[libvirt] [PATCH v1 2/2] add dump_memory_format in qemu.conf

Qiao Nuohan qiaonuohan at cn.fujitsu.com
Thu Feb 20 02:31:58 UTC 2014


This patch is used to add dump_memory_format to qemu.conf and libvirt will use
it to specify the default format in which qemu dumps guest's memory. But when
"--compress" is specified with "virsh dump --memory-only", the format configured
by dump_memory_format will be overrided. dump_memory_format can one of elf,
kdump-zlib, kdump-lzo and kdump-snappy. And elf is the default value.

Signed-off-by: Qiao Nuohan <qiaonuohan at cn.fujitsu.com>
---
  src/qemu/libvirtd_qemu.aug         |  1 +
  src/qemu/qemu.conf                 | 13 ++++++++++++-
  src/qemu/qemu_conf.c               |  3 +++
  src/qemu/qemu_conf.h               |  2 ++
  src/qemu/qemu_driver.c             | 37 ++++++++++++++++++++++++++++++++++---
  src/qemu/test_libvirtd_qemu.aug.in |  1 +
  6 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/src/qemu/libvirtd_qemu.aug b/src/qemu/libvirtd_qemu.aug
index a9ff421..d3704fc 100644
--- a/src/qemu/libvirtd_qemu.aug
+++ b/src/qemu/libvirtd_qemu.aug
@@ -61,6 +61,7 @@ module Libvirtd_qemu =
     let save_entry =  str_entry "save_image_format"
                   | str_entry "dump_image_format"
                   | str_entry "snapshot_image_format"
+                 | str_entry "dump_memory_format"
                   | str_entry "auto_dump_path"
                   | bool_entry "auto_dump_bypass_cache"
                   | bool_entry "auto_start_bypass_cache"
diff --git a/src/qemu/qemu.conf b/src/qemu/qemu.conf
index e436084..148a6bc 100644
--- a/src/qemu/qemu.conf
+++ b/src/qemu/qemu.conf
@@ -292,7 +292,8 @@
  # dump_image_format is used when you use 'virsh dump' at emergency
  # crashdump, and if the specified dump_image_format is not valid, or
  # the requested compression program can't be found, this falls
-# back to "raw" compression.
+# back to "raw" compression. Note, dump_image_format doesn't work when you use
+# "virsh dump --memory-only".
  #
  # snapshot_image_format specifies the compression algorithm of the memory save
  # image when an external snapshot of a domain is taken. This does not apply
@@ -303,6 +304,16 @@
  #dump_image_format = "raw"
  #snapshot_image_format = "raw"

+# Qemu can dump guest's memory in elf format or in kdump-compressed format, and
+# the compression of kdump_compressed format can be zlib/lzo/snappy.
+#
+# dump_memory_format is used to specify the format in which qemu dumps guest's
+# memory. However, if "--compress" is specified with 'virsh dump --memory-only',
+# dump_memory_format will not work.
+# dump_memory_format can be elf, kdump-zlib, kdump-lzo and kdump-snappy.
+#
+#dump_memory_format = "elf"
+
  # When a domain is configured to be auto-dumped when libvirtd receives a
  # watchdog event from qemu guest, libvirtd will save dump files in directory
  # specified by auto_dump_path. Default value is /var/lib/libvirt/qemu/dump
diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c
index ecaaf81..7d225da 100644
--- a/src/qemu/qemu_conf.c
+++ b/src/qemu/qemu_conf.c
@@ -296,6 +296,7 @@ static void virQEMUDriverConfigDispose(void *obj)

      VIR_FREE(cfg->saveImageFormat);
      VIR_FREE(cfg->dumpImageFormat);
+    VIR_FREE(cfg->dumpMemoryFormat);
      VIR_FREE(cfg->autoDumpPath);

      virStringFreeList(cfg->securityDriverNames);
@@ -548,6 +549,8 @@ int virQEMUDriverConfigLoadFile(virQEMUDriverConfigPtr cfg,
      GET_VALUE_STR("dump_image_format", cfg->dumpImageFormat);
      GET_VALUE_STR("snapshot_image_format", cfg->snapshotImageFormat);

