backends/iommufd: Extend iommufd_backend_get_device_info() to fetch HW capabilities

The helper will be able to fetch vendor agnostic IOMMU capabilities
supported both by hardware and software. Right now it is only iommu dirty
tracking.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>

backends/iommufd.c

@@ -209,7 +209,7 @@ int iommufd_backend_unmap_dma(IOMMUFDBackend *be, uint32_t ioas_id,
 
 bool iommufd_backend_get_device_info(IOMMUFDBackend *be, uint32_t devid,
                                      uint32_t *type, void *data, uint32_t len,
-                                     Error **errp)
+                                     uint64_t *caps, Error **errp)
 {
     struct iommu_hw_info info = {
         .size = sizeof(info),
@@ -225,6 +225,8 @@ bool iommufd_backend_get_device_info(IOMMUFDBackend *be, uint32_t devid,
 
     g_assert(type);
     *type = info.out_data_type;
+    g_assert(caps);
+    *caps = info.out_capabilities;
 
     return true;
 }

hw/vfio/iommufd.c

@@ -628,11 +628,13 @@ static bool hiod_iommufd_vfio_realize(HostIOMMUDevice *hiod, void *opaque,
     union {
         struct iommu_hw_info_vtd vtd;
     } data;
+    uint64_t hw_caps;
 
     hiod->agent = opaque;
 
     if (!iommufd_backend_get_device_info(vdev->iommufd, vdev->devid,
-                                         &type, &data, sizeof(data), errp)) {
+                                         &type, &data, sizeof(data),
+                                         &hw_caps, errp)) {
         return false;
     }
 

include/sysemu/iommufd.h

@@ -49,7 +49,7 @@ 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);
+                                     uint64_t *caps, Error **errp);
 
 #define TYPE_HOST_IOMMU_DEVICE_IOMMUFD TYPE_HOST_IOMMU_DEVICE "-iommufd"
 #endif