Re: [PATCH RFC 02/11] iommu: Add iommu_domain type for SVA

Lu Baolu
2022-03-21T10:23:24Z

On 2022/3/21 15:06, Tian, Kevin wrote:
>> From: Lu Baolu<baolu.lu@linux.intel.com>
>> Sent: Sunday, March 20, 2022 2:40 PM
>>
>> Add a new iommu domain type IOMMU_DOMAIN_SVA to represent an I/O
>> page
>> table which is shared from CPU host VA. Add a sva_cookie field in the
>> iommu_domain structure to save the mm_struct which represent the CPU
>> memory page table.
>>
>> Signed-off-by: Lu Baolu<baolu.lu@linux.intel.com>
>> ---
>> include/linux/iommu.h | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
>> index 36f43af0af53..3e179b853380 100644
>> --- a/include/linux/iommu.h
>> +++ b/include/linux/iommu.h
>> @@ -64,6 +64,9 @@ struct iommu_domain_geometry {
>> #define __IOMMU_DOMAIN_PT (1U << 2) /* Domain is identity
>> mapped */
>> #define __IOMMU_DOMAIN_DMA_FQ (1U << 3) /* DMA-API uses
>> flush queue */
>>
>> +#define __IOMMU_DOMAIN_SHARED (1U << 4) /* Page table shared from
>> CPU */
>> +#define __IOMMU_DOMAIN_HOST_VA (1U << 5) /* Host CPU virtual
>> address */
> suppose the SHARED bit will be also used for KVM page table sharing and
> HOST_VA bit is to differentiate mm sharing from the latter?
>

Yes, that's my intention.

Best regards,
baolu