spice: set device address and device display ID in QXL interface

Calls the new SPICE QXL interface function spice_qxl_set_device_info to
set the hardware address of the graphics device represented by the QXL
interface (e.g. a PCI path) and the device display IDs (the IDs of the
device's monitors that belong to this QXL interface).

Also stops using the deprecated spice_qxl_set_max_monitors, the new
interface function replaces it.

Signed-off-by: Lukáš Hrázký <lhrazky@redhat.com>
Message-Id: <20190215150919.8263-1-lhrazky@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/ui/spice-core.c b/ui/spice-core.c
index a40fb2c..37fae3c 100644
--- a/ui/spice-core.c
+++ b/ui/spice-core.c
@@ -34,6 +34,7 @@
 #include "qemu/option.h"
 #include "migration/misc.h"
 #include "hw/hw.h"
+#include "hw/pci/pci_bus.h"
 #include "ui/spice-display.h"
 
 /* core bits */
@@ -863,6 +864,56 @@
     return false;
 }
 
+/*
+ * 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_spice_fill_device_address(QemuConsole *con,
+                                    char *device_address,
+                                    size_t size)
+{
+    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) {
+        warn_report("Setting device address of a display device to SPICE: "
+                    "Not a PCI device.");
+        return false;
+    }
+
+    strncpy(device_address, "pci/0000", size);
+    if (!append_pci_address(device_address, size, pci)) {
+        warn_report("Setting device address of a display device to SPICE: "
+            "Too many PCI devices in the chain.");
+        return false;
+    }
+
+    return true;
+}
+
 int qemu_spice_add_display_interface(QXLInstance *qxlin, QemuConsole *con)
 {
     if (g_slist_find(spice_consoles, con)) {