#!/usr/bin/python # # Compares vmstate information stored in JSON format, obtained from # the -dump-vmstate QEMU command. # # Copyright 2014 Amit Shah <amit.shah@redhat.com> # Copyright 2014 Red Hat, Inc. # # This program is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 2 of the License, or # (at your option) any later version. # # This program 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 General Public License for more details. # # You should have received a copy of the GNU General Public License along # with this program; if not, see <http://www.gnu.org/licenses/>. import argparse import json import sys # Count the number of errors found taint = 0 def bump_taint(): global taint # Ensure we don't wrap around or reset to 0 -- the shell only has # an 8-bit return value. if taint < 255: taint = taint + 1 def check_fields_match(name, s_field, d_field): if s_field == d_field: return True # Some fields changed names between qemu versions. This list # is used to whitelist such changes in each section / description. changed_names = { 'apic': ['timer', 'timer_expiry'], 'e1000': ['dev', 'parent_obj'], 'ehci': ['dev', 'pcidev'], 'I440FX': ['dev', 'parent_obj'], 'ich9_ahci': ['card', 'parent_obj'], 'ich9-ahci': ['ahci', 'ich9_ahci'], 'ioh3420': ['PCIDevice', 'PCIEDevice'], 'ioh-3240-express-root-port': ['port.br.dev', 'parent_obj.parent_obj.parent_obj', 'port.br.dev.exp.aer_log', 'parent_obj.parent_obj.parent_obj.exp.aer_log'], 'lsiscsi': ['dev', 'parent_obj'], 'mch': ['d', 'parent_obj'], 'pci_bridge': ['bridge.dev', 'parent_obj', 'bridge.dev.shpc', 'shpc'], 'pcnet': ['pci_dev', 'parent_obj'], 'PIIX3': ['pci_irq_levels', 'pci_irq_levels_vmstate'], 'piix4_pm': ['dev', 'parent_obj', 'pci0_status', 'acpi_pci_hotplug.acpi_pcihp_pci_status[0x0]', 'pm1a.sts', 'ar.pm1.evt.sts', 'pm1a.en', 'ar.pm1.evt.en', 'pm1_cnt.cnt', 'ar.pm1.cnt.cnt', 'tmr.timer', 'ar.tmr.timer', 'tmr.overflow_time', 'ar.tmr.overflow_time', 'gpe', 'ar.gpe'], 'rtl8139': ['dev', 'parent_obj'], 'qxl': ['num_surfaces', 'ssd.num_surfaces'], 'usb-ccid': ['abProtocolDataStructure', 'abProtocolDataStructure.data'], 'usb-host': ['dev', 'parent_obj'], 'usb-mouse': ['usb-ptr-queue', 'HIDPointerEventQueue'], 'usb-tablet': ['usb-ptr-queue', 'HIDPointerEventQueue'], 'vmware_vga': ['card', 'parent_obj'], 'vmware_vga_internal': ['depth', 'new_depth'], 'xhci': ['pci_dev', 'parent_obj'], 'x3130-upstream': ['PCIDevice', 'PCIEDevice'], 'xio3130-express-downstream-port': ['port.br.dev', 'parent_obj.parent_obj.parent_obj', 'port.br.dev.exp.aer_log', 'parent_obj.parent_obj.parent_obj.exp.aer_log'], 'xio3130-downstream': ['PCIDevice', 'PCIEDevice'], 'xio3130-express-upstream-port': ['br.dev', 'parent_obj.parent_obj', 'br.dev.exp.aer_log', 'parent_obj.parent_obj.exp.aer_log'], } if not name in changed_names: return False if s_field in changed_names[name] and d_field in changed_names[name]: return True return False def get_changed_sec_name(sec): # Section names can change -- see commit 292b1634 for an example. changes = { "ICH9 LPC": "ICH9-LPC", } for item in changes: if item == sec: return changes[item] if changes[item] == sec: return item return "" def exists_in_substruct(fields, item): # Some QEMU versions moved a few fields inside a substruct. This # kept the on-wire format the same. This function checks if # something got shifted inside a substruct. For example, the # change in commit 1f42d22233b4f3d1a2933ff30e8d6a6d9ee2d08f if not "Description" in fields: return False if not "Fields" in fields["Description"]: return False substruct_fields = fields["Description"]["Fields"] if substruct_fields == []: return False return check_fields_match(fields["Description"]["name"], substruct_fields[0]["field"], item) def check_fields(src_fields, dest_fields, desc, sec): # This function checks for