EGLBE: Allow specifying an EGL device without DRI

EGL doesn't actually require DRI, so it isn't necessary to use a DRI
device path to specify an EGL device.  The EGL device can simply be
specified by an "EGL device ID" of the form egl{n}, where {n} is the
device's index in the array of valid EGL devices returned by
eglQueryDevicesEXT().  This facilitates using the EGL back end on
systems that, for whatever reason, have not loaded the nvidia_drm
module.  This also allows the Mesa unaccelerated EGL device to be
specified, although the usefulness of that is doubtful.

Closes #207

ChangeLog.md

@@ -10,6 +10,11 @@ display manager was restarted.
 
 2. Fixed compilation errors when building with libX11 1.8.x.
 
+3. When using the EGL back end, a GPU can now be specified by an EGL device ID
+of the form `egl{n}`, where `{n}` is a zero-based index, or by a DRI device
+path.  A list of valid EGL device IDs and their associated DRI device paths can
+be obtained by running `/opt/VirtualGL/bin/eglinfo -e`.
+
 
 3.0.1
 =====

demos/eglinfo.c

@@ -1,7 +1,7 @@
 /*
  * Copyright (C) 1999-2014  Brian Paul   All Rights Reserved.
  * Copyright (C) 2005-2007  Sun Microsystems, Inc.   All Rights Reserved.
- * Copyright (C) 2011, 2013, 2015, 2019-2021  D. R. Commander
+ * Copyright (C) 2011, 2013, 2015, 2019-2022  D. R. Commander
  *                                            All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
@@ -242,7 +242,7 @@ create_context_with_config(EGLDisplay edpy, EGLConfig config,
 
 static GLboolean
 print_display_info(EGLDisplay edpy,
-                   const struct options *opts,
+                   const struct options *opts, int eglDeviceID,
                    GLboolean coreProfile, GLboolean limits,
                    GLboolean coreWorked)
 {
@@ -315,7 +315,12 @@ print_display_info(EGLDisplay edpy,
       CheckError(__LINE__);
 
       if (!coreWorked) {
-         printf("device: %s\n", opts->displayName);
+         printf("EGL device ID: egl%d", eglDeviceID);
+         if (eglDeviceID == 0)
+            printf(" or egl");
+         printf("\n");
+         if (opts->displayName)
+            printf("DRI device path: %s\n", opts->displayName);
          if (opts->mode != Brief) {
             printf("EGL client APIs string: %s\n", eglAPIs);
             printf("EGL vendor string: %s\n", eglVendor);
@@ -610,8 +615,9 @@ static void
 usage(void)
 {
    printf("Usage: eglinfo <device> [-v] [-h] [-l] [-s]\n");
-   printf("\t<device>: Print EGL configs for the specified DRI device.\n");
-   printf("\t          (\"egl\" = print EGL configs for the first DRI device)\n");
+   printf("\t<device>: Print EGL configs for the specified EGL device.  <device> can\n");
+   printf("\t          be a DRI device path or an EGL device ID (use -e for a list.)\n");
+   printf("\t-e: List all valid EGL devices\n");
    printf("\t-B: brief output, print only the basics.\n");
    printf("\t-v: Print config info in verbose form.\n");
    printf("\t-h: This information.\n");
@@ -623,8 +629,8 @@ usage(void)
 int
 main(int argc, char *argv[])
 {
-   const char *exts;
-   int numDevices, major, minor, i;
+   const char *exts, *devStr = NULL;
+   int numDevices, major, minor, i, list = 0, validDevices = 0;
    EGLDeviceEXT *devices = NULL;
    EGLDisplay edpy;
    struct options opts;
@@ -660,11 +666,14 @@ main(int argc, char *argv[])
       else if (strcmp(argv[i], "-s") == 0) {
          opts.singleLine = GL_TRUE;
       }
+      else if (strcmp(argv[i], "-e") == 0) {
+         list = 1;
+      }
       else {
          opts.displayName = argv[i];
       }
    }
-   if (!opts.displayName) {
+   if (!opts.displayName && !list) {
       usage();
       exit(0);
    }
@@ -712,18 +721,38 @@ main(int argc, char *argv[])
       return -1;
    }
    for (i = 0; i < numDevices; i++) {
-      const char *devStr;
-
       edpy = _eglGetPlatformDisplayEXT(EGL_PLATFORM_DEVICE_EXT, devices[i],
                                        NULL);
       if (!edpy || !eglInitialize(edpy, &major, &minor))
          continue;
       eglTerminate(edpy);
-      if (!strcasecmp(opts.displayName, "egl"))
-         break;
       devStr = _eglQueryDeviceStringEXT(devices[i], EGL_DRM_DEVICE_FILE_EXT);
-      if (devStr && !strcmp(devStr, opts.displayName))
-         break;
+      if (opts.displayName && !list) {
+         if (!strcasecmp(opts.displayName, "egl"))
+            break;
+         if (!strncasecmp(opts.displayName, "egl", 3)) {
+            char temps[80];
+
+            snprintf(temps, 80, "egl%d", validDevices);
+            if (!strcasecmp(opts.displayName, temps))
+               break;
+         }
+         if (devStr && !strcmp(devStr, opts.displayName))
+            break;
+      }
+      if (list) {
+         printf("EGL device ID: egl%d", validDevices);
+         if (validDevices == 0)
+            printf(" or egl");
+         if (devStr)
+            printf(", DRI device path: %s", devStr);
+         printf("\n");
+      }
+      validDevices++;
+   }
+   if (list) {
+      free(devices);
+      return 0;
    }
    if (i == numDevices) {
       fprintf(stderr, "Error: invalid EGL device\n");
@@ -742,9 +771,11 @@ main(int argc, char *argv[])
       return -1;
    }
 
