libxl: remove unnecessary check from libxl__device_pci_add()

The code currently checks explicitly whether the device is already assigned,
but this is actually unnecessary as assigned devices do not form part of
the list returned by libxl_device_pci_assignable_list() and hence the
libxl_pci_assignable() test would have already failed.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
Reviewed-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Acked-by: Wei Liu <wl@xen.org>

tools/libs/light/libxl_pci.c

@@ -1555,8 +1555,7 @@ void libxl__device_pci_add(libxl__egc *egc, uint32_t domid,
 {
     STATE_AO_GC(aodev->ao);
     libxl_ctx *ctx = libxl__gc_owner(gc);
-    libxl_device_pci *assigned;
-    int num_assigned, rc;
+    int rc;
     int stubdomid = 0;
     pci_add_state *pas;
 
@@ -1595,19 +1594,6 @@ void libxl__device_pci_add(libxl__egc *egc, uint32_t domid,
         goto out;
     }
 
-    rc = get_all_assigned_devices(gc, &assigned, &num_assigned);
-    if ( rc ) {
-        LOGD(ERROR, domid,
-             "cannot determine if device is assigned, refusing to continue");
-        goto out;
-    }
-    if ( is_pci_in_array(assigned, num_assigned, pci->domain,
-                         pci->bus, pci->dev, pci->func) ) {
-        LOGD(ERROR, domid, "PCI device already attached to a domain");
-        rc = ERROR_FAIL;
-        goto out;
-    }
-
     libxl__device_pci_reset(gc, pci->domain, pci->bus, pci->dev, pci->func);
 
     stubdomid = libxl_get_stubdom_id(ctx, domid);