Date: Sun, 22 Aug 2021 15:16:25 +0300
Updated: Wed, 03 Jan 2024 14:12:39 +0300
From: Michael Tokarev <mjt@tls.msk.ru>
Subject: Note missing module package name
Debian-Specific: yes
Forwarded: not-needed

Debian ships different modules in different packages.
By default qemu ignores the fact that it can not load
a module, pretending this module never existed.
Give a useful hint about the package where the module
in question resides.

This is a hack, but it makes qemu packaged in debian
more user-friendly.

diff --git a/audio/audio.c b/audio/audio.c
index 7ac74f9e16..15f1071bdc 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -1745,5 +1745,9 @@ static AudioState *audio_init(Audiodev *dev, Error **errp)
             done = !audio_driver_init(s, driver, dev, errp);
         } else {
-            error_setg(errp, "Unknown audio driver `%s'", drvname);
+            error_setg(errp, "Unknown audio driver `%s'. Perhaps you want to install %s package?",
+                       drvname,
+                       !strcmp(drvname, "spice") ? "qemu-system-modules-spice" :
+                       !strcmp(drvname, "dbus") ? "qemu-system-modules-opengl" :
+                       "qemu-system-gui");
         }
         if (!done) {
diff --git a/block.c b/block.c
index bfb0861ec6..8de988961d 100644
--- a/block.c
+++ b/block.c
@@ -453,4 +453,10 @@ static BlockDriver *bdrv_do_find_format(const char *format_name)
 }
 
+static void note_block_package_name(const char *b)
+{
+    error_report("Unable to load module %s. Perhaps you want to install qemu-block-extra or qemu-block-supplemental package?",
+                 b);
+}
+
 BlockDriver *bdrv_find_format(const char *format_name)
 {
@@ -476,4 +482,5 @@ BlockDriver *bdrv_find_format(const char *format_name)
                 error_report_err(local_err);
             }
+            else note_block_package_name(block_driver_modules[i].library_name);
             break;
         }
@@ -966,5 +973,8 @@ BlockDriver *bdrv_find_protocol(const char *filename,
                 return NULL;
             }
-            break;
+            else {
+                note_block_package_name(block_driver_modules[i].library_name);
+                return NULL;
+            }
         }
     }
diff --git a/system/vl.c b/system/vl.c
index e18fa3ce46..91019d6952 100644
--- a/system/vl.c
+++ b/system/vl.c
@@ -1049,5 +1049,7 @@ static void select_vgahw(const MachineClass *machine_class, const char *p)
         if (ti->opt_name && strstart(p, ti->opt_name, &opts)) {
             if (!vga_interface_available(t)) {
-                error_report("%s not available", ti->name);
+                error_report("%s not available. Perhaps you want to install %s package?", ti->name,
+                        /* qxl is in spice, some are in opengl, the some are in common */
+                        !strcmp(ti->opt_name, "qxl") ? "qemu-system-modules-spice" : "qemu-system-modules-opengl");
                 exit(1);
             }
@@ -3500,5 +3502,10 @@ void qemu_init(int argc, char **argv)
 #ifdef CONFIG_SPICE
             case QEMU_OPTION_spice:
-                opts = qemu_opts_parse_noisily(qemu_find_opts("spice"), optarg, false);
+                olist = qemu_find_opts("spice");
+                if (!olist) {
+                    error_report("Perhaps you want to install qemu-system-modules-spice package?");
+                    exit(1);
+                }
+                opts = qemu_opts_parse_noisily(olist, optarg, false);
                 if (!opts) {
                     exit(1);
diff --git a/ui/console.c b/ui/console.c
index 832055675c..a930f88d68 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -1659,6 +1659,8 @@ void qemu_display_early_init(DisplayOptions *opts)
     }
     if (dpys[opts->type] == NULL) {
-        error_report("Display '%s' is not available.",
-                     DisplayType_str(opts->type));
+        error_report("Display '%s' is not available. Perhaps you want to install %s package?",
+                     DisplayType_str(opts->type),
+                     (!strcmp(DisplayType_str(opts->type), "dbus") || !strcmp(DisplayType_str(opts->type), "egl-headless"))
+                      ? "qemu-system-modules-opengl" : "qemu-system-gui");
         exit(1);
     }