introducing a new, dedicated memory dump mechanism

}

memory_mapping.c +13 -0

+
+int qemu_get_guest_memory_mapping(MemoryMappingList *list)
+{
+    CPUState *env;
+    RAMBlock *block;
+    ram_addr_t offset, length;
+    int ret;
+    bool paging_mode;
+
+#if defined(CONFIG_HAVE_GET_MEMORY_MAPPING)
+    paging_mode = cpu_paging_enabled(first_cpu);
+    if (paging_mode) {
+        for (env = first_cpu; env != NULL; env = env->next_cpu) {

From: Wen Congyang <[email protected]>
Subject: [RFC][PATCH 05/14 v9] Add API to get memory mapping
Date: Wed, 14 Mar 2012 10:07:48 +0800

Quoted 14 lines

}

memory_mapping.c +13 -0

+
+int qemu_get_guest_memory_mapping(MemoryMappingList *list)
+{
+    CPUState *env;
+    RAMBlock *block;
+    ram_addr_t offset, length;
+    int ret;
+    bool paging_mode;
+
+#if defined(CONFIG_HAVE_GET_MEMORY_MAPPING)
+    paging_mode = cpu_paging_enabled(first_cpu);
+    if (paging_mode) {
+        for (env = first_cpu; env != NULL; env = env->next_cpu) {

memory_mapping.c void memory_mapping_list_init(MemoryMappingList *list) · line 189

Quoted 10 lines

memory_mapping.c +10 -0

+            ret = cpu_get_memory_mapping(list, env);
+            if (ret < 0) {
+                return -1;
+            }
+        }
+        return 0;
+    }
+#else
+    return -2;
+#endif

Is it better to define the below somewhere else?

#ifndef CONFIG_HAVE_GET_MEMORY_MAPPING
static inline int qemu_get_guest_memory_mapping(MemoryMappingList *list)

{
	return -2;
}

#endif

Thanks.
HATAYAMA, Daisuke

Add API to get all virtual address and physical address mapping.
If the guest doesn't use paging, the virtual address is equal to the phyical address. The virtual address and physical address mapping is for gdb's user, and it does not include the memory that is not referenced by the page table. So if you want to use crash to anaylze the vmcore, please do not specify -p option.

From: Wen Congyang <[email protected]>
Subject: [RFC][PATCH 05/14 v9] Add API to get memory mapping
Date: Wed, 14 Mar 2012 10:07:48 +0800

Quoted 5 lines

Add API to get all virtual address and physical address mapping.
If the guest doesn't use paging, the virtual address is equal to the phyical address. The virtual address and physical address mapping is for gdb's user, and it does not include the memory that is not referenced by the page table. So if you want to use crash to anaylze the vmcore, please do not specify -p option.

It's necessary to write the reason why the -p option is not default
explicitly: guest machine in a catastrophic state can have corrupted memory, which we cannot trust.

Thanks.
HATAYAMA, Daisuke

+ descsz = 336; /* sizeof(prstatus_t) is 336 on x86_64 box */

+ descsz = 144; /* sizeof(prstatus_t) is 144 on x86 box */

+ descsz = 144; /* sizeof(prstatus_t) is 144 on x86 box */

From: Wen Congyang <[email protected]>
Subject: [RFC][PATCH 08/14 v9] target-i386: Add API to write cpu status to core file
Date: Wed, 14 Mar 2012 10:09:26 +0800

target-i386/arch_dump.c int cpu_write_elf32_note(write_core_dump_function f, CPUState *env, int cpuid, · line 371

Quoted 12 lines

target-i386/arch_dump.c +12 -0

+    memset(note, 0, note_size);
+    if (type == 0) {
+        note32 = note;
+        note32->n_namesz = cpu_to_le32(name_size);
+        note32->n_descsz = cpu_to_le32(descsz);
+        note32->n_type = 0;
+    } else {
+        note64 = note;
+        note64->n_namesz = cpu_to_le32(name_size);
+        note64->n_descsz = cpu_to_le32(descsz);
+        note64->n_type = 0;
+    }

Why not give new type for this note information an explicit name? Like NT_QEMUCPUSTATE? There might be another type in the future. This way there's also a merit that we can know all the existing notes relevant to qemu dump by looking at the names in a header file.

Thanks.
HATAYAMA, Daisuke

At 03/16/2012 09:48 AM, HATAYAMA Daisuke Wrote:

Quoted 17 lines

From: Wen Congyang <[email protected]>
Subject: [RFC][PATCH 08/14 v9] target-i386: Add API to write cpu status to core file
Date: Wed, 14 Mar 2012 10:09:26 +0800

Quoted 12 lines

target-i386/arch_dump.c +12 -0

+    memset(note, 0, note_size);
+    if (type == 0) {
+        note32 = note;
+        note32->n_namesz = cpu_to_le32(name_size);
+        note32->n_descsz = cpu_to_le32(descsz);
+        note32->n_type = 0;
+    } else {
+        note64 = note;
+        note64->n_namesz = cpu_to_le32(name_size);
+        note64->n_descsz = cpu_to_le32(descsz);
+        note64->n_type = 0;
+    }

Quoted 4 lines

Why not give new type for this note information an explicit name? Like NT_QEMUCPUSTATE? There might be another type in the future. This way there's also a merit that we can know all the existing notes relevant to qemu dump by looking at the names in a header file.

Hmm, how to add a new type? Does someont manage this?

The command's usage:
dump [-p] file
file should be start with "file:"(the file's path) or "fd:"(the fd's name).

Note:
1. If you want to use gdb to analyse the core, please specify -p option.
2. This command doesn't support the fd that is is associated with a pipe, socket, or FIFO(lseek will fail with such fd).

Signed-off-by Wen Congyang <[email protected]>

---
 Makefile.target  |    2 +-
 dump.c           |  714 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 elf.h            |    5 +
 hmp-commands.hx  |   21 ++
 hmp.c            |   10 +
 hmp.h            |    1 +
 qapi-schema.json |   14 +
 qmp-commands.hx  |   34 +++
 8 files changed, 800 insertions(+), 1 deletions(-)
 create mode 100644 dump.c

Makefile.target +1 -1

index c81c4fa..287fbe7 100644
@@ -213,7 +213,7 @@ obj-$(CONFIG_NO_KVM) += kvm-stub.o
 obj-$(CONFIG_VGA) += vga.o
 obj-y += memory.o savevm.o
 obj-y += memory_mapping.o
-obj-$(CONFIG_HAVE_CORE_DUMP) += arch_dump.o
+obj-$(CONFIG_HAVE_CORE_DUMP) += arch_dump.o dump.o
 LIBS+=-lz
 
 obj-i386-$(CONFIG_KVM) += hyperv.o

dump.c new file +85 -0

new file mode 100644
index 0000000..42e1681
@@ -0,0 +1,714 @@
+/*
+ * QEMU dump
+ *
+ * Copyright Fujitsu, Corp. 2011
+ *
+ * Authors:
+ *     Wen Congyang <[email protected]>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu-common.h"
+#include <unistd.h>
+#include "elf.h"
+#include <sys/procfs.h>
+#include <glib.h>
+#include "cpu.h"
+#include "cpu-all.h"
+#include "targphys.h"
+#include "monitor.h"
+#include "kvm.h"
+#include "dump.h"
+#include "sysemu.h"
+#include "bswap.h"
+#include "memory_mapping.h"
+#include "error.h"
+#include "qmp-commands.h"
+#include "gdbstub.h"
+
+static inline uint16_t cpu_convert_to_target16(uint16_t val, int endian)
+{
+    if (endian == ELFDATA2LSB) {
+        val = cpu_to_le16(val);
+    } else {
+        val = cpu_to_be16(val);
+    }
+
+    return val;
+}
+
+static inline uint32_t cpu_convert_to_target32(uint32_t val, int endian)
+{
+    if (endian == ELFDATA2LSB) {
+        val = cpu_to_le32(val);
+    } else {
+        val = cpu_to_be32(val);
+    }
+
+    return val;
+}
+
+static inline uint64_t cpu_convert_to_target64(uint64_t val, int endian)
+{
+    if (endian == ELFDATA2LSB) {
+        val = cpu_to_le64(val);
+    } else {
+        val = cpu_to_be64(val);
+    }
+
+    return val;
+}
+
+enum {
+    DUMP_STATE_ERROR,
+    DUMP_STATE_SETUP,
+    DUMP_STATE_CANCELLED,
+    DUMP_STATE_ACTIVE,
+    DUMP_STATE_COMPLETED,
+};
+
+typedef struct DumpState {
+    ArchDumpInfo dump_info;
+    MemoryMappingList list;
+    uint16_t phdr_num;
+    uint32_t sh_info;
+    bool have_section;
+    int state;
+    bool resume;
+    char *error;
+    target_phys_addr_t memory_offset;
+    write_core_dump_function f;
+    void (*cleanup)(void *opaque);
+    void *opaque;

