[Qemu-devel] [RFC PATCH qemu v2 2/2] spice: set device address and device display ID in QXL interface

["Lukáš Hrázký" <lhrazky@redhat.com>]

Calls new SPICE QXL interface functions to set:

* The hardware address of the graphics device represented by the QXL
  interface (e.g. a PCI path):
  spice_qxl_set_device_address(...)

* The device display IDs (the IDs of the device's monitors that belong
  to this QXL interface):
  spice_qxl_monitor_set_device_display_id(...)

Signed-off-by: Lukáš Hrázký <lhrazky@redhat.com>
---
 hw/display/qxl.c   |  8 ++++++++
 ui/spice-core.c    | 45 ++++++++++++++++++++++++++++++++++++++++++++-
 ui/spice-display.c |  5 +++++
 3 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/hw/display/qxl.c b/hw/display/qxl.c
index f608abc769..63144f42b4 100644
--- a/hw/display/qxl.c
+++ b/hw/display/qxl.c
@@ -2184,6 +2184,14 @@ static void qxl_realize_common(PCIQXLDevice *qxl, Error **errp)
                    SPICE_INTERFACE_QXL_MAJOR, SPICE_INTERFACE_QXL_MINOR);
         return;
     }
+
+#if SPICE_SERVER_VERSION >= 0x000e02 /* release 0.14.2 */
+    // register all possible device display IDs to SPICE server
+    for (int i = 0; i < qxl->max_outputs; ++i) {
+        spice_qxl_monitor_set_device_display_id(&qxl->ssd.qxl, i, i);
+    }
+#endif
+
     qemu_add_vm_change_state_handler(qxl_vm_change_state_handler, qxl);
 
     qxl->update_irq = qemu_bh_new(qxl_update_irq_bh, qxl);
diff --git a/ui/spice-core.c b/ui/spice-core.c
index a4fbbc3898..2e01beea03 100644
--- a/ui/spice-core.c
+++ b/ui/spice-core.c
@@ -35,6 +35,8 @@
 #include "qemu/option.h"
 #include "migration/misc.h"
 #include "hw/hw.h"
+#include "hw/pci/pci.h"
+#include "hw/pci/pci_bus.h"
 #include "ui/spice-display.h"
 
 /* core bits */
@@ -871,6 +873,26 @@ bool qemu_spice_have_display_interface(QemuConsole *con)
     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_recursive(char *buf, size_t buf_size, const PCIDevice *pci)
+{
+    PCIBus *bus = pci_get_bus(pci);
+    if (!pci_bus_is_root(bus)) {
+        append_pci_address_recursive(buf, buf_size, bus->parent_dev);
+    }
+
+    size_t len = strlen(buf);
+    size_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;
+}
+
 int qemu_spice_add_display_interface(QXLInstance *qxlin, QemuConsole *con)
 {
     if (g_slist_find(spice_consoles, con)) {
@@ -878,7 +900,28 @@ int qemu_spice_add_display_interface(QXLInstance *qxlin, QemuConsole *con)
     }
     qxlin->id = qemu_console_get_index(con);
     spice_consoles = g_slist_append(spice_consoles, con);
-    return qemu_spice_add_interface(&qxlin->base);
+    int res = qemu_spice_add_interface(&qxlin->base);
+
+#if SPICE_SERVER_VERSION >= 0x000e02 /* release 0.14.2 */
+    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 PCI path of a display device to SPICE: Not a PCI device.");
+        return res;
+    }
+
+    char device_path[128] = "pci/0000";  // hardcoded PCI domain 0000
+    if (!append_pci_address_recursive(device_path, sizeof(device_path), pci)) {
+        warn_report("Setting PCI path of a display device to SPICE: "
+            "Too many PCI devices in the chain.");
+        return res;
+    }
+
+    spice_qxl_set_device_address(qxlin, device_path);
+#endif
+
+    return res;
 }
 
 static int qemu_spice_set_ticket(bool fail_if_conn, bool disconnect_if_conn)
diff --git a/ui/spice-display.c b/ui/spice-display.c
index 2f8adb6b9f..f620750803 100644
--- a/ui/spice-display.c
+++ b/ui/spice-display.c
@@ -1129,6 +1129,11 @@ static void qemu_spice_display_init_one(QemuConsole *con)
 
     ssd->qxl.base.sif = &dpy_interface.base;
     qemu_spice_add_display_interface(&ssd->qxl, con);
+
+#if SPICE_SERVER_VERSION >= 0x000e02 /* release 0.14.2 */
+    spice_qxl_monitor_set_device_display_id(&ssd->qxl, 0, qemu_console_get_head(con));
+#endif
+
     qemu_spice_create_host_memslot(ssd);
 
     register_displaychangelistener(&ssd->dcl);
-- 
2.19.1