[Qemu-devel] [PATCH v9 00/14] Make 'dump-guest-memory' dump in kdump-compressed format

[Qemu-devel] [PATCH v9 00/14] Make 'dump-guest-memory' dump in kdump-compressed format

[qiaonuohan]

Hi, all

The last version is here:
http://lists.nongnu.org/archive/html/qemu-devel/2014-01/msg03669.html

Command 'dump-guest-memory' was introduced to dump guest's memory. But the
vmcore's format is only elf32 or elf64. The message is here:
http://lists.gnu.org/archive/html/qemu-devel/2012-04/msg03379.html

Compared with migration, the missing of compression feature means regression
to 'dump-guest-memory'. So we post these patches to make 'dump-guest-memory' be
able to dump guest's in kdump-compressed format. Then vmcore can be much
smaller, and easily to be delivered.

The kdump-compressed format is *linux specific* *linux standard* crash dump
format used in kdump framework. 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. To get more detailed information about
kdump-compressed format, please refer to the following URL:
http://sourceforge.net/projects/makedumpfile/

Note:
1. The guest should be x86/x86_64/s390x. The other arch is not supported now.
2. If the OS is in the second kernel, gdb may not work well, and crash can
   work by specifying '--machdep phys_addr=xxx' in the command line. The
   reason is that the second kernel will update the page table, and we can
   not get the page table for the first kernel.
3. The cpu's state is stored in QEMU note.
4. The vmcore are able to be compressed with zlib, lzo or snappy. zlib is
   available by default, and option '--enable-lzo' or '--enable-snappy'
   should be specified with 'configure' to make lzo or snappy available.

Changelog:
Changes from v8 to v9:
1. add Ekaterina's patch(support s390x) into series
2. modify query-dump-guest-memory-capability according to Paolo Bonzini's
   suggestion
3. fix compiling error on 32-bit host

Changes from v7 to v8:
1. rebase get_max_mapnr()
2. fix bug of using dh->block_size directly in create_header64()
3. abandon using static variables in get_next_page()
4. redefine 'struct PageDesc' to 'struct QEMU_PACKED PageDescriptor'
5. add return when format checking fails
Changes from v6 to v7:
1. support BE host
2. abandon non-flatten format to avoid using seek on vmcore
3. abandon using of very large array
4. use get_next_page to replace the iteration of guest's pages
5. abandon the support of HMP

Changes from v5 to v6:
1. add run-time check for compression format(lzo/snappy)
2. address Stefan's comments about reusing code and coding style
3. update the version of kdump-compressed format to 6th
4. resplit the patches
5. Add 'query-dump-guest-memory-capability' command

Changes from v4 to v5:
1. using flatten format to avoid using temporary files according to Stefan's
   comments
2. Address Andreas's comments about coding style

Changes from v3 to v4:
1. change to avoid conflict with Andreas's patches
2. rebase

Changes from v2 to v3:
1. Address Eric's comment

Changes from v1 to v2:
1. Address Eric & Daniel's comment: fix manner of string copy.
2. Address Eric's comment: replace reinventing new constants by using the
   ready-made ones accoring.
3. Address Andreas's comment: remove useless include.

qiaonuohan (14):
  dump: const-qualify the buf of WriteCoreDumpFunction
  dump: add argument to write_elfxx_notes
  dump: add API to write header of flatten format
  dump: add API to write vmcore
  dump: add API to write elf notes to buffer
  dump: add support for lzo/snappy
  dump: add members to DumpState and init some of them
  dump: add API to write dump header
  dump: add API to write dump_bitmap
  dump: add APIs to operate DataCache
  dump: add API to write dump pages
  dump: make kdump-compressed format available for 'dump-guest-memory'
  Define the architecture for compressed dump format
  dump: add 'query-dump-guest-memory-capability' command

 configure             |   54 +++
 dump.c                |  960 ++++++++++++++++++++++++++++++++++++++++++++++++-
 hmp.c                 |    5 +-
 include/qom/cpu.h     |    3 +-
 include/sysemu/dump.h |  138 +++++++
 qapi-schema.json      |   49 +++-
 qmp-commands.hx       |   27 ++-
 target-i386/cpu.h     |    2 +
 target-s390x/cpu.h    |    1 +
 9 files changed, 1219 insertions(+), 20 deletions(-)

[Qemu-devel] [PATCH v9 01/14] dump: const-qualify the buf of WriteCoreDumpFunction

[qiaonuohan]

WriteCoreDumpFunction is a function pointer that points to the function used to
write content in "buf" into core file, so "buf" should be const-qualify.

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---
 dump.c            |    2 +-
 include/qom/cpu.h |    3 ++-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/dump.c b/dump.c
index 80a9116..42622de 100644
--- a/dump.c
+++ b/dump.c
@@ -99,7 +99,7 @@ static void dump_error(DumpState *s, const char *reason)
     dump_cleanup(s);
 }
 
-static int fd_write_vmcore(void *buf, size_t size, void *opaque)
+static int fd_write_vmcore(const void *buf, size_t size, void *opaque)
 {
     DumpState *s = opaque;
     size_t written_size;
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index 367eda1..d734be8 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -28,7 +28,8 @@
 #include "qemu/tls.h"
 #include "qemu/typedefs.h"
 
-typedef int (*WriteCoreDumpFunction)(void *buf, size_t size, void *opaque);
+typedef int (*WriteCoreDumpFunction)(const void *buf, size_t size,
+                                     void *opaque);
 
 /**
  * vaddr:
-- 
1.7.1

[Qemu-devel] [PATCH v9 02/14] dump: add argument to write_elfxx_notes

[qiaonuohan]

write_elf32_notes/wirte_elf64_notes use fd_write_vmcore to write elf notes to
vmcore. Adding parameter "WriteCoreDumpFunction f" makes it available to choose
the method of writing elf notes

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---
 dump.c |   16 ++++++++--------
 1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/dump.c b/dump.c
index 42622de..c9d3492 100644
--- a/dump.c
+++ b/dump.c
@@ -271,7 +271,7 @@ static inline int cpu_index(CPUState *cpu)
     return cpu->cpu_index + 1;
 }
 
-static int write_elf64_notes(DumpState *s)
+static int write_elf64_notes(WriteCoreDumpFunction f, DumpState *s)
 {
     CPUState *cpu;
     int ret;
@@ -279,7 +279,7 @@ static int write_elf64_notes(DumpState *s)
 
     CPU_FOREACH(cpu) {
         id = cpu_index(cpu);
-        ret = cpu_write_elf64_note(fd_write_vmcore, cpu, id, s);
+        ret = cpu_write_elf64_note(f, cpu, id, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write elf notes.\n");
             return -1;
@@ -287,7 +287,7 @@ static int write_elf64_notes(DumpState *s)
     }
 
     CPU_FOREACH(cpu) {
-        ret = cpu_write_elf64_qemunote(fd_write_vmcore, cpu, s);
+        ret = cpu_write_elf64_qemunote(f, cpu, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write CPU status.\n");
             return -1;
@@ -321,7 +321,7 @@ static int write_elf32_note(DumpState *s)
     return 0;
 }
 
-static int write_elf32_notes(DumpState *s)
+static int write_elf32_notes(WriteCoreDumpFunction f, DumpState *s)
 {
     CPUState *cpu;
     int ret;
@@ -329,7 +329,7 @@ static int write_elf32_notes(DumpState *s)
 
     CPU_FOREACH(cpu) {
         id = cpu_index(cpu);
-        ret = cpu_write_elf32_note(fd_write_vmcore, cpu, id, s);
+        ret = cpu_write_elf32_note(f, cpu, id, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write elf notes.\n");
             return -1;
@@ -337,7 +337,7 @@ static int write_elf32_notes(DumpState *s)
     }
 
     CPU_FOREACH(cpu) {
-        ret = cpu_write_elf32_qemunote(fd_write_vmcore, cpu, s);
+        ret = cpu_write_elf32_qemunote(f, cpu, s);
         if (ret < 0) {
             dump_error(s, "dump: failed to write CPU status.\n");
             return -1;
@@ -574,7 +574,7 @@ static int dump_begin(DumpState *s)
         }
 
         /* write notes to vmcore */
-        if (write_elf64_notes(s) < 0) {
+        if (write_elf64_notes(fd_write_vmcore, s) < 0) {
             return -1;
         }
 
@@ -597,7 +597,7 @@ static int dump_begin(DumpState *s)
         }
 
         /* write notes to vmcore */
-        if (write_elf32_notes(s) < 0) {
+        if (write_elf32_notes(fd_write_vmcore, s) < 0) {
             return -1;
         }
     }
-- 
1.7.1

[Qemu-devel] [PATCH v9 03/14] dump: add API to write header of flatten format

[qiaonuohan]

flatten format will be used when writing kdump-compressed format. The format is
also used by makedumpfile, you can refer to the following URL to get more
detailed information about flatten format of kdump-compressed format:
http://sourceforge.net/projects/makedumpfile/

The two functions here are used to write start flat header and end flat header
to vmcore, and they will be called later when flatten format is used.

struct MakedumpfileHeader stored at the head of vmcore is used to indicate the
vmcore is in flatten format.

struct MakedumpfileHeader {
    char signature[16];     /* = "makedumpfile" */
    int64_t type;           /* = 1 */
    int64_t version;        /* = 1 */
};

And struct MakedumpfileDataHeader, with offset and buf_size set to -1, is used
to indicate the end of vmcore in flatten format.

struct MakedumpfileDataHeader {
    int64_t offset;         /* = -1 */
    int64_t buf_size;       /* = -1 */
};

