Introduce a helper function iommufd_backend_get_device_info() to get
host IOMMU related information through iommufd uAPI.

Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 include/sysemu/iommufd.h |  3 +++
 backends/iommufd.c       | 22 ++++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/include/sysemu/iommufd.h b/include/sysemu/iommufd.h
index f6e6d6e1f9..9edfec6045 100644
--- a/include/sysemu/iommufd.h
+++ b/include/sysemu/iommufd.h
@@ -47,6 +47,9 @@ int iommufd_backend_map_dma(IOMMUFDBackend *be, uint32_t ioas_id, hwaddr iova,
                             ram_addr_t size, void *vaddr, bool readonly);
 int iommufd_backend_unmap_dma(IOMMUFDBackend *be, uint32_t ioas_id,
                               hwaddr iova, ram_addr_t size);
+bool iommufd_backend_get_device_info(IOMMUFDBackend *be, uint32_t devid,
+                                     uint32_t *type, void *data, uint32_t len,
+                                     Error **errp);
 
 #define TYPE_HOST_IOMMU_DEVICE_IOMMUFD TYPE_HOST_IOMMU_DEVICE "-iommufd"
 #endif
diff --git a/backends/iommufd.c b/backends/iommufd.c
index 012f18d8d8..c7e969d6f7 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -208,6 +208,28 @@ int iommufd_backend_unmap_dma(IOMMUFDBackend *be, uint32_t ioas_id,
     return ret;
 }
 
+bool iommufd_backend_get_device_info(IOMMUFDBackend *be, uint32_t devid,
+                                     uint32_t *type, void *data, uint32_t len,
+                                     Error **errp)
+{
+    struct iommu_hw_info info = {
+        .size = sizeof(info),
+        .dev_id = devid,
+        .data_len = len,
+        .data_uptr = (uintptr_t)data,
+    };
+
+    if (ioctl(be->fd, IOMMU_GET_HW_INFO, &info)) {
+        error_setg_errno(errp, errno, "Failed to get hardware info");
+        return false;
+    }
+
+    g_assert(type);
+    *type = info.out_data_type;
+
+    return true;
+}
+
 static const TypeInfo types[] = {
     {
         .name = TYPE_IOMMUFD_BACKEND,
-- 
2.34.1