ui/util.c

   1 /*
   2  * Copyright (C) 2021 Red Hat, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 or
   7  * (at your option) version 3 of the License.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include "qemu/osdep.h"
  19
  20 #include "hw/pci/pci.h"
  21 #include "hw/pci/pci_bus.h"
  22 #include "qapi/error.h"
  23 #include "ui/console.h"
  24
  25 /*
  26  * Recursively (in reverse order) appends addresses of PCI devices as it moves
  27  * up in the PCI hierarchy.
  28  *
  29  * @returns true on success, false when the buffer wasn't large enough
  30  */
  31 static bool append_pci_address(char *buf, size_t buf_size, const PCIDevice *pci)
  32 {
  33     PCIBus *bus = pci_get_bus(pci);
  34     /*
  35      * equivalent to if (!pci_bus_is_root(bus)), but the function is not built
  36      * with PCI_CONFIG=n, avoid using an #ifdef by checking directly
  37      */
  38     if (bus->parent_dev != NULL) {
  39         append_pci_address(buf, buf_size, bus->parent_dev);
  40     }
  41
  42     size_t len = strlen(buf);
  43     ssize_t written = snprintf(buf + len, buf_size - len, "/%02x.%x",
  44         PCI_SLOT(pci->devfn), PCI_FUNC(pci->devfn));
  45
  46     return written > 0 && written < buf_size - len;
  47 }
  48
  49 bool qemu_console_fill_device_address(QemuConsole *con,
  50                                       char *device_address,
  51                                       size_t size,
  52                                       Error **errp)
  53 {
  54     ERRP_GUARD();
  55     DeviceState *dev = DEVICE(object_property_get_link(OBJECT(con),
  56                                                        "device",
  57                                                        &error_abort));
  58     PCIDevice *pci = (PCIDevice *) object_dynamic_cast(OBJECT(dev),
  59                                                        TYPE_PCI_DEVICE);
  60
  61     if (pci == NULL) {
  62         error_setg(errp, "Setting device address of a display device: "
  63                    "Not a PCI device.");
  64         return false;
  65     }
  66
  67     strncpy(device_address, "pci/0000", size);
  68     if (!append_pci_address(device_address, size, pci)) {
  69         error_setg(errp, "Setting device address of a display device: "
  70                    "Too many PCI devices in the chain.");
  71         return false;
  72     }
  73
  74     return true;
  75 }