dump.c new file +469 -0

+
+static int dump_cleanup(DumpState *s)
+{
+    int ret = 0;
+
+    memory_mapping_list_free(&s->list);
+    s->cleanup(s->opaque);
+    if (s->resume) {
+        vm_start();
+    }
+
+    return ret;
+}
+
+static void dump_error(DumpState *s, const char *reason)
+{
+    s->state = DUMP_STATE_ERROR;
+    s->error = g_strdup(reason);
+    dump_cleanup(s);
+}
+
+static int write_elf64_header(DumpState *s)
+{
+    Elf64_Ehdr elf_header;
+    int ret;
+    int endian = s->dump_info.d_endian;
+
+    memset(&elf_header, 0, sizeof(Elf64_Ehdr));
+    memcpy(&elf_header, ELFMAG, 4);
+    elf_header.e_ident[EI_CLASS] = ELFCLASS64;
+    elf_header.e_ident[EI_DATA] = s->dump_info.d_endian;
+    elf_header.e_ident[EI_VERSION] = EV_CURRENT;
+    elf_header.e_type = cpu_convert_to_target16(ET_CORE, endian);
+    elf_header.e_machine = cpu_convert_to_target16(s->dump_info.d_machine,
+                                                   endian);
+    elf_header.e_version = cpu_convert_to_target32(EV_CURRENT, endian);
+    elf_header.e_ehsize = cpu_convert_to_target16(sizeof(elf_header), endian);
+    elf_header.e_phoff = cpu_convert_to_target64(sizeof(Elf64_Ehdr), endian);
+    elf_header.e_phentsize = cpu_convert_to_target16(sizeof(Elf64_Phdr),
+                                                     endian);
+    elf_header.e_phnum = cpu_convert_to_target16(s->phdr_num, endian);
+    if (s->have_section) {
+        uint64_t shoff = sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr) * s->sh_info;
+
+        elf_header.e_shoff = cpu_convert_to_target64(shoff, endian);
+        elf_header.e_shentsize = cpu_convert_to_target16(sizeof(Elf64_Shdr),
+                                                         endian);
+        elf_header.e_shnum = cpu_convert_to_target16(1, endian);
+    }
+
+    ret = s->f(0, &elf_header, sizeof(elf_header), s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write elf header.\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int write_elf32_header(DumpState *s)
+{
+    Elf32_Ehdr elf_header;
+    int ret;
+    int endian = s->dump_info.d_endian;
+
+    memset(&elf_header, 0, sizeof(Elf32_Ehdr));
+    memcpy(&elf_header, ELFMAG, 4);
+    elf_header.e_ident[EI_CLASS] = ELFCLASS32;
+    elf_header.e_ident[EI_DATA] = endian;
+    elf_header.e_ident[EI_VERSION] = EV_CURRENT;
+    elf_header.e_type = cpu_convert_to_target16(ET_CORE, endian);
+    elf_header.e_machine = cpu_convert_to_target16(s->dump_info.d_machine,
+                                                   endian);
+    elf_header.e_version = cpu_convert_to_target32(EV_CURRENT, endian);
+    elf_header.e_ehsize = cpu_convert_to_target16(sizeof(elf_header), endian);
+    elf_header.e_phoff = cpu_convert_to_target32(sizeof(Elf32_Ehdr), endian);
+    elf_header.e_phentsize = cpu_convert_to_target16(sizeof(Elf32_Phdr),
+                                                     endian);
+    elf_header.e_phnum = cpu_convert_to_target16(s->phdr_num, endian);
+    if (s->have_section) {
+        uint32_t shoff = sizeof(Elf32_Ehdr) + sizeof(Elf32_Phdr) * s->sh_info;
+
+        elf_header.e_shoff = cpu_convert_to_target32(shoff, endian);
+        elf_header.e_shentsize = cpu_convert_to_target16(sizeof(Elf32_Shdr),
+                                                         endian);
+        elf_header.e_shnum = cpu_convert_to_target16(1, endian);
+    }
+
+    ret = s->f(0, &elf_header, sizeof(elf_header), s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write elf header.\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
+                            int phdr_index, target_phys_addr_t offset)
+{
+    Elf64_Phdr phdr;
+    off_t phdr_offset;
+    int ret;
+    int endian = s->dump_info.d_endian;
+
+    memset(&phdr, 0, sizeof(Elf64_Phdr));
+    phdr.p_type = cpu_convert_to_target32(PT_LOAD, endian);
+    phdr.p_offset = cpu_convert_to_target64(offset, endian);
+    phdr.p_paddr = cpu_convert_to_target64(memory_mapping->phys_addr, endian);
+    if (offset == -1) {
+        phdr.p_filesz = 0;
+    } else {
+        phdr.p_filesz = cpu_convert_to_target64(memory_mapping->length, endian);
+    }
+    phdr.p_memsz = cpu_convert_to_target64(memory_mapping->length, endian);
+    phdr.p_vaddr = cpu_convert_to_target64(memory_mapping->virt_addr, endian);
+
+    phdr_offset = sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr)*phdr_index;
+    ret = s->f(phdr_offset, &phdr, sizeof(Elf64_Phdr), s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write program header table.\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
+                            int phdr_index, target_phys_addr_t offset)
+{
+    Elf32_Phdr phdr;
+    off_t phdr_offset;
+    int ret;
+    int endian = s->dump_info.d_endian;
+
+    memset(&phdr, 0, sizeof(Elf32_Phdr));
+    phdr.p_type = cpu_convert_to_target32(PT_LOAD, endian);
+    phdr.p_offset = cpu_convert_to_target32(offset, endian);
+    phdr.p_paddr = cpu_convert_to_target32(memory_mapping->phys_addr, endian);
+    if (offset == -1) {
+        phdr.p_filesz = 0;
+    } else {
+        phdr.p_filesz = cpu_convert_to_target32(memory_mapping->length, endian);
+    }
+    phdr.p_memsz = cpu_convert_to_target32(memory_mapping->length, endian);
+    phdr.p_vaddr = cpu_convert_to_target32(memory_mapping->virt_addr, endian);
+
+    phdr_offset = sizeof(Elf32_Ehdr) + sizeof(Elf32_Phdr)*phdr_index;
+    ret = s->f(phdr_offset, &phdr, sizeof(Elf32_Phdr), s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write program header table.\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int write_elf64_notes(DumpState *s, int phdr_index,
+                             target_phys_addr_t *offset)
+{
+    CPUState *env;
+    int ret;
+    target_phys_addr_t begin = *offset;
+    Elf64_Phdr phdr;
+    off_t phdr_offset;
+    int id;
+    int endian = s->dump_info.d_endian;
+
+    for (env = first_cpu; env != NULL; env = env->next_cpu) {
+        id = gdb_id(env);
+        ret = cpu_write_elf64_note(s->f, env, id, offset, s->opaque);
+        if (ret < 0) {
+            dump_error(s, "dump: failed to write elf notes.\n");
+            return -1;
+        }
+    }
+
+    for (env = first_cpu; env != NULL; env = env->next_cpu) {
+        ret = cpu_write_elf64_qemunote(s->f, env, offset, s->opaque);
+        if (ret < 0) {
+            dump_error(s, "dump: failed to write CPU status.\n");
+            return -1;
+        }
+    }
+
+    memset(&phdr, 0, sizeof(Elf64_Phdr));
+    phdr.p_type = cpu_convert_to_target32(PT_NOTE, endian);
+    phdr.p_offset = cpu_convert_to_target64(begin, endian);
+    phdr.p_paddr = 0;
+    phdr.p_filesz = cpu_convert_to_target64(*offset - begin, endian);
+    phdr.p_memsz = cpu_convert_to_target64(*offset - begin, endian);
+    phdr.p_vaddr = 0;
+
+    phdr_offset = sizeof(Elf64_Ehdr);
+    ret = s->f(phdr_offset, &phdr, sizeof(Elf64_Phdr), s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write program header table.\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int write_elf32_notes(DumpState *s, int phdr_index,
+                             target_phys_addr_t *offset)
+{
+    CPUState *env;
+    int ret;
+    target_phys_addr_t begin = *offset;
+    Elf32_Phdr phdr;
+    off_t phdr_offset;
+    int id;
+    int endian = s->dump_info.d_endian;
+
+    for (env = first_cpu; env != NULL; env = env->next_cpu) {
+        id = gdb_id(env);
+        ret = cpu_write_elf32_note(s->f, env, id, offset, s->opaque);
+        if (ret < 0) {
+            dump_error(s, "dump: failed to write elf notes.\n");
+            return -1;
+        }
+    }
+
+    for (env = first_cpu; env != NULL; env = env->next_cpu) {
+        ret = cpu_write_elf32_qemunote(s->f, env, offset, s->opaque);
+        if (ret < 0) {
+            dump_error(s, "dump: failed to write CPU status.\n");
+            return -1;
+        }
+    }
+
+    memset(&phdr, 0, sizeof(Elf32_Phdr));
+    phdr.p_type = cpu_convert_to_target32(PT_NOTE, endian);
+    phdr.p_offset = cpu_convert_to_target32(begin, endian);
+    phdr.p_paddr = 0;
+    phdr.p_filesz = cpu_convert_to_target32(*offset - begin, endian);
+    phdr.p_memsz = cpu_convert_to_target32(*offset - begin, endian);
+    phdr.p_vaddr = 0;
+
+    phdr_offset = sizeof(Elf32_Ehdr);
+    ret = s->f(phdr_offset, &phdr, sizeof(Elf32_Phdr), s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write program header table.\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int write_elf_section(DumpState *s, target_phys_addr_t *offset, int type)
+{
+    Elf32_Shdr shdr32;
+    Elf64_Shdr shdr64;
+    int endian = s->dump_info.d_endian;
+    int shdr_size;
+    void *shdr;
+    int ret;
+
+    if (type == 0) {
+        shdr_size = sizeof(Elf32_Shdr);
+        memset(&shdr32, 0, shdr_size);
+        shdr32.sh_info = cpu_convert_to_target32(s->sh_info, endian);
+        shdr = &shdr32;
+    } else {
+        shdr_size = sizeof(Elf64_Shdr);
+        memset(&shdr64, 0, shdr_size);
+        shdr64.sh_info = cpu_convert_to_target32(s->sh_info, endian);
+        shdr = &shdr64;
+    }
+
+    ret = s->f(*offset, &shdr, shdr_size, s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write section header table.\n");
+        return -1;
+    }
+
+    *offset += shdr_size;
+    return 0;
+}
+
+static int write_data(DumpState *s, void *buf, int length,
+                      target_phys_addr_t *offset)
+{
+    int ret;
+
+    ret = s->f(*offset, buf, length, s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to save memory.\n");
+        return -1;
+    }
+
+    *offset += length;
+    return 0;
+}
+
+/* write the memroy to vmcore. 1 page per I/O. */
+static int write_memory(DumpState *s, RAMBlock *block,
+                        target_phys_addr_t *offset)
+{
+    int i, ret;
+
+    for (i = 0; i < block->length / TARGET_PAGE_SIZE; i++) {
+        ret = write_data(s, block->host + i * TARGET_PAGE_SIZE,
+                         TARGET_PAGE_SIZE, offset);
+        if (ret < 0) {
+            return -1;
+        }
+    }
+
+    if ((block->length % TARGET_PAGE_SIZE) != 0) {
+        ret = write_data(s, block->host + i * TARGET_PAGE_SIZE,
+                         block->length % TARGET_PAGE_SIZE, offset);
+        if (ret < 0) {
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+/* get the memory's offset in the vmcore */
+static target_phys_addr_t get_offset(target_phys_addr_t phys_addr,
+                                     target_phys_addr_t memory_offset)
+{
+    RAMBlock *block;
+    target_phys_addr_t offset = memory_offset;
+
+    QLIST_FOREACH(block, &ram_list.blocks, next) {
+        if (phys_addr >= block->offset &&
+            phys_addr < block->offset + block->length) {
+            return phys_addr - block->offset + offset;
+        }
+        offset += block->length;
+    }
+
+    return -1;
+}
+
+/* write elf header, PT_NOTE and elf note to vmcore. */
+static int dump_begin(DumpState *s)
+{
+    target_phys_addr_t offset;
+    int ret;
+
+    s->state = DUMP_STATE_ACTIVE;
+
+    /*
+     * the vmcore's format is:
+     *   --------------
+     *   |  elf header |
+     *   --------------
+     *   |  PT_NOTE    |
+     *   --------------
+     *   |  PT_LOAD    |
+     *   --------------
+     *   |  ......     |
+     *   --------------
+     *   |  PT_LOAD    |
+     *   --------------
+     *   |  sec_hdr    |
+     *   --------------
+     *   |  elf note   |
+     *   --------------
+     *   |  memory     |
+     *   --------------
+     *
+     * we only know where the memory is saved after we write elf note into
+     * vmcore.
+     */
+
+    /* write elf header to vmcore */
+    if (s->dump_info.d_class == ELFCLASS64) {
+        ret = write_elf64_header(s);
+    } else {
+        ret = write_elf32_header(s);
+    }
+    if (ret < 0) {
+        return -1;
+    }
+
+    /* write elf section and notes to vmcore */
+    if (s->dump_info.d_class == ELFCLASS64) {
+        if (s->have_section) {
+            offset = sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr)*s->sh_info;
+            if (write_elf_section(s, &offset, 1) < 0) {
+                return -1;
+            }
+        } else {
+            offset = sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr)*s->phdr_num;
+        }
+        ret = write_elf64_notes(s, 0, &offset);
+    } else {
+        if (s->have_section) {
+            offset = sizeof(Elf32_Ehdr) + sizeof(Elf32_Phdr)*s->sh_info;
+            if (write_elf_section(s, &offset, 0) < 0) {
+                return -1;
+            }
+        } else {
+            offset = sizeof(Elf32_Ehdr) + sizeof(Elf32_Phdr)*s->phdr_num;
+        }
+        ret = write_elf32_notes(s, 0, &offset);
+    }
+
+    if (ret < 0) {
+        return -1;
+    }
+
+    s->memory_offset = offset;
+    return 0;
+}
+
+/* write PT_LOAD to vmcore */
+static int dump_completed(DumpState *s)
+{
+    target_phys_addr_t offset;
+    MemoryMapping *memory_mapping;
+    int phdr_index = 1, ret;
+
+    QTAILQ_FOREACH(memory_mapping, &s->list.head, next) {
+        offset = get_offset(memory_mapping->phys_addr, s->memory_offset);
+        if (s->dump_info.d_class == ELFCLASS64) {
+            ret = write_elf64_load(s, memory_mapping, phdr_index++, offset);
+        } else {
+            ret = write_elf32_load(s, memory_mapping, phdr_index++, offset);
+        }
+        if (ret < 0) {
+            return -1;
+        }
+    }
+
+    s->state = DUMP_STATE_COMPLETED;
+    dump_cleanup(s);
+    return 0;
+}
+
+/* write all memory to vmcore */
+static int dump_iterate(DumpState *s)
+{
+    RAMBlock *block;
+    target_phys_addr_t offset = s->memory_offset;
+    int ret;
+
+    /* write all memory to vmcore */
+    QLIST_FOREACH(block, &ram_list.blocks, next) {
+        ret = write_memory(s, block, &offset);
+        if (ret < 0) {
+            return -1;
+        }
+    }
+
+    return dump_completed(s);
+}
+
+static int create_vmcore(DumpState *s)
+{
+    int ret;
+
+    ret = dump_begin(s);
+    if (ret < 0) {
+        return -1;
+    }
+
+    ret = dump_iterate(s);
+    if (ret < 0) {
+        return -1;
+    }
+
+    return 0;
+}

