Re: [PATCH rfcv2 01/20] backends/iommufd: Add helpers for invalidating user-managed HWPT

[Eric Auger]

Hi Zhenzhong,


On 2/19/25 9:22 AM, Zhenzhong Duan wrote:
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
in the title, there is only a single helper here. a small commit msg may
help the reader
> ---
>  include/system/iommufd.h |  3 +++
>  backends/iommufd.c       | 30 ++++++++++++++++++++++++++++++
>  backends/trace-events    |  1 +
>  3 files changed, 34 insertions(+)
>
> diff --git a/include/system/iommufd.h b/include/system/iommufd.h
> index cbab75bfbf..5d02e9d148 100644
> --- a/include/system/iommufd.h
> +++ b/include/system/iommufd.h
> @@ -61,6 +61,9 @@ bool iommufd_backend_get_dirty_bitmap(IOMMUFDBackend *be, 
> uint32_t hwpt_id,
>                                        uint64_t iova, ram_addr_t size,
>                                        uint64_t page_size, uint64_t *data,
>                                        Error **errp);
> +int iommufd_backend_invalidate_cache(IOMMUFDBackend *be, uint32_t hwpt_id,
> +                                     uint32_t data_type, uint32_t entry_len,
> +                                     uint32_t *entry_num, void *data_ptr);
>  
>  #define TYPE_HOST_IOMMU_DEVICE_IOMMUFD TYPE_HOST_IOMMU_DEVICE "-iommufd"
>  #endif
> diff --git a/backends/iommufd.c b/backends/iommufd.c
> index d57da44755..fc32aad5cb 100644
> --- a/backends/iommufd.c
> +++ b/backends/iommufd.c
> @@ -311,6 +311,36 @@ bool iommufd_backend_get_device_info(IOMMUFDBackend *be, 
> uint32_t devid,
>      return true;
>  }
>  
> +int iommufd_backend_invalidate_cache(IOMMUFDBackend *be, uint32_t hwpt_id,
> +                                     uint32_t data_type, uint32_t entry_len,
> +                                     uint32_t *entry_num, void *data_ptr)
> +{
> +    int ret, fd = be->fd;
> +    struct iommu_hwpt_invalidate cache = {
> +        .size = sizeof(cache),
> +        .hwpt_id = hwpt_id,
> +        .data_type = data_type,
> +        .entry_len = entry_len,
> +        .entry_num = *entry_num,
> +        .data_uptr = (uintptr_t)data_ptr,
> +    };
> +
> +    ret = ioctl(fd, IOMMU_HWPT_INVALIDATE, &cache);
> +
> +    trace_iommufd_backend_invalidate_cache(fd, hwpt_id, data_type, entry_len,
> +                                           *entry_num, cache.entry_num,
> +                                           (uintptr_t)data_ptr, ret);
> +    if (ret) {
> +        *entry_num = cache.entry_num;
> +        error_report("IOMMU_HWPT_INVALIDATE failed: %s", strerror(errno));
nit: you may report *entry_num also.
Wouldn't it be useful to have an Error *errp passed to the function
> +        ret = -errno;
> +    } else {
> +        g_assert(*entry_num == cache.entry_num);
> +    }
> +
> +    return ret;
> +}
> +
>  static int hiod_iommufd_get_cap(HostIOMMUDevice *hiod, int cap, Error **errp)
>  {
>      HostIOMMUDeviceCaps *caps = &hiod->caps;
> diff --git a/backends/trace-events b/backends/trace-events
> index 40811a3162..5a23db6c8a 100644
> --- a/backends/trace-events
> +++ b/backends/trace-events
> @@ -18,3 +18,4 @@ iommufd_backend_alloc_hwpt(int iommufd, uint32_t dev_id, 
> uint32_t pt_id, uint32_
>  iommufd_backend_free_id(int iommufd, uint32_t id, int ret) " iommufd=%d 
> id=%d (%d)"
>  iommufd_backend_set_dirty(int iommufd, uint32_t hwpt_id, bool start, int 
> ret) " iommufd=%d hwpt=%u enable=%d (%d)"
>  iommufd_backend_get_dirty_bitmap(int iommufd, uint32_t hwpt_id, uint64_t 
> iova, uint64_t size, uint64_t page_size, int ret) " iommufd=%d hwpt=%u 
> iova=0x%"PRIx64" size=0x%"PRIx64" page_size=0x%"PRIx64" (%d)"
> +iommufd_backend_invalidate_cache(int iommufd, uint32_t hwpt_id, uint32_t 
> data_type, uint32_t entry_len, uint32_t entry_num, uint32_t done_num, 
> uint64_t data_ptr, int ret) " iommufd=%d hwpt_id=%u data_type=%u entry_len=%u 
> entry_num=%u done_num=%u data_ptr=0x%"PRIx64" (%d)"
Eric