qapi: Turn generators into modules - bwlp/qemu.git - Experimental fork of QEMU with video encoding patches

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author	Markus Armbruster	2018-02-26 20:39:37 +0100
committer	Eric Blake	2018-03-02 20:14:09 +0100
commit	26df4e7fab06422b21e11d039c64243ca4003147 (patch)
tree	6ec019a9caa809c7b14e812829afbcb840d612b1 /scripts/qapi-types.py
parent	qapi: Reduce use of global variables in generators some (diff)
download	qemu-26df4e7fab06422b21e11d039c64243ca4003147.tar.gz qemu-26df4e7fab06422b21e11d039c64243ca4003147.tar.xz qemu-26df4e7fab06422b21e11d039c64243ca4003147.zip

qapi: Turn generators into modules

The next commit will introduce a common driver program for all generators. The generators need to be modules for that. qapi2texi.py already is. Make the other generators follow suit. The changes are actually trivial. Obvious in the diffs once you view them with whitespace changes ignored. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20180211093607.27351-8-armbru@redhat.com> Reviewed-by: Michael Roth <mdroth@linux.vnet.ibm.com> [eblake: minor tweak to keep 'blurb' one line] Signed-off-by: Eric Blake <eblake@redhat.com>

Diffstat (limited to 'scripts/qapi-types.py')

