runqemu: direct mesa to use its own drivers, rather than ones provided by host distro

With mesa 23.0, it is not longer possible to use the host drivers, as
mesa upstream has added strict checks for matching builds between
drivers and libraries that load them.

Add a check and a hint to runqemu so that there is a helpful error when
there is no native/nativesdk opengl/virgl support.

(From OE-Core rev: f0946844df7270fe368858d8929e6b380675b78b)

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

scripts/runqemu

@@ -450,30 +450,16 @@ class BaseConfig(object):
             self.set("MACHINE", arg)
 
     def set_dri_path(self):
-        # As runqemu can be run within bitbake (when using testimage, for example),
-        # we need to ensure that we run host pkg-config, and that it does not
-        # get mis-directed to native build paths set by bitbake.
-        env = os.environ.copy()
-        try:
-            del env['PKG_CONFIG_PATH']
-            del env['PKG_CONFIG_DIR']
-            del env['PKG_CONFIG_LIBDIR']
-            del env['PKG_CONFIG_SYSROOT_DIR']
-        except KeyError:
-            pass
-        try:
-            dripath = subprocess.check_output("PATH=/bin:/usr/bin:$PATH pkg-config --variable=dridriverdir dri", shell=True, env=env)
-        except subprocess.CalledProcessError as e:
-            raise RunQemuError("Could not determine the path to dri drivers on the host via pkg-config.\nPlease install Mesa development files (particularly, dri.pc) on the host machine.")
-        self.qemu_environ['LIBGL_DRIVERS_PATH'] = dripath.decode('utf-8').strip()
-
-        # This preloads uninative libc pieces and therefore ensures that RPATH/RUNPATH
-        # in host mesa drivers doesn't trick uninative into loading host libc.
-        preload_items = ['libdl.so.2', 'librt.so.1', 'libpthread.so.0']
-        uninative_path = os.path.dirname(self.get("UNINATIVE_LOADER"))
-        if os.path.exists(uninative_path):
-            preload_paths = [os.path.join(uninative_path, i) for i in preload_items]
-            self.qemu_environ['LD_PRELOAD'] = " ".join(preload_paths)
+        drivers_path = os.path.join(self.bindir_native, '../lib/dri')
+        if not os.path.exists(drivers_path) or not os.listdir(drivers_path):
+            raise RunQemuError("""
+qemu has been built without opengl support and accelerated graphics support is not available.
+To enable it, add:
+DISTRO_FEATURES_NATIVE:append = " opengl"
+DISTRO_FEATURES_NATIVESDK:append = " opengl"
+to your build configuration.
+""")
+        self.qemu_environ['LIBGL_DRIVERS_PATH'] = drivers_path
 
     def check_args(self):
         for debug in ("-d", "--debug"):