-   coreWorked = print_display_info(edpy, &opts, GL_TRUE, opts.limits,
-                                   GL_FALSE);
-   print_display_info(edpy, &opts, GL_FALSE, opts.limits, coreWorked);
+   opts.displayName = (char *)devStr;
+   coreWorked = print_display_info(edpy, &opts, validDevices, GL_TRUE,
+                                   opts.limits, GL_FALSE);
+   print_display_info(edpy, &opts, validDevices, GL_FALSE, opts.limits,
+                      coreWorked);
 
    printf("\n");
 

doc/advancedconfig.txt

@@ -113,9 +113,10 @@ previous method:
 	''VGL_COMPRESS'' to any numeric value >= 0 (Default value = ''0''.)  The
 	plugin can choose to respond to this value as it sees fit.
 
+{anchor: VGL_DISPLAY}
 | Environment Variable | {pcode: VGL_DISPLAY = __{d}__ } |
 | ''vglrun'' argument | {pcode: -d __{d}__ } |
-| Summary | __''{d}''__ = the X display/screen or DRI device to use for 3D \
+| Summary | __''{d}''__ = the X display/screen or EGL device to use for 3D \
 	rendering |
 | Image Transports | All |
 | Default Value | '':0'' |
@@ -127,9 +128,11 @@ previous method:
 	'':0.1'' would cause VirtualGL to use the GLX back end and redirect all of
 	the OpenGL rendering from the 3D application to a GPU attached to Screen 1 on
 	X display :0.  Setting ''VGL_DISPLAY'' to (or invoking ''vglrun -d'' with)
-	''/dev/dri/card0'' or ''egl'' would cause VirtualGL to use the EGL back end
-	and redirect all of the OpenGL rendering from the 3D application to the first
-	GPU in the system.
+	a DRI device path (such as ''/dev/dri/card0'') or an EGL device ID (such as
+	''egl0'') would cause VirtualGL to use the EGL back end and redirect all of
+	the OpenGL rendering from the 3D application to the specified EGL device.
+	''/opt/VirtualGL/bin/eglinfo -e'' lists all valid EGL device IDs and their
+	associated DRI device paths.
 
