Re: [Qemu-devel] [PATCH v2 1/6] scripts/replay-dump.py: replay log dumper

[Philippe Mathieu-Daudé]

On 05/17/2017 11:52 AM, Alex Bennée wrote:

This script is a debugging tool for looking through the contents of a
replay log file. It is incomplete but should fail gracefully at events
it doesn't understand.

It currently understands two different log formats as the audio
record/replay support was merged during since MTTCG. It was written to
help debug what has caused the BQL changes to break replay support.

Signed-off-by: Alex Bennée 


Reviewed-by: Philippe Mathieu-Daudé 


---
 scripts/replay-dump.py | 272 +
 1 file changed, 272 insertions(+)
 create mode 100755 scripts/replay-dump.py

diff --git a/scripts/replay-dump.py b/scripts/replay-dump.py
new file mode 100755
index 00..fdd178aba0
--- /dev/null
+++ b/scripts/replay-dump.py
@@ -0,0 +1,272 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Dump the contents of a recorded execution stream
+#
+#  Copyright (c) 2017 Alex Bennée 
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, see .
+
+import argparse
+import struct
+from collections import namedtuple
+
+# This mirrors some of the global replay state which some of the
+# stream loading refers to. Some decoders may read the next event so
+# we need handle that case. Calling reuse_event will ensure the next
+# event is read from the cache rather than advancing the file.
+
+class ReplayState(object):
+def __init__(self):
+self.event = -1
+self.event_count = 0
+self.already_read = False
+self.current_checkpoint = 0
+self.checkpoint = 0
+
+def set_event(self, ev):
+self.event = ev
+self.event_count += 1
+
+def get_event(self):
+self.already_read = False
+return self.event
+
+def reuse_event(self, ev):
+self.event = ev
+self.already_read = True
+
+def set_checkpoint(self):
+self.checkpoint = self.event - self.checkpoint_start
+
+def get_checkpoint(self):
+return self.checkpoint
+
+replay_state = ReplayState()
+
+# Simple read functions that mirror replay-internal.c
+# The file-stream is big-endian and manually written out a byte at a time.
+
+def read_byte(fin):
+"Read a single byte"
+return struct.unpack('>B', fin.read(1))[0]
+
+def read_event(fin):
+"Read a single byte event, but save some state"
+if replay_state.already_read:
+return replay_state.get_event()
+else:
+replay_state.set_event(read_byte(fin))
+return replay_state.event
+
+def read_word(fin):
+"Read a 16 bit word"
+return struct.unpack('>H', fin.read(2))[0]
+
+def read_dword(fin):
+"Read a 32 bit word"
+return struct.unpack('>I', fin.read(4))[0]
+
+def read_qword(fin):
+"Read a 64 bit word"
+return struct.unpack('>Q', fin.read(8))[0]
+
+# Generic decoder structure
+Decoder = namedtuple("Decoder", "eid name fn")
+
+def call_decode(table, index, dumpfile):
+"Search decode table for next step"
+decoder = next((d for d in table if d.eid == index), None)
+if not decoder:
+print "Could not decode index: %d" % (index)
+print "Entry is: %s" % (decoder)
+print "Decode Table is:\n%s" % (table)
+return False
+else:
+return decoder.fn(decoder.eid, decoder.name, dumpfile)
+
+# Print event
+def print_event(eid, name, string=None, event_count=None):
+"Print event with count"
+if not event_count:
+event_count = replay_state.event_count
+
+if string:
+print "%d:%s(%d) %s" % (event_count, name, eid, string)
+else:
+print "%d:%s(%d)" % (event_count, name, eid)
+
+
+# Decoders for each event type
+
+def decode_unimp(eid, name, _unused_dumpfile):
+"Unimplimented decoder, will trigger exit"
+print "%s not handled - will now stop" % (name)
+return False
+
+# Checkpoint decoder
+def swallow_async_qword(eid, name, dumpfile):
+"Swallow a qword of data without looking at it"
+step_id = read_qword(dumpfile)
+print "  %s(%d) @ %d" % (name, eid, step_id)
+return True
+
+async_decode_table = [ Decoder(0, "REPLAY_ASYNC_EVENT_BH", 
swallow_async_qword),
+   Decoder(1, "REPLAY_ASYNC_INPUT", decode_unimp),
+   Decoder(2, "REPLAY_ASYNC_INPUT_SYNC", decode_unimp),
+   Decoder(3, "REPLAY_ASYNC_CHAR_READ", decode_unimp),
+   

[Qemu-devel] [PATCH v2 1/6] scripts/replay-dump.py: replay log dumper

[Alex Bennée]

This script is a debugging tool for looking through the contents of a
replay log file. It is incomplete but should fail gracefully at events
it doesn't understand.