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---
 dump.c                |   42 ++++++++++++++++++++++++++++++++++++++++++
 include/sysemu/dump.h |   17 +++++++++++++++++
 2 files changed, 59 insertions(+), 0 deletions(-)

diff --git a/dump.c b/dump.c
index c9d3492..f233b3e 100644
--- a/dump.c
+++ b/dump.c
@@ -686,6 +686,48 @@ static int create_vmcore(DumpState *s)
     return 0;
 }
 
+static int write_start_flat_header(int fd)
+{
+    uint8_t *buf;
+    MakedumpfileHeader mh;
+    int ret = 0;
+
+    memset(&mh, 0, sizeof(mh));
+    strncpy(mh.signature, MAKEDUMPFILE_SIGNATURE,
+            strlen(MAKEDUMPFILE_SIGNATURE));
+
+    mh.type = cpu_to_be64(TYPE_FLAT_HEADER);
+    mh.version = cpu_to_be64(VERSION_FLAT_HEADER);
+
+    buf = g_malloc0(MAX_SIZE_MDF_HEADER);
+    memcpy(buf, &mh, sizeof(mh));
+
+    size_t written_size;
+    written_size = qemu_write_full(fd, buf, MAX_SIZE_MDF_HEADER);
+    if (written_size != MAX_SIZE_MDF_HEADER) {
+        ret = -1;
+    }
+
+    g_free(buf);
+    return ret;
+}
+
+static int write_end_flat_header(int fd)
+{
+    MakedumpfileDataHeader mdh;
+
+    mdh.offset = END_FLAG_FLAT_HEADER;
+    mdh.buf_size = END_FLAG_FLAT_HEADER;
+
+    size_t written_size;
+    written_size = qemu_write_full(fd, &mdh, sizeof(mdh));
+    if (written_size != sizeof(mdh)) {
+        return -1;
+    }
+
+    return 0;
+}
+
 static ram_addr_t get_start_block(DumpState *s)
 {
     GuestPhysBlock *block;
diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h
index 19fafb2..b32b390 100644
--- a/include/sysemu/dump.h
+++ b/include/sysemu/dump.h
@@ -14,12 +14,29 @@
 #ifndef DUMP_H
 #define DUMP_H
 
+#define MAKEDUMPFILE_SIGNATURE      "makedumpfile"
+#define MAX_SIZE_MDF_HEADER         (4096) /* max size of makedumpfile_header */
+#define TYPE_FLAT_HEADER            (1)    /* type of flattened format */
+#define VERSION_FLAT_HEADER         (1)    /* version of flattened format */
+#define END_FLAG_FLAT_HEADER        (-1)
+
 typedef struct ArchDumpInfo {
     int d_machine;  /* Architecture */
     int d_endian;   /* ELFDATA2LSB or ELFDATA2MSB */
     int d_class;    /* ELFCLASS32 or ELFCLASS64 */
 } ArchDumpInfo;
 
+typedef struct QEMU_PACKED MakedumpfileHeader {
+    char signature[16];     /* = "makedumpfile" */
+    int64_t type;
+    int64_t version;
+} MakedumpfileHeader;
+
+typedef struct QEMU_PACKED MakedumpfileDataHeader {
+    int64_t offset;
+    int64_t buf_size;
+} MakedumpfileDataHeader;
+
 struct GuestPhysBlockList; /* memory_mapping.h */
 int cpu_get_dump_info(ArchDumpInfo *info,
                       const struct GuestPhysBlockList *guest_phys_blocks);
-- 
1.7.1

[Qemu-devel] [PATCH v9 04/14] dump: add API to write vmcore

[qiaonuohan]

Function is used to write vmcore in flatten format. In flatten format, data is
written block by block, and in front of each block, a struct
MakedumpfileDataHeader is stored there to indicate the offset and size of the
data block.

struct MakedumpfileDataHeader {
    int64_t offset;
    int64_t buf_size;
};

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---
 dump.c |   21 +++++++++++++++++++++
 1 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/dump.c b/dump.c
index f233b3e..238ffa5 100644
--- a/dump.c
+++ b/dump.c
@@ -728,6 +728,27 @@ static int write_end_flat_header(int fd)
     return 0;
 }
 
+static int write_buffer(int fd, off_t offset, const void *buf, size_t size)
+{
+    size_t written_size;
+    MakedumpfileDataHeader mdh;
+
+    mdh.offset = cpu_to_be64(offset);
+    mdh.buf_size = cpu_to_be64(size);
+
+    written_size = qemu_write_full(fd, &mdh, sizeof(mdh));
+    if (written_size != sizeof(mdh)) {
+        return -1;
+    }
+
+    written_size = qemu_write_full(fd, buf, size);
+    if (written_size != size) {
+        return -1;
+    }
+
+    return 0;
+}
+
 static ram_addr_t get_start_block(DumpState *s)
 {
     GuestPhysBlock *block;
-- 
1.7.1

[Qemu-devel] [PATCH v9 05/14] dump: add API to write elf notes to buffer

[qiaonuohan]

the function can be used by write_elf32_notes/write_elf64_notes to write notes
to a buffer. If fd_write_vmcore is used, write_elf32_notes/write_elf64_notes
will write elf notes to vmcore directly. Instead, if buf_write_note is used,
elf notes will be written to opaque->note_buf at first.

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---
 dump.c |   19 +++++++++++++++++++
 1 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/dump.c b/dump.c
index 238ffa5..2b940bd 100644
--- a/dump.c
+++ b/dump.c
@@ -76,6 +76,9 @@ typedef struct DumpState {
     int64_t begin;
     int64_t length;
     Error **errp;
+
+    uint8_t *note_buf;          /* buffer for notes */
+    size_t note_buf_offset;     /* the writing place in note_buf */
 } DumpState;
 
 static int dump_cleanup(DumpState *s)
@@ -749,6 +752,22 @@ static int write_buffer(int fd, off_t offset, const void *buf, size_t size)
     return 0;
 }
 
+static int buf_write_note(const void *buf, size_t size, void *opaque)
+{
+    DumpState *s = opaque;
+
+    /* note_buf is not enough */
+    if (s->note_buf_offset + size > s->note_size) {
+        return -1;
+    }
+
+    memcpy(s->note_buf + s->note_buf_offset, buf, size);
+
+    s->note_buf_offset += size;
+
+    return 0;
+}
+
 static ram_addr_t get_start_block(DumpState *s)
 {
     GuestPhysBlock *block;
-- 
1.7.1

[Qemu-devel] [PATCH v9 06/14] dump: add support for lzo/snappy

[qiaonuohan]

kdump-compressed format supports three compression format, zlib/lzo/snappy.
Currently, only zlib is available. This patch is used to support lzo/snappy.
'--enable-lzo/--enable-snappy' is needed to be specified with configure to make
lzo/snappy available for qemu

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---
 configure |   54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 54 insertions(+), 0 deletions(-)

diff --git a/configure b/configure
index 4648117..8631d9b 100755
--- a/configure
+++ b/configure
@@ -245,6 +245,8 @@ libusb=""
 usb_redir=""
 glx=""
 zlib="yes"
+lzo="no"
+snappy="no"
 guest_agent=""
 guest_agent_with_vss="no"
 vss_win32_sdk=""
@@ -953,6 +955,10 @@ 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"
@@ -1242,6 +1248,8 @@ Advanced options (experts only):
   --enable-libusb          enable libusb (for usb passthrough)
   --disable-usb-redir      disable usb network redirection support
   --enable-usb-redir       enable usb network redirection support
+  --enable-lzo             enable the support of lzo compression library
+  --enable-snappy          enable the support of snappy compression library
   --disable-guest-agent    disable building of the QEMU Guest Agent
   --enable-guest-agent     enable building of the QEMU Guest Agent
   --with-vss-sdk=SDK-path  enable Windows VSS support in QEMU Guest Agent
@@ -1553,6 +1561,42 @@ 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
@@ -3872,6 +3916,8 @@ echo "libssh2 support   $libssh2"
 echo "TPM passthrough   $tpm_passthrough"
 echo "QOM debugging     $qom_cast_debug"
 echo "vhdx              $vhdx"
+echo "lzo support       $lzo"
+echo "snappy support    $snappy"
 
 if test "$sdl_too_old" = "yes"; then
 echo "-> Your SDL version is too old - please upgrade to have SDL support"
@@ -4187,6 +4233,14 @@ if test "$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" >> $config_host_mak
   if test "$libiscsi_version" = "1.4.0"; then
-- 
1.7.1

[Qemu-devel] [PATCH v9 07/14] dump: add members to DumpState and init some of them

[qiaonuohan]

add some members to DumpState that will be used in writing vmcore in
kdump-compressed format. some of them, like page_size, will be initialized
in the patch.

