[Qemu-devel] [PATCH v4 9/9] dump: Make kdump-compressed format available for 'dump-guest-memory'

[qiaonuohan@cn.fujitsu.com]

From: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>

Make monitor command 'dump-guest-memory' be able to dump in kdump-compressed
format. The command's usage:

  dump [-p] protocol [begin] [length] [format]

'format' is used to specified the format of vmcore and can be:
1. 'elf': ELF format, without compression
2. 'zlib': kdump-compressed format, with zlib-compressed
3. 'lzo': kdump-compressed format, with lzo-compressed
4. 'snappy': kdump-compressed format, with snappy-compressed
And without 'format' being set, it is same as 'elf'.

Note:
  1. The kdump-compressed format is readable only with the crash utility, and
     it can be smaller than the ELF format because of the compression support.
  2. The kdump-compressed format is the 5th edition.

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Signed-off-by: Zhang Xiaohe <zhangxh@cn.fujitsu.com>
---
 configure                    |   50 ++++++++++++++++++++
 dump.c                       |  102 +++++++++++++++++++++++++++++++++++++-----
 hmp-commands.hx              |   12 +++--
 hmp.c                        |   23 +++++++++-
 include/sysemu/dump_memory.h |    1 +
 qapi-schema.json             |   22 +++++++++-
 qmp-commands.hx              |    6 ++-
 7 files changed, 197 insertions(+), 19 deletions(-)

diff --git a/configure b/configure
index eb74510..5f459a5 100755
--- a/configure
+++ b/configure
@@ -230,6 +230,8 @@ libusb=""
 usb_redir=""
 glx=""
 zlib="yes"
+lzo="no"
+snappy="no"
 guest_agent="yes"
 want_tools="yes"
 libiscsi=""
@@ -902,6 +904,10 @@ for opt do
   ;;
   --disable-zlib-test) zlib="no"
   ;;
+  --enable-lzo) lzo="yes"
+  ;;
+  --enable-snappy) snappy="yes"
+  ;;
   --enable-guest-agent) guest_agent="yes"
   ;;
   --disable-guest-agent) guest_agent="no"
@@ -1499,6 +1505,42 @@ fi
 libs_softmmu="$libs_softmmu -lz"
 
 ##########################################
+# lzo check
+
+if test "$lzo" != "no" ; then
+    cat > $TMPC << EOF
+#include <lzo/lzo1x.h>
+int main(void) { lzo_version(); return 0; }
+EOF
+    if compile_prog "" "-llzo2" ; then
+        :
+    else
+        error_exit "lzo check failed" \
+            "Make sure to have the lzo libs and headers installed."
+    fi
+
+    libs_softmmu="$libs_softmmu -llzo2"
+fi
+
+##########################################
+# snappy check
+
+if test "$snappy" != "no" ; then
+    cat > $TMPC << EOF
+#include <snappy-c.h>
+int main(void) { snappy_max_compressed_length(4096); return 0; }
+EOF
+    if compile_prog "" "-lsnappy" ; then
+        :
+    else
+        error_exit "snappy check failed" \
+            "Make sure to have the snappy libs and headers installed."
+    fi
+
+    libs_softmmu="$libs_softmmu -lsnappy"
+fi
+
+##########################################
 # libseccomp check
 
 if test "$seccomp" != "no" ; then
@@ -3901,6 +3943,14 @@ if test "$glx" = "yes" ; then
   echo "GLX_LIBS=$glx_libs" >> $config_host_mak
 fi
 
+if test "$lzo" = "yes" ; then
+  echo "CONFIG_LZO=y" >> $config_host_mak
+fi
+
+if test "$snappy" = "yes" ; then
+  echo "CONFIG_SNAPPY=y" >> $config_host_mak
+fi
+
 if test "$libiscsi" = "yes" ; then
   echo "CONFIG_LIBISCSI=y" >> $config_host_mak
 fi
diff --git a/dump.c b/dump.c
index 17686ad..274249f 100644
--- a/dump.c
+++ b/dump.c
@@ -1036,6 +1036,16 @@ static int create_header64(DumpState *s)
     return 0;
 }
 
