Commit d23bfa91 authored by Marc-André Lureau's avatar Marc-André Lureau Committed by Michael S. Tsirkin
Browse files

scripts/dump-guest-memory.py: add vmcoreinfo 



Add a vmcoreinfo ELF note in the dump if vmcoreinfo device has the
memory location details.

Signed-off-by: default avatarMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 9ada575b

scripts/dump-guest-memory.py

+61 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ the COPYING file in the top-level directory. 
"""



import ctypes

import struct



UINTPTR_T = gdb.lookup_type("uintptr_t")
@@ -45,6 +46,17 @@ 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."""
@@ -120,6 +132,25 @@ class ELF(object): 
        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."""
@@ -505,6 +536,35 @@ shape and this command should mostly work.""" 
                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 not gdb.parse_and_eval("vmcoreinfo_find()") \

           or not gdb.parse_and_eval("vmcoreinfo_find()->has_vmcoreinfo"):

            return



        fmt = gdb.parse_and_eval("vmcoreinfo_find()->vmcoreinfo.guest_format")

        addr = gdb.parse_and_eval("vmcoreinfo_find()->vmcoreinfo.paddr")

        size = gdb.parse_and_eval("vmcoreinfo_find()->vmcoreinfo.size")



        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(vmcoreinfo.tobytes())



    def invoke(self, args, from_tty):

        """Handles command invocation from gdb."""
@@ -518,6 +578,7 @@ shape and this command should mostly work.""" 


        self.elf = ELF(argv[1])

        self.guest_phys_blocks = get_guest_phys_blocks()

        self.add_vmcoreinfo()



        with open(argv[0], "wb") as vmcore:

            self.dump_init(vmcore)