vdagentd: Autogenerate a Xinerama xorg.conf for multi monitor setups

The autogenerated file will get written as /etc/X11/xorg.conf.spice

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

4 files changed, 198 insertions, 3 deletions

diff --git a/Makefile.am b/Makefile.am
index c3881ef..1102c02 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -7,10 +7,11 @@ src_spice_vdagent_CFLAGS = $(X_CFLAGS) $(SPICE_CFLAGS)
 src_spice_vdagent_LDADD = $(X_LIBS) $(SPICE_LIBS)
 src_spice_vdagent_SOURCES = src/vdagent.c src/vdagent-x11.c src/udscs.c
 
-src_spice_vdagentd_CFLAGS = $(DBUS_CFLAGS) $(SPICE_CFLAGS)
-src_spice_vdagentd_LDADD = $(DBUS_LIBS) $(SPICE_LIBS)
+src_spice_vdagentd_CFLAGS = $(DBUS_CFLAGS) $(PCIACCESS_CFLAGS) $(SPICE_CFLAGS)
+src_spice_vdagentd_LDADD = $(DBUS_LIBS) $(PCIACCESS_LIBS) $(SPICE_LIBS)
 src_spice_vdagentd_SOURCES = src/vdagentd.c \
                              src/vdagentd-uinput.c \
+                             src/vdagentd-xorg-conf.c \
                              src/vdagent-virtio-port.c \
                              src/udscs.c
 if HAVE_CONSOLE_KIT
@@ -22,6 +23,7 @@ noinst_HEADERS = src/console-kit.h \
                  src/vdagent-x11.h \
                  src/udscs.h \
                  src/vdagentd-uinput.h \
+                 src/vdagentd-xorg-conf.h \
                  src/vdagentd-proto.h \
                  src/vdagent-virtio-port.h
 
diff --git a/configure.ac b/configure.ac
index 6c9c156..c4659f8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -18,14 +18,24 @@ AC_ARG_ENABLE([console-kit],
               [enable_console_kit="$enableval"],
               [enable_console_kit="yes"])
 
+AC_ARG_ENABLE([pciaccess],
+              [AS_HELP_STRING([--enable-pciaccess], [Enable libpciaccess use for auto generation of Xinerama xorg.conf (default: yes)])],
+              [enable_pciaccess="$enableval"],
+              [enable_pciaccess="yes"])
+
 PKG_PROG_PKG_CONFIG
 PKG_CHECK_MODULES(X, [xfixes xrandr xinerama x11])
+PKG_CHECK_MODULES(SPICE, [spice-protocol >= 0.8.0])
 if test x"$enable_console_kit" = "xyes" ; then
     PKG_CHECK_MODULES(DBUS, [dbus-1])
     AC_DEFINE([HAVE_CONSOLE_KIT], [1], [If defined, vdagentd will be compiled with ConsoleKit support] )
 fi
 AM_CONDITIONAL(HAVE_CONSOLE_KIT, test x"$enable_console_kit" = "xyes")
-PKG_CHECK_MODULES(SPICE, [spice-protocol >= 0.8.0])
+if test x"$enable_pciaccess" = "xyes" ; then
+    PKG_CHECK_MODULES(PCIACCESS, [pciaccess >= 0.10])
+    AC_DEFINE([HAVE_PCIACCESS], [1], [If defined, vdagentd will be compiled with pciaccess support] )
+fi
+AM_CONDITIONAL(HAVE_PCIACCESS, test x"$enable_pciaccess" = "xyes")
 