dump.c new file +14 -0

+    } else {
+        s->resume = false;
+    }
+    s->state = DUMP_STATE_SETUP;
+    if (s->error) {
+        g_free(s->error);
+        s->error = NULL;
+    }
+
+    /*
+     * get dump info: endian, class and architecture.
+     * If the target architecture is not supported, cpu_get_dump_info() will
+     * return -1.
+     *

dump.c new file +40 -0

+        return NULL;
+    }
+
+    /* get memory mapping */
+    memory_mapping_list_init(&s->list);
+    if (paging) {
+        qemu_get_guest_memory_mapping(&s->list);
+    } else {
+        qemu_get_guest_simple_memory_mapping(&s->list);
+    }
+
+    /*
+     * calculate phdr_num
+     *
+     * the type of phdr->num is uint16_t, so we should avoid overflow
+     */
+    s->phdr_num = 1; /* PT_NOTE */
+    if (s->list.num < (1 << 16) - 2) {
+        s->phdr_num += s->list.num;
+        s->have_section = false;
+    } else {
+        s->have_section = true;
+        s->phdr_num = PN_XNUM;
+
+        /* the type of shdr->sh_info is uint32_t, so we should avoid overflow */
+        if (s->list.num > (1ULL << 32) - 2) {
+            s->sh_info = 0xffffffff;
+        } else {
+            s->sh_info += s->list.num;
+        }
+    }
+
+    return s;
+}
+
+static int fd_write_vmcore(target_phys_addr_t offset, void *buf, size_t size,
+                           void *opaque)
+{
+    int fd = (int)(intptr_t)opaque;
+    int ret;

dump.c new file +14 -0

+
+    return 0;
+}
+
+static void fd_cleanup(void *opaque)
+{
+    int fd = (int)(intptr_t)opaque;
+
+    if (fd != -1) {
+        close(fd);
+    }
+}
+
+static DumpState *dump_init_fd(int fd, bool paging, Error **errp)

dump.c new file +20 -0

+        if (fd < 0) {
+            error_set(errp, QERR_OPEN_FILE_FAILED, p);
+            return;
+        }
+    }
+
+    if (fd == -1) {
+        error_set(errp, QERR_INVALID_PARAMETER, "file");
+        return;
+    }
+
+    s = dump_init_fd(fd, paging, errp);
+    if (!s) {
+        return;
+    }
+
+    if (create_vmcore(s) < 0) {
+        error_set(errp, QERR_IO_ERROR);
+    }
+}

elf.h +5 -0

index 2e05d34..6a10657 100644
@@ -1000,6 +1000,11 @@ typedef struct elf64_sym {
 
 #define EI_NIDENT	16
 
+/* Special value for e_phnum.  This indicates that the real number of
+   program headers is too large to fit into e_phnum.  Instead the real
+   value is in the field sh_info of section 0.  */
+#define PN_XNUM         0xffff
+
 typedef struct elf32_hdr{
   unsigned char	e_ident[EI_NIDENT];
   Elf32_Half	e_type;

hmp-commands.hx +21 -0

index 6980214..d4cf2e5 100644
@@ -880,6 +880,27 @@ server will ask the spice/vnc client to automatically reconnect using the
 new parameters (if specified) once the vm migration finished successfully.
 ETEXI
 
+#if defined(CONFIG_HAVE_CORE_DUMP)
+    {
+        .name       = "dump",
+        .args_type  = "paging:-p,file:s",
+        .params     = "[-p] file",
+        .help       = "dump to file",
+        .user_print = monitor_user_noop,
+        .mhandler.cmd = hmp_dump,
+    },
+
+
+STEXI
+@item dump [-p] @var{file}
+@findex dump
+Dump to @var{file}. The file can be processed with crash or gdb.
+    file: destination file(started with "file:") or destination file descriptor
+          (started with "fd:")
+  paging: do paging to get guest's memory mapping
+ETEXI
+#endif
+
     {
         .name       = "snapshot_blkdev",
         .args_type  = "reuse:-n,device:B,snapshot-file:s?,format:s?",

hmp.c +0 -0

index 290c43d..e13b793 100644
@@ -860,3 +860,13 @@ void hmp_block_job_cancel(Monitor *mon, const QDict *qdict)
 

hmp.c +2 -0

+    hmp_handle_error(mon, &errp);
+}

hmp.h +1 -0

index 5409464..b055e50 100644
@@ -59,5 +59,6 @@ void hmp_block_set_io_throttle(Monitor *mon, const QDict *qdict);
 void hmp_block_stream(Monitor *mon, const QDict *qdict);
 void hmp_block_job_set_speed(Monitor *mon, const QDict *qdict);
 void hmp_block_job_cancel(Monitor *mon, const QDict *qdict);
+void hmp_dump(Monitor *mon, const QDict *qdict);
 
 #endif

qapi-schema.json +0 -0

index 04fa84f..81b8c7c 100644

qapi-schema.json +6 -0

+#
+# Returns: nothing on success
+#
+# Since: 1.1
+##
+{ 'command': 'dump', 'data': { 'paging': 'bool', 'file': 'str' } }

qmp-commands.hx +34 -0

index dfe8a5b..9e39bd9 100644
@@ -586,6 +586,40 @@ Example:
 
 EQMP
 
+#if defined(CONFIG_HAVE_CORE_DUMP)
+    {
+        .name       = "dump",
+        .args_type  = "paging:-p,file:s",
+        .params     = "[-p] file",
+        .help       = "dump to file",
+        .user_print = monitor_user_noop,
+        .mhandler.cmd_new = qmp_marshal_input_dump,
+    },
+
+SQMP
+dump
+
+
+Dump to file. The file can be processed with crash or gdb.
+
+Arguments:
+
+- "paging": do paging to get guest's memory mapping (json-bool)
+- "file": destination file(started with "file:") or destination file descriptor
+          (started with "fd:") (json-string)
+
+Example:
+
+-> { "execute": "dump", "arguments": { "file": "fd:dump" } }
+<- { "return": {} }
+
+Notes:
+
+(1) All boolean arguments default to false
+
+EQMP
+#endif
+
     {
         .name       = "netdev_add",
         .args_type  = "netdev:O",

On Wed, 14 Mar 2012 10:11:35 +0800
Wen Congyang <[email protected]> wrote:

You just dropped a few asynchronous bits and resent this as a synchronous command, letting all the asynchronous infrastructure in. This is bad, as the command is more complex then it should be and doesn't make full use of the added infrastructure.

For example, does the synchronous version really uses DumpState? If it doesn't, let's just drop it and everything else which is not necessary.

*However*, note that while it's fine with me to have this as a synchronous command we need a few more ACKs (from libvirt and Anthony and/or Jan). So, I wouldn't go too far on making changes before we get those ACKs.

Can we start by posting a non-RFC because we start discussing committing this.

are sufficient that I'm okay with a synchronous-only version for qemu 1.1.

dump.c line 648

Quoted 4 lines

dump.c new file +4 -0

+    ret = write(fd, buf, size);
+    if (ret != size) {
+        return -1;
+    }  

I think you should use send_all() instead of plain write().

Quoted 126 lines · On Wed, 14 Mar 2012 10:11:35 +0800 Wen Congyang <[email protected]> wrote:

The command's usage:
dump [-p] file
file should be start with "file:"(the file's path) or "fd:"(the fd's name).

Note:
1. If you want to use gdb to analyse the core, please specify -p option.
2. This command doesn't support the fd that is is associated with a pipe, socket, or FIFO(lseek will fail with such fd).

