Message-ID: <515B149B.8070604@erley.org>
Date:	Tue, 02 Apr 2013 13:25:47 -0400
From:	Pat Erley <pat-lkml@...ey.org>
To:	Andrew Cooks <acooks@...il.com>
CC:	"open list:INTEL IOMMU, (VT-d)" <iommu@...ts.linux-foundation.org>,
	"bhelgaas@...gle.com" <bhelgaas@...gle.com>,
	Alex Williamson <alex.williamson@...hat.com>,
	Gaudenz Steinlin <gaudenz@...iologie.ch>,
	"list@...ote.erley.org:PCI SUBSYSTEM" <linux-pci@...r.kernel.org>,
	open list <linux-kernel@...r.kernel.org>,
	Justin Piszcz <jpiszcz@...idpixels.com>
Subject: Re: [PATCH v4] Quirk for buggy dma source tags with Intel IOMMU.

On 04/02/2013 11:47 AM, Pat Erley wrote:
> On 04/02/2013 10:50 AM, Andrew Cooks wrote:
>> On 2 Apr 2013 15:37, "Pat Erley" <pat-lkml@...ey.org
>> <mailto:pat-lkml@...ey.org>> wrote:
>>  >
>>  > On 03/07/2013 09:35 PM, Andrew Cooks wrote:
>>  >>
>>  >> --- a/drivers/pci/quirks.c
>>  >> +++ b/drivers/pci/quirks.c
>>  >>
>>  >> +/* Table of multiple (ghost) source functions. This is similar to
>> the
>>  >> + * translated sources above, but with the following differences:
>>  >> + * 1. the device may use multiple functions as DMA sources,
>>  >> + * 2. these functions cannot be assumed to be actual devices,
>> they're simply
>>  >> + * incorrect DMA tags.
>>  >> + * 3. the specific ghost function for a request can not always be
>> predicted.
>>  >> + * For example, the actual device could be xx:yy.1 and it could use
>>  >> + * both 0 and 1 for different requests, with no obvious way to tell
>> when
>>  >> + * DMA will be tagged as comming from xx.yy.0 and and when it will
>> be tagged
>>  >> + * as comming from xx.yy.1.
>>  >> + * The bitmap contains all of the functions used in DMA tags,
>> including the
>>  >> + * actual device.
>>  >> + * See https://bugzilla.redhat.com/show_bug.cgi?id=757166,
>>  >> + * https://bugzilla.kernel.org/show_bug.cgi?id=42679
>>  >> + * https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1089768
>>  >> + */
>>  >> +static const struct pci_dev_dma_multi_func_sources {
>>  >> +       u16 vendor;
>>  >> +       u16 device;
>>  >> +       u8 func_map;    /* bit map. lsb is fn 0. */
>>  >> +} pci_dev_dma_multi_func_sources[] = {
>>  >> +       { PCI_VENDOR_ID_MARVELL_2, 0x9123, (1<<0)|(1<<1)},
>>  >> +       { PCI_VENDOR_ID_MARVELL_2, 0x9125, (1<<0)|(1<<1)},
>>  >> +       { PCI_VENDOR_ID_MARVELL_2, 0x9128, (1<<0)|(1<<1)},
>>  >> +       { PCI_VENDOR_ID_MARVELL_2, 0x9130, (1<<0)|(1<<1)},
>>  >> +       { PCI_VENDOR_ID_MARVELL_2, 0x9143, (1<<0)|(1<<1)},
>>  >> +       { PCI_VENDOR_ID_MARVELL_2, 0x9172, (1<<0)|(1<<1)},
>>  >> +       { 0 }
>>  >> +};
>>  >
>>  >
>>  > Adding another buggy device.  I have a Ricoh multifunction device:
>>  >
>>  > 17:00.0 SD Host controller: Ricoh Co Ltd MMC/SD Host Controller
>> (rev 01)
>>  > 17:00.3 FireWire (IEEE 1394): Ricoh Co Ltd R5C832 PCIe IEEE 1394
>>  >         Controller (rev 01)
>>  >
>>  > 17:00.0 0805: 1180:e822 (rev 01)
>>  > 17:00.3 0c00: 1180:e832 (rev 01)
>>  >
>>
>> The Ricoh device issue has been known for some time and a quirk has been
>> available since commit 12ea6cad1c7d046 in June 2012.  It's slightly
>> different than the problem this patch tries to work around [1].
>
> Hmm, I've had this problem with many recent (vanilla) kernels, up to and
> including 3.9-rc5
>
>>  > that adding entries for also fixed booting.  I don't have any SD
>> cards or firewire devices handy to test that they work, but the system
>> now boots, which was not the case without your patch and IOMMU/DMAR
>> enabled.
>>
>> That is really strange. Could you tell us what kernel version you tested
>> and provide dmesg output?
>
> I'll capture a vanilla 3.8.5 boot without any patches and iommu=off,
> then try to find another machine to catch what I can of a netconsole
> boot with iommu=on.  What's the preferred way to send these?  pastebin
> links?
>
> I'd been running the 'dirty' fix that's in the redhat bugzilla entry.  I
> checked my .config and have CONFIG_PCI_QUIRKS=y, and verified my devices
> are in the quirks table for the pci_func_0_dma_source fixup.
>
>>  >  Here's a previous patch used for similar hardware that may also be
>> fixed by this:
>>  >
>>  >
>> http://lists.fedoraproject.org/pipermail/scm-commits/2010-October/510785.html
>>
>>  >
>>  > and another thread/bug report this may solve:
>>  >
>>  > https://bugzilla.redhat.com/show_bug.cgi?id=605888
>>
>> I believe this is referenced in drivers/pci/quirks.c for versions newer
>> than 3.5.
>>
>>
>>  > Feel free to include me in any future iterations of this patch you'd
>> like tested.
>>  >
>>  > Tested-By: Pat Erley <pat-lkml@...ey.org <mailto:pat-lkml@...ey.org>>
>>  >
>>
>> Thanks for testing!
>>
>> [1] In the Ricoh case, multiple functions are used for real devices and
>> the bug is that these devices all use function 0 during DMA. In this
>> particular case, I'd expect the FireWire device 17:00.3 to issue DMA
>> from the SD Host Controller address 17:00.0. The quirk is not too much
>> of a terrible hack - it's a fairly simple translation.
>>
>> In the Marvell case, the real device uses DMA source tags that don't
>> actually belong to any visible devices. The quirk to make this work is
>> more invasive, not nearly as elegant and has not attracted much
>> enthusiasm from subsystem maintainers, though I'm still hopeful that a
>> quirk will be merged in some form or another.
>>
>
> Thanks for explaining the difference!
>
> Pat
> --