 AC_CONFIG_FILES([
 Makefile
diff --git a/src/vdagentd-xorg-conf.c b/src/vdagentd-xorg-conf.c
new file mode 100644
index 0000000..5610837
--- /dev/null
+++ b/src/vdagentd-xorg-conf.c
@@ -0,0 +1,171 @@
+/*  vdagentd.c vdagentd xorg.conf writing code
+
+    Copyright 2011 Red Hat, Inc.
+
+    Red Hat Authors:
+    Hans de Goede <hdegoede@redhat.com>
+
+    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 3 of the License, or
+    (at your option) any later version.
+
+    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/>.
+*/
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#ifdef HAVE_PCIACCESS
+#include <pciaccess.h>
+#endif
+
+#include <string.h>
+#include <errno.h>
+#include <limits.h>
+#include "vdagentd-xorg-conf.h"
+
+#define FPRINTF(...) \
+    do { \
+        r = fprintf(f, __VA_ARGS__); \
+        if (r < 0) { \
+            fprintf(logfile, "Error writing to %s: %s\n", \
+                    xorg_conf, strerror(errno)); \
+            fclose(f); \
+            pci_system_cleanup(); \
+            return; \
+        } \
+    } while(0)
+
+void vdagentd_write_xorg_conf(VDAgentMonitorsConfig *monitor_conf,
+                              FILE *logfile)
+{
+#ifdef HAVE_PCIACCESS
+    int i, r, count, min_x = INT_MAX, min_y = INT_MAX;
+    FILE *f;
+    struct pci_device_iterator *it;
+    struct pci_device *dev;
+    const struct pci_id_match qxl_id_match = {
+        .vendor_id = 0x1b36,
+        .device_id = 0x0100,
+        .subvendor_id = PCI_MATCH_ANY,
+        .subdevice_id = PCI_MATCH_ANY,
+    };
+    const char *xorg_conf = "/var/run/spice-vdagentd/xorg.conf.spice";
+    const char *xorg_conf_old = "/var/run/spice-vdagentd/xorg.conf.spice.old";
+
+    r = rename(xorg_conf, xorg_conf_old);
+    if (r && errno != ENOENT) {
+        fprintf(logfile,
+                "Error renaming %s to %s: %s, not generating xorg.conf\n",
+                xorg_conf, xorg_conf_old, strerror(errno));
+        return;
+    }
+
+    r = pci_system_init();
+    if (r) {
+        fprintf(logfile, "Error initializing libpciaccess: %d, not generating xorg.conf\n", r);
+        return;
+    }
+
+    it = pci_id_match_iterator_create(&qxl_id_match);
+    if (!it) {
+        fprintf(logfile, "Error could not create pci id iterator for QXL devices, not generating xorg.conf\n");
+        pci_system_cleanup();
+        return;
+    }
+
+    dev = pci_device_next(it);
+    if (!dev) {
+        fprintf(logfile, "No QXL devices found, not generating xorg.conf\n");
+        pci_system_cleanup();
+        return;
+    }
+
+    f = fopen(xorg_conf, "w");
+    if (!f) {
+        fprintf(logfile, "Error opening %s for writing: %s\n",
+                xorg_conf, strerror(errno));
+        pci_system_cleanup();
+        return;
+    }
+
+    FPRINTF("# xorg.conf generated by spice-vdagentd\n");
+    FPRINTF("# generated from monitor info provided by the client\n\n");
+
+    if (monitor_conf->num_of_monitors == 1) {
+        FPRINTF("# Client has only 1 monitor\n");
+        FPRINTF("# This works best with no xorg.conf, leaving xorg.conf empty\n");
+        fclose(f);
+        pci_system_cleanup();
+        return;
+    }
+
+    FPRINTF("Section \"ServerFlags\"\n");
+    FPRINTF("\tOption\t\t\"Xinerama\"\t\"true\"\n");
+    FPRINTF("EndSection\n\n");
+
+    i = 0;
+    do {