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---
 dump.c                |   28 ++++++++++++++++++++++++++++
 include/sysemu/dump.h |    7 +++++++
 2 files changed, 35 insertions(+), 0 deletions(-)

diff --git a/dump.c b/dump.c
index 2b940bd..3a1944e 100644
--- a/dump.c
+++ b/dump.c
@@ -79,6 +79,16 @@ typedef struct DumpState {
 
     uint8_t *note_buf;          /* buffer for notes */
     size_t note_buf_offset;     /* the writing place in note_buf */
+    uint32_t nr_cpus;           /* number of guest's cpu */
+    size_t page_size;           /* guest's page size */
+    uint32_t page_shift;        /* guest's page shift */
+    uint64_t max_mapnr;         /* the biggest guest's phys-mem's number */
+    size_t len_dump_bitmap;     /* the size of the place used to store
+                                   dump_bitmap in vmcore */
+    off_t offset_dump_bitmap;   /* offset of dump_bitmap part in vmcore */
+    off_t offset_page;          /* offset of page part in vmcore */
+    size_t num_dumpable;        /* number of page that can be dumped */
+    uint32_t flag_compress;     /* indicate the compression format */
 } DumpState;
 
 static int dump_cleanup(DumpState *s)
@@ -796,6 +806,14 @@ static ram_addr_t get_start_block(DumpState *s)
     return -1;
 }
 
+static void get_max_mapnr(DumpState *s)
+{
+    GuestPhysBlock *last_block;
+
+    last_block = QTAILQ_LAST(&s->guest_phys_blocks.head, GuestPhysBlockHead);
+    s->max_mapnr = paddr_to_pfn(last_block->target_end, s->page_shift);
+}
+
 static int dump_init(DumpState *s, int fd, bool paging, bool has_filter,
                      int64_t begin, int64_t length, Error **errp)
 {
@@ -864,6 +882,16 @@ static int dump_init(DumpState *s, int fd, bool paging, bool has_filter,
         qemu_get_guest_simple_memory_mapping(&s->list, &s->guest_phys_blocks);
     }
 
+    s->nr_cpus = nr_cpus;
+    s->page_size = TARGET_PAGE_SIZE;
+    s->page_shift = ffs(s->page_size) - 1;
+
+    get_max_mapnr(s);
+
+    uint64_t tmp;
+    tmp = DIV_ROUND_UP(DIV_ROUND_UP(s->max_mapnr, CHAR_BIT), s->page_size);
+    s->len_dump_bitmap = tmp * s->page_size;
+
     if (s->has_filter) {
         memory_mapping_filter(&s->list, s->begin, s->length);
     }
diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h
index b32b390..995bf47 100644
--- a/include/sysemu/dump.h
+++ b/include/sysemu/dump.h
@@ -20,6 +20,13 @@
 #define VERSION_FLAT_HEADER         (1)    /* version of flattened format */
 #define END_FLAG_FLAT_HEADER        (-1)
 
+#define ARCH_PFN_OFFSET             (0)
+
+#define paddr_to_pfn(X, page_shift) \
+    (((unsigned long long)(X) >> (page_shift)) - ARCH_PFN_OFFSET)
+#define pfn_to_paddr(X, page_shift) \
+    (((unsigned long long)(X) + ARCH_PFN_OFFSET) << (page_shift))
+
 typedef struct ArchDumpInfo {
     int d_machine;  /* Architecture */
     int d_endian;   /* ELFDATA2LSB or ELFDATA2MSB */
-- 
1.7.1

[Qemu-devel] [PATCH v9 08/14] dump: add API to write dump header

[qiaonuohan]

the functions are used to write header of kdump-compressed format to vmcore.
Header of kdump-compressed format includes:
1. common header: DiskDumpHeader32 / DiskDumpHeader64
2. sub header: KdumpSubHeader32 / KdumpSubHeader64
3. extra information: only elf notes here

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---
 dump.c                |  223 +++++++++++++++++++++++++++++++++++++++++++++++++
 include/sysemu/dump.h |   96 +++++++++++++++++++++
 2 files changed, 319 insertions(+), 0 deletions(-)

diff --git a/dump.c b/dump.c
index 3a1944e..4b2799f 100644
--- a/dump.c
+++ b/dump.c
@@ -778,6 +778,229 @@ static int buf_write_note(const void *buf, size_t size, void *opaque)
     return 0;
 }
 
+/* write common header, sub header and elf note to vmcore */
+static int create_header32(DumpState *s)
+{
+    int ret = 0;
+    DiskDumpHeader32 *dh = NULL;
+    KdumpSubHeader32 *kh = NULL;
+    size_t size;
+    int endian = s->dump_info.d_endian;
+    uint32_t block_size;
+    uint32_t sub_hdr_size;
+    uint32_t bitmap_blocks;
+    uint32_t status = 0;
+    uint64_t offset_note;
+
+    /* write common header, the version of kdump-compressed format is 6th */
+    size = sizeof(DiskDumpHeader32);
+    dh = g_malloc0(size);
+
+    strncpy(dh->signature, KDUMP_SIGNATURE, strlen(KDUMP_SIGNATURE));
+    dh->header_version = cpu_convert_to_target32(6, endian);
+    block_size = s->page_size;
+    dh->block_size = cpu_convert_to_target32(block_size, endian);
+    sub_hdr_size = sizeof(struct KdumpSubHeader32) + s->note_size;
+    sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
+    dh->sub_hdr_size = cpu_convert_to_target32(sub_hdr_size, endian);
+    /* dh->max_mapnr may be truncated, full 64bit is in kh.max_mapnr_64 */
+    dh->max_mapnr = cpu_convert_to_target32(MIN(s->max_mapnr, UINT_MAX),
+                                            endian);
+    dh->nr_cpus = cpu_convert_to_target32(s->nr_cpus, endian);
+    bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
+    dh->bitmap_blocks = cpu_convert_to_target32(bitmap_blocks, endian);
+    memcpy(&(dh->utsname.machine), "i686", 4);
+
+    if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
+        status |= DUMP_DH_COMPRESSED_ZLIB;
+    }
+#ifdef CONFIG_LZO
+    if (s->flag_compress & DUMP_DH_COMPRESSED_LZO) {
+        status |= DUMP_DH_COMPRESSED_LZO;
+    }
+#endif
+#ifdef CONFIG_SNAPPY
+    if (s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) {
+        status |= DUMP_DH_COMPRESSED_SNAPPY;
+    }
+#endif
+    dh->status = cpu_convert_to_target32(status, endian);
+
+    if (write_buffer(s->fd, 0, dh, size) < 0) {
+        dump_error(s, "dump: failed to write disk dump header.\n");
+        ret = -1;
+        goto out;
+    }
+
+    /* write sub header */
+    size = sizeof(KdumpSubHeader32);
+    kh = g_malloc0(size);
+
+    /* 64bit max_mapnr_64 */
+    kh->max_mapnr_64 = cpu_convert_to_target64(s->max_mapnr, endian);
+    kh->phys_base = cpu_convert_to_target32(PHYS_BASE, endian);
+    kh->dump_level = cpu_convert_to_target32(DUMP_LEVEL, endian);
+
+    offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size;
+    kh->offset_note = cpu_convert_to_target64(offset_note, endian);
+    kh->note_size = cpu_convert_to_target32(s->note_size, endian);
+
+    if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
+                     block_size, kh, size) < 0) {
+        dump_error(s, "dump: failed to write kdump sub header.\n");
+        ret = -1;
+        goto out;
+    }
+
+    /* write note */
+    s->note_buf = g_malloc0(s->note_size);
+    s->note_buf_offset = 0;
+
+    /* use s->note_buf to store notes temporarily */
+    if (write_elf32_notes(buf_write_note, s) < 0) {
+        ret = -1;
+        goto out;
+    }
+
+    if (write_buffer(s->fd, offset_note, s->note_buf,
+                     s->note_size) < 0) {
+        dump_error(s, "dump: failed to write notes");
+        ret = -1;
+        goto out;
+    }
+
+    /* get offset of dump_bitmap */
+    s->offset_dump_bitmap = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size) *
+                             block_size;
+
+    /* get offset of page */
+    s->offset_page = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size + bitmap_blocks) *
+                     block_size;
+
+out:
+    g_free(dh);
+    g_free(kh);
+    g_free(s->note_buf);
+
+    return ret;
+}
+
+/* write common header, sub header and elf note to vmcore */
+static int create_header64(DumpState *s)
+{
+    int ret = 0;
+    DiskDumpHeader64 *dh = NULL;
+    KdumpSubHeader64 *kh = NULL;
+    size_t size;
+    int endian = s->dump_info.d_endian;
+    uint32_t block_size;
+    uint32_t sub_hdr_size;
+    uint32_t bitmap_blocks;
+    uint32_t status = 0;
+    uint64_t offset_note;
+
+    /* write common header, the version of kdump-compressed format is 6th */
+    size = sizeof(DiskDumpHeader64);
+    dh = g_malloc0(size);
+
+    strncpy(dh->signature, KDUMP_SIGNATURE, strlen(KDUMP_SIGNATURE));
+    dh->header_version = cpu_convert_to_target32(6, endian);
+    block_size = s->page_size;
+    dh->block_size = cpu_convert_to_target32(block_size, endian);
+    sub_hdr_size = sizeof(struct KdumpSubHeader64) + s->note_size;
+    sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
+    dh->sub_hdr_size = cpu_convert_to_target32(sub_hdr_size, endian);
+    /* dh->max_mapnr may be truncated, full 64bit is in kh.max_mapnr_64 */
+    dh->max_mapnr = cpu_convert_to_target32(MIN(s->max_mapnr, UINT_MAX),
+                                            endian);
+    dh->nr_cpus = cpu_convert_to_target32(s->nr_cpus, endian);
+    bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
+    dh->bitmap_blocks = cpu_convert_to_target32(bitmap_blocks, endian);
+    memcpy(&(dh->utsname.machine), "x86_64", 6);
+
+    if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
+        status |= DUMP_DH_COMPRESSED_ZLIB;
+    }
+#ifdef CONFIG_LZO
+    if (s->flag_compress & DUMP_DH_COMPRESSED_LZO) {
+        status |= DUMP_DH_COMPRESSED_LZO;
+    }
+#endif
+#ifdef CONFIG_SNAPPY
+    if (s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) {
+        status |= DUMP_DH_COMPRESSED_SNAPPY;
+    }
+#endif
+    dh->status = cpu_convert_to_target32(status, endian);
+
+    if (write_buffer(s->fd, 0, dh, size) < 0) {
+        dump_error(s, "dump: failed to write disk dump header.\n");
+        ret = -1;
+        goto out;
+    }
+
+    /* write sub header */
+    size = sizeof(KdumpSubHeader64);
+    kh = g_malloc0(size);
+
+    /* 64bit max_mapnr_64 */
+    kh->max_mapnr_64 = cpu_convert_to_target64(s->max_mapnr, endian);
+    kh->phys_base = cpu_convert_to_target64(PHYS_BASE, endian);
+    kh->dump_level = cpu_convert_to_target32(DUMP_LEVEL, endian);
+
+    offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size;
+    kh->offset_note = cpu_convert_to_target64(offset_note, endian);
+    kh->note_size = cpu_convert_to_target64(s->note_size, endian);
+
+    if (write_buffer(s->fd, DISKDUMP_HEADER_BLOCKS *
+                     block_size, kh, size) < 0) {
+        dump_error(s, "dump: failed to write kdump sub header.\n");
+        ret = -1;
+        goto out;
+    }
+
+    /* write note */
+    s->note_buf = g_malloc0(s->note_size);
+    s->note_buf_offset = 0;
+
+    /* use s->note_buf to store notes temporarily */
+    if (write_elf64_notes(buf_write_note, s) < 0) {
+        ret = -1;
+        goto out;
+    }
+
+    if (write_buffer(s->fd, offset_note, s->note_buf,
+                     s->note_size) < 0) {
+        dump_error(s, "dump: failed to write notes");
+        ret = -1;
+        goto out;
+    }
+
+    /* get offset of dump_bitmap */
+    s->offset_dump_bitmap = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size) *
+                             block_size;
+
+    /* get offset of page */
+    s->offset_page = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size + bitmap_blocks) *
+                     block_size;
+
+out:
+    g_free(dh);
+    g_free(kh);
+    g_free(s->note_buf);
+
+    return ret;
+}
+
+static int write_dump_header(DumpState *s)
+{
+    if (s->dump_info.d_machine == EM_386) {
+        return create_header32(s);
+    } else {
+        return create_header64(s);
+    }
+}
+
 static ram_addr_t get_start_block(DumpState *s)
 {
     GuestPhysBlock *block;
diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h
index 995bf47..dfee238 100644
--- a/include/sysemu/dump.h
+++ b/include/sysemu/dump.h
@@ -27,6 +27,19 @@
 #define pfn_to_paddr(X, page_shift) \
     (((unsigned long long)(X) + ARCH_PFN_OFFSET) << (page_shift))
 