Signed-off-by Wen Congyang <[email protected]>

---
 Makefile.target  |    2 +-
 dump.c           |  714 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 elf.h            |    5 +
 hmp-commands.hx  |   21 ++
 hmp.c            |   10 +
 hmp.h            |    1 +
 qapi-schema.json |   14 +
 qmp-commands.hx  |   34 +++
 8 files changed, 800 insertions(+), 1 deletions(-)
 create mode 100644 dump.c

Makefile.target +1 -1

index c81c4fa..287fbe7 100644
@@ -213,7 +213,7 @@ obj-$(CONFIG_NO_KVM) += kvm-stub.o
 obj-$(CONFIG_VGA) += vga.o
 obj-y += memory.o savevm.o
 obj-y += memory_mapping.o
-obj-$(CONFIG_HAVE_CORE_DUMP) += arch_dump.o
+obj-$(CONFIG_HAVE_CORE_DUMP) += arch_dump.o dump.o
 LIBS+=-lz
 
 obj-i386-$(CONFIG_KVM) += hyperv.o

dump.c new file +85 -0

new file mode 100644
index 0000000..42e1681
@@ -0,0 +1,714 @@
+/*
+ * QEMU dump
+ *
+ * Copyright Fujitsu, Corp. 2011
+ *
+ * Authors:
+ *     Wen Congyang <[email protected]>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu-common.h"
+#include <unistd.h>
+#include "elf.h"
+#include <sys/procfs.h>
+#include <glib.h>
+#include "cpu.h"
+#include "cpu-all.h"
+#include "targphys.h"
+#include "monitor.h"
+#include "kvm.h"
+#include "dump.h"
+#include "sysemu.h"
+#include "bswap.h"
+#include "memory_mapping.h"
+#include "error.h"
+#include "qmp-commands.h"
+#include "gdbstub.h"
+
+static inline uint16_t cpu_convert_to_target16(uint16_t val, int endian)
+{
+    if (endian == ELFDATA2LSB) {
+        val = cpu_to_le16(val);
+    } else {
+        val = cpu_to_be16(val);
+    }
+
+    return val;
+}
+
+static inline uint32_t cpu_convert_to_target32(uint32_t val, int endian)
+{
+    if (endian == ELFDATA2LSB) {
+        val = cpu_to_le32(val);
+    } else {
+        val = cpu_to_be32(val);
+    }
+
+    return val;
+}
+
+static inline uint64_t cpu_convert_to_target64(uint64_t val, int endian)
+{
+    if (endian == ELFDATA2LSB) {
+        val = cpu_to_le64(val);
+    } else {
+        val = cpu_to_be64(val);
+    }
+
+    return val;
+}
+
+enum {
+    DUMP_STATE_ERROR,
+    DUMP_STATE_SETUP,
+    DUMP_STATE_CANCELLED,
+    DUMP_STATE_ACTIVE,
+    DUMP_STATE_COMPLETED,
+};
+
+typedef struct DumpState {
+    ArchDumpInfo dump_info;
+    MemoryMappingList list;
+    uint16_t phdr_num;
+    uint32_t sh_info;
+    bool have_section;
+    int state;
+    bool resume;
+    char *error;
+    target_phys_addr_t memory_offset;
+    write_core_dump_function f;
+    void (*cleanup)(void *opaque);
+    void *opaque;

dump.c line 95

Quoted 10 lines

dump.c new file +10 -0

+} DumpState;
+
+static DumpState *dump_get_current(void)
+{
+    static DumpState current_dump = {
+        .state = DUMP_STATE_SETUP,
+    };
+
+    return &current_dump;
+}

You just dropped a few asynchronous bits and resent this as a synchronous command, letting all the asynchronous infrastructure in. This is bad, as the command is more complex then it should be and doesn't make full use of the added infrastructure.

For example, does the synchronous version really uses DumpState? If it doesn't, let's just drop it and everything else which is not necessary.

*However*, note that while it's fine with me to have this as a synchronous command we need a few more ACKs (from libvirt and Anthony and/or Jan). So, I wouldn't go too far on making changes before we get those ACKs.