 | Environment Variable | {pcode: VGL_EGLLIB = __{l}__ } |
 | Summary | __''{l}''__ = the location of an alternate EGL library |

doc/index.html

@@ -3,7 +3,7 @@
 <head>
 <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1">
 <meta name="language" content="en">
-<meta name="date" content="2022-06-14T11:36:37">
+<meta name="date" content="2022-07-08T11:41:34">
 <meta name="generator" content="deplate.rb 0.8.5">
 <title>User&rsquo;s Guide for VirtualGL 3.0.2</title>
 <link rel="start" href="index.html" title="Frontpage">
@@ -369,7 +369,7 @@ <h2 id="hd002001">2.1&nbsp;Terminology</h2>
         API, so it can only access a GPU through an attached X server (the 3D X 
         server.)  The EGL back end uses the EGL API with the 
         <code>EGL_EXT_platform_device</code> extension, so it accesses a GPU 
-        through an associated DRI device without the need for a 3D X server.  
+        through an associated EGL device without the need for a 3D X server.  
         The EGL back end emulates a subset of the GLX API using the EGL API.  
         Since the EGL API does not support multi-buffering (double buffering or 
         quad-buffered stereo) with off-screen surfaces, the EGL back end 
@@ -469,15 +469,14 @@ <h1 id="hd003"><a name="file003"></a>3&nbsp;Overview</h1>
 delivery of X11 2D drawing commands to the X server.  For the most part, 
 VGL does not interfere with the delivery of OpenGL commands to the GPU, 
 either.  VGL merely forces the OpenGL commands to be delivered to a GPU 
-in the application server, either through the 3D X server attached to 
-the GPU or through a DRI device, rather than to the X server to which 
-the 2D drawing commands are delivered (the 2D X server.)  Once the 
-OpenGL rendering has been redirected to an off-screen buffer, everything 
-(including esoteric OpenGL extensions, fragment/vertex shaders, etc.) 
-should &ldquo;just work.&rdquo;  If an OpenGL application runs correctly 
-when accessing a 3D server/workstation locally, then the same 
-application should run correctly with VirtualGL when accessing the same 
-machine remotely.</p>
+in the application server (through the 3D X server or EGL device 
+attached to the GPU) rather than to the X server to which the 2D drawing 
+commands are delivered (the 2D X server.)  Once the OpenGL rendering has 
+been redirected to an off-screen buffer, everything (including esoteric 
+OpenGL extensions, fragment/vertex shaders, etc.) should &ldquo;just 
+work.&rdquo;  If an OpenGL application runs correctly when accessing a 
+3D server/workstation locally, then the same application should run 
+correctly with VirtualGL when accessing the same machine remotely.</p>
 
 <p>VirtualGL has two built-in &ldquo;image transports&rdquo; that can be 
 used to deliver rendered frames to the 2D X server:</p>
@@ -1206,10 +1205,9 @@ <h3 id="hd006002001">6.2.1&nbsp;Sanity Check</h3>
 
 <h2 id="hd006003">6.3&nbsp;EGL Back End: Granting Access to the GPU(s)</h2>
 
-<p>When using the EGL back end, accessing a GPU requires going through an 
-associated DRI device, so the only way to share the application 
+<p>When using the EGL back end, the only way to share the application 
 server&rsquo;s GPU(s) among multiple users is to grant those users 
-access to the DRI device(s) associated with the GPU(s).</p>
+access to the device(s) associated with the GPU(s).</p>
 
 <p>This section will explain how to configure a VirtualGL server such that 
 selected users can use the EGL back end.</p>
@@ -1276,7 +1274,7 @@ <h3 id="hd006003001">6.3.1&nbsp;Sanity Check</h3>
 execute the following command in the SSH session:</p>
 
 <pre class="verbatim">
-/opt/VirtualGL/bin/eglinfo&nbsp;/dev/dri/card0
+/opt/VirtualGL/bin/eglinfo&nbsp;egl0
 </pre>
 
 <p>This command should output a list of EGL configs and should complete 
@@ -1299,11 +1297,12 @@ <h2 id="hd006004">6.4&nbsp;Using VirtualGL with Multiple GPUs</h2>
 with) <code>:0.0</code>, <code>:1.0</code>, <code>:2.0</code>, etc.</p>
 
