From e40871f4bf8ca981075eb7baa5a8ff0f3f8f4a67 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 13:39:07 +0100

Subject: [PATCH 36/41] scripts/dump-guest-memory.py: Cleanup functions

MIME-Version: 1.0

Content-Type: text/plain; charset=UTF-8

Content-Transfer-Encoding: 8bit

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

Message-id: <20171213133912.26176-37-marcandre.lureau@redhat.com>

Patchwork-id: 78387

O-Subject: [RHEL-7.5 qemu-kvm PATCH v3 36/41] scripts/dump-guest-memory.py: Cleanup functions

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>

From: Janosch Frank <frankja@linux.vnet.ibm.com>

Increase readability by adding newlines and comments, as well as

removing wrong whitespaces and C style braces around conditionals and

loops.

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

Signed-off-by: Janosch Frank <frankja@linux.vnet.ibm.com>

Message-Id: <1453464520-3882-5-git-send-email-frankja@linux.vnet.ibm.com>

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

(cherry picked from commit 6782c0e785a0ba48cd96d99f2402cb87af027d26)

RHEL: conflicts due to qtailq usage

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

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

---

 scripts/dump-guest-memory.py | 69 +++++++++++++++++++++++++++++---------------

 1 file changed, 46 insertions(+), 23 deletions(-)

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

index d44de99..3d54d05 100644

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

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

@@ -69,35 +69,58 @@ ELF64_PHDR = ("I"  # p_type

           )

 def int128_get64(val):

-    assert (val["hi"] == 0)

+    """Returns low 64bit part of Int128 struct."""

+

+    assert val["hi"] == 0

     return val["lo"]

 def qtailq_foreach(head, field_str):

+    """Generator for qtails."""

+

     var_p = head["tqh_first"]

     while (var_p != 0):

         var = var_p.dereference()

-        yield var

         var_p = var[field_str]["tqe_next"]

+        yield var

 def qemu_get_ram_block(ram_addr):

+    """Returns the RAMBlock struct to which the given address belongs."""

+

     ram_blocks = gdb.parse_and_eval("ram_list.blocks")

+

     for block in qtailq_foreach(ram_blocks, "next"):

         if (ram_addr - block["offset"] < block["length"]):

             return block

+

     raise gdb.GdbError("Bad ram offset %x" % ram_addr)

+

 def qemu_get_ram_ptr(ram_addr):

+    """Returns qemu vaddr for given guest physical address."""

+

     block = qemu_get_ram_block(ram_addr)

     return block["host"] + (ram_addr - block["offset"])

-def memory_region_get_ram_ptr(mr):

-    if (mr["alias"] != 0):

-        return (memory_region_get_ram_ptr(mr["alias"].dereference()) +

-                mr["alias_offset"])

-    return qemu_get_ram_ptr(mr["ram_addr"] & TARGET_PAGE_MASK)

+

+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_get_ram_ptr(memory_region["ram_addr"] & TARGET_PAGE_MASK)

+

 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")

@@ -111,29 +134,29 @@ def get_guest_phys_blocks():

     # 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()

-        mr           = flat_range["mr"].dereference()

+        flat_range = (current_map["ranges"] + cur).dereference()

+        memory_region = flat_range["mr"].dereference()

         # we only care about RAM

-        if (not mr["ram"]):

+        if not memory_region["ram"]:

             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(mr) +

-                        flat_range["offset_in_region"])

+        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):

+        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)

+            assert predecessor["target_end"] <= target_start

             # we want continuity in both guest-physical and

             # host-virtual memory

@@ -141,11 +164,11 @@ def get_guest_phys_blocks():

                 predecessor["host_addr"] + predecessor_size != host_addr):

                 predecessor = None

-        if (predecessor is 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})

+                                      "target_end":   target_end,

+                                      "host_addr":    host_addr})

             message = "added"

         else:

             # expand predecessor until @target_end; predecessor's

@@ -282,7 +305,7 @@ shape and this command should mostly work."""

         # We should never reach PN_XNUM for paging=false dumps: there's

         # just a handful of discontiguous ranges after merging.

         self.phdr_num += len(self.guest_phys_blocks)

-        assert (self.phdr_num < PN_XNUM)

+        assert self.phdr_num < PN_XNUM

         # Calculate the ELF file offset where the memory dump commences:

         #

@@ -313,15 +336,15 @@ shape and this command should mostly work."""

     def dump_iterate(self, vmcore):

         qemu_core = gdb.inferiors()[0]

         for block in self.guest_phys_blocks:

-            cur  = block["host_addr"]

+            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):

+            while left > 0:

                 chunk_size = min(TARGET_PAGE_SIZE, left)

                 chunk = qemu_core.read_memory(cur, chunk_size)

                 vmcore.write(chunk)

-                cur  += chunk_size

+                cur += chunk_size

                 left -= chunk_size

     def create_vmcore(self, filename):

@@ -336,7 +359,7 @@ shape and this command should mostly work."""

         self.dont_repeat()

         argv = gdb.string_to_argv(args)

-        if (len(argv) != 1):

+        if len(argv) != 1:

             raise gdb.GdbError("usage: dump-guest-memory FILE")

         self.dump_init()

-- 

1.8.3.1