From 8a0fb382404cba1a4d88dd489a14d585fc95f3cf Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= <marcandre.lureau@redhat.com>

Date: Wed, 13 Dec 2017 13:39:10 +0100

Subject: [PATCH 39/41] scripts/dump-guest-memory.py: add vmcoreinfo

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RH-Author: Marc-André Lureau <marcandre.lureau@redhat.com>

Message-id: <20171213133912.26176-40-marcandre.lureau@redhat.com>

Patchwork-id: 78389

O-Subject: [RHEL-7.5 qemu-kvm PATCH v3 39/41] scripts/dump-guest-memory.py: add vmcoreinfo

Bugzilla: 1411490

RH-Acked-by: Laszlo Ersek <lersek@redhat.com>

RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>

RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

Add a vmcoreinfo ELF note in the dump if vmcoreinfo device has the

memory location details.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

(cherry picked from commit d23bfa91b7789534d16ede6cb7d925bfac3f3c4c)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

---

 scripts/dump-guest-memory.py | 61 ++++++++++++++++++++++++++++++++++++++++++++

 1 file changed, 61 insertions(+)

diff --git a/scripts/dump-guest-memory.py b/scripts/dump-guest-memory.py

index 03d692d..471aa73 100644

--- a/scripts/dump-guest-memory.py

+++ b/scripts/dump-guest-memory.py

@@ -17,6 +17,7 @@

 # gdb.

 import ctypes

+import struct

 UINTPTR_T = gdb.lookup_type("uintptr_t")

@@ -48,6 +49,17 @@ EM_S390 = 22

 EM_AARCH = 183

 EM_X86_64 = 62

+VMCOREINFO_FORMAT_ELF = 1

+

+def le16_to_cpu(val):

+    return struct.unpack("

+

+def le32_to_cpu(val):

+    return struct.unpack("

+

+def le64_to_cpu(val):

+    return struct.unpack("

+

 class ELF(object):

     """Representation of a ELF file."""

@@ -123,6 +135,25 @@ 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("X86_64")

         self.guest_phys_blocks = get_guest_phys_blocks()

+        self.add_vmcoreinfo()

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

             self.dump_init(vmcore)

-- 

1.8.3.1