-rw-r--r--

scripts/qapi-types.py

1 files changed, 31 insertions, 25 deletions

""" This python script adds a new gdb command, "dump-guest-memory". It should be loaded with "source dump-guest-memory.py" at the (gdb) prompt. Copyright (C) 2013, Red Hat, Inc. Authors: Laszlo Ersek <lersek@redhat.com> Janosch Frank <frankja@linux.vnet.ibm.com> This work is licensed under the terms of the GNU GPL, version 2 or later. See the COPYING file in the top-level directory. """ import ctypes import struct try: UINTPTR_T = gdb.lookup_type("uintptr_t") except Exception as inst: raise gdb.GdbError("Symbols must be loaded prior to sourcing dump-guest-memory.\n" "Symbols may be loaded by 'attach'ing a QEMU process id or by " "'load'ing a QEMU binary.") TARGET_PAGE_SIZE = 0x1000 TARGET_PAGE_MASK = 0xFFFFFFFFFFFFF000 # Special value for e_phnum. This indicates that the real number of # program headers is too large to fit into e_phnum. Instead the real # value is in the field sh_info of section 0. PN_XNUM = 0xFFFF EV_CURRENT = 1 ELFCLASS32 = 1 ELFCLASS64 = 2 ELFDATA2LSB = 1 ELFDATA2MSB = 2 ET_CORE = 4 PT_LOAD = 1 PT_NOTE = 4 EM_386 = 3 EM_PPC = 20 EM_PPC64 = 21 EM_S390 = 22 EM_AARCH = 183 EM_X86_64 = 62 VMCOREINFO_FORMAT_ELF = 1 def le16_to_cpu(val): return struct.unpack("<H", struct.pack("=H", val))[0] def le32_to_cpu(val): return struct.unpack("<I", struct.pack("=I", val))[0] def le64_to_cpu(val): return struct.unpack("<Q", struct.pack("=Q", val))[0] class ELF(object): """Representation of a ELF file.""" def __init__(self, arch): self.ehdr = None self.notes = [] self.segments = [] self.notes_size = 0 self.endianness = None self.elfclass = ELFCLASS64 if arch == 'aarch64-le': self.endianness = ELFDATA2LSB self.elfclass = ELFCLASS64 self.ehdr = get_arch_ehdr(self.endianness, self.elfclass) self.ehdr.e_machine = EM_AARCH elif arch == 'aarch64-be': self.endianness = ELFDATA2MSB self.ehdr = get_arch_ehdr(self.endianness, self.elfclass) self.ehdr.e_machine = EM_AARCH elif arch == 'X86_64': self.endianness = ELFDATA2LSB self.ehdr = get_arch_ehdr(self.endianness, self.elfclass) self.ehdr.e_machine = EM_X86_64 elif arch == '386': self.endianness = ELFDATA2LSB self.elfclass = ELFCLASS32 self.ehdr = get_arch_ehdr(self.endianness, self.elfclass) self.ehdr.e_machine = EM_386 elif arch == 's390': self.endianness = ELFDATA2MSB self.ehdr = get_arch_ehdr(self.endianness, self.elfclass) self.ehdr.e_machine = EM_S390 elif arch == 'ppc64-le': self.endianness = ELFDATA2LSB self.ehdr = get_arch_ehdr(self.endianness, self.elfclass) self.ehdr.e_machine = EM_PPC64 elif arch == 'ppc64-be': self.endianness = ELFDATA2MSB self.ehdr = get_arch_ehdr(self.endianness, self.elfclass) self.ehdr.e_machine = EM_PPC64 else: raise gdb.GdbError("No valid arch type specified.\n" "Currently supported types:\n" "aarch64-be, aarch64-le, X86_64, 386, s390, " "ppc64-be, ppc64-le") self.add_segment(PT_NOTE, 0, 0) def add_note(self, n_name, n_desc, n_type): """Adds a note to the ELF.""" note = get_arch_note(self.endianness, len(n_name), len(n_desc)) note.n_namesz = len(n_name) + 1 note.n_descsz = len(n_desc) note.n_name = n_name.encode() note.n_type = n_type # Desc needs to be 4 byte aligned (although the 64bit spec # specifies 8 byte). When defining n_desc as uint32 it will be # automatically aligned but we need the memmove to copy the # string into it. ctypes.memmove(note.n_desc, n_desc.encode(), len(n_desc)) self.notes.append(note) self.segments[0].p_filesz += ctypes.sizeof(note) self.segments[0].p_memsz += ctypes.sizeof(note) def add_vmcoreinfo_note(self, vmcoreinfo): """Adds a vmcoreinfo note to the ELF dump.""" # compute the header size, and copy that many bytes from the note header = get_arch_note(self.endianness, 0, 0) ctypes.memmove(ctypes.pointer(header), vmcoreinfo, ctypes.sizeof(header)) if header.n_descsz > 1 << 20: print('warning: invalid vmcoreinfo size') return # now get the full note note = get_arch_note(self.endianness, header.n_namesz - 