From: "Pasi Kärkkäinen" <pasik@iki.fi>
To: Govinda Tatti <govinda.tatti@oracle.com>
Cc: Jan Beulich <JBeulich@suse.com>,
Konrad Wilk <konrad.wilk@oracle.com>,
Juergen Gross <jgross@suse.com>,
xen-devel@lists.xenproject.org,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
linux-kernel@vger.kernel.org
Subject: Re: [Xen-devel] [PATCH] Xen/pciback: Implement PCI slot or bus reset with 'do_flr' SysFS attribute
Date: Wed, 29 Nov 2017 20:05:29 +0200 [thread overview]
Message-ID: <20171129180529.GQ20756@reaktio.net> (raw)
In-Reply-To: <fb6d3c3b-2fba-1903-d3b1-bf7aeefd7ee8@oracle.com>
On Wed, Nov 29, 2017 at 11:25:09AM -0600, Govinda Tatti wrote:
>
> >>>Furthermore, contrary to what you claim in
> >>>your reply to Pasi, I can't see where you try an actual FLR first -
> >>>you go straight to pci_probe_reset_{slot,bus}(). If you actually
> >>>tried FLR first, only falling back to the other methods as "emulation",
> >>>I could certainly agree with the file name chosen.
> >>Currently, multiple resets are being invoked (independently) in the context
> >>of "xl attach/detach/shutdown/reboot".
> >>
> >>- pci_reset_function_locked (invoked by pcistub_put_pci_dev())
> >> This function tries various PCI reset methods including FLR.
> >>- pcistub_reset_dev (called by toolsstack based on "do_flr" attribute)
> >While related in a certain way, I can't really see how this addresses
> >the comment.
>
> pcistub_reset_dev() just tries slot or bus reset but not FLR since it is
> being
> checked and executed by pci_reset_function_locked() if supported. May be we
> can
> add FLR reset code to pcistub_reset_dev() and try FLR first before fall-back
> to
> slot/bus reset.
>
Hmm.. is the suitable reset method something that can be figured out automatically?
I mean if FLR is tried first, but it isn't supported by the device, is it OK to go ahead and do a slot/bus reset automatically?
What if there are other devices in the same bus, wouldn't automatic bus reset be a bad thing?
Or should the reset-method be configured by the user for the VM / PCI device ?
Just thinking out loud here..
> Cheers
> GOVINDA
>
Thanks,
-- Pasi
next prev parent reply other threads:[~2017-11-29 18:15 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-06 17:48 [PATCH] Xen/pciback: Implement PCI slot or bus reset with 'do_flr' SysFS attribute Govinda Tatti
2017-11-07 11:21 ` [Xen-devel] " Roger Pau Monné
2017-11-08 15:00 ` Govinda Tatti
2017-11-08 15:09 ` Juergen Gross
2017-11-08 15:34 ` Govinda Tatti
2017-11-07 14:40 ` Jan Beulich
2017-11-08 15:44 ` Govinda Tatti
2017-11-08 17:38 ` Pasi Kärkkäinen
2017-11-08 23:26 ` Govinda Tatti
2017-11-09 8:28 ` Jan Beulich
2017-11-29 15:08 ` Govinda Tatti
2017-11-29 15:35 ` Jan Beulich
2017-11-29 16:29 ` Konrad Rzeszutek Wilk
2017-11-29 16:40 ` Jan Beulich
2017-11-29 19:26 ` Konrad Rzeszutek Wilk
2017-11-29 19:44 ` Govinda Tatti
2017-11-30 8:29 ` Jan Beulich
2017-11-30 13:55 ` Govinda Tatti
2017-11-29 17:25 ` Govinda Tatti
2017-11-29 18:05 ` Pasi Kärkkäinen [this message]
2017-11-29 19:51 ` Govinda Tatti
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=20171129180529.GQ20756@reaktio.net \
--to=pasik@iki.fi \
--cc=JBeulich@suse.com \
--cc=boris.ostrovsky@oracle.com \
--cc=govinda.tatti@oracle.com \
--cc=jgross@suse.com \
--cc=konrad.wilk@oracle.com \
--cc=linux-kernel@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;
as well as URLs for NNTP newsgroup(s).