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dump: Add command interface for kdump-raw formats
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The QMP dump API represents the dump format as an enumeration. Add three
new enumerators, one for each supported kdump compression, each named
"kdump-raw-*".

For the HMP command line, rather than adding a new flag corresponding to
each format, it seems more human-friendly to add a single flag "-R" to
switch the kdump formats to "raw" mode. The choice of "-R" also
correlates nicely to the "makedumpfile -R" option, which would serve to
reassemble a flattened vmcore.

Signed-off-by: Stephen Brennan <[email protected]>
Reviewed-by: Daniel P. Berrangé <[email protected]>
[ Marc-André: replace loff_t with off_t, indent fixes ]
Reviewed-by: Marc-André Lureau <[email protected]>
Message-Id: <[email protected]>
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@brenns10 @elmarco
brenns10 authored and elmarco committed Nov 2, 2023
1 parent d43a01d commit e654919
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Showing 4 changed files with 76 additions and 11 deletions.
21 changes: 17 additions & 4 deletions dump/dump-hmp-cmds.c
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Original file line number Diff line number Diff line change
Expand Up @@ -19,6 +19,7 @@ void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict)
bool paging = qdict_get_try_bool(qdict, "paging", false);
bool zlib = qdict_get_try_bool(qdict, "zlib", false);
bool lzo = qdict_get_try_bool(qdict, "lzo", false);
bool raw = qdict_get_try_bool(qdict, "raw", false);
bool snappy = qdict_get_try_bool(qdict, "snappy", false);
const char *file = qdict_get_str(qdict, "filename");
bool has_begin = qdict_haskey(qdict, "begin");
Expand All @@ -40,16 +41,28 @@ void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict)
dump_format = DUMP_GUEST_MEMORY_FORMAT_WIN_DMP;
}

if (zlib) {
dump_format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB;
if (zlib && raw) {
if (raw) {
dump_format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_RAW_ZLIB;
} else {
dump_format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB;
}
}

if (lzo) {
dump_format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO;
if (raw) {
dump_format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_RAW_LZO;
} else {
dump_format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO;
}
}

if (snappy) {
dump_format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY;
if (raw) {
dump_format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_RAW_SNAPPY;
} else {
dump_format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY;
}
}

if (has_begin) {
Expand Down
33 changes: 32 additions & 1 deletion dump/dump.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2090,6 +2090,7 @@ void qmp_dump_guest_memory(bool paging, const char *file,
int fd = -1;
DumpState *s;
bool detach_p = false;
bool kdump_raw = false;

if (runstate_check(RUN_STATE_INMIGRATE)) {
error_setg(errp, "Dump not allowed during incoming migration.");
Expand All @@ -2103,6 +2104,29 @@ void qmp_dump_guest_memory(bool paging, const char *file,
return;
}

/*
* externally, we represent kdump-raw-* as separate formats, but internally
* they are handled the same, except for the "raw" flag
*/
if (has_format) {
switch (format) {
case DUMP_GUEST_MEMORY_FORMAT_KDUMP_RAW_ZLIB:
format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB;
kdump_raw = true;
break;
case DUMP_GUEST_MEMORY_FORMAT_KDUMP_RAW_LZO:
format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO;
kdump_raw = true;
break;
case DUMP_GUEST_MEMORY_FORMAT_KDUMP_RAW_SNAPPY:
format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY;
kdump_raw = true;
break;
default:
break;
}
}

/*
* kdump-compressed format need the whole memory dumped, so paging or
* filter is not supported here.
Expand Down Expand Up @@ -2166,6 +2190,10 @@ void qmp_dump_guest_memory(bool paging, const char *file,
error_setg(errp, QERR_INVALID_PARAMETER, "protocol");
return;
}
if (kdump_raw && lseek(fd, 0, SEEK_CUR) == (off_t) -1) {
error_setg(errp, "kdump-raw formats require a seekable file");
return;
}

if (!dump_migration_blocker) {
error_setg(&dump_migration_blocker,
Expand All @@ -2186,7 +2214,7 @@ 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, kdump_raw, errp);
if (*errp) {
qatomic_set(&s->status, DUMP_STATUS_FAILED);
return;
Expand Down Expand Up @@ -2214,15 +2242,18 @@ DumpGuestMemoryCapability *qmp_query_dump_guest_memory_capability(Error **errp)

/* kdump-zlib is always available */
QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB);
QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_RAW_ZLIB);

/* add new item if kdump-lzo is available */
#ifdef CONFIG_LZO
QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO);
QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_RAW_LZO);
#endif

/* add new item if kdump-snappy is available */
#ifdef CONFIG_SNAPPY
QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY);
QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_RAW_SNAPPY);
#endif

if (win_dump_available(NULL)) {
Expand Down
9 changes: 7 additions & 2 deletions hmp-commands.hx
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Original file line number Diff line number Diff line change
Expand Up @@ -1085,14 +1085,16 @@ 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,raw:-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), use raw rather than makedumpfile-flattened\n\t\t\t"
" 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"
Expand All @@ -1115,6 +1117,9 @@ 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), use raw rather than makedumpfile-flattened
format
``-w``
dump in Windows crashdump format (can be used instead of ELF-dump converting),
for Windows x64 guests with vmcoreinfo driver only
Expand Down
24 changes: 20 additions & 4 deletions qapi/dump.json
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Original file line number Diff line number Diff line change
Expand Up @@ -15,19 +15,35 @@
#
# @elf: elf format
#
# @kdump-zlib: kdump-compressed format with zlib-compressed
# @kdump-zlib: makedumpfile flattened, kdump-compressed format with zlib
# compression
#
# @kdump-lzo: kdump-compressed format with lzo-compressed
# @kdump-lzo: makedumpfile flattened, kdump-compressed format with lzo
# compression
#
# @kdump-snappy: kdump-compressed format with snappy-compressed
# @kdump-snappy: makedumpfile flattened, kdump-compressed format with snappy
# compression
#
# @kdump-raw-zlib: raw assembled kdump-compressed format with zlib compression
# (since 8.2)
#
# @kdump-raw-lzo: raw assembled kdump-compressed format with lzo compression
# (since 8.2)
#
# @kdump-raw-snappy: raw assembled kdump-compressed format with snappy
# compression (since 8.2)
#
# @win-dmp: Windows full crashdump format, can be used instead of ELF
# converting (since 2.13)
#
# Since: 2.0
##
{ 'enum': 'DumpGuestMemoryFormat',
'data': [ 'elf', 'kdump-zlib', 'kdump-lzo', 'kdump-snappy', 'win-dmp' ] }
'data': [
'elf',
'kdump-zlib', 'kdump-lzo', 'kdump-snappy',
'kdump-raw-zlib', 'kdump-raw-lzo', 'kdump-raw-snappy',
'win-dmp' ] }

##
# @dump-guest-memory:
Expand Down

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