+/*
+ * flag for compressed format
+ */
+#define DUMP_DH_COMPRESSED_ZLIB     (0x1)
+#define DUMP_DH_COMPRESSED_LZO      (0x2)
+#define DUMP_DH_COMPRESSED_SNAPPY   (0x4)
+
+#define KDUMP_SIGNATURE             "KDUMP   "
+#define SIG_LEN                     (sizeof(KDUMP_SIGNATURE) - 1)
+#define PHYS_BASE                   (0)
+#define DUMP_LEVEL                  (1)
+#define DISKDUMP_HEADER_BLOCKS      (1)
+
 typedef struct ArchDumpInfo {
     int d_machine;  /* Architecture */
     int d_endian;   /* ELFDATA2LSB or ELFDATA2MSB */
@@ -44,6 +57,89 @@ typedef struct QEMU_PACKED MakedumpfileDataHeader {
     int64_t buf_size;
 } MakedumpfileDataHeader;
 
+typedef struct QEMU_PACKED NewUtsname {
+    char sysname[65];
+    char nodename[65];
+    char release[65];
+    char version[65];
+    char machine[65];
+    char domainname[65];
+} NewUtsname;
+
+typedef struct QEMU_PACKED DiskDumpHeader32 {
+    char signature[SIG_LEN];        /* = "KDUMP   " */
+    uint32_t header_version;        /* Dump header version */
+    NewUtsname utsname;             /* copy of system_utsname */
+    char timestamp[10];             /* Time stamp */
+    uint32_t status;                /* Above flags */
+    uint32_t block_size;            /* Size of a block in byte */
+    uint32_t sub_hdr_size;          /* Size of arch dependent header in block */
+    uint32_t bitmap_blocks;         /* Size of Memory bitmap in block */
+    uint32_t max_mapnr;             /* = max_mapnr ,
+                                       obsoleted in header_version 6 */
+    uint32_t total_ram_blocks;      /* Number of blocks should be written */
+    uint32_t device_blocks;         /* Number of total blocks in dump device */
+    uint32_t written_blocks;        /* Number of written blocks */
+    uint32_t current_cpu;           /* CPU# which handles dump */
+    uint32_t nr_cpus;               /* Number of CPUs */
+} DiskDumpHeader32;
+
+typedef struct QEMU_PACKED DiskDumpHeader64 {
+    char signature[SIG_LEN];        /* = "KDUMP   " */
+    uint32_t header_version;        /* Dump header version */
+    NewUtsname utsname;             /* copy of system_utsname */
+    char timestamp[22];             /* Time stamp */
+    uint32_t status;                /* Above flags */
+    uint32_t block_size;            /* Size of a block in byte */
+    uint32_t sub_hdr_size;          /* Size of arch dependent header in block */
+    uint32_t bitmap_blocks;         /* Size of Memory bitmap in block */
+    uint32_t max_mapnr;             /* = max_mapnr,
+                                       obsoleted in header_version 6 */
+    uint32_t total_ram_blocks;      /* Number of blocks should be written */
+    uint32_t device_blocks;         /* Number of total blocks in dump device */
+    uint32_t written_blocks;        /* Number of written blocks */
+    uint32_t current_cpu;           /* CPU# which handles dump */
+    uint32_t nr_cpus;               /* Number of CPUs */
+} DiskDumpHeader64;
+
+typedef struct QEMU_PACKED KdumpSubHeader32 {
+    uint32_t phys_base;
+    uint32_t dump_level;            /* header_version 1 and later */
+    uint32_t split;                 /* header_version 2 and later */
+    uint32_t start_pfn;             /* header_version 2 and later,
+                                       obsoleted in header_version 6 */
+    uint32_t end_pfn;               /* header_version 2 and later,
+                                       obsoleted in header_version 6 */
+    uint64_t offset_vmcoreinfo;     /* header_version 3 and later */
+    uint32_t size_vmcoreinfo;       /* header_version 3 and later */
+    uint64_t offset_note;           /* header_version 4 and later */
+    uint32_t note_size;             /* header_version 4 and later */
+    uint64_t offset_eraseinfo;      /* header_version 5 and later */
+    uint32_t size_eraseinfo;        /* header_version 5 and later */
+    uint64_t start_pfn_64;          /* header_version 6 and later */
+    uint64_t end_pfn_64;            /* header_version 6 and later */
+    uint64_t max_mapnr_64;          /* header_version 6 and later */
+} KdumpSubHeader32;
+
+typedef struct QEMU_PACKED KdumpSubHeader64 {
+    uint64_t phys_base;
+    uint32_t dump_level;            /* header_version 1 and later */
+    uint32_t split;                 /* header_version 2 and later */
+    uint64_t start_pfn;             /* header_version 2 and later,
+                                       obsoleted in header_version 6 */
+    uint64_t end_pfn;               /* header_version 2 and later,
+                                       obsoleted in header_version 6 */
+    uint64_t offset_vmcoreinfo;     /* header_version 3 and later */
+    uint64_t size_vmcoreinfo;       /* header_version 3 and later */
+    uint64_t offset_note;           /* header_version 4 and later */
+    uint64_t note_size;             /* header_version 4 and later */
+    uint64_t offset_eraseinfo;      /* header_version 5 and later */
+    uint64_t size_eraseinfo;        /* header_version 5 and later */
+    uint64_t start_pfn_64;          /* header_version 6 and later */
+    uint64_t end_pfn_64;            /* header_version 6 and later */
+    uint64_t max_mapnr_64;          /* header_version 6 and later */
+} KdumpSubHeader64;
+
 struct GuestPhysBlockList; /* memory_mapping.h */
 int cpu_get_dump_info(ArchDumpInfo *info,
                       const struct GuestPhysBlockList *guest_phys_blocks);
-- 
1.7.1

[Qemu-devel] [PATCH v9 09/14] dump: add API to write dump_bitmap

[qiaonuohan]

functions are used to write 1st and 2nd dump_bitmap of kdump-compressed format,
which is used to indicate whether the corresponded page is existed in vmcore.
1st and 2nd dump_bitmap are same, because dump level is specified to 1 here.

