scripts/run.py: allow to pass block device cache mode to qemu

Signed-off-by: Waldemar Kozaczuk <jwkozaczuk@gmail.com>

Author: wkozaczuk

scripts/run.py

@@ -90,8 +90,10 @@ def is_direct_io_supported(path):
 
 def start_osv_qemu(options):
 
-    if options.unsafe_cache or not is_direct_io_supported(options.image_file):
+    if not is_direct_io_supported(options.image_file):
         aio = 'cache=unsafe,aio=threads'
+    elif options.block_device_cache != None:
+        aio = 'cache=%s,aio=threads'% options.block_device_cache
     else:
         aio = 'cache=none,aio=native'
 
@@ -464,8 +466,8 @@ def main(options):
                         help="don't restart qemu automatically (allow debugger to connect on early errors)")
     parser.add_argument("-s", "--with-signals", action="store_true", default=False,
                         help="qemu only. handle signals instead of passing keys to the guest. pressing ctrl+c from console will kill the emulator")
-    parser.add_argument("-u", "--unsafe-cache", action="store_true",
-                        help="Set cache to unsafe. Use it at your own risk.")
+    parser.add_argument("--block-device-cache", action="store", default=None,
+                        help="Set QEMU block device cache to: none, writethrough, writeback, directsync or unsafe.")
     parser.add_argument("-g", "--graphics", action="store_true",
                         help="Enable graphics mode.")
     parser.add_argument("-V", "--verbose", action="store_true",

scripts/tests/testing.py

@@ -239,7 +239,7 @@ def __init__(self, args, forward=[], hold_with_poweroff=False, show_output_on_er
             for rule in forward:
                 args.extend(['--forward', 'tcp::%s-:%s' % rule])
 
-            args.extend(['--unsafe-cache'])
+            args.extend(['--block-device-cache', 'unsafe'])
 
         if _verbose_output:
             print('Running OSv on %s with parameters: [%s]' % (hypervisor, " ".join(args)))

scripts/upload_manifest.py

@@ -154,7 +154,7 @@ def main():
 
     image_path = os.path.abspath(options.output)
     upload_port = find_free_port()
-    osv = subprocess.Popen('cd ../..; scripts/run.py --vnc none -m 512 -c1 -i "%s" -u -s -e "--norandom --nomount --noinit /tools/mkfs.so; /tools/cpiod.so --prefix /zfs/zfs/; /zfs.so set compression=off osv" --forward tcp:127.0.0.1:%s-:10000' % (image_path,upload_port), shell=True, stdout=subprocess.PIPE)
+    osv = subprocess.Popen('cd ../..; scripts/run.py --vnc none -m 512 -c1 -i "%s" --block-device-cache unsafe -s -e "--norandom --nomount --noinit /tools/mkfs.so; /tools/cpiod.so --prefix /zfs/zfs/; /zfs.so set compression=off osv" --forward tcp:127.0.0.1:%s-:10000' % (image_path,upload_port), shell=True, stdout=subprocess.PIPE)
 
     upload(osv, manifest, depends, upload_port)