1, header.n_descsz) ctypes.memmove(ctypes.pointer(note), vmcoreinfo, ctypes.sizeof(note)) self.notes.append(note) self.segments[0].p_filesz += ctypes.sizeof(note) self.segments[0].p_memsz += ctypes.sizeof(note) def add_segment(self, p_type, p_paddr, p_size): """Adds a segment to the elf.""" phdr = get_arch_phdr(self.endianness, self.elfclass) phdr.p_type = p_type phdr.p_paddr = p_paddr phdr.p_vaddr = p_paddr phdr.p_filesz = p_size phdr.p_memsz = p_size self.segments.append(phdr) self.ehdr.e_phnum += 1 def to_file(self, elf_file): """Writes all ELF structures to the passed file. Structure: Ehdr Segment 0:PT_NOTE Segment 1:PT_LOAD Segment N:PT_LOAD Note 0..N Dump contents """ elf_file.write(self.ehdr) off = ctypes.sizeof(self.ehdr) + \ len(self.segments) * ctypes.sizeof(self.segments[0]) for phdr in self.segments: phdr.p_offset = off elf_file.write(phdr) off += phdr.p_filesz for note in self.notes: elf_file.write(note) def get_arch_note(endianness, len_name, len_desc): """Returns a Note class with the specified endianness.""" if endianness == ELFDATA2LSB: superclass = ctypes.LittleEndianStructure else: superclass = ctypes.BigEndianStructure len_name = len_name + 1 class Note(superclass): """Represents an ELF note, includes the content.""" _fields_ = [("n_namesz", ctypes.c_uint32), ("n_descsz", ctypes.c_uint32), ("n_type", ctypes.c_uint32), ("n_name", ctypes.c_char * len_name), ("n_desc", ctypes.c_uint32 * ((len_desc + 3) // 4))] return Note() class Ident(ctypes.Structure): """Represents the ELF ident array in the ehdr structure.""" _fields_ = [('ei_mag0', ctypes.c_ubyte), ('ei_mag1', ctypes.c_ubyte), ('ei_mag2', ctypes.c_ubyte), ('ei_mag3', ctypes.c_ubyte), ('ei_class', ctypes.c_ubyte), ('ei_data', ctypes.c_ubyte), ('ei_version', ctypes.c_ubyte), ('ei_osabi', ctypes.c_ubyte), ('ei_abiversion', ctypes.c_ubyte), ('ei_pad', ctypes.c_ubyte * 7)] def __init__(self, endianness, elfclass): self.ei_mag0 = 0x7F self.ei_mag1 = ord('E') self.ei_mag2 = ord('L') self.ei_mag3 = ord('F') self.ei_class = elfclass self.ei_data = endianness self.ei_version = EV_CURRENT def get_arch_ehdr(endianness, elfclass): """Returns a EHDR64 class with the specified endianness.""" if endianness == ELFDATA2LSB: superclass = ctypes.LittleEndianStructure else: superclass = ctypes.BigEndianStructure class EHDR64(superclass): """Represents the 64 bit ELF header struct.""" _fields_ = [('e_ident', Ident), ('e_type', ctypes.c_uint16), ('e_machine', ctypes.c_uint16), ('e_version', ctypes.c_uint32), ('e_entry', ctypes.c_uint64), ('e_phoff', ctypes.c_uint64), ('e_shoff', ctypes.c_uint64), ('e_flags', ctypes.c_uint32), ('e_ehsize', ctypes.c_uint16), ('e_phentsize', ctypes.c_uint16), ('e_phnum', ctypes.c_uint16), ('e_shentsize', ctypes.c_uint16), ('e_shnum', ctypes.c_uint16), ('e_shstrndx', ctypes.c_uint16)] def __init__(self): super(superclass, self).__init__() self.e_ident = Ident(endianness, elfclass) self.e_type = ET_CORE self.e_version = EV_CURRENT self.e_ehsize = ctypes.sizeof(self) self.e_phoff = ctypes.sizeof(self) self.e_phentsize = ctypes.sizeof(get_arch_phdr(endianness, elfclass)) self.e_phnum = 0 class EHDR32(superclass): """Represents the 32 bit ELF header struct.""" _fields_ = [('e_ident', Ident), ('e_type', ctypes.c_uint16), ('e_machine', ctypes.c_uint16), ('e_version', ctypes.c_uint32), ('e_entry', ctypes.c_uint32), ('e_phoff', ctypes.c_uint32), ('e_shoff', ctypes.c_uint32), ('e_flags', ctypes.c_uint32), ('e_ehsize', ctypes.c_uint16), ('e_phentsize', ctypes.c_uint16), ('e_phnum', ctypes.c_uint16), ('e_shentsize', ctypes.c_uint16), ('e_shnum', ctypes.c_uint16), ('e_shstrndx', ctypes.c_uint16)] def __init__(self): super(superclass, self).