[Qemu-devel] [PATCH] HMP: support specifying dump format for dump-guest-memory

[Qiao Nuohan <qiaonuohan@cn.fujitsu.com>]

Dumping guest memory is available to specify the dump format now. This patch
adds options '-z|-l|-s' to HMP command dump-guest-memory to specify dumping in
kdump-compression format, with zlib/lzo/snappy compression. And without these
options ELF format will be used.

The discussion about this feature is here:

http://lists.nongnu.org/archive/html/qemu-devel/2014-03/msg04235.html

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Suggested-by: Christian Borntraeger <borntraeger@de.ibm.com>
---
 hmp-commands.hx | 11 +++++++----
 hmp.c           | 25 ++++++++++++++++++++++++-
 2 files changed, 31 insertions(+), 5 deletions(-)

diff --git a/hmp-commands.hx b/hmp-commands.hx
index f3fc514..4b9989f 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -998,8 +998,8 @@ ETEXI
 
     {
         .name       = "dump-guest-memory",
-        .args_type  = "paging:-p,filename:F,begin:i?,length:i?",
-        .params     = "[-p] filename [begin] [length]",
+        .args_type  = "paging:-p,zlib:-z,lzo:-l,snappy:-s,filename:F,begin:i?,length:i?",
+        .params     = "[-p] [-z|-l|-s] filename [begin] [length]",
         .help       = "dump guest memory to file"
                       "\n\t\t\t begin(optional): the starting physical address"
                       "\n\t\t\t length(optional): the memory size, in bytes",
@@ -1008,12 +1008,15 @@ ETEXI
 
 
 STEXI
-@item dump-guest-memory [-p] @var{protocol} @var{begin} @var{length}
+@item dump-guest-memory [-p] [-z|-l|-s] @var{protocol} @var{begin} @var{length}
 @findex dump-guest-memory
 Dump guest memory to @var{protocol}. The file can be processed with crash or
-gdb.
+gdb. Without -z|-l|-s, the dump format is ELF.
   filename: dump file name
     paging: do paging to get guest's memory mapping
+      zlib: dump in kdump-compressed format, with zlib compression
+       lzo: dump in kdump-compressed format, with lzo compression
+    snappy: dump in kdump-compressed format, with snappy compression
      begin: the starting physical address. It's optional, and should be
             specified with length together.
     length: the memory size, in bytes. It's optional, and should be specified
diff --git a/hmp.c b/hmp.c
index 2f279c4..37c3961 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1308,16 +1308,39 @@ void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict)
 {
     Error *errp = NULL;
     int paging = qdict_get_try_bool(qdict, "paging", 0);
+    int zlib = qdict_get_try_bool(qdict, "zlib", 0);
+    int lzo = qdict_get_try_bool(qdict, "lzo", 0);
+    int snappy = qdict_get_try_bool(qdict, "snappy", 0);
     const char *file = qdict_get_str(qdict, "filename");
     bool has_begin = qdict_haskey(qdict, "begin");
     bool has_length = qdict_haskey(qdict, "length");
-    /* kdump-compressed format is not supported for HMP */
     bool has_format = false;
     int64_t begin = 0;
     int64_t length = 0;
     enum DumpGuestMemoryFormat dump_format = DUMP_GUEST_MEMORY_FORMAT_ELF;
     char *prot;
 
+    if ((zlib + lzo + snappy) > 1) {
+        error_setg(&errp, "only one of '-z|-l|-s' can be set");
+        hmp_handle_error(mon, &errp);
+        return;
+    }
+
+    if (zlib) {
+        has_format = true;
+        dump_format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB;
+    }
+
+    if (lzo) {
+        has_format = true;
+        dump_format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO;
+    }
+
+    if (snappy) {
+        has_format = true;
+        dump_format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY;
+    }
+
     if (has_begin) {
         begin = qdict_get_int(qdict, "begin");
     }
-- 
1.8.5.3