Quoted 469 lines

dump.c new file +469 -0

+
+static int dump_cleanup(DumpState *s)
+{
+    int ret = 0;
+
+    memory_mapping_list_free(&s->list);
+    s->cleanup(s->opaque);
+    if (s->resume) {
+        vm_start();
+    }
+
+    return ret;
+}
+
+static void dump_error(DumpState *s, const char *reason)
+{
+    s->state = DUMP_STATE_ERROR;
+    s->error = g_strdup(reason);
+    dump_cleanup(s);
+}
+
+static int write_elf64_header(DumpState *s)
+{
+    Elf64_Ehdr elf_header;
+    int ret;
+    int endian = s->dump_info.d_endian;
+
+    memset(&elf_header, 0, sizeof(Elf64_Ehdr));
+    memcpy(&elf_header, ELFMAG, 4);
+    elf_header.e_ident[EI_CLASS] = ELFCLASS64;
+    elf_header.e_ident[EI_DATA] = s->dump_info.d_endian;
+    elf_header.e_ident[EI_VERSION] = EV_CURRENT;
+    elf_header.e_type = cpu_convert_to_target16(ET_CORE, endian);
+    elf_header.e_machine = cpu_convert_to_target16(s->dump_info.d_machine,
+                                                   endian);
+    elf_header.e_version = cpu_convert_to_target32(EV_CURRENT, endian);
+    elf_header.e_ehsize = cpu_convert_to_target16(sizeof(elf_header), endian);
+    elf_header.e_phoff = cpu_convert_to_target64(sizeof(Elf64_Ehdr), endian);
+    elf_header.e_phentsize = cpu_convert_to_target16(sizeof(Elf64_Phdr),
+                                                     endian);
+    elf_header.e_phnum = cpu_convert_to_target16(s->phdr_num, endian);
+    if (s->have_section) {
+        uint64_t shoff = sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr) * s->sh_info;
+
+        elf_header.e_shoff = cpu_convert_to_target64(shoff, endian);
+        elf_header.e_shentsize = cpu_convert_to_target16(sizeof(Elf64_Shdr),
+                                                         endian);
+        elf_header.e_shnum = cpu_convert_to_target16(1, endian);
+    }
+
+    ret = s->f(0, &elf_header, sizeof(elf_header), s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write elf header.\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int write_elf32_header(DumpState *s)
+{
+    Elf32_Ehdr elf_header;
+    int ret;
+    int endian = s->dump_info.d_endian;
+
+    memset(&elf_header, 0, sizeof(Elf32_Ehdr));
+    memcpy(&elf_header, ELFMAG, 4);
+    elf_header.e_ident[EI_CLASS] = ELFCLASS32;
+    elf_header.e_ident[EI_DATA] = endian;
+    elf_header.e_ident[EI_VERSION] = EV_CURRENT;
+    elf_header.e_type = cpu_convert_to_target16(ET_CORE, endian);
+    elf_header.e_machine = cpu_convert_to_target16(s->dump_info.d_machine,
+                                                   endian);
+    elf_header.e_version = cpu_convert_to_target32(EV_CURRENT, endian);
+    elf_header.e_ehsize = cpu_convert_to_target16(sizeof(elf_header), endian);
+    elf_header.e_phoff = cpu_convert_to_target32(sizeof(Elf32_Ehdr), endian);
+    elf_header.e_phentsize = cpu_convert_to_target16(sizeof(Elf32_Phdr),
+                                                     endian);
+    elf_header.e_phnum = cpu_convert_to_target16(s->phdr_num, endian);
+    if (s->have_section) {
+        uint32_t shoff = sizeof(Elf32_Ehdr) + sizeof(Elf32_Phdr) * s->sh_info;
+
+        elf_header.e_shoff = cpu_convert_to_target32(shoff, endian);
+        elf_header.e_shentsize = cpu_convert_to_target16(sizeof(Elf32_Shdr),
+                                                         endian);
+        elf_header.e_shnum = cpu_convert_to_target16(1, endian);
+    }
+
+    ret = s->f(0, &elf_header, sizeof(elf_header), s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write elf header.\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
+                            int phdr_index, target_phys_addr_t offset)
+{
+    Elf64_Phdr phdr;
+    off_t phdr_offset;
+    int ret;
+    int endian = s->dump_info.d_endian;
+
+    memset(&phdr, 0, sizeof(Elf64_Phdr));
+    phdr.p_type = cpu_convert_to_target32(PT_LOAD, endian);
+    phdr.p_offset = cpu_convert_to_target64(offset, endian);
+    phdr.p_paddr = cpu_convert_to_target64(memory_mapping->phys_addr, endian);
+    if (offset == -1) {
+        phdr.p_filesz = 0;
+    } else {
+        phdr.p_filesz = cpu_convert_to_target64(memory_mapping->length, endian);
+    }
+    phdr.p_memsz = cpu_convert_to_target64(memory_mapping->length, endian);
+    phdr.p_vaddr = cpu_convert_to_target64(memory_mapping->virt_addr, endian);
+
+    phdr_offset = sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr)*phdr_index;
+    ret = s->f(phdr_offset, &phdr, sizeof(Elf64_Phdr), s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write program header table.\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
+                            int phdr_index, target_phys_addr_t offset)
+{
+    Elf32_Phdr phdr;
+    off_t phdr_offset;
+    int ret;
+    int endian = s->dump_info.d_endian;
+
+    memset(&phdr, 0, sizeof(Elf32_Phdr));
+    phdr.p_type = cpu_convert_to_target32(PT_LOAD, endian);
+    phdr.p_offset = cpu_convert_to_target32(offset, endian);
+    phdr.p_paddr = cpu_convert_to_target32(memory_mapping->phys_addr, endian);
+    if (offset == -1) {
+        phdr.p_filesz = 0;
+    } else {
+        phdr.p_filesz = cpu_convert_to_target32(memory_mapping->length, endian);
+    }
+    phdr.p_memsz = cpu_convert_to_target32(memory_mapping->length, endian);
+    phdr.p_vaddr = cpu_convert_to_target32(memory_mapping->virt_addr, endian);
+
+    phdr_offset = sizeof(Elf32_Ehdr) + sizeof(Elf32_Phdr)*phdr_index;
+    ret = s->f(phdr_offset, &phdr, sizeof(Elf32_Phdr), s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write program header table.\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int write_elf64_notes(DumpState *s, int phdr_index,
+                             target_phys_addr_t *offset)
+{
+    CPUState *env;
+    int ret;
+    target_phys_addr_t begin = *offset;
+    Elf64_Phdr phdr;
+    off_t phdr_offset;
+    int id;
+    int endian = s->dump_info.d_endian;
+
+    for (env = first_cpu; env != NULL; env = env->next_cpu) {
+        id = gdb_id(env);
+        ret = cpu_write_elf64_note(s->f, env, id, offset, s->opaque);
+        if (ret < 0) {
+            dump_error(s, "dump: failed to write elf notes.\n");
+            return -1;
+        }
+    }
+
+    for (env = first_cpu; env != NULL; env = env->next_cpu) {
+        ret = cpu_write_elf64_qemunote(s->f, env, offset, s->opaque);
+        if (ret < 0) {
+            dump_error(s, "dump: failed to write CPU status.\n");
+            return -1;
+        }
+    }
+
+    memset(&phdr, 0, sizeof(Elf64_Phdr));
+    phdr.p_type = cpu_convert_to_target32(PT_NOTE, endian);
+    phdr.p_offset = cpu_convert_to_target64(begin, endian);
+    phdr.p_paddr = 0;
+    phdr.p_filesz = cpu_convert_to_target64(*offset - begin, endian);
+    phdr.p_memsz = cpu_convert_to_target64(*offset - begin, endian);
+    phdr.p_vaddr = 0;
+
+    phdr_offset = sizeof(Elf64_Ehdr);
+    ret = s->f(phdr_offset, &phdr, sizeof(Elf64_Phdr), s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write program header table.\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int write_elf32_notes(DumpState *s, int phdr_index,
