On 6/13/2013 2:54 AM, Jan Beulich
wrote:
On 13.06.13 at 03:44, Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx> wrote:
On 6/12/2013 5:37 PM, Suravee Suthikulpanit wrote:
Since we are modifying the IOMMU interrupt enabling/disabling, I have
been doing some more testing on the IOMMU interrupt handling. I found
that IOMMU MSI interrupt is currently broken, but I think this is
because of some older changes. I am still tracking down the issue,
and will update my findings.
The following commit broke the IOMMU MSI interrupt:
2012-11-28 899110e3f6d2a191638e8b50a981c551eeec49e6 AMD IOMMU:
include IOMMU interrupt information in 'M' debug key output
(http://xenbits.xen.org/gitweb/?p=xen.git;a=commit;h=899110e3f6d2a191638e8b5
0a981c551eeec49e6)
This patch also need the following patch to resolve kernel panic:
c759fee45bf44f2947a3480d54c03ff7e028c39e AMD IOMMU: add locking missing
from c/s 26198:ba90ecb0231f
(http://xenbits.xen.org/gitweb/?p=xen.git;a=commit;h=c759fee45bf44f2947a3480
d54c03ff7e028c39e)
I'll update once I root cause the issue.
I'll also take a look, but it would help to know in what way it is
broken: Some sort of crash, no interrupt delivered, ... This surely
needs to be resolved before 4.3 can go out - George, can you put
this on your bug list, please?
Jan
Basically I am not seeing any interrupts coming in from the IOMMU. I was testing it by setting the
ComWaitIntEn bit of the IOMMU control register to let the IOMMU hardware generate MSI interrupts for
the COMPLETION_WAIT command. I am not seeing any interrupts (i.e. The interrupt handler and
tasklet handler function is never executed). I have double checked this in the latest Xen-4.2.x, and they
are working fine. The same MSI interrupt is also used for PPR and Event Log.
Suravee
|