__init__() self.e_ident = Ident(endianness, elfclass) self.e_type = ET_CORE self.e_version = EV_CURRENT self.e_ehsize = ctypes.sizeof(self) self.e_phoff = ctypes.sizeof(self) self.e_phentsize = ctypes.sizeof(get_arch_phdr(endianness, elfclass)) self.e_phnum = 0 # End get_arch_ehdr if elfclass == ELFCLASS64: return EHDR64() else: return EHDR32() def get_arch_phdr(endianness, elfclass): """Returns a 32 or 64 bit PHDR class with the specified endianness.""" if endianness == ELFDATA2LSB: superclass = ctypes.LittleEndianStructure else: superclass = ctypes.BigEndianStructure class PHDR64(superclass): """Represents the 64 bit ELF program header struct.""" _fields_ = [('p_type', ctypes.c_uint32), ('p_flags', ctypes.c_uint32), ('p_offset', ctypes.c_uint64), ('p_vaddr', ctypes.c_uint64), ('p_paddr', ctypes.c_uint64), ('p_filesz', ctypes.c_uint64), ('p_memsz', ctypes.c_uint64), ('p_align', ctypes.c_uint64)] class PHDR32(superclass): """Represents the 32 bit ELF program header struct.""" _fields_ = [('p_type', ctypes.c_uint32), ('p_offset', ctypes.c_uint32), ('p_vaddr', ctypes.c_uint32), ('p_paddr', ctypes.c_uint32), ('p_filesz', ctypes.c_uint32), ('p_memsz', ctypes.c_uint32), ('p_flags', ctypes.c_uint32), ('p_align', ctypes.c_uint32)] # End get_arch_phdr if elfclass == ELFCLASS64: return PHDR64() else: return PHDR32() def int128_get64(val): """Returns low 64bit part of Int128 struct.""" try: assert val["hi"] == 0 return val["lo"] except gdb.error: u64t = gdb.lookup_type('uint64_t').array(2) u64 = val.cast(u64t) if sys.byteorder == 'little': assert u64[1] == 0 return u64[0] else: assert u64[0] == 0 return u64[1] def qlist_foreach(head, field_str): """Generator for qlists.""" var_p = head["lh_first"] while var_p != 0: var = var_p.dereference() var_p = var[field_str]["le_next"] yield var def qemu_map_ram_ptr(block, offset): """Returns qemu vaddr for given guest physical address.""" return block["host"] + offset def memory_region_get_ram_ptr(memory_region): if memory_region["alias"] != 0: return (memory_region_get_ram_ptr(memory_region["alias"].dereference()) + memory_region["alias_offset"]) return qemu_map_ram_ptr(memory_region["ram_block"], 0) def get_guest_phys_blocks(): """Returns a list of ram blocks. Each block entry contains: 'target_start': guest block phys start address 'target_end': guest block phys end address 'host_addr': qemu vaddr of the block's start """ guest_phys_blocks = [] print("guest RAM blocks:") print("target_start target_end host_addr message " "count") print("---------------- ---------------- ---------------- ------- " "-----") current_map_p = gdb.parse_and_eval("address_space_memory.current_map") current_map = current_map_p.dereference() # Conversion to int is needed for python 3 # compatibility. Otherwise range doesn't cast the value itself and # breaks. for cur in range(int(current_map["nr"])): flat_range = (current_map["ranges"] + cur).dereference() memory_region = flat_range["mr"].dereference() # we only care about RAM if (not memory_region["ram"] or memory_region["ram_device"] or memory_region["nonvolatile"]): continue section_size = int128_get64(flat_range["addr"]["size"]) target_start = int128_get64(flat_range["addr"]["start"]) target_end = target_start + section_size host_addr = (memory_region_get_ram_ptr(memory_region) + flat_range["offset_in_region"]) predecessor = None # find continuity in guest physical address space if len(guest_phys_blocks) > 0: predecessor = guest_phys_blocks[-1] predecessor_size = (predecessor["target_end"] - predecessor["target_start"]) # the memory API guarantees monotonically increasing # traversal assert predecessor["target_end"] <= target_start # we want continuity in both guest-physical and # host-virtual memory if (predecessor["target_end"] < target_start or predecessor["host_addr"] + predecessor_size != host_addr): predecessor = None if predecessor is None: # isolated mapping, add it to the list guest_phys_blocks.append({"target_start": target_start, "target_end": target_end, "host_addr": host_addr}) message = "added" else: # expand predecessor until @target_end; predecessor's # start doesn't change predecessor["target_end"] = target_end message = "joined" print("%016x %016x %016x %-7s %5u" % (target_start, target_end, host_addr.cast(UINTPTR_T), message, len(guest_phys_blocks))) return guest_phys_blocks # The leading