+    GET_VALUE_STR("dump_memory_format", cfg->dumpMemoryFormat);
+
      GET_VALUE_STR("auto_dump_path", cfg->autoDumpPath);
      GET_VALUE_BOOL("auto_dump_bypass_cache", cfg->autoDumpBypassCache);
      GET_VALUE_BOOL("auto_start_bypass_cache", cfg->autoStartBypassCache);
diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h
index 1f44a76..97b0f67 100644
--- a/src/qemu/qemu_conf.h
+++ b/src/qemu/qemu_conf.h
@@ -149,6 +149,8 @@ struct _virQEMUDriverConfig {
      char *dumpImageFormat;
      char *snapshotImageFormat;

+    char *dumpMemoryFormat;
+
      char *autoDumpPath;
      bool autoDumpBypassCache;
      bool autoStartBypassCache;
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 19b4dd2..c6f8ae9 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -3410,6 +3410,21 @@ static int qemuDumpToFd(virQEMUDriverPtr driver, 
virDomainObjPtr vm,
      return ret;
  }

+typedef enum {
+    QEMU_DUMP_MEMORY_FORMAT_ELF = 0,
+    QEMU_DUMP_MEMORY_FORMAT_KDUMP_ZLIB = 1,
+    QEMU_DUMP_MEMORY_FORMAT_KDUMP_LZO = 2,
+    QEMU_DUMP_MEMORY_FORMAT_KDUMP_SNAPPY = 3,
+    QEMU_DUMP_MEMORY_FORMAT_LAST
+} virQEMUDumpMemoryFormat;
+
+VIR_ENUM_DECL(qemuDumpMemoryFormat)
+VIR_ENUM_IMPL(qemuDumpMemoryFormat, QEMU_DUMP_MEMORY_FORMAT_LAST,
+              "elf",
+              "kdump-zlib",
+              "kdump-lzo",
+              "kdump-snappy")
+
  static int
  doCoreDump(virQEMUDriverPtr driver,
             virDomainObjPtr vm,
@@ -3422,7 +3437,9 @@ doCoreDump(virQEMUDriverPtr driver,
      virFileWrapperFdPtr wrapperFd = NULL;
      int directFlag = 0;
      unsigned int flags = VIR_FILE_WRAPPER_NON_BLOCKING;
-    const char *dump_format;
+    const char *dump_format = "elf";
+    virQEMUDriverConfigPtr cfg = NULL;
+    int dump_memory_format;

      /* Create an empty file with appropriate ownership.  */
      if (dump_flags & VIR_DUMP_BYPASS_CACHE) {
@@ -3452,8 +3469,22 @@ doCoreDump(virQEMUDriverPtr driver,
              dump_format = "kdump-lzo";
          else if (dump_flags & VIR_DUMP_COMPRESS_SNAPPY)
              dump_format = "kdump-snappy";
-        else
-            dump_format = "elf";
+        else {
+            /* when --compress option is specified, qemu.conf will not work */
+            cfg = virQEMUDriverGetConfig(driver);
+            if (cfg->dumpMemoryFormat) {
+                dump_memory_format = qemuDumpMemoryFormatTypeFromString(
+                                                        cfg->dumpMemoryFormat);
+                if (dump_memory_format == QEMU_DUMP_MEMORY_FORMAT_KDUMP_ZLIB)
+                    dump_format = "kdump-zlib";
+                else if (dump_memory_format ==
+                                            QEMU_DUMP_MEMORY_FORMAT_KDUMP_LZO)
+                    dump_format = "kdump-lzo";
+                else if (dump_memory_format ==
+                                        QEMU_DUMP_MEMORY_FORMAT_KDUMP_SNAPPY)
+                    dump_format = "kdump-snappy";
+            }
+        }
          ret = qemuDumpToFd(driver, vm, fd, QEMU_ASYNC_JOB_DUMP,
                             dump_format);
      } else {
diff --git a/src/qemu/test_libvirtd_qemu.aug.in b/src/qemu/test_libvirtd_qemu.aug.in
index 81fedd6..9d0bcec 100644
--- a/src/qemu/test_libvirtd_qemu.aug.in
+++ b/src/qemu/test_libvirtd_qemu.aug.in
@@ -51,6 +51,7 @@ module Test_libvirtd_qemu =
  }
  { "save_image_format" = "raw" }
  { "dump_image_format" = "raw" }
+{ "dump_memory_format" = "elf" }
  { "snapshot_image_format" = "raw" }
  { "auto_dump_path" = "/var/lib/libvirt/qemu/dump" }
  { "auto_dump_bypass_cache" = "0" }




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