+static void get_max_mapnr(DumpState *s)
+{
+    MemoryMapping *memory_mapping;
+
+    QTAILQ_FOREACH(memory_mapping, &s->list.head, next) {
+        s->max_mapnr = paddr_to_pfn(memory_mapping->phys_addr +
+                        memory_mapping->length, s->page_shift);
+    }
+}
+
 /*
  * gather data of header and sub header
  */
@@ -1404,12 +1414,14 @@ out:
     return ret;
 }
 
-static int dump_init(DumpState *s, int fd, bool paging, bool has_filter,
-                     int64_t begin, int64_t length, Error **errp)
+static int dump_init(DumpState *s, int fd, bool has_format,
+                    DumpGuestMemoryFormat format, bool paging, bool has_filter,
+                    int64_t begin, int64_t length, Error **errp)
 {
     CPUArchState *env;
     int nr_cpus;
     int ret;
+    unsigned long tmp;
 
     if (runstate_is_running()) {
         vm_stop(RUN_STATE_SAVE_VM);
@@ -1464,6 +1476,56 @@ static int dump_init(DumpState *s, int fd, bool paging, bool has_filter,
         qemu_get_guest_simple_memory_mapping(&s->list);
     }
 
+    /* init for kdump-compressed format */
+    if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
+        switch (format) {
+        case DUMP_GUEST_MEMORY_FORMAT_ZLIB:
+            s->flag_compress = DUMP_DH_COMPRESSED_ZLIB;
+            break;
+        case DUMP_GUEST_MEMORY_FORMAT_LZO:
+            s->flag_compress = DUMP_DH_COMPRESSED_LZO;
+            break;
+        case DUMP_GUEST_MEMORY_FORMAT_SNAPPY:
+            s->flag_compress = DUMP_DH_COMPRESSED_SNAPPY;
+            break;
+        default:
+            s->flag_compress = 0;
+        }
+
+        s->nr_cpus = nr_cpus;
+        s->page_size = PAGE_SIZE;
+        s->page_shift = ffs(s->page_size) - 1;
+
+        get_max_mapnr(s);
+
+        tmp = divideup(divideup(s->max_mapnr, CHAR_BIT), s->page_size);
+        s->len_dump_bitmap = tmp * s->page_size * 2;
+
+        /*
+         * gather data of header, dump_bitmap, page_desc and page_data, then
+         * cache them in tmp files
+         */
+        ret = create_header(s);
+        if (ret < 0) {
+            error_set(errp, QERR_UNSUPPORTED);
+            goto cleanup;
+        }
+
+        ret = create_dump_bitmap(s);
+        if (ret < 0) {
+            error_set(errp, QERR_UNSUPPORTED);
+            goto cleanup;
+        }
+
+        ret = create_pages(s);
+        if (ret < 0) {
+            error_set(errp, QERR_UNSUPPORTED);
+            goto cleanup;
+        }
+
+        return 0;
+    }
+
     if (s->has_filter) {
         memory_mapping_filter(&s->list, s->begin, s->length);
     }
@@ -1539,15 +1601,23 @@ static void clean_state(DumpState *s)
     free_cache_data(s->page_data);
 }
 
-void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
-                           int64_t begin, bool has_length, int64_t length,
-                           Error **errp)
+void qmp_dump_guest_memory(bool paging, const char *protocol, bool has_begin,
+                            int64_t begin, bool has_length,
+                            int64_t length, bool has_format,
+                            DumpGuestMemoryFormat format, Error **errp)
 {
     const char *p;
     int fd = -1;
     DumpState *s;
     int ret;
 
+    /* kdump-compressed format is invalid with paging or filter */
+    if ((has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) &&
+        (paging || has_begin || has_length)) {
+        error_set(errp, QERR_INVALID_PARAMETER_COMBINATION);
+        return;
+    }
+
     if (has_begin && !has_length) {
         error_set(errp, QERR_MISSING_PARAMETER, "length");
         return;
@@ -1558,7 +1628,7 @@ void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
     }
 