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---
 dump.c                |  164 +++++++++++++++++++++++++++++++++++++++++++++++++
 include/sysemu/dump.h |    2 +
 2 files changed, 166 insertions(+), 0 deletions(-)

diff --git a/dump.c b/dump.c
index 4b2799f..5755534 100644
--- a/dump.c
+++ b/dump.c
@@ -1001,6 +1001,170 @@ static int write_dump_header(DumpState *s)
     }
 }
 
+/*
+ * set dump_bitmap sequencely. the bit before last_pfn is not allowed to be
+ * rewritten, so if need to set the first bit, set last_pfn and pfn to 0.
+ * set_dump_bitmap will always leave the recently set bit un-sync. And setting
+ * (last bit + sizeof(buf) * 8) to 0 will do flushing the content in buf into
+ * vmcore, ie. synchronizing un-sync bit into vmcore.
+ */
+static int set_dump_bitmap(uint64_t last_pfn, uint64_t pfn, bool value,
+                           uint8_t *buf, DumpState *s)
+{
+    off_t old_offset, new_offset;
+    off_t offset_bitmap1, offset_bitmap2;
+    uint32_t byte, bit;
+
+    /* should not set the previous place */
+    assert(last_pfn <= pfn);
+
+    /*
+     * if the bit needed to be set is not cached in buf, flush the data in buf
+     * to vmcore firstly.
+     * making new_offset be bigger than old_offset can also sync remained data
+     * into vmcore.
+     */
+    old_offset = BUFSIZE_BITMAP * (last_pfn / PFN_BUFBITMAP);
+    new_offset = BUFSIZE_BITMAP * (pfn / PFN_BUFBITMAP);
+
+    while (old_offset < new_offset) {
+        /* calculate the offset and write dump_bitmap */
+        offset_bitmap1 = s->offset_dump_bitmap + old_offset;
+        if (write_buffer(s->fd, offset_bitmap1, buf,
+                         BUFSIZE_BITMAP) < 0) {
+            return -1;
+        }
+
+        /* dump level 1 is chosen, so 1st and 2nd bitmap are same */
+        offset_bitmap2 = s->offset_dump_bitmap + s->len_dump_bitmap +
+                         old_offset;
+        if (write_buffer(s->fd, offset_bitmap2, buf,
+                         BUFSIZE_BITMAP) < 0) {
+            return -1;
+        }
+
+        memset(buf, 0, BUFSIZE_BITMAP);
+        old_offset += BUFSIZE_BITMAP;
+    }
+
+    /* get the exact place of the bit in the buf, and set it */
+    byte = (pfn % PFN_BUFBITMAP) / CHAR_BIT;
+    bit = (pfn % PFN_BUFBITMAP) % CHAR_BIT;
+    if (value) {
+        buf[byte] |= 1u << bit;
+    } else {
+        buf[byte] &= ~(1u << bit);
+    }
+
+    return 0;
+}
+
+/*
+ * exam every page and return the page frame number and the address of the page.
+ * bufptr can be NULL. note: the blocks here is supposed to reflect guest-phys
+ * blocks, so block->target_start and block->target_end should be interal
+ * multiples of the target page size.
+ */
+static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr,
+                          uint8_t **bufptr, DumpState *s)
+{
+    GuestPhysBlock *block = *blockptr;
+    hwaddr addr;
+    uint8_t *buf;
+
+    /* block == NULL means the start of the iteration */
+    if (!block) {
+        block = QTAILQ_FIRST(&s->guest_phys_blocks.head);
+        *blockptr = block;
+        assert(block->target_start % s->page_size == 0);
+        assert(block->target_end % s->page_size == 0);
+        *pfnptr = paddr_to_pfn(block->target_start, s->page_shift);
+        if (bufptr) {
+            *bufptr = block->host_addr;
+        }
+        return true;
+    }
+
+    *pfnptr = *pfnptr + 1;
+    addr = pfn_to_paddr(*pfnptr, s->page_shift);
+
+    if ((addr >= block->target_start) &&
+        (addr + s->page_size <= block->target_end)) {
+        buf = block->host_addr + (addr - block->target_start);
+    } else {
+        /* the next page is in the next block */
+        block = QTAILQ_NEXT(block, next);
+        *blockptr = block;
+        if (!block) {
+            return false;
+        }
+        assert(block->target_start % s->page_size == 0);
+        assert(block->target_end % s->page_size == 0);
+        *pfnptr = paddr_to_pfn(block->target_start, s->page_shift);
+        buf = block->host_addr;
+    }
+
+    if (bufptr) {
+        *bufptr = buf;
+    }
+
+    return true;
+}
+
+static int write_dump_bitmap(DumpState *s)
+{
+    int ret = 0;
+    uint64_t last_pfn, pfn;
+    void *dump_bitmap_buf;
+    size_t num_dumpable;
+    GuestPhysBlock *block_iter = NULL;
+
+    /* dump_bitmap_buf is used to store dump_bitmap temporarily */
+    dump_bitmap_buf = g_malloc0(BUFSIZE_BITMAP);
+
+    num_dumpable = 0;
+    last_pfn = 0;
+
+    /*
+     * exam memory page by page, and set the bit in dump_bitmap corresponded
+     * to the existing page.
+     */
+    while (get_next_page(&block_iter, &pfn, NULL, s)) {
+        ret = set_dump_bitmap(last_pfn, pfn, true, dump_bitmap_buf, s);
+        if (ret < 0) {
+            dump_error(s, "dump: failed to set dump_bitmap.\n");
+            ret = -1;
+            goto out;
+        }
+
+        last_pfn = pfn;
+        num_dumpable++;
+    }
+
+    /*
+     * set_dump_bitmap will always leave the recently set bit un-sync. Here we
+     * set last_pfn + PFN_BUFBITMAP to 0 and those set but un-sync bit will be
+     * synchronized into vmcore.
+     */
+    if (num_dumpable > 0) {
+        ret = set_dump_bitmap(last_pfn, last_pfn + PFN_BUFBITMAP, false,
+                              dump_bitmap_buf, s);
+        if (ret < 0) {
+            dump_error(s, "dump: failed to sync dump_bitmap.\n");
+            ret = -1;
+            goto out;
+        }
+    }
+
+    /* number of dumpable pages that will be dumped later */
+    s->num_dumpable = num_dumpable;
+
+out:
+    g_free(dump_bitmap_buf);
+
+    return ret;
+}
+
 static ram_addr_t get_start_block(DumpState *s)
 {
     GuestPhysBlock *block;
diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h
index dfee238..6d4d0bc 100644
--- a/include/sysemu/dump.h
+++ b/include/sysemu/dump.h
@@ -39,6 +39,8 @@
 #define PHYS_BASE                   (0)
 #define DUMP_LEVEL                  (1)
 #define DISKDUMP_HEADER_BLOCKS      (1)
+#define BUFSIZE_BITMAP              (TARGET_PAGE_SIZE)
+#define PFN_BUFBITMAP               (CHAR_BIT * BUFSIZE_BITMAP)
 
 typedef struct ArchDumpInfo {
     int d_machine;  /* Architecture */
-- 
1.7.1

[Qemu-devel] [PATCH v9 10/14] dump: add APIs to operate DataCache

[qiaonuohan]

DataCache is used to store data temporarily, then the data will be written to
vmcore. These functions will be called later when writing data of page to
vmcore.

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---
 dump.c                |   47 +++++++++++++++++++++++++++++++++++++++++++++++
 include/sysemu/dump.h |    9 +++++++++
 2 files changed, 56 insertions(+), 0 deletions(-)

diff --git a/dump.c b/dump.c
index 5755534..a7a85d3 100644
--- a/dump.c
+++ b/dump.c
@@ -1165,6 +1165,53 @@ out:
     return ret;
 }
 
+static void prepare_data_cache(DataCache *data_cache, DumpState *s,
+                               off_t offset)
+{
+    data_cache->fd = s->fd;
+    data_cache->data_size = 0;
+    data_cache->buf_size = BUFSIZE_DATA_CACHE;
+    data_cache->buf = g_malloc0(BUFSIZE_DATA_CACHE);
+    data_cache->offset = offset;
+}
+
+static int write_cache(DataCache *dc, const void *buf, size_t size,
+                       bool flag_sync)
+{
+    /*
+     * dc->buf_size should not be less than size, otherwise dc will never be
+     * enough
+     */
+    assert(size <= dc->buf_size);
+
+    /*
+     * if flag_sync is set, synchronize data in dc->buf into vmcore.
+     * otherwise check if the space is enough for caching data in buf, if not,
+     * write the data in dc->buf to dc->fd and reset dc->buf
+     */
+    if ((!flag_sync && dc->data_size + size > dc->buf_size) ||
+        (flag_sync && dc->data_size > 0)) {
+        if (write_buffer(dc->fd, dc->offset, dc->buf, dc->data_size) < 0) {
+            return -1;
+        }
+
+        dc->offset += dc->data_size;
+        dc->data_size = 0;
+    }
+
+    if (!flag_sync) {
+        memcpy(dc->buf + dc->data_size, buf, size);
+        dc->data_size += size;
+    }
+
+    return 0;
+}
+
+static void free_data_cache(DataCache *data_cache)
+{
+    g_free(data_cache->buf);
+}
+
 static ram_addr_t get_start_block(DumpState *s)
 {
     GuestPhysBlock *block;
diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h
index 6d4d0bc..92a95e4 100644
--- a/include/sysemu/dump.h
+++ b/include/sysemu/dump.h
@@ -41,6 +41,7 @@
 #define DISKDUMP_HEADER_BLOCKS      (1)
 #define BUFSIZE_BITMAP              (TARGET_PAGE_SIZE)
 #define PFN_BUFBITMAP               (CHAR_BIT * BUFSIZE_BITMAP)
+#define BUFSIZE_DATA_CACHE          (TARGET_PAGE_SIZE * 4)
 
 typedef struct ArchDumpInfo {
     int d_machine;  /* Architecture */
@@ -142,6 +143,14 @@ typedef struct QEMU_PACKED KdumpSubHeader64 {
     uint64_t max_mapnr_64;          /* header_version 6 and later */
 } KdumpSubHeader64;
 
+typedef struct DataCache {
+    int fd;             /* fd of the file where to write the cached data */
+    uint8_t *buf;       /* buffer for cached data */
+    size_t buf_size;    /* size of the buf */
+    size_t data_size;   /* size of cached data in buf */
+    off_t offset;       /* offset of the file */
+} DataCache;
+
 struct GuestPhysBlockList; /* memory_mapping.h */
 int cpu_get_dump_info(ArchDumpInfo *info,
                       const struct GuestPhysBlockList *guest_phys_blocks);
-- 
1.7.1

[Qemu-devel] [PATCH v9 11/14] dump: add API to write dump pages

[qiaonuohan]

functions are used to write page to vmcore. vmcore is written page by page.
page desc is used to store the information of a page, including a page's size,
offset, compression format, etc.