Here are my relevant logs and configs from a vanilla 3.8.5 kernel:

   http://www.erley.org/oops/

* the -nots files have had timestamps stripped for ease of diffing.

* no_iommu_no_fw.txt is a diff of the -nots logs.

* loading_fw.txt is an excerpt of log once I load the firewire-ohci
   module (causing, for all practical purposes, a complete system lock.)

* the .gz of the same name is the 55mb of logs it generated in 36
   seconds.

I was hesitant to send 100k of text to the ML, here is the only 
'interesting' difference in the logs, from my inspection:

-PCI-DMA: Using software bounce buffering for IO (SWIOTLB)
-(64MB) mapped at [ffff8800b7a7c000-ffff8800bba7bfff]
+DMAR: No ATSR found
+IOMMU 0 0xfed90000: using Queued invalidation
+IOMMU: Setting RMRR:
+IOMMU: Setting identity map for device 0000:00:1a.0 [0xbbee9000 - 
0xbbefffff]
+IOMMU: Setting identity map for device 0000:00:1d.0 [0xbbee9000 - 
0xbbefffff]
+IOMMU: Prepare 0-16MiB unity mapping for LPC
+IOMMU: Setting identity map for device 0000:00:1f.0 [0x0 - 0xffffff]
+PCI-DMA: Intel(R) Virtualization Technology for Directed I/O

I was not able to find another machine with working network right now 
(at families house for the week), so the only way I was able to compare was:

Case 1:
  Boot iommu=off with firewire-ohci not blacklisted

Case 2:
  Boot iommu=on with firewire-ohci blacklisted
  Load firewire-ohci

With your patch(admittedly, only tested on 3.9-rc5), Case 2 works, 
without it, I get my logs spammed with:

dmar: DRHD: handling fault status reg 2
dmar: DMAR:[DMA Read] Request device [17:00.0] fault addr fffff000
DMAR:[fault reason 02] Present bit in context entry is clear

When loading firewire.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists