must not allow
the guest to control, but I'd like to be certain)?
If my guess is correct, then I think rather than adding some
hackish workaround to pciback you'd better see whether there's
a way to cause a pci_disable_device() through your driver before
the reset, and a pci_enable_device() after. Or actually, I think
you can do this via plain config space writes from your driver: Try
writing the Command Register with the two decode bits clear
right before restoring the intended value (see the logic close to
the top of command_write()).
Jan
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xen.org
http://lists.xen.org/xen-devel
next prev parent reply other threads:[~2016-06-15 13:14 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-15 10:45 Issues with PCI-Passtrough (VT-d) in HVM with Xen 4.6 Andrey Grodzovsky
2016-06-15 13:14 ` Jan Beulich [this message]
2016-06-18 3:24 ` Andrey Grodzovsky
2016-06-20 6:57 ` Jan Beulich
-- strict thread matches above, loose matches on Subject: below --
2016-06-02 19:59 Sylwester Sosnowski
2016-06-02 20:06 ` Konrad Rzeszutek Wilk
2016-06-02 20:11 ` Sylwester Sosnowski
2016-06-03 7:24 ` Sylwester Sosnowski
2016-06-03 11:52 ` Jan Beulich
2016-06-03 12:02 ` Jürgen Walter
2016-06-03 13:26 ` Jan Beulich
2016-06-03 14:20 ` Jan Beulich
2016-06-04 14:36 ` Jürgen Walter
2016-06-06 7:59 ` Jan Beulich
2016-06-04 15:15 ` Jürgen Walter
2016-06-06 8:41 ` Jan Beulich
2016-06-06 9:09 ` Jürgen Walter
2016-06-06 9:43 ` Jan Beulich
2016-06-06 14:01 ` Boris Ostrovsky
2016-06-06 14:21 ` Jan Beulich
2016-06-06 14:45 ` Boris Ostrovsky
2016-06-02 19:49 Sylwester Sosnowski
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=576170CA02000078000F5556@prv-mh.provo.novell.com \
--to=jbeulich@suse.com \
--cc=andrey2805@gmail.com \
--cc=jw@quattru.com \
--cc=xen-devel@lists.xen.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).