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---
 dump.c                |  231 +++++++++++++++++++++++++++++++++++++++++++++++++
 include/sysemu/dump.h |    7 ++
 2 files changed, 238 insertions(+), 0 deletions(-)

diff --git a/dump.c b/dump.c
index a7a85d3..a7b5117 100644
--- a/dump.c
+++ b/dump.c
@@ -25,6 +25,14 @@
 #include "qapi/error.h"
 #include "qmp-commands.h"
 
+#include <zlib.h>
+#ifdef CONFIG_LZO
+#include <lzo/lzo1x.h>
+#endif
+#ifdef CONFIG_SNAPPY
+#include <snappy-c.h>
+#endif
+
 static uint16_t cpu_convert_to_target16(uint16_t val, int endian)
 {
     if (endian == ELFDATA2LSB) {
@@ -1212,6 +1220,229 @@ static void free_data_cache(DataCache *data_cache)
     g_free(data_cache->buf);
 }
 
+static size_t get_len_buf_out(size_t page_size, uint32_t flag_compress)
+{
+    size_t len_buf_out_zlib, len_buf_out_lzo, len_buf_out_snappy;
+    size_t len_buf_out;
+
+    /* init buf_out */
+    len_buf_out_zlib = len_buf_out_lzo = len_buf_out_snappy = 0;
+
+    /* buf size for zlib */
+    len_buf_out_zlib = compressBound(page_size);
+
+    /* buf size for lzo */
+#ifdef CONFIG_LZO
+    if (flag_compress & DUMP_DH_COMPRESSED_LZO) {
+        if (lzo_init() != LZO_E_OK) {
+            /* return 0 to indicate lzo is unavailable */
+            return 0;
+        }
+    }
+
+    /*
+     * LZO will expand incompressible data by a little amount. please check the
+     * following URL to see the expansion calculation:
+     * http://www.oberhumer.com/opensource/lzo/lzofaq.php
+     */
+    len_buf_out_lzo = page_size + page_size / 16 + 64 + 3;
+#endif
+
+#ifdef CONFIG_SNAPPY
+    /* buf size for snappy */
+    len_buf_out_snappy = snappy_max_compressed_length(page_size);
+#endif
+
+    /* get the biggest that can store all kinds of compressed page */
+    len_buf_out = MAX(len_buf_out_zlib,
+                      MAX(len_buf_out_lzo, len_buf_out_snappy));
+
+    return len_buf_out;
+}
+
+/*
+ * check if the page is all 0
+ */
+static inline bool is_zero_page(const uint8_t *buf, size_t page_size)
+{
+    return buffer_is_zero(buf, page_size);
+}
+
+static int write_dump_pages(DumpState *s)
+{
+    int ret = 0;
+    DataCache page_desc, page_data;
+    size_t len_buf_out, size_out;
+#ifdef CONFIG_LZO
+    lzo_bytep wrkmem = NULL;
+#endif
+    uint8_t *buf_out = NULL;
+    off_t offset_desc, offset_data;
+    PageDescriptor pd, pd_zero;
+    uint8_t *buf;
+    int endian = s->dump_info.d_endian;
+    GuestPhysBlock *block_iter = NULL;
+    uint64_t pfn_iter;
+
+    /* get offset of page_desc and page_data in dump file */
+    offset_desc = s->offset_page;
+    offset_data = offset_desc + sizeof(PageDescriptor) * s->num_dumpable;
+
+    prepare_data_cache(&page_desc, s, offset_desc);
+    prepare_data_cache(&page_data, s, offset_data);
+
+    /* prepare buffer to store compressed data */
+    len_buf_out = get_len_buf_out(s->page_size, s->flag_compress);
+    if (len_buf_out == 0) {
+        dump_error(s, "dump: failed to get length of output buffer.\n");
+        goto out;
+    }
+
+#ifdef CONFIG_LZO
+    wrkmem = g_malloc(LZO1X_1_MEM_COMPRESS);
+#endif
+
+    buf_out = g_malloc(len_buf_out);
+
+    /*
+     * init zero page's page_desc and page_data, because every zero page
+     * uses the same page_data
+     */
+    pd_zero.size = cpu_convert_to_target32(s->page_size, endian);
+    pd_zero.flags = cpu_convert_to_target32(0, endian);
+    pd_zero.offset = cpu_convert_to_target64(offset_data, endian);
+    pd_zero.page_flags = cpu_convert_to_target64(0, endian);
+    buf = g_malloc0(s->page_size);
+    ret = write_cache(&page_data, buf, s->page_size, false);
+    g_free(buf);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write page data(zero page).\n");
+        goto out;
+    }
+
+    offset_data += s->page_size;
+
+    /*
+     * dump memory to vmcore page by page. zero page will all be resided in the
+     * first page of page section
+     */
+    while (get_next_page(&block_iter, &pfn_iter, &buf, s)) {
+        /* check zero page */
+        if (is_zero_page(buf, s->page_size)) {
+            ret = write_cache(&page_desc, &pd_zero, sizeof(PageDescriptor),
+                              false);
+            if (ret < 0) {
+                dump_error(s, "dump: failed to write page desc.\n");
+                goto out;
+            }
+        } else {
+            /*
+             * not zero page, then:
+             * 1. compress the page
+             * 2. write the compressed page into the cache of page_data
+             * 3. get page desc of the compressed page and write it into the
+             *    cache of page_desc
+             *
+             * only one compression format will be used here, for
+             * s->flag_compress is set. But when compression fails to work,
+             * we fall back to save in plaintext.
+             */
+             size_out = len_buf_out;
+             if ((s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) &&
+                    (compress2(buf_out, (uLongf *)&size_out, buf, s->page_size,
+                    Z_BEST_SPEED) == Z_OK) && (size_out < s->page_size)) {
+                pd.flags = cpu_convert_to_target32(DUMP_DH_COMPRESSED_ZLIB,
+                                                   endian);
+                pd.size  = cpu_convert_to_target32(size_out, endian);
+
+                ret = write_cache(&page_data, buf_out, size_out, false);
+                if (ret < 0) {
+                    dump_error(s, "dump: failed to write page data.\n");
+                    goto out;
+                }
+#ifdef CONFIG_LZO
+            } else if ((s->flag_compress & DUMP_DH_COMPRESSED_LZO) &&
+                    (lzo1x_1_compress(buf, s->page_size, buf_out,
+                    (lzo_uint *)&size_out, wrkmem) == LZO_E_OK) &&
+                    (size_out < s->page_size)) {
+                pd.flags = cpu_convert_to_target32(DUMP_DH_COMPRESSED_LZO,
+                                                   endian);
+                pd.size  = cpu_convert_to_target32(size_out, endian);
+
+                ret = write_cache(&page_data, buf_out, size_out, false);
+                if (ret < 0) {
+                    dump_error(s, "dump: failed to write page data.\n");
+                    goto out;
+                }
+#endif
+#ifdef CONFIG_SNAPPY
+            } else if ((s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) &&
+                    (snappy_compress((char *)buf, s->page_size,
+                    (char *)buf_out, &size_out) == SNAPPY_OK) &&
+                    (size_out < s->page_size)) {
+                pd.flags = cpu_convert_to_target32(
+                                        DUMP_DH_COMPRESSED_SNAPPY, endian);
+                pd.size  = cpu_convert_to_target32(size_out, endian);
+
+                ret = write_cache(&page_data, buf_out, size_out, false);
+                if (ret < 0) {
+                    dump_error(s, "dump: failed to write page data.\n");
+                    goto out;
+                }
+#endif
+            } else {
+                /*
+                 * fall back to save in plaintext, size_out should be
+                 * assigned to s->page_size
+                 */
+                pd.flags = cpu_convert_to_target32(0, endian);
+                size_out = s->page_size;
+                pd.size = cpu_convert_to_target32(size_out, endian);
+
+                ret = write_cache(&page_data, buf, s->page_size, false);
+                if (ret < 0) {
+                    dump_error(s, "dump: failed to write page data.\n");
+                    goto out;
+                }
+            }
+
+            /* get and write page desc here */
+            pd.page_flags = cpu_convert_to_target64(0, endian);
+            pd.offset = cpu_convert_to_target64(offset_data, endian);
+            offset_data += size_out;
+
+            ret = write_cache(&page_desc, &pd, sizeof(PageDescriptor), false);
+            if (ret < 0) {
+                dump_error(s, "dump: failed to write page desc.\n");
+                goto out;
+            }
+        }
+    }
+
+    ret = write_cache(&page_desc, NULL, 0, true);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to sync cache for page_desc.\n");
+        goto out;
+    }
+    ret = write_cache(&page_data, NULL, 0, true);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to sync cache for page_data.\n");
+        goto out;
+    }
+
+out:
+    free_data_cache(&page_desc);
+    free_data_cache(&page_data);
+
+#ifdef CONFIG_LZO
+    g_free(wrkmem);
+#endif
+
+    g_free(buf_out);
+
+    return ret;
+}
+
 static ram_addr_t get_start_block(DumpState *s)
 {
     GuestPhysBlock *block;
diff --git a/include/sysemu/dump.h b/include/sysemu/dump.h
index 92a95e4..efab7a3 100644
--- a/include/sysemu/dump.h
+++ b/include/sysemu/dump.h
@@ -151,6 +151,13 @@ typedef struct DataCache {
     off_t offset;       /* offset of the file */
 } DataCache;
 
+typedef struct QEMU_PACKED PageDescriptor {
+    uint64_t offset;                /* the offset of the page data*/
+    uint32_t size;                  /* the size of this dump page */
+    uint32_t flags;                 /* flags */
+    uint64_t page_flags;            /* page flags */
+} PageDescriptor;
+
 struct GuestPhysBlockList; /* memory_mapping.h */
 int cpu_get_dump_info(ArchDumpInfo *info,
                       const struct GuestPhysBlockList *guest_phys_blocks);
-- 
1.7.1

[Qemu-devel] [PATCH v9 12/14] dump: make kdump-compressed format available for 'dump-guest-memory'

[qiaonuohan]

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. 'kdump-zlib': kdump-compressed format, with zlib-compressed
3. 'kdump-lzo': kdump-compressed format, with lzo-compressed
4. 'kdump-snappy': kdump-compressed format, with snappy-compressed
Without 'format' being set, it is same as 'elf'. And if non-elf format is
specified, paging and filter is not allowed.

