Re: [PATCH rfcv2 06/20] host_iommu_device: Define two new capabilities HOST_IOMMU_DEVICE_CAP_[NESTING|FS1GP]

[Eric Auger]

On 2/20/25 7:41 PM, Eric Auger wrote:
> Hi Zhenzhong,
> 
> 
> On 2/19/25 9:22 AM, Zhenzhong Duan wrote:
>> Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>
>> ---
>>  include/system/host_iommu_device.h | 8 ++++++++
>>  1 file changed, 8 insertions(+)
>>
>> diff --git a/include/system/host_iommu_device.h 
>> b/include/system/host_iommu_device.h
>> index df782598f2..18f8b5e5cf 100644
>> --- a/include/system/host_iommu_device.h
>> +++ b/include/system/host_iommu_device.h
>> @@ -22,10 +22,16 @@
>>   *
>>   * @hw_caps: host platform IOMMU capabilities (e.g. on IOMMUFD this 
>> represents
>>   *           the @out_capabilities value returned from IOMMU_GET_HW_INFO 
>> ioctl)
>> + *
>> + * @nesting: nesting page table support.
>> + *
>> + * @fs1gp: first stage(a.k.a, Stage-1) 1GB huge page support.
>>   */
>>  typedef struct HostIOMMUDeviceCaps {
>>      uint32_t type;
>>      uint64_t hw_caps;
>> +    bool nesting;
>> +    bool fs1gp;
> this looks quite vtd specific, isn't it? Shouldn't we hide this is a
> vendor specific cap struct?
>>  } HostIOMMUDeviceCaps;
>>  
>>  #define TYPE_HOST_IOMMU_DEVICE "host-iommu-device"
>> @@ -122,6 +128,8 @@ struct HostIOMMUDeviceClass {
>>   */
>>  #define HOST_IOMMU_DEVICE_CAP_IOMMU_TYPE        0
>>  #define HOST_IOMMU_DEVICE_CAP_AW_BITS           1
>> +#define HOST_IOMMU_DEVICE_CAP_NESTING           2
>> +#define HOST_IOMMU_DEVICE_CAP_FS1GP             3
>>  
>>  #define HOST_IOMMU_DEVICE_CAP_AW_BITS_MAX       64
>>  #endif
> 
> Maybe you could introduce the associated implementation of
> hiod_iommufd_get_cap in this patch too?
ignore this last comment :(

Eric
> 
> Eric