Re: [PATCH v4 2/7] iommu/core: split mapping to page sizes as supportedby the hardware

From: cody
Date: Thu Nov 10 2011 - 07:17:16 EST


On 11/10/2011 03:31 PM, Ohad Ben-Cohen wrote:
On Thu, Nov 10, 2011 at 8:17 AM, Kai Huang<mail.kai.huang@xxxxxxxxx> wrote:
Seems the unmap function don't take phys as parameter, does this mean
domain->ops->unmap will walk through the page table to find out the
actual page size?
The short answer is yes, and furthermore, we also consider to remove
the size param from domain->ops->unmap entirely at some point.

We had a long discussion about it, please see:

https://lkml.org/lkml/2011/10/10/234
Yes I've seen your discussion, I followed this thread from beginning:)

How about the IOTLB flush? As I said I think we need to consider that IOMMU (even does not exist now) may have some limitation on IOTLB flush, and hiding page size from IOTLB flush code may hurt performance, or even worse, trigger undefined behaviors.

-cody
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