+                             target_phys_addr_t *offset)
+{
+    CPUState *env;
+    int ret;
+    target_phys_addr_t begin = *offset;
+    Elf32_Phdr phdr;
+    off_t phdr_offset;
+    int id;
+    int endian = s->dump_info.d_endian;
+
+    for (env = first_cpu; env != NULL; env = env->next_cpu) {
+        id = gdb_id(env);
+        ret = cpu_write_elf32_note(s->f, env, id, offset, s->opaque);
+        if (ret < 0) {
+            dump_error(s, "dump: failed to write elf notes.\n");
+            return -1;
+        }
+    }
+
+    for (env = first_cpu; env != NULL; env = env->next_cpu) {
+        ret = cpu_write_elf32_qemunote(s->f, env, offset, s->opaque);
+        if (ret < 0) {
+            dump_error(s, "dump: failed to write CPU status.\n");
+            return -1;
+        }
+    }
+
+    memset(&phdr, 0, sizeof(Elf32_Phdr));
+    phdr.p_type = cpu_convert_to_target32(PT_NOTE, endian);
+    phdr.p_offset = cpu_convert_to_target32(begin, endian);
+    phdr.p_paddr = 0;
+    phdr.p_filesz = cpu_convert_to_target32(*offset - begin, endian);
+    phdr.p_memsz = cpu_convert_to_target32(*offset - begin, endian);
+    phdr.p_vaddr = 0;
+
+    phdr_offset = sizeof(Elf32_Ehdr);
+    ret = s->f(phdr_offset, &phdr, sizeof(Elf32_Phdr), s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write program header table.\n");
+        return -1;
+    }
+
+    return 0;
+}
+
+static int write_elf_section(DumpState *s, target_phys_addr_t *offset, int type)
+{
+    Elf32_Shdr shdr32;
+    Elf64_Shdr shdr64;
+    int endian = s->dump_info.d_endian;
+    int shdr_size;
+    void *shdr;
+    int ret;
+
+    if (type == 0) {
+        shdr_size = sizeof(Elf32_Shdr);
+        memset(&shdr32, 0, shdr_size);
+        shdr32.sh_info = cpu_convert_to_target32(s->sh_info, endian);
+        shdr = &shdr32;
+    } else {
+        shdr_size = sizeof(Elf64_Shdr);
+        memset(&shdr64, 0, shdr_size);
+        shdr64.sh_info = cpu_convert_to_target32(s->sh_info, endian);
+        shdr = &shdr64;
+    }
+
+    ret = s->f(*offset, &shdr, shdr_size, s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to write section header table.\n");
+        return -1;
+    }
+
+    *offset += shdr_size;
+    return 0;
+}
+
+static int write_data(DumpState *s, void *buf, int length,
+                      target_phys_addr_t *offset)
+{
+    int ret;
+
+    ret = s->f(*offset, buf, length, s->opaque);
+    if (ret < 0) {
+        dump_error(s, "dump: failed to save memory.\n");
+        return -1;
+    }
+
+    *offset += length;
+    return 0;
+}
+
+/* write the memroy to vmcore. 1 page per I/O. */
+static int write_memory(DumpState *s, RAMBlock *block,
+                        target_phys_addr_t *offset)
+{
+    int i, ret;
+
+    for (i = 0; i < block->length / TARGET_PAGE_SIZE; i++) {
+        ret = write_data(s, block->host + i * TARGET_PAGE_SIZE,
+                         TARGET_PAGE_SIZE, offset);
+        if (ret < 0) {
+            return -1;
+        }
+    }
+
+    if ((block->length % TARGET_PAGE_SIZE) != 0) {
+        ret = write_data(s, block->host + i * TARGET_PAGE_SIZE,
+                         block->length % TARGET_PAGE_SIZE, offset);
+        if (ret < 0) {
+            return -1;
+        }
+    }
+
+    return 0;
+}
+
+/* get the memory's offset in the vmcore */
+static target_phys_addr_t get_offset(target_phys_addr_t phys_addr,
+                                     target_phys_addr_t memory_offset)
+{
+    RAMBlock *block;
+    target_phys_addr_t offset = memory_offset;
+
+    QLIST_FOREACH(block, &ram_list.blocks, next) {
+        if (phys_addr >= block->offset &&
+            phys_addr < block->offset + block->length) {
+            return phys_addr - block->offset + offset;
+        }
+        offset += block->length;
+    }
+
+    return -1;
+}
+
+/* write elf header, PT_NOTE and elf note to vmcore. */
+static int dump_begin(DumpState *s)
+{
+    target_phys_addr_t offset;
+    int ret;
+
+    s->state = DUMP_STATE_ACTIVE;
+
+    /*
+     * the vmcore's format is:
+     *   --------------
+     *   |  elf header |
+     *   --------------
+     *   |  PT_NOTE    |
+     *   --------------
+     *   |  PT_LOAD    |
+     *   --------------
+     *   |  ......     |
+     *   --------------
+     *   |  PT_LOAD    |
+     *   --------------
+     *   |  sec_hdr    |
+     *   --------------
+     *   |  elf note   |
+     *   --------------
+     *   |  memory     |
+     *   --------------
+     *
+     * we only know where the memory is saved after we write elf note into
+     * vmcore.
+     */
+
+    /* write elf header to vmcore */
+    if (s->dump_info.d_class == ELFCLASS64) {
+        ret = write_elf64_header(s);
+    } else {
+        ret = write_elf32_header(s);
+    }
+    if (ret < 0) {
+        return -1;
+    }
+
+    /* write elf section and notes to vmcore */
+    if (s->dump_info.d_class == ELFCLASS64) {
+        if (s->have_section) {
+            offset = sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr)*s->sh_info;
+            if (write_elf_section(s, &offset, 1) < 0) {
+                return -1;
+            }
+        } else {
+            offset = sizeof(Elf64_Ehdr) + sizeof(Elf64_Phdr)*s->phdr_num;
+        }
+        ret = write_elf64_notes(s, 0, &offset);
+    } else {
+        if (s->have_section) {
+            offset = sizeof(Elf32_Ehdr) + sizeof(Elf32_Phdr)*s->sh_info;
+            if (write_elf_section(s, &offset, 0) < 0) {
+                return -1;
+            }
+        } else {
+            offset = sizeof(Elf32_Ehdr) + sizeof(Elf32_Phdr)*s->phdr_num;
+        }
+        ret = write_elf32_notes(s, 0, &offset);
+    }
+
+    if (ret < 0) {
+        return -1;
+    }
+
+    s->memory_offset = offset;
+    return 0;
+}
+
+/* write PT_LOAD to vmcore */
+static int dump_completed(DumpState *s)
+{
+    target_phys_addr_t offset;
+    MemoryMapping *memory_mapping;
+    int phdr_index = 1, ret;
+
+    QTAILQ_FOREACH(memory_mapping, &s->list.head, next) {
+        offset = get_offset(memory_mapping->phys_addr, s->memory_offset);
+        if (s->dump_info.d_class == ELFCLASS64) {
+            ret = write_elf64_load(s, memory_mapping, phdr_index++, offset);
+        } else {
+            ret = write_elf32_load(s, memory_mapping, phdr_index++, offset);
+        }
+        if (ret < 0) {
+            return -1;
+        }
+    }
+
+    s->state = DUMP_STATE_COMPLETED;
+    dump_cleanup(s);
+    return 0;
+}
+
+/* write all memory to vmcore */
+static int dump_iterate(DumpState *s)
+{
+    RAMBlock *block;
+    target_phys_addr_t offset = s->memory_offset;
+    int ret;
+
+    /* write all memory to vmcore */
+    QLIST_FOREACH(block, &ram_list.blocks, next) {
+        ret = write_memory(s, block, &offset);
+        if (ret < 0) {
+            return -1;
+        }
+    }
+
+    return dump_completed(s);
+}
+
+static int create_vmcore(DumpState *s)
+{
+    int ret;
+
+    ret = dump_begin(s);
+    if (ret < 0) {
+        return -1;
+    }
+
+    ret = dump_iterate(s);
+    if (ret < 0) {
+        return -1;
+    }
+
+    return 0;
+}

