Messages in this thread | | | Date | Mon, 11 Dec 2023 15:53:40 +0800 | Subject | Re: [PATCH v6 2/6] iommufd: Add IOMMU_HWPT_INVALIDATE | From | Yi Liu <> |
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On 2023/12/7 22:42, Jason Gunthorpe wrote: > On Thu, Dec 07, 2023 at 09:04:00AM +0000, Tian, Kevin wrote: >>> From: Liu, Yi L <yi.l.liu@intel.com> >>> Sent: Thursday, December 7, 2023 2:59 PM >>> >>> On 2023/11/17 21:07, Yi Liu wrote: >>>> @@ -613,4 +614,38 @@ struct iommu_hwpt_get_dirty_bitmap { >>>> #define IOMMU_HWPT_GET_DIRTY_BITMAP _IO(IOMMUFD_TYPE, \ >>>> >>> IOMMUFD_CMD_HWPT_GET_DIRTY_BITMAP) >>>> >>>> +/** >>>> + * struct iommu_hwpt_invalidate - ioctl(IOMMU_HWPT_INVALIDATE) >>>> + * @size: sizeof(struct iommu_hwpt_invalidate) >>>> + * @hwpt_id: HWPT ID of a nested HWPT for cache invalidation >>>> + * @reqs_uptr: User pointer to an array having @req_num of cache >>> invalidation >>>> + * requests. The request entries in the array are of fixed width >>>> + * @req_len, and contain a user data structure for invalidation >>>> + * request specific to the given hardware page table. >>>> + * @req_type: One of enum iommu_hwpt_data_type, defining the data >>> type of all >>>> + * the entries in the invalidation request array. It should suit >>>> + * with the data_type passed per the allocation of the hwpt pointed >>>> + * by @hwpt_id. >>> >>> @Jason and Kevin, >>> >>> Here a check with you two. I had a conversation with Nic on the definition >>> of req_type here. It was added to support potential multiple kinds of cache >>> invalidation data types for a invalidating cache for a single hwpt type[1]. >>> But we defined it as reusing the hwpt_data_type. In this way, it is not >>> able to support the potential case in[1]. is it? Shall we define a separate >>> enum for invalidation data types? And how can we let user know the >>> available invalidation data types for a hwpt type? Any idea? >>> >>> [1] https://lore.kernel.org/linux- >>> iommu/20231018163720.GA3952@nvidia.com/ >>> >> >> From that thread Jason mentioned to make the invalidation format >> part of domain allocation. If that is the direction to go then there >> won't be multiple invalidation formats per hwpt. The user should >> create multiple hwpt's per invalidation format (though mixing >> formats in one virtual platform is very unlikely)? > > I think we could do either, but I have a vauge cleanness preference > that the enums are just different? That would follow a pretty typical > pattern for a structure tag to reflect the content of the structure.
Is this still following the direction to make the invalidation format part of domain allocation?
-- Regards, Yi Liu
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