Note:
  1. The kdump-compressed format is readable only with the crash utility and
     makedumpfile, and it can be smaller than the ELF format because of the
     compression support.
  2. The kdump-compressed format is the 6th edition.

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
---
 dump.c           |  131 +++++++++++++++++++++++++++++++++++++++++++++++++++---
 hmp.c            |    5 ++-
 qapi-schema.json |   25 ++++++++++-
 qmp-commands.hx  |    7 ++-
 4 files changed, 158 insertions(+), 10 deletions(-)

diff --git a/dump.c b/dump.c
index a7b5117..fb0c896 100644
--- a/dump.c
+++ b/dump.c
@@ -1443,6 +1443,64 @@ out:
     return ret;
 }
 
+static int create_kdump_vmcore(DumpState *s)
+{
+    int ret;
+
+    /*
+     * the kdump-compressed format is:
+     *                                               File offset
+     *  +------------------------------------------+ 0x0
+     *  |    main header (struct disk_dump_header) |
+     *  |------------------------------------------+ block 1
+     *  |    sub header (struct kdump_sub_header)  |
+     *  |------------------------------------------+ block 2
+     *  |            1st-dump_bitmap               |
+     *  |------------------------------------------+ block 2 + X blocks
+     *  |            2nd-dump_bitmap               | (aligned by block)
+     *  |------------------------------------------+ block 2 + 2 * X blocks
+     *  |  page desc for pfn 0 (struct page_desc)  | (aligned by block)
+     *  |  page desc for pfn 1 (struct page_desc)  |
+     *  |                    :                     |
+     *  |------------------------------------------| (not aligned by block)
+     *  |         page data (pfn 0)                |
+     *  |         page data (pfn 1)                |
+     *  |                    :                     |
+     *  +------------------------------------------+
+     */
+
+    ret = write_start_flat_header(s->fd);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write start flat header.\n");
+        return -1;
+    }
+
+    ret = write_dump_header(s);
+    if (ret < 0) {
+        return -1;
+    }
+
+    ret = write_dump_bitmap(s);
+    if (ret < 0) {
+        return -1;
+    }
+
+    ret = write_dump_pages(s);
+    if (ret < 0) {
+        return -1;
+    }
+
+    ret = write_end_flat_header(s->fd);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write end flat header.\n");
+        return -1;
+    }
+
+    dump_completed(s);
+
+    return 0;
+}
+
 static ram_addr_t get_start_block(DumpState *s)
 {
     GuestPhysBlock *block;
@@ -1479,7 +1537,8 @@ static void get_max_mapnr(DumpState *s)
     s->max_mapnr = paddr_to_pfn(last_block->target_end, s->page_shift);
 }
 
-static int dump_init(DumpState *s, int fd, bool paging, bool has_filter,
+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)
 {
     CPUState *cpu;
@@ -1487,6 +1546,11 @@ static int dump_init(DumpState *s, int fd, bool paging, bool has_filter,
     Error *err = NULL;
     int ret;
 
+    /* kdump-compressed is conflict with paging and filter */
+    if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
+        assert(!paging && !has_filter);
+    }
+
     if (runstate_is_running()) {
         vm_stop(RUN_STATE_SAVE_VM);
         s->resume = true;
@@ -1557,6 +1621,28 @@ static int dump_init(DumpState *s, int fd, bool paging, bool has_filter,
     tmp = DIV_ROUND_UP(DIV_ROUND_UP(s->max_mapnr, CHAR_BIT), s->page_size);
     s->len_dump_bitmap = tmp * s->page_size;
 
+    /* init for kdump-compressed format */
+    if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
+        switch (format) {
+        case DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB:
+            s->flag_compress = DUMP_DH_COMPRESSED_ZLIB;
+            break;
+
+        case DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO:
+            s->flag_compress = DUMP_DH_COMPRESSED_LZO;
+            break;
+
+        case DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY:
+            s->flag_compress = DUMP_DH_COMPRESSED_SNAPPY;
+            break;
+
+        default:
+            s->flag_compress = 0;
+        }
+
+        return 0;
+    }
+
     if (s->has_filter) {
         memory_mapping_filter(&s->list, s->begin, s->length);
     }
@@ -1616,14 +1702,25 @@ cleanup:
 }
 
 void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
-                           int64_t begin, bool has_length, int64_t length,
-                           Error **errp)
+                           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 need the whole memory dumped, so paging or
+     * filter is not supported here.
+     */
+    if ((has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) &&
+        (paging || has_begin || has_length)) {
+        error_setg(errp, "kdump-compressed format doesn't support paging or "
+                         "filter");
+        return;
+    }
     if (has_begin && !has_length) {
         error_set(errp, QERR_MISSING_PARAMETER, "length");
         return;
@@ -1633,6 +1730,21 @@ void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
         return;
     }
 
+    /* check whether lzo/snappy is supported */
+#ifndef CONFIG_LZO
+    if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO) {
+        error_setg(errp, "kdump-lzo is not available now");
+        return;
+    }
+#endif
+
+#ifndef CONFIG_SNAPPY
+    if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY) {
+        error_setg(errp, "kdump-snappy is not available now");
+        return;
+    }
+#endif
+
 #if !defined(WIN32)
     if (strstart(file, "fd:", &p)) {
         fd = monitor_get_fd(cur_mon, p, errp);
@@ -1657,14 +1769,21 @@ void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
 
     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);
+        }
     }
 
     g_free(s);
diff --git a/hmp.c b/hmp.c
index 1af0809..4f756ce 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1310,8 +1310,11 @@ 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");
+    /* 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 (has_begin) {
@@ -1324,7 +1327,7 @@ void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict)
     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/qapi-schema.json b/qapi-schema.json
index 7cfb5e5..905a8af 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -2716,6 +2716,24 @@
 { 'command': 'device_del', 'data': {'id': 'str'} }
 
 ##
+# @DumpGuestMemoryFormat:
+#
+# An enumeration of guest-memory-dump's format.
+#
+# @elf: elf format
+#
+# @kdump-zlib: kdump-compressed format with zlib-compressed
+#
+# @kdump-lzo: kdump-compressed format with lzo-compressed
+#
+# @kdump-snappy: kdump-compressed format with snappy-compressed
+#
+# Since: 2.0
+##
+{ 'enum': 'DumpGuestMemoryFormat',
+  'data': [ 'elf', 'kdump-zlib', 'kdump-lzo', 'kdump-snappy' ] }
+
+##
 # @dump-guest-memory
 #
 # Dump guest's memory to vmcore. It is a synchronous operation that can take
@@ -2751,13 +2769,18 @@
 #          want to dump all guest's memory, please specify the start @begin
 #          and @length
 #
+# @format: #optional 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 at the
+#          same time (since 2.0)
+#
 # 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 cce6b81..019dde6 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -791,8 +791,8 @@ 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?,end: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,
@@ -813,6 +813,9 @@ 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|kdump-zlib|kdump-lzo|kdump-snappy, but non-elf formats will
+            conflict with paging and filter, ie. begin and length (json-string)
 
 Example:
 
-- 
1.7.1

[Qemu-devel] [PATCH v9 13/14] Define the architecture for compressed dump format

[qiaonuohan]

Signed-off-by: Ekaterina Tumanova <tumanova@linux.vnet.ibm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
---
 dump.c             |    7 +++++--
 target-i386/cpu.h  |    2 ++
 target-s390x/cpu.h |    1 +
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/dump.c b/dump.c
index fb0c896..2c81318 100644
--- a/dump.c
+++ b/dump.c
@@ -32,6 +32,9 @@
 #ifdef CONFIG_SNAPPY
 #include <snappy-c.h>
 #endif
+#ifndef ELF_MACHINE_UNAME
+#define ELF_MACHINE_UNAME "Unknown"
+#endif
 
 static uint16_t cpu_convert_to_target16(uint16_t val, int endian)
 {
@@ -817,7 +820,7 @@ static int create_header32(DumpState *s)
     dh->nr_cpus = cpu_convert_to_target32(s->nr_cpus, endian);
     bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
     dh->bitmap_blocks = cpu_convert_to_target32(bitmap_blocks, endian);
-    memcpy(&(dh->utsname.machine), "i686", 4);
+    strncpy(dh->utsname.machine, ELF_MACHINE_UNAME, sizeof(dh->utsname.machine));
 
     if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
         status |= DUMP_DH_COMPRESSED_ZLIB;
@@ -924,7 +927,7 @@ static int create_header64(DumpState *s)
     dh->nr_cpus = cpu_convert_to_target32(s->nr_cpus, endian);
     bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
     dh->bitmap_blocks = cpu_convert_to_target32(bitmap_blocks, endian);
-    memcpy(&(dh->utsname.machine), "x86_64", 6);
+    strncpy(dh->utsname.machine, ELF_MACHINE_UNAME, sizeof(dh->utsname.machine));
 
     if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
         status |= DUMP_DH_COMPRESSED_ZLIB;
diff --git a/target-i386/cpu.h b/target-i386/cpu.h
index 1b94f0f..6abcd23 100644
--- a/target-i386/cpu.h
+++ b/target-i386/cpu.h
@@ -38,8 +38,10 @@
 
