Re: [Qemu-devel] [PATCH v2 2/8] dump-guest-memory: add "detach" flag for QMP/HMP interfaces.

[Fam Zheng <famz@redhat.com>]

On Fri, 11/27 10:48, Peter Xu wrote:
> This patch only adds the interfaces, but not implements them.
> "detach" parameter is made optional, to make sure that all the old
> dump-guest-memory requests will still be able to work.
> 
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>  dump.c           | 5 +++--
>  hmp-commands.hx  | 5 +++--
>  hmp.c            | 9 +++++++--
>  qapi-schema.json | 8 ++++++--
>  qmp-commands.hx  | 6 ++++--
>  5 files changed, 23 insertions(+), 10 deletions(-)
> 
> diff --git a/dump.c b/dump.c
> index 445e739..d79e0ed 100644
> --- a/dump.c
> +++ b/dump.c
> @@ -1580,8 +1580,9 @@ cleanup:
>      dump_cleanup(s);
>  }
>  
> -void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
> -                           int64_t begin, bool has_length,
> +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,
>                             DumpGuestMemoryFormat format, Error **errp)
>  {
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index bb52e4d..664d794 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -1056,10 +1056,11 @@ ETEXI
>  
>      {
>          .name       = "dump-guest-memory",
> -        .args_type  = "paging:-p,zlib:-z,lzo:-l,snappy:-s,filename:F,begin:i?,length:i?",
> -        .params     = "[-p] [-z|-l|-s] filename [begin length]",
> +        .args_type  = "paging:-p,detach:-d,zlib:-z,lzo:-l,snappy:-s,filename:F,begin:i?,length:i?",
> +        .params     = "[-p] [-d] [-z|-l|-s] 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"
> diff --git a/hmp.c b/hmp.c
> index 2140605..dccb457 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -1586,8 +1586,10 @@ void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict)
>      const char *file = qdict_get_str(qdict, "filename");
>      bool has_begin = qdict_haskey(qdict, "begin");
>      bool has_length = qdict_haskey(qdict, "length");
> +    bool has_detach = qdict_haskey(qdict, "detach");
>      int64_t begin = 0;
>      int64_t length = 0;
> +    bool detach = false;
>      enum DumpGuestMemoryFormat dump_format = DUMP_GUEST_MEMORY_FORMAT_ELF;
>      char *prot;
>  
> @@ -1615,11 +1617,14 @@ void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict)
>      if (has_length) {
>          length = qdict_get_int(qdict, "length");
>      }
> +    if (has_detach) {
> +        detach = qdict_get_try_bool(qdict, "detach", false);
> +    }
>  
>      prot = g_strconcat("file:", file, NULL);
>  
> -    qmp_dump_guest_memory(paging, prot, has_begin, begin, has_length, length,
> -                          true, dump_format, &err);
> +    qmp_dump_guest_memory(paging, prot, has_detach, detach, has_begin, begin,
> +                          has_length, length, true, dump_format, &err);
>      hmp_handle_error(mon, &err);
>      g_free(prot);
>  }
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 8b1a423..fd81ce2 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -2115,6 +2115,9 @@
>  #            2. fd: the protocol starts with "fd:", and the following string
>  #               is the fd's name.
>  #
> +# @detach: #optional if true, QMP will return immediately rather than
> +#          waiting dump to be finished (since 2.6).
> +#

Is it better to mention the related query command and events here...

>  # @begin: #optional if specified, the starting physical address.
>  #
>  # @length: #optional if specified, the memory size, in bytes. If you don't
> @@ -2131,8 +2134,9 @@
>  # Since: 1.2
>  ##
>  { 'command': 'dump-guest-memory',
> -  'data': { 'paging': 'bool', 'protocol': 'str', '*begin': 'int',
> -            '*length': 'int', '*format': 'DumpGuestMemoryFormat' } }
> +  'data': { 'paging': 'bool', 'protocol': 'str', '*detach': 'bool',
> +            '*begin': 'int', '*length': 'int',
> +            '*format': 'DumpGuestMemoryFormat'} }
>  
>  ##
>  # @DumpGuestMemoryCapability:
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index 9d8b42f..bbb08e1 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -840,8 +840,8 @@ EQMP
>  
>      {
>          .name       = "dump-guest-memory",
> -        .args_type  = "paging:b,protocol:s,begin:i?,end:i?,format:s?",
> -        .params     = "-p protocol [begin] [length] [format]",
> +        .args_type  = "paging:b,protocol:s,detach:b?,begin:i?,end:i?,format:s?",
> +        .params     = "-p protocol [-d] [begin] [length] [format]",
>          .help       = "dump guest memory to file",
>          .mhandler.cmd_new = qmp_marshal_dump_guest_memory,
>      },
> @@ -857,6 +857,8 @@ Arguments:
>  - "paging": do paging to get guest's memory mapping (json-bool)
>  - "protocol": destination file(started with "file:") or destination file
>                descriptor (started with "fd:") (json-string)
> +- "detach": if specificed, command will return immediately, without waiting
> +            for dump to be finished (json-bool)

... and here?

Fam

>  - "begin": the starting physical address. It's optional, and should be specified
>             with length together (json-int)
>  - "length": the memory size, in bytes. It's optional, and should be specified
> -- 
> 2.4.3
> 
>