[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH qemu v17 06/12] memory: Add reporting of support

From: Alexey Kardashevskiy
Subject: Re: [Qemu-devel] [PATCH qemu v17 06/12] memory: Add reporting of supported page sizes
Date: Wed, 8 Jun 2016 16:05:48 +1000
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.1.0

On 08/06/16 16:00, David Gibson wrote:
> On Mon, Jun 06, 2016 at 03:31:04PM +0200, Paolo Bonzini wrote:
>> On 02/06/2016 05:35, David Gibson wrote:
>>> On Wed, Jun 01, 2016 at 06:57:37PM +1000, Alexey Kardashevskiy wrote:
>>>>> Every IOMMU has some granularity which MemoryRegionIOMMUOps::translate
>>>>> uses when translating, however this information is not available outside
>>>>> the translate context for various checks.
>>>>> This adds a get_page_sizes callback to MemoryRegionIOMMUOps and
>>>>> a wrapper for it so IOMMU users (such as VFIO) can know the actual
>>>>> page size(s) used by an IOMMU.
>>>>> As IOMMU MR represents a guest IOMMU, this uses TARGET_PAGE_SIZE
>>>>> as fallback.
>>>>> This removes vfio_container_granularity() and uses new helper in
>>>>> memory_region_iommu_replay() when replaying IOMMU mappings on added
>>>>> IOMMU memory region.
>>>>> Signed-off-by: Alexey Kardashevskiy <address@hidden>
>>>>> Reviewed-by: David Gibson <address@hidden>
>>> Paolo,
>>> Looks like you were left off the CC for this one.
>>> I think this is ready to go - do you want to merge, comment or ack and
>>> we'll take it either through my tree or Alex's?
>> It's okay for you to merge, but the callback should be called
>> "get_page_size" or "get_replay_granularity".  The plural is weird.
> Hm, no, it really could return multiple page sizes if the logical
> (guest side) IOMMU supports them.

It could but it does not now and I cannot see it coming in near future so I
am really confused now about the naming and what the callback should return
- one page size or a mask. What should it be now?

> That might be useful at some point
> in the future.  For now, it's sufficient for the replay to use the
> smallest pagesize.


Attachment: signature.asc
Description: OpenPGP digital signature

reply via email to

[Prev in Thread] Current Thread [Next in Thread]