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[PATCH v2 qemu 3/3] dump: Add qmp argument "reassembled"
From: |
Stephen Brennan |
Subject: |
[PATCH v2 qemu 3/3] dump: Add qmp argument "reassembled" |
Date: |
Wed, 13 Sep 2023 18:03:15 -0700 |
This can be used from QMP command line as "-R" to mirror the
corresponding flag for makedumpfile. This enables the kdump_reassembled
flag introduced in the previous patch.
Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
---
dump/dump-hmp-cmds.c | 8 +++++++-
dump/dump.c | 12 +++++++++++-
hmp-commands.hx | 7 +++++--
qapi/dump.json | 14 +++++++++++++-
4 files changed, 36 insertions(+), 5 deletions(-)
diff --git a/dump/dump-hmp-cmds.c b/dump/dump-hmp-cmds.c
index b038785fee..1d882e4bd8 100644
--- a/dump/dump-hmp-cmds.c
+++ b/dump/dump-hmp-cmds.c
@@ -24,9 +24,11 @@ void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict)
bool has_begin = qdict_haskey(qdict, "begin");
bool has_length = qdict_haskey(qdict, "length");
bool has_detach = qdict_haskey(qdict, "detach");
+ bool has_reassembled = qdict_haskey(qdict, "reassembled");
int64_t begin = 0;
int64_t length = 0;
bool detach = false;
+ bool reassembled = false;
enum DumpGuestMemoryFormat dump_format = DUMP_GUEST_MEMORY_FORMAT_ELF;
char *prot;
@@ -61,11 +63,15 @@ void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict)
if (has_detach) {
detach = qdict_get_bool(qdict, "detach");
}
+ if (has_reassembled) {
+ reassembled = qdict_get_bool(qdict, "reassembled");
+ }
prot = g_strconcat("file:", file, NULL);
qmp_dump_guest_memory(paging, prot, true, detach, has_begin, begin,
- has_length, length, true, dump_format, &err);
+ has_length, length, true, has_reassembled,
+ reassembled, dump_format, &err);
hmp_handle_error(mon, err);
g_free(prot);
}
diff --git a/dump/dump.c b/dump/dump.c
index fb9040cfbc..42d4015fb3 100644
--- a/dump/dump.c
+++ b/dump/dump.c
@@ -2089,6 +2089,7 @@ void qmp_dump_guest_memory(bool paging, const char *file,
bool has_detach, bool detach,
bool has_begin, int64_t begin, bool has_length,
int64_t length, bool has_format,
+ bool has_reassembled, bool reassembled,
DumpGuestMemoryFormat format, Error **errp)
{
ERRP_GUARD();
@@ -2119,6 +2120,12 @@ void qmp_dump_guest_memory(bool paging, const char *file,
"filter");
return;
}
+ if (has_reassembled && format != DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB
+ && format != DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO
+ && format != DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY) {
+ error_setg(errp, "'reassembled' only applies to kdump format");
+ return;
+ }
if (has_begin && !has_length) {
error_setg(errp, QERR_MISSING_PARAMETER, "length");
return;
@@ -2130,6 +2137,9 @@ void qmp_dump_guest_memory(bool paging, const char *file,
if (has_detach) {
detach_p = detach;
}
+ if (!has_reassembled) {
+ reassembled = false;
+ }
/* check whether lzo/snappy is supported */
#ifndef CONFIG_LZO
@@ -2192,7 +2202,7 @@ void qmp_dump_guest_memory(bool paging, const char *file,
dump_state_prepare(s);
dump_init(s, fd, has_format, format, paging, has_begin,
- begin, length, false, errp);
+ begin, length, reassembled, errp);
if (*errp) {
qatomic_set(&s->status, DUMP_STATUS_FAILED);
return;
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 2cbd0f77a0..c3062da470 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -1085,14 +1085,15 @@ ERST
{
.name = "dump-guest-memory",
- .args_type =
"paging:-p,detach:-d,windmp:-w,zlib:-z,lzo:-l,snappy:-s,filename:F,begin:l?,length:l?",
- .params = "[-p] [-d] [-z|-l|-s|-w] filename [begin length]",
+ .args_type =
"paging:-p,detach:-d,windmp:-w,zlib:-z,lzo:-l,snappy:-s,reassembled:-R,filename:F,begin:l?,length:l?",
+ .params = "[-p] [-d] [-z|-l|-s|-w] [-R] filename [begin length]",
.help = "dump guest memory into file 'filename'.\n\t\t\t"
"-p: do paging to get guest's memory mapping.\n\t\t\t"
"-d: return immediately (do not wait for
completion).\n\t\t\t"
"-z: dump in kdump-compressed format, with zlib
compression.\n\t\t\t"
"-l: dump in kdump-compressed format, with lzo
compression.\n\t\t\t"
"-s: dump in kdump-compressed format, with snappy
compression.\n\t\t\t"
+ "-R: when using kdump (-z, -l, -s), try to avoid the
flattened format.\n\t\t\t"
"-w: dump in Windows crashdump format (can be used
instead of ELF-dump converting),\n\t\t\t"
" for Windows x86 and x64 guests with vmcoreinfo
driver only.\n\t\t\t"
"begin: the starting physical address.\n\t\t\t"
@@ -1115,6 +1116,8 @@ SRST
dump in kdump-compressed format, with lzo compression.
``-s``
dump in kdump-compressed format, with snappy compression.
+ ``-R``
+ when using kdump (-z, -l, -s), try to avoid the flattened format.
``-w``
dump in Windows crashdump format (can be used instead of ELF-dump
converting),
for Windows x64 guests with vmcoreinfo driver only
diff --git a/qapi/dump.json b/qapi/dump.json
index 4ae1f722a9..9cc7c3ea93 100644
--- a/qapi/dump.json
+++ b/qapi/dump.json
@@ -69,6 +69,18 @@
# to dump all guest's memory, please specify the start @begin and
# @length
#
+# @reassembled: if false (the default), the kdump output formats will use the
+# "makedumpfile flattened" variant of the format, which is less broadly
+# compatible with analysis tools. The flattened dump can be reassembled
+# after the fact using the command "makedumpfile -R". If true, Qemu
+# attempts to generate the standard kdump format. This requires a
+# seekable file as output -- if the output file is not seekable, then
+# the flattened format is still generated. The standard format is more
+# broadly compatible with debugging tools, but generating it requires a
+# seekable output file descriptor, and could use more system memory due
+# to page cache utilization. This should be left unspecified for non-kdump
+# output formats.
+#
# @format: if specified, the format of guest memory dump. But non-elf
# format is conflict with paging and filter, ie. @paging, @begin
# and @length is not allowed to be specified with non-elf @format
@@ -89,7 +101,7 @@
{ 'command': 'dump-guest-memory',
'data': { 'paging': 'bool', 'protocol': 'str', '*detach': 'bool',
'*begin': 'int', '*length': 'int',
- '*format': 'DumpGuestMemoryFormat'} }
+ '*reassembled': 'bool', '*format': 'DumpGuestMemoryFormat'} }
##
# @DumpStatus:
--
2.39.3