Bug 35592

Summary:	AMD-Vi: Enabling IOMMU crashes with NULL pointer dereference
Product:	Platform Specific/Hardware	Reporter:	Jan Losinski (losinski)
Component:	x86-64	Assignee:	Joerg Roedel (joro)
Status:	RESOLVED CODE_FIX
Severity:	high	CC:	joro
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.39	Subsystem:
Regression:	No	Bisected commit-id:
Attachments:	Dump of the bug-console-output Dump of lspci -vv Kernel Config

Description Jan Losinski 2011-05-22 00:13:09 UTC

Created attachment 58962 [details]
Dump of the bug-console-output

Booting 2.6.39 with enabled IOMMU crashes with a "unable to handle kernel NULL pointer dereference" bug followed by a panic. The hardware is a Tyan Thunder Tyan S8230WGM4NR with a 	AMD SR5690 + SP5100 chipset and two AMD Operon 6128 cpus.

The bug can prevented by disabling the Option CHIPSET->RD890->IOMMU within the BIOS Settings. I've attached a lspci -vv dump, my kernel configuration and a dump of the bug, captured with a serial console.

Comment 1 Jan Losinski 2011-05-22 00:15:39 UTC

Created attachment 58972 [details]
Dump of lspci -vv

Comment 2 Jan Losinski 2011-05-22 00:16:12 UTC

Created attachment 58982 [details]
Kernel Config

Comment 3 Joerg Roedel 2011-05-27 08:14:23 UTC

I'll take a look at the machine directly next monday.

Comment 4 Joerg Roedel 2011-06-10 12:40:16 UTC

Fixed upstream by recent patch-set:

https://lkml.org/lkml/2011/6/10/196

Fixed for -stable are available too, commit-id:

26018874e3584f1658570d41d57d4c34f6a53aa0

(depends on 27c2127a15d340706c0aa84e311188a14468d841)

Comment 5 Joerg Roedel 2011-06-10 12:41:02 UTC

Fixes are available.