It currently understands two different log formats as the audio
record/replay support was merged during since MTTCG. It was written to
help debug what has caused the BQL changes to break replay support.

Signed-off-by: Alex Bennée 
---
 scripts/replay-dump.py | 272 +
 1 file changed, 272 insertions(+)
 create mode 100755 scripts/replay-dump.py

diff --git a/scripts/replay-dump.py b/scripts/replay-dump.py
new file mode 100755
index 00..fdd178aba0
--- /dev/null
+++ b/scripts/replay-dump.py
@@ -0,0 +1,272 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+# Dump the contents of a recorded execution stream
+#
+#  Copyright (c) 2017 Alex Bennée 
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, see .
+
+import argparse
+import struct
+from collections import namedtuple
+
+# This mirrors some of the global replay state which some of the
+# stream loading refers to. Some decoders may read the next event so
+# we need handle that case. Calling reuse_event will ensure the next
+# event is read from the cache rather than advancing the file.
+
+class ReplayState(object):
+def __init__(self):
+self.event = -1
+self.event_count = 0
+self.already_read = False
+self.current_checkpoint = 0
+self.checkpoint = 0
+
+def set_event(self, ev):
+self.event = ev
+self.event_count += 1
+
+def get_event(self):
+self.already_read = False
+return self.event
+
+def reuse_event(self, ev):
+self.event = ev
+self.already_read = True
+
+def set_checkpoint(self):
+self.checkpoint = self.event - self.checkpoint_start
+
+def get_checkpoint(self):
+return self.checkpoint
+
+replay_state = ReplayState()
+
+# Simple read functions that mirror replay-internal.c
+# The file-stream is big-endian and manually written out a byte at a time.
+
+def read_byte(fin):
+"Read a single byte"
+return struct.unpack('>B', fin.read(1))[0]
+
+def read_event(fin):
+"Read a single byte event, but save some state"
+if replay_state.already_read:
+return replay_state.get_event()
+else:
+replay_state.set_event(read_byte(fin))
+return replay_state.event
+
+def read_word(fin):
+"Read a 16 bit word"
+return struct.unpack('>H', fin.read(2))[0]
+
+def read_dword(fin):
+"Read a 32 bit word"
+return struct.unpack('>I', fin.read(4))[0]
+
+def read_qword(fin):
+"Read a 64 bit word"
+return struct.unpack('>Q', fin.read(8))[0]
+
+# Generic decoder structure
+Decoder = namedtuple("Decoder", "eid name fn")
+
+def call_decode(table, index, dumpfile):
+"Search decode table for next step"
+decoder = next((d for d in table if d.eid == index), None)
+if not decoder:
+print "Could not decode index: %d" % (index)
+print "Entry is: %s" % (decoder)
+print "Decode Table is:\n%s" % (table)
+return False
+else:
+return decoder.fn(decoder.eid, decoder.name, dumpfile)
+
+# Print event
+def print_event(eid, name, string=None, event_count=None):
+"Print event with count"
+if not event_count:
+event_count = replay_state.event_count
+
+if string:
+print "%d:%s(%d) %s" % (event_count, name, eid, string)
+else:
+print "%d:%s(%d)" % (event_count, name, eid)
+
+
+# Decoders for each event type
+
+def decode_unimp(eid, name, _unused_dumpfile):
+"Unimplimented decoder, will trigger exit"
+print "%s not handled - will now stop" % (name)
+return False
+
+# Checkpoint decoder
+def swallow_async_qword(eid, name, dumpfile):
+"Swallow a qword of data without looking at it"
+step_id = read_qword(dumpfile)
+print "  %s(%d) @ %d" % (name, eid, step_id)
+return True
+
+async_decode_table = [ Decoder(0, "REPLAY_ASYNC_EVENT_BH", 
swallow_async_qword),
+   Decoder(1, "REPLAY_ASYNC_INPUT", decode_unimp),
+   Decoder(2, "REPLAY_ASYNC_INPUT_SYNC", decode_unimp),
+   Decoder(3, "REPLAY_ASYNC_CHAR_READ", decode_unimp),
+   Decoder(4, "REPLAY_ASYNC_EVENT_BLOCK", decode_unimp),
+   Decoder(