On 20/03/2019 16:37, Jacob Pan wrote:
[...]
>> +struct iommu_inv_addr_info {
>> +#define IOMMU_INV_ADDR_FLAGS_PASID  (1 << 0)
>> +#define IOMMU_INV_ADDR_FLAGS_ARCHID (1 << 1)
>> +#define IOMMU_INV_ADDR_FLAGS_LEAF   (1 << 2)
>> +    __u32   flags;
>> +    __u32   archid;
>> +    __u64   pasid;
>> +    __u64   addr;
>> +    __u64   granule_size;
>> +    __u64   nb_granules;
>> +};
>> +
>> +/**
>> + * First level/stage invalidation information
>> + * @cache: bitfield that allows to select which caches to invalidate
>> + * @granularity: defines the lowest granularity used for the
>> invalidation:
>> + *     domain > pasid > addr
>> + *
>> + * Not all the combinations of cache/granularity make sense:
>> + *
>> + *         type |   DEV_IOTLB   |     IOTLB     |      PASID    |
>> + * granularity      |               |               |
>> cache        |
>> + * -------------+---------------+---------------+---------------+
>> + * DOMAIN   |       N/A     |       Y       |
>> Y    |
>> + * PASID    |       Y       |       Y       |
>> Y    |
>> + * ADDR             |       Y       |       Y       |
>> N/A  |
>> + */
>> +struct iommu_cache_invalidate_info {
>> +#define IOMMU_CACHE_INVALIDATE_INFO_VERSION_1 1
>> +    __u32   version;
>> +/* IOMMU paging structure cache */
>> +#define IOMMU_CACHE_INV_TYPE_IOTLB  (1 << 0) /* IOMMU IOTLB */
>> +#define IOMMU_CACHE_INV_TYPE_DEV_IOTLB      (1 << 1) /* Device
>> IOTLB */ +#define IOMMU_CACHE_INV_TYPE_PASID (1 << 2) /* PASID
>> cache */
> Just a clarification, this used to be an enum. You do intend to issue a
> single invalidation request on multiple cache types? Perhaps for
> virtio-IOMMU? I only see a single cache type in your patch #14. For VT-d
> we plan to issue one cache type at a time for now. So this format works
> for us.

Yes for virtio-iommu I'd like as little overhead as possible, which
means a single invalidation message to hit both IOTLB and ATC at once,
and the ability to specify multiple pages with @nb_granules.

> However, if multiple cache types are issued in a single invalidation.
> They must share a single granularity, not all combinations are valid.
> e.g. dev IOTLB does not support domain granularity. Just a reminder,
> not an issue. Driver could filter out invalid combinations.

Agreed. Even the core could filter out invalid combinations based on the
table above: IOTLB and domain granularity are N/A.

Thanks,
Jean

> 
>> +    __u8    cache;
>> +    __u8    granularity;
>> +    __u8    padding[2];
>> +    union {
>> +            __u64   pasid;
>> +            struct iommu_inv_addr_info addr_info;
>> +    };
>> +};
>> +
>> +
>>  #endif /* _UAPI_IOMMU_H */
> 
> [Jacob Pan]
> _______________________________________________
> iommu mailing list
> iommu@lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/iommu
> 

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