dump.c line 574

Quoted 10 lines

dump.c new file +10 -0

+
+static DumpState *dump_init(bool paging, Error **errp)
+{
+    CPUState *env;
+    DumpState *s = dump_get_current();
+    int ret;
+
+    if (runstate_is_running()) {
+        vm_stop(RUN_STATE_PAUSED);
+        s->resume = true;

Hmm, you actually stop the VM. Seems obvious now, but when people talked about making this asynchronous I automatically assumed that what we didn't want was having the global mutex held for too much time (ie. while this command was running).

The only disadvantage of having this as a synchronous command is that libvirt won't be able to cancel it and won't be able to run other commands in parallel. Doesn't seem that serious to me.

Btw, RUN_STATE_PAUSED is not a good one. Doesn't matter that much, as this is unlikely to be visible, but you should use RUN_STATE_SAVE_VM or RUN_STATE_DEBUG.

Quoted 14 lines

dump.c new file +14 -0

+    } else {
+        s->resume = false;
+    }
+    s->state = DUMP_STATE_SETUP;
+    if (s->error) {
+        g_free(s->error);
+        s->error = NULL;
+    }
+
+    /*
+     * get dump info: endian, class and architecture.
+     * If the target architecture is not supported, cpu_get_dump_info() will
+     * return -1.
+     *

dump.c line 598

Quoted 10 lines

dump.c new file +10 -0

+     * if we use kvm, we should synchronize the register before we get dump
+     * info.
+     */
+    for (env = first_cpu; env != NULL; env = env->next_cpu) {
+        cpu_synchronize_state(env);
+    }
+
+    ret = cpu_get_dump_info(&s->dump_info);
+    if (ret < 0) {
+        error_set(errp, QERR_UNSUPPORTED);

This will let the VM paused.

Quoted 40 lines

dump.c new file +40 -0

+        return NULL;
+    }
+
+    /* get memory mapping */
+    memory_mapping_list_init(&s->list);
+    if (paging) {
+        qemu_get_guest_memory_mapping(&s->list);
+    } else {
+        qemu_get_guest_simple_memory_mapping(&s->list);
+    }
+
+    /*
+     * calculate phdr_num
+     *
+     * the type of phdr->num is uint16_t, so we should avoid overflow
+     */
+    s->phdr_num = 1; /* PT_NOTE */
+    if (s->list.num < (1 << 16) - 2) {
+        s->phdr_num += s->list.num;
+        s->have_section = false;
+    } else {
+        s->have_section = true;
+        s->phdr_num = PN_XNUM;
+
+        /* the type of shdr->sh_info is uint32_t, so we should avoid overflow */
+        if (s->list.num > (1ULL << 32) - 2) {
+            s->sh_info = 0xffffffff;
+        } else {
+            s->sh_info += s->list.num;
+        }
+    }
+
+    return s;
+}
+
+static int fd_write_vmcore(target_phys_addr_t offset, void *buf, size_t size,
+                           void *opaque)
+{
+    int fd = (int)(intptr_t)opaque;
+    int ret;

dump.c line 648

Quoted 10 lines

dump.c new file +10 -0

+
+    ret = lseek(fd, offset, SEEK_SET);
+    if (ret < 0) {
+        return -1;
+    }
+
+    ret = write(fd, buf, size);
+    if (ret != size) {
+        return -1;
+    }

I think you should use send_all() instead of plain write().

Quoted 14 lines

dump.c new file +14 -0

+
+    return 0;
+}
+
+static void fd_cleanup(void *opaque)
+{
+    int fd = (int)(intptr_t)opaque;
+
+    if (fd != -1) {
+        close(fd);
+    }
+}
+
+static DumpState *dump_init_fd(int fd, bool paging, Error **errp)

dump.c line 672

Quoted 10 lines

dump.c new file +10 -0

+{
+    DumpState *s = dump_init(paging, errp);
+
+    if (s == NULL) {
+        return NULL;
+    }
+
+    s->f = fd_write_vmcore;
+    s->cleanup = fd_cleanup;
+    s->opaque = (void *)(intptr_t)fd;

Do we really need all these indirections?

dump.c line 685

Quoted 13 lines

dump.c new file +13 -0

+
+    return s;
+}
+
+void qmp_dump(bool paging, const char *file, Error **errp)
+{
+    const char *p;
+    int fd = -1;
+    DumpState *s;
+
+#if !defined(WIN32)
+    if (strstart(file, "fd:", &p)) {
+        fd = qemu_get_fd(p);

qemu_get_fd() won't be merged, you should use monitor_get_fd(cur_mon, p);

dump.c line 694

Quoted 9 lines

dump.c new file +9 -0

+        if (fd == -1) {
+            error_set(errp, QERR_FD_NOT_FOUND, p);
+            return;
+        }
+    }
+#endif
+
+    if  (strstart(file, "file:", &p)) {
+        fd = open(p, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR);

This is minor, but I'd use qemu_open() here.