 #if !defined(WIN32)
-    if (strstart(file, "fd:", &p)) {
+    if (strstart(protocol, "fd:", &p)) {
         fd = monitor_get_fd(cur_mon, p, errp);
         if (fd == -1) {
             return;
@@ -1566,7 +1636,7 @@ void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
     }
 #endif
 
-    if  (strstart(file, "file:", &p)) {
+    if  (strstart(protocol, "file:", &p)) {
         fd = qemu_open(p, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR);
         if (fd < 0) {
             error_set(errp, QERR_OPEN_FILE_FAILED, p);
@@ -1579,17 +1649,27 @@ void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
         return;
     }
 
-    s = g_malloc(sizeof(DumpState));
+    /* initialize DumpState to zero */
+    s = g_malloc0(sizeof(DumpState));
 
-    ret = dump_init(s, fd, paging, has_begin, begin, length, errp);
+    ret = dump_init(s, fd, has_format, format, paging, has_begin,
+                    begin, length, errp);
     if (ret < 0) {
         g_free(s);
         return;
     }
 
-    if (create_vmcore(s) < 0 && !error_is_set(s->errp)) {
-        error_set(errp, QERR_IO_ERROR);
+    if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
+        if (create_kdump_vmcore(s) < 0 && !error_is_set(s->errp)) {
+            error_set(errp, QERR_IO_ERROR);
+        }
+    } else {
+        if (create_vmcore(s) < 0 && !error_is_set(s->errp)) {
+            error_set(errp, QERR_IO_ERROR);
+        }
     }
 
+    clean_state(s);
+
     g_free(s);
 }
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 9cea415..b12e50b 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -992,17 +992,19 @@ ETEXI
 #if defined(CONFIG_HAVE_CORE_DUMP)
     {
         .name       = "dump-guest-memory",
-        .args_type  = "paging:-p,filename:F,begin:i?,length:i?",
-        .params     = "[-p] filename [begin] [length]",
+        .args_type  = "paging:-p,filename:F,begin:i?,length:i?,format:s?",
+        .params     = "[-p] filename [begin] [length] [format]",
         .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",
+                      "\n\t\t\t length(optional): the memory size, in bytes"
+                      "\n\t\t\t format(optional): the format of guest memory dump,"
+                      "\n\t\t\t it can be elf|zlib|lzo|snappy",
         .mhandler.cmd = hmp_dump_guest_memory,
     },
 
 
 STEXI
-@item dump-guest-memory [-p] @var{protocol} @var{begin} @var{length}
+@item dump-guest-memory [-p] @var{protocol} @var{begin} @var{length} @var{format}
 @findex dump-guest-memory
 Dump guest memory to @var{protocol}. The file can be processed with crash or
 gdb.
@@ -1012,6 +1014,8 @@ gdb.
             specified with length together.
     length: the memory size, in bytes. It's optional, and should be specified
             with begin together.
+    format: the format of guest memory dump. It's optional, and can be
+            elf|zlib|lzo|snappy.
 ETEXI
 #endif
 
diff --git a/hmp.c b/hmp.c
index 4fb76ec..e863267 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1185,9 +1185,12 @@ 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_format = qdict_haskey(qdict, "format");
     int64_t begin = 0;
     int64_t length = 0;
+    const char *format = NULL;
     char *prot;
+    enum DumpGuestMemoryFormat dump_format;
 