+        FPRINTF("Section \"Device\"\n");
+        FPRINTF("\tIdentifier\t\"qxl%d\"\n", i++);
+        FPRINTF("\tDriver\t\t\"qxl\"\n");
+        FPRINTF("\tBusID\t\t\"PCI:%02d:%02d:%d\"\n",
+                dev->bus, dev->dev, dev->func);
+        FPRINTF("EndSection\n\n");
+    } while ((dev = pci_device_next(it)));
+
+    if (i < monitor_conf->num_of_monitors) {
+        fprintf(logfile, "Client has %d monitors, but only %d qxl devices found\n",
+                monitor_conf->num_of_monitors, i);
+        FPRINTF("# Client has %d monitors, but only %d qxl devices found\n",
+                monitor_conf->num_of_monitors, i);
+        FPRINTF("# Only generation %d \"Screen\" sections\n\n", i);
+        count = i;
+    } else {
+        count = monitor_conf->num_of_monitors;
+    }
+
+    for (i = 0; i < count; i++) {
+        FPRINTF("Section \"Screen\"\n");
+        FPRINTF("\tIdentifier\t\"Screen%d\"\n", i);
+        FPRINTF("\tDevice\t\t\"qxl%d\"\n", i);
+        FPRINTF("\tDefaultDepth\t24\n");
+        FPRINTF("\tSubSection \"Display\"\n");
+        FPRINTF("\t\tViewport\t0 0\n");
+        FPRINTF("\t\tDepth\t\t24\n");
+        FPRINTF("\t\tModes\t\t\"%dx%d\"\n", monitor_conf->monitors[i].width,
+                monitor_conf->monitors[i].height);
+        FPRINTF("\tEndSubSection\n");
+        FPRINTF("EndSection\n\n");
+    }
+
+    /* monitor_conf may contain negative values, convert these to 0 - # */
+    for (i = 0; i < count; i++) {
+        if (monitor_conf->monitors[i].x < min_x) {
+            min_x = monitor_conf->monitors[i].x;
+        }
+        if (monitor_conf->monitors[i].y < min_y) {
+            min_y = monitor_conf->monitors[i].y;
+        }
+    }
+
+    FPRINTF("Section \"ServerLayout\"\n");
+    FPRINTF("\tIdentifier\t\"layout\"\n");
+    for (i = 0; i < count; i++) {
+        FPRINTF("\tScreen\t\t\"Screen%d\" %d %d\n", i,
+                monitor_conf->monitors[i].x - min_x,
+                monitor_conf->monitors[i].y - min_y);
+    }
+    FPRINTF("EndSection\n");
+
+    fclose(f);
+    pci_system_cleanup();
+#endif
+}
diff --git a/src/vdagentd.c b/src/vdagentd.c
index cee779b..939d36a 100644
--- a/src/vdagentd.c
+++ b/src/vdagentd.c
@@ -38,6 +38,7 @@
 #include "vdagentd-proto.h"
 #include "vdagentd-proto-strings.h"
 #include "vdagentd-uinput.h"
+#include "vdagentd-xorg-conf.h"
 #include "vdagent-virtio-port.h"
 #include "console-kit.h"
 
@@ -118,6 +119,16 @@ static void do_client_monitors(struct vdagent_virtio_port *vport, int port_nr,
         return;
     }
 
+    vdagentd_write_xorg_conf(new_monitors, logfile);
+
+    if (new_monitors->num_of_monitors != 1) {
+        /* No use in sending this to the session agent it cannot handle it
+           anyways */
+        free(mon_config);
+        mon_config = NULL;
+        goto ack;
+    }
+
     if (!mon_config ||
             mon_config->num_of_monitors != new_monitors->num_of_monitors) {
         free(mon_config);
@@ -133,6 +144,7 @@ static void do_client_monitors(struct vdagent_virtio_port *vport, int port_nr,
     udscs_server_write_all(server, VDAGENTD_MONITORS_CONFIG, 0, 0,
                            (uint8_t *)mon_config, size);
 
+ack:
     /* Acknowledge reception of monitors config to spice server / client */
     reply.type  = VD_AGENT_MONITORS_CONFIG;
     reply.error = VD_AGENT_SUCCESS;