Messages in this thread | | | Subject | Re: [PATCH v11 05/22] vfio iommu: Added pin and unpin callback functions to vfio_iommu_driver_ops | From | Kirti Wankhede <> | Date | Wed, 9 Nov 2016 00:17:53 +0530 |
| |
On 11/8/2016 10:09 PM, Alex Williamson wrote: > On Tue, 8 Nov 2016 19:25:35 +0530 > Kirti Wankhede <kwankhede@nvidia.com> wrote: > ...
>>>> - >>>> + int (*pin_pages)(void *iommu_data, unsigned long *user_pfn, >>>> + int npage, int prot, >>>> + unsigned long *phys_pfn); >>>> + int (*unpin_pages)(void *iommu_data, >>> >>> Are we changing from long to int here simply because of the absurdity >>> in passing in more than a 2^31 entry array, that would already consume >>> more than 16GB itself? >>> >> >> These are on demand pin/unpin request, will that request go beyond 16GB >> limit? For Nvidia vGPU solution, pin request will not go beyond this limit. > > 16G is simply the size of the user_pfn or phys_pfn arrays at a maximal > int32_t npage value, the interface actually allows mapping up to 8TB > per call, but at that point we have 16GB of input, 16GB of output, and > 80GB of vfio_pfns created. So I don't really have a problem changing > form long to int given lack of scalability in the API in general, but > it does make me second guess the API itself. Thanks, >
Changing to 'long', in future we might enhance this API without changing it signature.
Thanks, Kirti
| |