Re: [PATCH 2/3] iommu/amd: Add IOMMU event log injection interface for testing event flag decoding logic

[Suravee Suthikulanit <suravee.suthikulpanit-5C7GfCeVMHo@public.gmane.org>]

On 4/2/2013 9:35 AM, Joerg Roedel wrote:
> On Wed, Mar 27, 2013 at 06:51:34PM -0500, suravee.suthikulpanit-5C7GfCeVMHo@public.gmane.org wrote:
>> From: Suravee Suthikulpanit <suravee.suthikulpanit-5C7GfCeVMHo@public.gmane.org>
>>
>> Add IOMMU event log injection interface for testing event flag decoding logic.
>> This interface allows users to specify device id, event flag, and event types via debugfs.
>>
>> echo 0x300 > /sys/kernel/debug/amd-iommu-evninj/devid // (e.g. Bus:Dev.fun 3:0.0)
>> echo 0xfff > /sys/kernel/debug/amd-iommu-evninj/flags // (e.g. Specify flag value)
>> echo 2 > /sys/kernel/debug/amd-iommu-evninj/type      // (e.g. for IO_PAGE_FAULT event)
>>
>> Once the event is injected, IOMMU driver will parse and print out the event information
>> in kernel log (dmesg) with the various information depending on the types of event and flag
>> specified.
> Why is this needed? I think the risk of regressions in the
> event-handling code is to low to justify the need for an event-injection
> mechanism.
You are right, it is not needed.  I create this interface to provide a 
way for reviewers to test out how the report will be generated for each 
type of events/errors.

Suravee
>
> 	Joerg
>
>
>