 <p>Setting <code>VGL_DISPLAY</code> to (or invoking 
-<code>vglrun&nbsp;-d</code> with) <code>egl</code> or the path to a DRI 
-device enables the EGL back end.  When using the EGL back end, a 
-specific GPU can be selected by setting <code>VGL_DISPLAY</code> to (or 
-invoking <code>vglrun&nbsp;-d</code> with) <code>/dev/dri/card0</code>, 
-<code>/dev/dri/card1</code>, <code>/dev/dri/card2</code>, etc.</p>
+<code>vglrun&nbsp;-d</code> with) a DRI device path 
+(<code>/dev/dri/card0</code>, <code>/dev/dri/card1</code>, 
+<code>/dev/dri/card2</code>, etc.) or an EGL device ID 
+(<code>egl0</code>, <code>egl1</code>, <code>egl2</code>, etc.) enables 
+the EGL back end and selects the specified GPU.  See Section 
+<a href="#VGL_DISPLAY" class="ref">19.1</a> for more details.</p>
 
 
 
@@ -3097,6 +3096,8 @@ <h2 id="hd0019001">19.1&nbsp;Faker Settings</h2>
     </dd>
 </dl>
 
+<p><a name="VGL_DISPLAY"></a></p>
+
 <div class="table">
 <table class="standard">
   <tr class="standard">
@@ -3109,7 +3110,7 @@ <h2 id="hd0019001">19.1&nbsp;Faker Settings</h2>
   </tr>
   <tr class="standard">
     <td class="high standard">Summary</td>
-    <td class="standard"><em><code>{d}</code></em> = the X display/screen or DRI device to use for 3D rendering</td>
+    <td class="standard"><em><code>{d}</code></em> = the X display/screen or EGL device to use for 3D rendering</td>
   </tr>
   <tr class="standard">
     <td class="high standard">Image Transports</td>
@@ -3133,10 +3134,12 @@ <h2 id="hd0019001">19.1&nbsp;Faker Settings</h2>
         VirtualGL to use the GLX back end and redirect all of the OpenGL 
         rendering from the 3D application to a GPU attached to Screen 1 on X 
         display :0.  Setting <code>VGL_DISPLAY</code> to (or invoking 
-        <code>vglrun&nbsp;-d</code> with) <code>/dev/dri/card0</code> or 
-        <code>egl</code> would cause VirtualGL to use the EGL back end and 
+        <code>vglrun&nbsp;-d</code> with) a DRI device path (such as 
+        <code>/dev/dri/card0</code>) or an EGL device ID (such as 
+        <code>egl0</code>) would cause VirtualGL to use the EGL back end and 
         redirect all of the OpenGL rendering from the 3D application to the 
-        first GPU in the system.
+        specified EGL device. <code>/opt/VirtualGL/bin/eglinfo&nbsp;-e</code> 
+        lists all valid EGL device IDs and their associated DRI device paths.
     </dd>
 </dl>
 

doc/overview.txt

@@ -47,14 +47,14 @@ X11 commands and events to determine when windows have been resized, etc., but
 it does not interfere in any way with the delivery of X11 2D drawing commands
 to the X server.  For the most part, VGL does not interfere with the delivery
 of OpenGL commands to the GPU, either.  VGL merely forces the OpenGL commands
-to be delivered to a GPU in the application server, either through the 3D X
-server attached to the GPU or through a DRI device, rather than to the X server
-to which the 2D drawing commands are delivered (the 2D X server.)  Once the
-OpenGL rendering has been redirected to an off-screen buffer, everything
-(including esoteric OpenGL extensions, fragment/vertex shaders, etc.) should
-"just work."  If an OpenGL application runs correctly when accessing a 3D
-server/workstation locally, then the same application should run correctly with
-VirtualGL when accessing the same machine remotely.
+to be delivered to a GPU in the application server (through the 3D X server or
+EGL device attached to the GPU) rather than to the X server to which the 2D
+drawing commands are delivered (the 2D X server.)  Once the OpenGL rendering
+has been redirected to an off-screen buffer, everything (including esoteric
+OpenGL extensions, fragment/vertex shaders, etc.) should "just work."  If an
+OpenGL application runs correctly when accessing a 3D server/workstation
+locally, then the same application should run correctly with VirtualGL when
+accessing the same machine remotely.
 
