spice: allow to specify drm rendernode

When multiple GPU are available, picking the first one isn't always the
best choice. Learn to specify a device rendernode.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20170212112118.16044-1-marcandre.lureau@redhat.com
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>

include/ui/egl-helpers.h

@@ -14,8 +14,7 @@ extern int qemu_egl_rn_fd;
 extern struct gbm_device *qemu_egl_rn_gbm_dev;
 extern EGLContext qemu_egl_rn_ctx;
 
-int qemu_egl_rendernode_open(void);
-int egl_rendernode_init(void);
+int egl_rendernode_init(const char *rendernode);
 int egl_get_fd_for_texture(uint32_t tex_id, EGLint *stride, EGLint *fourcc);
 
 #endif

qemu-options.hx

@@ -1066,7 +1066,7 @@ DEF("spice", HAS_ARG, QEMU_OPTION_spice,
     "       [,streaming-video=[off|all|filter]][,disable-copy-paste]\n"
     "       [,disable-agent-file-xfer][,agent-mouse=[on|off]]\n"
     "       [,playback-compression=[on|off]][,seamless-migration=[on|off]]\n"
-    "       [,gl=[on|off]]\n"
+    "       [,gl=[on|off]][,rendernode=<file>]\n"
     "   enable spice\n"
     "   at least one of {port, tls-port} is mandatory\n",
     QEMU_ARCH_ALL)
@@ -1161,6 +1161,10 @@ Enable/disable spice seamless migration. Default is off.
 @item gl=[on|off]
 Enable/disable OpenGL context. Default is off.
 
+@item rendernode=<file>
+DRM render node for OpenGL rendering. If not specified, it will pick
+the first available. (Since 2.9)
+
 @end table
 ETEXI
 

ui/egl-helpers.c

@@ -44,13 +44,17 @@ int qemu_egl_rn_fd;
 struct gbm_device *qemu_egl_rn_gbm_dev;
 EGLContext qemu_egl_rn_ctx;
 
-int qemu_egl_rendernode_open(void)
+static int qemu_egl_rendernode_open(const char *rendernode)
 {
     DIR *dir;
     struct dirent *e;
     int r, fd;
     char *p;
 
+    if (rendernode) {
+        return open(rendernode, O_RDWR | O_CLOEXEC | O_NOCTTY | O_NONBLOCK);
+    }
+
     dir = opendir("/dev/dri");
     if (!dir) {
         return -1;
@@ -85,11 +89,11 @@ int qemu_egl_rendernode_open(void)
     return fd;
 }
 
-int egl_rendernode_init(void)
+int egl_rendernode_init(const char *rendernode)
 {
     qemu_egl_rn_fd = -1;
 
-    qemu_egl_rn_fd = qemu_egl_rendernode_open();
+    qemu_egl_rn_fd = qemu_egl_rendernode_open(rendernode);
     if (qemu_egl_rn_fd == -1) {
         error_report("egl: no drm render node available");
         goto err;

ui/spice-core.c

@@ -501,6 +501,9 @@ static QemuOptsList qemu_spice_opts = {
         },{
             .name = "gl",
             .type = QEMU_OPT_BOOL,
+        },{
+            .name = "rendernode",
+            .type = QEMU_OPT_STRING,
 #endif
         },
         { /* end of list */ }
@@ -833,7 +836,7 @@ void qemu_spice_init(void)
                          "incompatible with -spice port/tls-port");
             exit(1);
         }
-        if (egl_rendernode_init() != 0) {
+        if (egl_rendernode_init(qemu_opt_get(opts, "rendernode")) != 0) {
             error_report("Failed to initialize EGL render node for SPICE GL");
             exit(1);
         }