Hi
On Thu, Sep 14, 2023 at 5:03 AM Stephen Brennan
<stephen.s.bren...@oracle.com> wrote:
>
> 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.bren...@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
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
Will have to be adjusted to return an error if we drop the fallback behaviour.
> +# 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
>
--
Marc-André Lureau
