On 21/03/2019 13:54, Auger Eric wrote:
> Hi Jacob, Jean-Philippe,
> 
> On 3/20/19 5:50 PM, Jean-Philippe Brucker wrote:
>> 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.
> The original request/explanation from Jean-Philippe can be found here:
> https://lkml.org/lkml/2019/1/28/1497
> 
>>
>>> 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.
> Sure I will add a comment about this restriction.
>>
>> Agreed. Even the core could filter out invalid combinations based on the
>> table above: IOTLB and domain granularity are N/A.
> I don't get this sentence. What about vtd IOTLB domain-selective
> invalidation:

My mistake: I meant dev-IOTLB and domain granularity are N/A

Thanks,
Jean

> "
> • IOTLB entries caching mappings associated with the specified domain-id
> are invalidated.
> • Paging-structure-cache entries caching mappings associated with the
> specified domain-id are invalidated.
> "
> 
> Thanks
> 
> Eric
> 
>>
>> 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
>>> [email protected]
>>> https://lists.linuxfoundation.org/mailman/listinfo/iommu
>>>
>>
> _______________________________________________
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