all the fields in a section. If some # fields got embedded into a substruct, this function will also # attempt to check inside the substruct. d_iter = iter(dest_fields) s_iter = iter(src_fields) # Using these lists as stacks to store previous value of s_iter # and d_iter, so that when time comes to exit out of a substruct, # we can go back one level up and continue from where we left off. s_iter_list = [] d_iter_list = [] advance_src = True advance_dest = True unused_count = 0 while True: if advance_src: try: s_item = s_iter.next() except StopIteration: if s_iter_list == []: break s_iter = s_iter_list.pop() continue else: if unused_count == 0: # We want to avoid advancing just once -- when entering a # dest substruct, or when exiting one. advance_src = True if advance_dest: try: d_item = d_iter.next() except StopIteration: if d_iter_list == []: # We were not in a substruct print "Section \"" + sec + "\",", print "Description " + "\"" + desc + "\":", print "expected field \"" + s_item["field"] + "\",", print "while dest has no further fields" bump_taint() break d_iter = d_iter_list.pop() advance_src = False continue else: if unused_count == 0: advance_dest = True if unused_count > 0: if advance_dest == False: unused_count = unused_count - s_item["size"] if unused_count == 0: advance_dest = True continue if unused_count < 0: print "Section \"" + sec + "\",", print "Description \"" + desc + "\":", print "unused size mismatch near \"", print s_item["field"] + "\"" bump_taint() break continue if advance_src == False: unused_count = unused_count - d_item["size"] if unused_count == 0: advance_src = True continue if unused_count < 0: print "Section \"" + sec + "\",", print "Description \"" + desc + "\":", print "unused size mismatch near \"", print d_item["field"] + "\"" bump_taint() break continue if not check_fields_match(desc, s_item["field"], d_item["field"]): # Some fields were put in substructs, keeping the # on-wire format the same, but breaking static tools # like this one. # First, check if dest has a new substruct. if exists_in_substruct(d_item, s_item["field"]): # listiterators don't have a prev() function, so we # have to store our current location, descend into the # substruct, and ensure we come out as if nothing # happened when the substruct is over. # # Essentially we're opening the substructs that got # added which didn't change the wire format. d_iter_list.append(d_iter) substruct_fields = d_item["Description"]["Fields"] d_iter = iter(substruct_fields) advance_src = False continue # Next, check if src has substruct that dest removed # (can happen in backward migration: 2.0 -> 1.5) if exists_in_substruct(s_item, d_item["field"]): s_iter_list.append(s_iter) substruct_fields = s_item["Description"]["Fields"] s_iter = iter(substruct_fields) advance_dest = False continue if s_item["field"] == "unused" or d_item["field"] == "unused": if s_item["size"] == d_item["size"]: continue if d_item["field"] == "unused": advance_dest = False unused_count = d_item["size"] - s_item["size"] continue if s_item["field"] == "unused": advance_src = False unused_count = s_item["size"] - d_item["size"] continue print "Section \"" + sec + "\",", print "Description \"" + desc + "\":", print "expected field \"" + s_item["field"] + "\",", print "got \"" + d_item["field"] + "\"; skipping rest" bump_taint() break check_version(s_item, d_item, sec, desc) if not "Description" in s_item: # Check size of this field only if it's not a VMSTRUCT entry check_size(s_item, d_item, sec, desc, s_item["field"]) check_description_in_list(s_item, d_item, sec, desc) def check_subsections(src_sub, dest_sub, desc, sec): for s_item in src_sub: found = False for d_item in dest_sub: if s_item["name"] != d_item["name"]: continue found = True check_descriptions(s_item, d_item, sec) if