     if (has_begin) {
         begin = qdict_get_int(qdict, "begin");
@@ -1195,11 +1198,29 @@ void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict)
     if (has_length) {
         length = qdict_get_int(qdict, "length");
     }
+    if (has_format) {
+        format = qdict_get_str(qdict, "format");
+    }
+
+    if (strcmp(format, "elf") == 0) {
+        dump_format = DUMP_GUEST_MEMORY_FORMAT_ELF;
+    } else if (strcmp(format, "zlib") == 0) {
+        dump_format = DUMP_GUEST_MEMORY_FORMAT_ZLIB;
+    } else if (strcmp(format, "lzo") == 0) {
+        dump_format = DUMP_GUEST_MEMORY_FORMAT_LZO;
+    } else if (strcmp(format, "snappy") == 0) {
+        dump_format = DUMP_GUEST_MEMORY_FORMAT_SNAPPY;
+    } else {
+        error_set(&errp, QERR_INVALID_PARAMETER_VALUE,
+                  "format", "elf|zlib|lzo|snappy");
+        hmp_handle_error(mon, &errp);
+        return;
+    }
 
     prot = g_strconcat("file:", file, NULL);
 
     qmp_dump_guest_memory(paging, prot, has_begin, begin, has_length, length,
-                          &errp);
+                          has_format, dump_format, &errp);
     hmp_handle_error(mon, &errp);
     g_free(prot);
 }
diff --git a/include/sysemu/dump_memory.h b/include/sysemu/dump_memory.h
index 6848f91..f7c5f4d 100644
--- a/include/sysemu/dump_memory.h
+++ b/include/sysemu/dump_memory.h
@@ -38,6 +38,7 @@
 #define KDUMP_SIGNATURE             "KDUMP   "
 #define SIG_LEN                     (sizeof(KDUMP_SIGNATURE) - 1)
 #define DISKDUMP_HEADER_BLOCKS      (1)
+#define PAGE_SIZE                   (4096)
 #define PHYS_BASE                   (0)
 #define DUMP_LEVEL                  (1)
 #define TMP_BUF_SIZE                (1024)
diff --git a/qapi-schema.json b/qapi-schema.json
index ef1f657..95f7e20 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -2380,6 +2380,24 @@
 { 'command': 'device_del', 'data': {'id': 'str'} }
 
 ##
+# @DumpGuestMemoryFormat:
+#
+# An enumeration of guest-memory-dump's format.
+#
+# @elf: elf format
+#
+# @zlib: kdump-compressed format with zlib-compressed
+#
+# @lzo: kdump-compressed format with zlib-compressed
+#
+# @snappy: kdump-compressed format with zlib-compressed
+#
+# Since: 1.6
+##
+{ 'enum': 'DumpGuestMemoryFormat',
+  'data': [ 'elf', 'zlib', 'lzo', 'snappy' ] }
+
+##
 # @dump-guest-memory
 #
 # Dump guest's memory to vmcore. It is a synchronous operation that can take
@@ -2415,13 +2433,15 @@
 #          want to dump all guest's memory, please specify the start @begin
 #          and @length
 #
+# @format: #optional if specified, the format of guest memory dump. (since 1.6)
+#
 # Returns: nothing on success
 #
 # Since: 1.2
 ##
 { 'command': 'dump-guest-memory',
   'data': { 'paging': 'bool', 'protocol': 'str', '*begin': 'int',
-            '*length': 'int' } }
+            '*length': 'int', '*format': 'DumpGuestMemoryFormat' } }
 
 ##
 # @netdev_add:
diff --git a/qmp-commands.hx b/qmp-commands.hx
index ffd130e..5c274fb 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -788,8 +788,8 @@ EQMP
 
     {
         .name       = "dump-guest-memory",
-        .args_type  = "paging:b,protocol:s,begin:i?,end:i?",
-        .params     = "-p protocol [begin] [length]",
+        .args_type  = "paging:b,protocol:s,begin:i?,length:i?,format:s?",
+        .params     = "-p protocol [begin] [length] [format]",
         .help       = "dump guest memory to file",
         .user_print = monitor_user_noop,
         .mhandler.cmd_new = qmp_marshal_input_dump_guest_memory,
@@ -810,6 +810,8 @@ Arguments:
            with length together (json-int)
 - "length": the memory size, in bytes. It's optional, and should be specified
             with begin together (json-int)
+- "format": the format of guest memory dump. It's optional, and can be
+            elf|zlib|lzo|snappy (json-string)
 
 Example:
 
-- 
1.7.1