 #ifdef TARGET_X86_64
 #define ELF_MACHINE     EM_X86_64
+#define ELF_MACHINE_UNAME "x86_64"
 #else
 #define ELF_MACHINE     EM_386
+#define ELF_MACHINE_UNAME "i686"
 #endif
 
 #define CPUArchState struct CPUX86State
diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h
index 96c2b4a..6d46827 100644
--- a/target-s390x/cpu.h
+++ b/target-s390x/cpu.h
@@ -28,6 +28,7 @@
 #define TARGET_LONG_BITS 64
 
 #define ELF_MACHINE	EM_S390
+#define ELF_MACHINE_UNAME "S390X"
 
 #define CPUArchState struct CPUS390XState
 
-- 
1.7.1

[Qemu-devel] [PATCH v9 14/14] dump: add 'query-dump-guest-memory-capability' command

[qiaonuohan]

'query-dump-guest-memory-capability' is used to query the available formats for
'dump-guest-memory'. The output of the command will be like:

-> { "execute": "query-dump-guest-memory-capability" }
<- { "return": { "formats":
                    ["elf", "kdump-zlib", "kdump-lzo", "kdump-snappy"] }

Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
---
 dump.c           |   33 +++++++++++++++++++++++++++++++++
 qapi-schema.json |   24 ++++++++++++++++++++++++
 qmp-commands.hx  |   20 ++++++++++++++++++++
 3 files changed, 77 insertions(+), 0 deletions(-)

diff --git a/dump.c b/dump.c
index 2c81318..14b3d1d 100644
--- a/dump.c
+++ b/dump.c
@@ -1791,3 +1791,36 @@ void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
 
     g_free(s);
 }
+
+DumpGuestMemoryCapability *qmp_query_dump_guest_memory_capability(Error **errp)
+{
+    DumpGuestMemoryFormatList *item;
+    DumpGuestMemoryCapability *cap =
+                                  g_malloc0(sizeof(DumpGuestMemoryCapability));
+
+    /* elf is always available */
+    item = g_malloc0(sizeof(DumpGuestMemoryFormatList));
+    cap->formats = item;
+    item->value = DUMP_GUEST_MEMORY_FORMAT_ELF;
+
+    /* kdump-zlib is always available */
+    item->next = g_malloc0(sizeof(DumpGuestMemoryFormatList));
+    item = item->next;
+    item->value = DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB;
+
+    /* add new item if kdump-lzo is available */
+#ifdef CONFIG_LZO
+    item->next = g_malloc0(sizeof(DumpGuestMemoryFormatList));
+    item = item->next;
+    item->value = DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO;
+#endif
+
+    /* add new item if kdump-snappy is available */
+#ifdef CONFIG_SNAPPY
+    item->next = g_malloc0(sizeof(DumpGuestMemoryFormatList));
+    item = item->next;
+    item->value = DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY;
+#endif
+
+    return cap;
+}
diff --git a/qapi-schema.json b/qapi-schema.json
index 905a8af..3eeb261 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -2783,6 +2783,30 @@
             '*length': 'int', '*format': 'DumpGuestMemoryFormat' } }
 
 ##
+# @DumpGuestMemoryCapability:
+#
+# A list of the available formats for dump-guest-memory
+#
+# Since: 2.0
+##
+{ 'type': 'DumpGuestMemoryCapability',
+  'data': {
+      'formats': ['DumpGuestMemoryFormat'] } }
+
+##
+# @query-dump-guest-memory-capability:
+#
+# Returns the available formats for dump-guest-memory
+#
+# Returns:  A @DumpGuestMemoryCapability object listing available formats for
+#           dump-guest-memory
+#
+# Since: 2.0
+##
+{ 'command': 'query-dump-guest-memory-capability',
+  'returns': 'DumpGuestMemoryCapability' }
+
+##
 # @netdev_add:
 #
 # Add a network backend.
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 019dde6..f38007c 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -829,6 +829,26 @@ Notes:
 EQMP
 
     {
+        .name       = "query-dump-guest-memory-capability",
+        .args_type  = "",
+    .mhandler.cmd_new = qmp_marshal_input_query_dump_guest_memory_capability,
+    },
+
+SQMP
+query-dump-guest-memory-capability
+----------
+
+Show available formats for 'dump-guest-memory'
+
+Example:
+
+-> { "execute": "query-dump-guest-memory-capability" }
+<- { "return": { "formats":
+                    ["elf", "kdump-zlib", "kdump-lzo", "kdump-snappy"] }
+
+EQMP
+
+    {
         .name       = "netdev_add",
         .args_type  = "netdev:O",
         .mhandler.cmd_new = qmp_netdev_add,
-- 
1.7.1

Re: [Qemu-devel] [PATCH v9 00/14] Make 'dump-guest-memory' dump in kdump-compressed format

[Luiz Capitulino]

On Tue, 18 Feb 2014 14:11:24 +0800
qiaonuohan <qiaonuohan@cn.fujitsu.com> wrote:

> Hi, all
> 
> The last version is here:
> http://lists.nongnu.org/archive/html/qemu-devel/2014-01/msg03669.html
> 
> Command 'dump-guest-memory' was introduced to dump guest's memory. But the
> vmcore's format is only elf32 or elf64. The message is here:
> http://lists.gnu.org/archive/html/qemu-devel/2012-04/msg03379.html
> 
> Compared with migration, the missing of compression feature means regression
> to 'dump-guest-memory'. So we post these patches to make 'dump-guest-memory' be
> able to dump guest's in kdump-compressed format. Then vmcore can be much
> smaller, and easily to be delivered.
> 
> The kdump-compressed format is *linux specific* *linux standard* crash dump
> format used in kdump framework. 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. To get more detailed information about
> kdump-compressed format, please refer to the following URL:
> http://sourceforge.net/projects/makedumpfile/

Applied to the qmp branch, thanks.

PS: I had to fix a trivial conflict in configure because of commit
95c6bff3561ee.


> 
> Note:
> 1. The guest should be x86/x86_64/s390x. The other arch is not supported now.
> 2. If the OS is in the second kernel, gdb may not work well, and crash can
>    work by specifying '--machdep phys_addr=xxx' in the command line. The
>    reason is that the second kernel will update the page table, and we can
>    not get the page table for the first kernel.
> 3. The cpu's state is stored in QEMU note.
> 4. The vmcore are able to be compressed with zlib, lzo or snappy. zlib is
>    available by default, and option '--enable-lzo' or '--enable-snappy'
>    should be specified with 'configure' to make lzo or snappy available.
> 
> Changelog:
> Changes from v8 to v9:
> 1. add Ekaterina's patch(support s390x) into series
> 2. modify query-dump-guest-memory-capability according to Paolo Bonzini's
>    suggestion
> 3. fix compiling error on 32-bit host
> 
> Changes from v7 to v8:
> 1. rebase get_max_mapnr()
> 2. fix bug of using dh->block_size directly in create_header64()
> 3. abandon using static variables in get_next_page()
> 4. redefine 'struct PageDesc' to 'struct QEMU_PACKED PageDescriptor'
> 5. add return when format checking fails
> Changes from v6 to v7:
> 1. support BE host
> 2. abandon non-flatten format to avoid using seek on vmcore
> 3. abandon using of very large array
> 4. use get_next_page to replace the iteration of guest's pages
> 5. abandon the support of HMP
> 
> Changes from v5 to v6:
> 1. add run-time check for compression format(lzo/snappy)
> 2. address Stefan's comments about reusing code and coding style
> 3. update the version of kdump-compressed format to 6th
> 4. resplit the patches
> 5. Add 'query-dump-guest-memory-capability' command
> 
> Changes from v4 to v5:
> 1. using flatten format to avoid using temporary files according to Stefan's
>    comments
> 2. Address Andreas's comments about coding style
> 
> Changes from v3 to v4:
> 1. change to avoid conflict with Andreas's patches
> 2. rebase
> 
> Changes from v2 to v3:
> 1. Address Eric's comment
> 
> Changes from v1 to v2:
> 1. Address Eric & Daniel's comment: fix manner of string copy.
> 2. Address Eric's comment: replace reinventing new constants by using the
>    ready-made ones accoring.
> 3. Address Andreas's comment: remove useless include.
> 
> qiaonuohan (14):
>   dump: const-qualify the buf of WriteCoreDumpFunction
>   dump: add argument to write_elfxx_notes
>   dump: add API to write header of flatten format
>   dump: add API to write vmcore
>   dump: add API to write elf notes to buffer
>   dump: add support for lzo/snappy
>   dump: add members to DumpState and init some of them
>   dump: add API to write dump header
>   dump: add API to write dump_bitmap
>   dump: add APIs to operate DataCache
>   dump: add API to write dump pages
>   dump: make kdump-compressed format available for 'dump-guest-memory'
>   Define the architecture for compressed dump format
>   dump: add 'query-dump-guest-memory-capability' command
> 
>  configure             |   54 +++
>  dump.c                |  960 ++++++++++++++++++++++++++++++++++++++++++++++++-
>  hmp.c                 |    5 +-
>  include/qom/cpu.h     |    3 +-
>  include/sysemu/dump.h |  138 +++++++
>  qapi-schema.json      |   49 +++-
>  qmp-commands.hx       |   27 ++-
>  target-i386/cpu.h     |    2 +
>  target-s390x/cpu.h    |    1 +
>  9 files changed, 1219 insertions(+), 20 deletions(-)
> 
>