From: Keir Fraser <keir.xen@gmail.com>
To: Sander Eikelenboom <linux@eikelenboom.it>
Cc: "wei.wang2@amd.com" <wei.wang2@amd.com>,
Santosh Jodh <Santosh.Jodh@citrix.com>,
"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>
Subject: Re: Using debug-key 'o: Dump IOMMU p2m table, locks up machine
Date: Sun, 02 Sep 2012 15:58:58 +0100 [thread overview]
Message-ID: <CC6932C2.3D99D%keir.xen@gmail.com> (raw)
In-Reply-To: <40501859.20120902104331@eikelenboom.it>
On 02/09/2012 09:43, "Sander Eikelenboom" <linux@eikelenboom.it> wrote:
>> Quite simply, there likely needs to be more tracing on the IOMMU fault path.
>> That's a separate concern from your keyhandler of course, but just saying
>> I'd be looking for the former rather than the latter, for diagnosing
>> Sander's bug.
>
> Are there any printk's I could add to get more relevant info about the AMD-Vi:
> IO_PAGE_FAULT ?
No really straightforward one. I think we need a per-IOMMU-type handler to
walk the IOMMU page table for a given virtual address, and dump every
page-table-entry on the path. Like an IOMMU version of show_page_walk().
Personally I would suspect this is more useful than the dump-everything
handlers: just give a *full* *detailed* walk for the actually interesting
virtual address (the one faulted on).
> I have attached new output from xl dmesg, this time with iommu=debug on (the
> option changed from 4.1 to 4.2).
Not easy to glean any more from that, without extra tracing such as
described above, and/or digging into the guest to find what driver-side
actions are causing the faults.
-- Keir
>
>
>> -- Keir
>
next prev parent reply other threads:[~2012-09-02 14:58 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-31 21:45 Using debug-key 'o: Dump IOMMU p2m table, locks up machine Sander Eikelenboom
2012-08-31 22:24 ` Santosh Jodh
2012-08-31 22:42 ` Sander Eikelenboom
2012-08-31 22:57 ` Santosh Jodh
2012-08-31 23:16 ` Sander Eikelenboom
2012-08-31 23:58 ` Santosh Jodh
2012-09-01 0:42 ` Santosh Jodh
2012-09-03 8:14 ` Jan Beulich
2012-09-01 2:01 ` Keir Fraser
2012-09-01 17:03 ` Santosh Jodh
2012-09-01 19:13 ` Keir Fraser
2012-09-02 2:08 ` Santosh Jodh
2012-09-02 7:13 ` Keir Fraser
2012-09-02 7:19 ` Keir Fraser
2012-09-02 8:43 ` Sander Eikelenboom
2012-09-02 14:58 ` Keir Fraser [this message]
2012-09-02 15:14 ` Sander Eikelenboom
2012-09-03 15:20 ` Wei Wang
2012-09-04 8:21 ` Sander Eikelenboom
2012-09-04 16:43 ` Sander Eikelenboom
2012-09-05 10:14 ` Jan Beulich
2012-09-05 10:25 ` Sander Eikelenboom
2012-09-05 10:40 ` Jan Beulich
2012-09-05 10:48 ` Sander Eikelenboom
2012-09-05 11:41 ` Jan Beulich
2012-09-05 12:11 ` Sander Eikelenboom
2012-09-05 14:15 ` Wei Wang
2012-09-05 15:05 ` Jan Beulich
2012-09-05 12:48 ` Wei Wang
2012-09-05 12:30 ` Wei Wang
2012-09-03 8:21 ` Jan Beulich
2012-09-03 8:33 ` Sander Eikelenboom
2012-09-03 9:05 ` Jan Beulich
2012-09-04 7:08 ` Sander Eikelenboom
2012-09-04 7:46 ` Jan Beulich
2012-09-04 8:13 ` Sander Eikelenboom
2012-09-04 9:26 ` Jan Beulich
2012-10-02 20:09 ` Konrad Rzeszutek Wilk
2012-10-03 13:12 ` Jan Beulich
2012-10-02 20:54 ` Matt Wilson
2012-09-20 8:08 ` Jan Beulich
2012-09-28 14:08 ` Sander Eikelenboom
2012-09-28 21:26 ` Jeremy Fitzhardinge
2012-10-02 20:08 ` Konrad Rzeszutek Wilk
2012-09-02 7:42 ` Keir Fraser
2012-09-04 6:35 ` Jan Beulich
2012-09-04 6:52 ` Sander Eikelenboom
2012-09-04 7:01 ` Keir Fraser
2012-09-04 6:59 ` Keir Fraser
2012-09-04 7:55 ` Jan Beulich
2012-09-04 8:04 ` Keir Fraser
2012-09-04 8:11 ` Keir Fraser
2012-09-04 8:20 ` Sander Eikelenboom
2012-09-04 8:38 ` Jan Beulich
2012-09-04 8:54 ` Keir Fraser
2012-09-04 9:40 ` Jan Beulich
2012-09-04 13:29 ` Andrew Cooper
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