docstring doesn't have idiomatic Python formatting. It is # printed by gdb's "help" command (the first line is printed in the # "help data" summary), and it should match how other help texts look in # gdb. class DumpGuestMemory(gdb.Command): """Extract guest vmcore from qemu process coredump. The two required arguments are FILE and ARCH: FILE identifies the target file to write the guest vmcore to. ARCH specifies the architecture for which the core will be generated. This GDB command reimplements the dump-guest-memory QMP command in python, using the representation of guest memory as captured in the qemu coredump. The qemu process that has been dumped must have had the command line option "-machine dump-guest-core=on" which is the default. For simplicity, the "paging", "begin" and "end" parameters of the QMP command are not supported -- no attempt is made to get the guest's internal paging structures (ie. paging=false is hard-wired), and guest memory is always fully dumped. Currently aarch64-be, aarch64-le, X86_64, 386, s390, ppc64-be, ppc64-le guests are supported. The CORE/NT_PRSTATUS and QEMU notes (that is, the VCPUs' statuses) are not written to the vmcore. Preparing these would require context that is only present in the KVM host kernel module when the guest is alive. A fake ELF note is written instead, only to keep the ELF parser of "crash" happy. Dependent on how busted the qemu process was at the time of the coredump, this command might produce unpredictable results. If qemu deliberately called abort(), or it was dumped in response to a signal at a halfway fortunate point, then its coredump should be in reasonable shape and this command should mostly work.""" def __init__(self): super(DumpGuestMemory, self).__init__("dump-guest-memory", gdb.COMMAND_DATA, gdb.COMPLETE_FILENAME) self.elf = None self.guest_phys_blocks = None def dump_init(self, vmcore): """Prepares and writes ELF structures to core file.""" # Needed to make crash happy, data for more useful notes is # not available in a qemu core. self.elf.add_note("NONE", "EMPTY", 0) # We should never reach PN_XNUM for paging=false dumps, # there's just a handful of discontiguous ranges after # merging. # The constant is needed to account for the PT_NOTE segment. phdr_num = len(self.guest_phys_blocks) + 1 assert phdr_num < PN_XNUM for block in self.guest_phys_blocks: block_size = block["target_end"] - block["target_start"] self.elf.add_segment(PT_LOAD, block["target_start"], block_size) self.elf.to_file(vmcore) def dump_iterate(self, vmcore): """Writes guest core to file.""" qemu_core = gdb.inferiors()[0] for block in self.guest_phys_blocks: cur = block["host_addr"] left = block["target_end"] - block["target_start"] print("dumping range at %016x for length %016x" % (cur.cast(UINTPTR_T), left)) while left > 0: chunk_size = min(TARGET_PAGE_SIZE, left) chunk = qemu_core.read_memory(cur, chunk_size) vmcore.write(chunk) cur += chunk_size left -= chunk_size def phys_memory_read(self, addr, size): qemu_core = gdb.inferiors()[0] for block in self.guest_phys_blocks: if block["target_start"] <= addr \ and addr + size <= block["target_end"]: haddr = block["host_addr"] + (addr - block["target_start"]) return qemu_core.read_memory(haddr, size) return None def add_vmcoreinfo(self): if gdb.lookup_symbol("vmcoreinfo_realize")[0] is None: return vmci = 'vmcoreinfo_realize::vmcoreinfo_state' if not gdb.parse_and_eval("%s" % vmci) \ or not gdb.parse_and_eval("(%s)->has_vmcoreinfo" % vmci): return fmt = gdb.parse_and_eval("(%s)->vmcoreinfo.guest_format" % vmci) addr = gdb.parse_and_eval("(%s)->vmcoreinfo.paddr" % vmci) size = gdb.parse_and_eval("(%s)->vmcoreinfo.size" % vmci) fmt = le16_to_cpu(fmt) addr = le64_to_cpu(addr) size = le32_to_cpu(size) if fmt != VMCOREINFO_FORMAT_ELF: return vmcoreinfo = self.phys_memory_read(addr, size) if vmcoreinfo: self.elf.add_vmcoreinfo_note(bytes(vmcoreinfo)) def invoke(self, args, from_tty):


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