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From: "Roedel, Joerg" <Joerg.Roedel@amd.com>
To: Alex Williamson <alex.williamson@redhat.com>
Cc: Florian Dazinger <florian@dazinger.net>,
	<linux-kernel@vger.kernel.org>,
	iommu <iommu@lists.linux-foundation.org>
Subject: Re: 3.6-rc7 boot crash + bisection
Date: Wed, 26 Sep 2012 15:20:50 +0200	[thread overview]
Message-ID: <20120926132050.GB10549@amd.com> (raw)
In-Reply-To: <1348602226.28860.132.camel@bling.home>

On Tue, Sep 25, 2012 at 01:43:46PM -0600, Alex Williamson wrote:
> Joerg, any thoughts on a quirk for this?  Unfortunately we can't just
> skip IOMMU groups when an alias is broken because it puts the other
> IOMMU groups at risk that might not actually be isolated from this
> device.  It looks like we parse the alias info before PCI is probed, so
> maybe we'd need to call the quirk from iommu_init_device itself.

I fear that the BIOS does everything right and device 08:04.0 is indeed
using 08:00.0 as request-id. There are a couple of devices where this
happens, usually when the vendor just took the old 32bit PCI chip, added
a transparent PCIe-to-PCI bridge to the device and sell it a PCIe.

So the assumption that every request-id has a corresponding pci_dev
structure does not hold. I also had made that assumption in the
AMD IOMMU driver but had to add code which removes that assumption. We
should look for a way to remove that assumption from the group-code too.


	Joerg

-- 
AMD Operating System Research Center

Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach
General Managers: Alberto Bozzo
Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632


WARNING: multiple messages have this Message-ID (diff)
From: "Roedel, Joerg" <Joerg.Roedel-5C7GfCeVMHo@public.gmane.org>
To: Alex Williamson
	<alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Florian Dazinger
	<florian-Q0TRQrZM+Zzk1uMJSBkQmQ@public.gmane.org>,
	iommu
	<iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org>,
	linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: 3.6-rc7 boot crash + bisection
Date: Wed, 26 Sep 2012 15:20:50 +0200	[thread overview]
Message-ID: <20120926132050.GB10549@amd.com> (raw)
In-Reply-To: <1348602226.28860.132.camel-xdHQ/5r00wBBDLzU/O5InQ@public.gmane.org>

On Tue, Sep 25, 2012 at 01:43:46PM -0600, Alex Williamson wrote:
> Joerg, any thoughts on a quirk for this?  Unfortunately we can't just
> skip IOMMU groups when an alias is broken because it puts the other
> IOMMU groups at risk that might not actually be isolated from this
> device.  It looks like we parse the alias info before PCI is probed, so
> maybe we'd need to call the quirk from iommu_init_device itself.

I fear that the BIOS does everything right and device 08:04.0 is indeed
using 08:00.0 as request-id. There are a couple of devices where this
happens, usually when the vendor just took the old 32bit PCI chip, added
a transparent PCIe-to-PCI bridge to the device and sell it a PCIe.

So the assumption that every request-id has a corresponding pci_dev
structure does not hold. I also had made that assumption in the
AMD IOMMU driver but had to add code which removes that assumption. We
should look for a way to remove that assumption from the group-code too.


	Joerg

-- 
AMD Operating System Research Center

Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach
General Managers: Alberto Bozzo
Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632

  parent reply	other threads:[~2012-09-26 13:21 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-24 19:03 3.6-rc7 boot crash + bisection Florian Dazinger
2012-09-25 18:32 ` Alex Williamson
2012-09-25 18:42   ` Alex Williamson
2012-09-25 18:54   ` Florian Dazinger
2012-09-25 19:43     ` Alex Williamson
2012-09-25 19:43       ` Alex Williamson
2012-09-25 23:01       ` Florian Dazinger
2012-09-26  3:12         ` Alex Williamson
2012-09-26  3:12           ` Alex Williamson
2012-09-26 14:43         ` Roedel, Joerg
2012-09-26 14:43           ` Roedel, Joerg
2012-09-26 14:52           ` Alex Williamson
2012-09-26 14:52             ` Alex Williamson
2012-09-26 15:04             ` Roedel, Joerg
2012-09-26 15:04               ` Roedel, Joerg
2012-09-26 16:13               ` Alex Williamson
2012-09-26 16:13                 ` Alex Williamson
2012-09-26 16:43               ` Florian Dazinger
2012-09-26 16:43                 ` Florian Dazinger
2012-09-26 17:47               ` Florian Dazinger
2012-09-26 17:47                 ` Florian Dazinger
2012-09-26 13:20       ` Roedel, Joerg [this message]
2012-09-26 13:20         ` Roedel, Joerg
2012-09-26 14:35         ` Alex Williamson
2012-09-26 14:35           ` Alex Williamson
2012-09-26 15:10           ` Roedel, Joerg
2012-09-26 15:10             ` Roedel, Joerg
2012-09-26 16:21             ` Alex Williamson
2012-09-26 16:21               ` Alex Williamson
2012-09-26 19:50               ` Alex Williamson
2012-09-26 19:50                 ` Alex Williamson
2012-09-26 22:04                 ` Alex Williamson
2012-09-26 22:04                   ` Alex Williamson
2012-09-27 16:22                   ` Florian Dazinger
2012-09-27 16:22                     ` Florian Dazinger
2012-09-28 13:58                   ` Roedel, Joerg
2012-09-28 13:58                     ` Roedel, Joerg

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