Re: [PATCH 0/2] Introduce iommu_commit() function

KyongHo Cho
2011-11-16T02:00:59Z

On Wed, Jun 29, 2011 at 2:51 PM, Joerg Roedel <joro@8bytes.org> wrote:
> On Wed, Jun 29, 2011 at 02:02:02PM +0900, KyongHo Cho wrote:
>> Hi.
>>
>> On Fri, Jun 24, 2011 at 12:31 AM, Joerg Roedel <joerg.roedel@amd.com> wrote:
>> > It needs to be called whenever a some code changed a domain (either by
>> > attaching/detaching devices or by mapping/unmapping pages in
>> > the domain).
>>
>> Do you mean we can invalidate IOTLB with this iommu_commit()?
>> We need to invalidate IOTLB without updating page table for some
>> optimized solutions.
>>
>> If a device in one domain is moved to other domain, IOTLB of the
>> device must be invalidated
>> because it contains translation information of the previous domain.
>
> The classic use-case is to do a single iommu-tlb flush after a set of
> page-table updates, but flushing iotlbs after moving devices is a
> potential use-case too, so the answer is yes.
>

Hi.

In the 'next' branch of
http://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git,
I found that iommu_commit() is removed.

Why is it removed?

BTW, the comment of struct iommu_ops still contains description about commit.

Regards,

KyongHo