1 files changed, 75 insertions, 0 deletions
diff --git a/ui/util.c b/ui/util.c
new file mode 100644
index 0000000000..7e8fc1ea53
--- /dev/null
+++ b/ui/util.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2021 Red Hat, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 or
+ * (at your option) version 3 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "qemu/osdep.h"
+
+#include "hw/pci/pci.h"
+#include "hw/pci/pci_bus.h"
+#include "qapi/error.h"
+#include "ui/console.h"
+
+/*
+ * Recursively (in reverse order) appends addresses of PCI devices as it moves
+ * up in the PCI hierarchy.
+ *
+ * @returns true on success, false when the buffer wasn't large enough
+ */
+static bool append_pci_address(char *buf, size_t buf_size, const PCIDevice *pci)
+{
+    PCIBus *bus = pci_get_bus(pci);
+    /*
+     * equivalent to if (!pci_bus_is_root(bus)), but the function is not built
+     * with PCI_CONFIG=n, avoid using an #ifdef by checking directly
+     */
+    if (bus->parent_dev != NULL) {
+        append_pci_address(buf, buf_size, bus->parent_dev);
+    }
+
+    size_t len = strlen(buf);
+    ssize_t written = snprintf(buf + len, buf_size - len, "/%02x.%x",
+        PCI_SLOT(pci->devfn), PCI_FUNC(pci->devfn));
+
+    return written > 0 && written < buf_size - len;
+}
+
+bool qemu_console_fill_device_address(QemuConsole *con,
+                                      char *device_address,
+                                      size_t size,
+                                      Error **errp)
+{
+    ERRP_GUARD();
+    DeviceState *dev = DEVICE(object_property_get_link(OBJECT(con),
+                                                       "device",
+                                                       &error_abort));
+    PCIDevice *pci = (PCIDevice *) object_dynamic_cast(OBJECT(dev),
+                                                       TYPE_PCI_DEVICE);
+
+    if (pci == NULL) {
+        error_setg(errp, "Setting device address of a display device: "
+                   "Not a PCI device.");
+        return false;
+    }
+
+    strncpy(device_address, "pci/0000", size);
+    if (!append_pci_address(device_address, size, pci)) {
+        error_setg(errp, "Setting device address of a display device: "
+                   "Too many PCI devices in the chain.");
+        return false;
+    }
+
+    return true;
+}