 VirtualGL has two built-in "image transports" that can be used to deliver
 rendered frames to the 2D X server:

doc/prefix.txt

@@ -51,7 +51,7 @@ different directory, then adjust the instructions accordingly.
 	the GLX API, so it can only access a GPU through an attached X server (the 3D
 	X server.)  The EGL back end uses the EGL API with the
 	''EGL_EXT_platform_device'' extension, so it accesses a GPU through an
-	associated DRI device without the need for a 3D X server.  The EGL back end
+	associated EGL device without the need for a 3D X server.  The EGL back end
 	emulates a subset of the GLX API using the EGL API.  Since the EGL API does
 	not support multi-buffering (double buffering or quad-buffered stereo) with
 	off-screen surfaces, the EGL back end emulates multi-buffering using OpenGL

doc/unixconfig.txt

@@ -239,9 +239,8 @@ OpenGL renderer string.
 
 ** EGL Back End: Granting Access to the GPU(s)
 
-When using the EGL back end, accessing a GPU requires going through an
-associated DRI device, so the only way to share the application server's GPU(s)
-among multiple users is to grant those users access to the DRI device(s)
+When using the EGL back end, the only way to share the application server's
+GPU(s) among multiple users is to grant those users access to the device(s)
 associated with the GPU(s).
 
 This section will explain how to configure a VirtualGL server such that
@@ -292,7 +291,7 @@ end, log out of the server, log back into the server using SSH, and execute the
 following command in the SSH session:
 
 	#Verb <<---
-	/opt/VirtualGL/bin/eglinfo /dev/dri/card0
+	/opt/VirtualGL/bin/eglinfo egl0
 	---
 
 This command should output a list of EGL configs and should complete with no
@@ -310,11 +309,11 @@ by setting ''VGL_DISPLAY'' to (or invoking ''vglrun -d'' with) '':0.0'',
 a specific GPU can be selected by setting ''VGL_DISPLAY'' to (or invoking
 ''vglrun -d'' with) '':0.0'', '':1.0'', '':2.0'', etc.
 
-Setting ''VGL_DISPLAY'' to (or invoking ''vglrun -d'' with) ''egl'' or the path
-to a DRI device enables the EGL back end.  When using the EGL back end, a
-specific GPU can be selected by setting ''VGL_DISPLAY'' to (or invoking
-''vglrun -d'' with) ''/dev/dri/card0'', ''/dev/dri/card1'', ''/dev/dri/card2'',
-etc.
+Setting ''VGL_DISPLAY'' to (or invoking ''vglrun -d'' with) a DRI device path
+(''/dev/dri/card0'', ''/dev/dri/card1'', ''/dev/dri/card2'', etc.) or an EGL
+device ID (''egl0'', ''egl1'', ''egl2'', etc.) enables the EGL back end and
+selects the specified GPU.  See {ref prefix="Section ": VGL_DISPLAY} for more
+details.
 
 ** SSH Server Configuration
 

server/faker.cpp

@@ -177,7 +177,7 @@ Display *init3D(void)
 			#ifdef EGLBACKEND
 			if(fconfig.egl)
 			{
-				int numDevices = 0, i;
+				int numDevices = 0, i, validDevices = 0;
 				const char *exts = NULL;
 				EGLDeviceEXT *devices = NULL;
 
@@ -211,10 +211,19 @@ Display *init3D(void)
 						_eglTerminate(edpy);
 						if(!strcasecmp(fconfig.localdpystring, "egl"))
 							break;
+						if(!strncasecmp(fconfig.localdpystring, "egl", 3))
+						{
+							char temps[80];
+
+							snprintf(temps, 80, "egl%d", validDevices);
+							if(!strcasecmp(fconfig.localdpystring, temps))
+								break;
+						}
 						const char *devStr =
 							_eglQueryDeviceStringEXT(devices[i], EGL_DRM_DEVICE_FILE_EXT);
 						if(devStr && !strcmp(devStr, fconfig.localdpystring))
 							break;
+						validDevices++;
 					}
 					if(i == numDevices) THROW("Invalid EGL device");