not found: print "Section \"" + sec + "\", Description \"" + desc + "\":", print "Subsection \"" + s_item["name"] + "\" not found" bump_taint() def check_description_in_list(s_item, d_item, sec, desc): if not "Description" in s_item: return if not "Description" in d_item: print "Section \"" + sec + "\", Description \"" + desc + "\",", print "Field \"" + s_item["field"] + "\": missing description" bump_taint() return check_descriptions(s_item["Description"], d_item["Description"], sec) def check_descriptions(src_desc, dest_desc, sec): check_version(src_desc, dest_desc, sec, src_desc["name"]) if not check_fields_match(sec, src_desc["name"], dest_desc["name"]): print "Section \"" + sec + "\":", print "Description \"" + src_desc["name"] + "\"", print "missing, got \"" + dest_desc["name"] + "\" instead; skipping" bump_taint() return for f in src_desc: if not f in dest_desc: print "Section \"" + sec + "\"", print "Description \"" + src_desc["name"] + "\":", print "Entry \"" + f + "\" missing" bump_taint() continue if f == 'Fields': check_fields(src_desc[f], dest_desc[f], src_desc["name"], sec) if f == 'Subsections': check_subsections(src_desc[f], dest_desc[f], src_desc["name"], sec) def check_version(s, d, sec, desc=None): if s["version_id"] > d["version_id"]: print "Section \"" + sec + "\"", if desc: print "Description \"" + desc + "\":", print "version error:", s["version_id"], ">", d["version_id"] bump_taint() if not "minimum_version_id" in d: return if s["version_id"] < d["minimum_version_id"]: print "Section \"" + sec + "\"", if desc: print "Description \"" + desc + "\":", print "minimum version error:", s["version_id"], "<", print d["minimum_version_id"] bump_taint() def check_size(s, d, sec, desc=None, field=None): if s["size"] != d["size"]: print "Section \"" + sec + "\"", if desc: print "Description \"" + desc + "\"", if field: print "Field \"" + field + "\"", print "size mismatch:", s["size"], ",", d["size"] bump_taint() def check_machine_type(s, d): if s["Name"] != d["Name"]: print "Warning: checking incompatible machine types:", print "\"" + s["Name"] + "\", \"" + d["Name"] + "\"" return def main(): help_text = "Parse JSON-formatted vmstate dumps from QEMU in files SRC and DEST. Checks whether migration from SRC to DEST QEMU versions would break based on the VMSTATE information contained within the JSON outputs. The JSON output is created from a QEMU invocation with the -dump-vmstate parameter and a filename argument to it. Other parameters to QEMU do not matter, except the -M (machine type) parameter." parser = argparse.ArgumentParser(description=help_text) parser.add_argument('-s', '--src', type=file, required=True, help='json dump from src qemu') parser.add_argument('-d', '--dest', type=file, required=True, help='json dump from dest qemu') parser.add_argument('--reverse', required=False, default=False, action='store_true', help='reverse the direction') args = parser.parse_args() src_data = json.load(args.src) dest_data = json.load(args.dest) args.src.close() args.dest.close() if args.reverse: temp = src_data src_data = dest_data dest_data = temp for sec in src_data: dest_sec = sec if not dest_sec in dest_data: # Either the section name got changed, or the section # doesn't exist in dest. dest_sec = get_changed_sec_name(sec) if not dest_sec in dest_data: print "Section \"" + sec + "\" does not exist in dest" bump_taint() continue s = src_data[sec] d = dest_data[dest_sec] if sec == "vmschkmachine": check_machine_type(s, d) continue check_version(s, d, sec) for entry in s: if not entry in d: print "Section \"" + sec + "\": Entry \"" + entry + "\"", print "missing" bump_taint() continue if entry == "Description": check_descriptions(s[entry], d[entry], sec) return taint if __name__ == '__main__': sys.exit(main())