Quoted 74 lines

dump.c new file +20 -0

+        if (fd < 0) {
+            error_set(errp, QERR_OPEN_FILE_FAILED, p);
+            return;
+        }
+    }
+
+    if (fd == -1) {
+        error_set(errp, QERR_INVALID_PARAMETER, "file");
+        return;
+    }
+
+    s = dump_init_fd(fd, paging, errp);
+    if (!s) {
+        return;
+    }
+
+    if (create_vmcore(s) < 0) {
+        error_set(errp, QERR_IO_ERROR);
+    }
+}

elf.h +5 -0

index 2e05d34..6a10657 100644
@@ -1000,6 +1000,11 @@ typedef struct elf64_sym {
 
 #define EI_NIDENT	16
 
+/* Special value for e_phnum.  This indicates that the real number of
+   program headers is too large to fit into e_phnum.  Instead the real
+   value is in the field sh_info of section 0.  */
+#define PN_XNUM         0xffff
+
 typedef struct elf32_hdr{
   unsigned char	e_ident[EI_NIDENT];
   Elf32_Half	e_type;

hmp-commands.hx +21 -0

index 6980214..d4cf2e5 100644
@@ -880,6 +880,27 @@ server will ask the spice/vnc client to automatically reconnect using the
 new parameters (if specified) once the vm migration finished successfully.
 ETEXI
 
+#if defined(CONFIG_HAVE_CORE_DUMP)
+    {
+        .name       = "dump",
+        .args_type  = "paging:-p,file:s",
+        .params     = "[-p] file",
+        .help       = "dump to file",
+        .user_print = monitor_user_noop,
+        .mhandler.cmd = hmp_dump,
+    },
+
+
+STEXI
+@item dump [-p] @var{file}
+@findex dump
+Dump to @var{file}. The file can be processed with crash or gdb.
+    file: destination file(started with "file:") or destination file descriptor
+          (started with "fd:")
+  paging: do paging to get guest's memory mapping
+ETEXI
+#endif
+
     {
         .name       = "snapshot_blkdev",
         .args_type  = "reuse:-n,device:B,snapshot-file:s?,format:s?",

hmp.c +0 -0

index 290c43d..e13b793 100644
@@ -860,3 +860,13 @@ void hmp_block_job_cancel(Monitor *mon, const QDict *qdict)
 

hmp.c void hmp_block_job_cancel(Monitor *mon, const QDict *qdict) · line 870

Quoted 10 lines

hmp.c +8 -0

     hmp_handle_error(mon, &error);
 }
+
+void hmp_dump(Monitor *mon, const QDict *qdict)
+{
+    Error *errp = NULL;
+    int paging = qdict_get_try_bool(qdict, "paging", 0);
+    const char *file = qdict_get_str(qdict, "file");
+
+    qmp_dump(!!paging, file, &errp);

Why the double negation on 'paging'?

Quoted 18 lines

hmp.c +2 -0

+    hmp_handle_error(mon, &errp);
+}

hmp.h +1 -0

index 5409464..b055e50 100644
@@ -59,5 +59,6 @@ void hmp_block_set_io_throttle(Monitor *mon, const QDict *qdict);
 void hmp_block_stream(Monitor *mon, const QDict *qdict);
 void hmp_block_job_set_speed(Monitor *mon, const QDict *qdict);
 void hmp_block_job_cancel(Monitor *mon, const QDict *qdict);
+void hmp_dump(Monitor *mon, const QDict *qdict);
 
 #endif

qapi-schema.json +0 -0

index 04fa84f..81b8c7c 100644

qapi-schema.json line 1668

Quoted 6 lines

qapi-schema.json +3 -0

@@ -1663,3 +1663,17 @@
 { 'command': 'qom-list-types',
   'data': { '*implements': 'str', '*abstract': 'bool' },
   'returns': [ 'ObjectTypeInfo' ] }
+
+##
+# @dump

'dump' is too generic, please call this dump-guest-memory-vmcore or something more descriptive.

qapi-schema.json line 1673

Quoted 5 lines

qapi-schema.json +5 -0

+#
+# Dump guest's memory to vmcore.
+#
+# @paging: if true, do paging to get guest's memory mapping
+# @file: the filename or file descriptor of the vmcore.

'file' is not a good name because it can also dump to an fd, maybe 'protocol'?

Quoted 51 lines

qapi-schema.json +6 -0

+#
+# Returns: nothing on success
+#
+# Since: 1.1
+##
+{ 'command': 'dump', 'data': { 'paging': 'bool', 'file': 'str' } }

qmp-commands.hx +34 -0

index dfe8a5b..9e39bd9 100644
@@ -586,6 +586,40 @@ Example:
 
 EQMP
 
+#if defined(CONFIG_HAVE_CORE_DUMP)
+    {
+        .name       = "dump",
+        .args_type  = "paging:-p,file:s",
+        .params     = "[-p] file",
+        .help       = "dump to file",
+        .user_print = monitor_user_noop,
+        .mhandler.cmd_new = qmp_marshal_input_dump,
+    },
+
+SQMP
+dump
+
+
+Dump to file. The file can be processed with crash or gdb.
+
+Arguments:
+
+- "paging": do paging to get guest's memory mapping (json-bool)
+- "file": destination file(started with "file:") or destination file descriptor
+          (started with "fd:") (json-string)
+
+Example:
+
+-> { "execute": "dump", "arguments": { "file": "fd:dump" } }
+<- { "return": {} }
+
+Notes:
+
+(1) All boolean arguments default to false
+
+EQMP
+#endif
+
     {
         .name       = "netdev_add",
         .args_type  = "netdev:O",

Quoted 10 lines · On Wed, 14 Mar 2012 10:11:35 +0800 Wen Congyang <[email protected]> wrote:

The command's usage:
dump [-p] file
file should be start with "file:"(the file's path) or "fd:"(the fd's name).

Note:
1. If you want to use gdb to analyse the core, please specify -p option.
2. This command doesn't support the fd that is is associated with a pipe, socket, or FIFO(lseek will fail with such fd).

Signed-off-by Wen Congyang <[email protected]>

Quoted 7 lines

dump.c new file +7 -0

+
+static DumpState *dump_init(bool paging, Error **errp)
+{
+    CPUState *env;
+    DumpState *s = dump_get_current();
+    int ret;
+

dump.c line 574

Quoted 3 lines

dump.c new file +3 -0

+    if (runstate_is_running()) {
+        vm_stop(RUN_STATE_PAUSED);
+        s->resume = true;

Hmm, you actually stop the VM. Seems obvious now, but when people talked about making this asynchronous I automatically assumed that what we didn't want was having the global mutex held for too much time (ie. while this command was running).

The only disadvantage of having this as a synchronous command is that libvirt won't be able to cancel it and won't be able to run other commands in parallel. Doesn't seem that serious to me.

Btw, RUN_STATE_PAUSED is not a good one. Doesn't matter that much, as this is unlikely to be visible, but you should use RUN_STATE_SAVE_VM or RUN_STATE_DEBUG.

Quoted 2 lines

+ } else {

dump.c line 598

Quoted 3 lines

dump.c new file +3 -0

+    ret = cpu_get_dump_info(&s->dump_info);
+    if (ret < 0) {
+        error_set(errp, QERR_UNSUPPORTED);

This will let the VM paused.

Quoted 2 lines

+ return NULL;

dump.c line 648

Quoted 4 lines

dump.c new file +4 -0

+    ret = write(fd, buf, size);
+    if (ret != size) {
+        return -1;
+    }

I think you should use send_all() instead of plain write().

Quoted 4 lines

dump.c new file +3 -0

+
+    return 0;
+}

dump.c line 672

Quoted 4 lines

dump.c new file +4 -0

+
+    s->f = fd_write_vmcore;
+    s->cleanup = fd_cleanup;
+    s->opaque = (void *)(intptr_t)fd;

Do we really need all these indirections?

Is writing to file descriptor generic enough? What if we want to dump via QMP, letting the receiver side decide about where to write it?

Quoted 4 lines

dump.c new file +3 -0

+
+    return s;
+}

dump.c line 685

Quoted 10 lines

dump.c new file +10 -0

+
+void qmp_dump(bool paging, const char *file, Error **errp)
+{
+    const char *p;
+    int fd = -1;
+    DumpState *s;
+
+#if !defined(WIN32)
+    if (strstart(file, "fd:", &p)) {
+        fd = qemu_get_fd(p);

qemu_get_fd() won't be merged, you should use monitor_get_fd(cur_mon, p);

dump.c line 694

Quoted 10 lines

dump.c new file +9 -0

+        if (fd == -1) {
+            error_set(errp, QERR_FD_NOT_FOUND, p);
+            return;
+        }
+    }
+#endif
+
+    if  (strstart(file, "file:", &p)) {
+        fd = open(p, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR);

This is minor, but I'd use qemu_open() here.

Quoted 2 lines

+ if (fd < 0) {

hmp.c void hmp_block_job_cancel(Monitor *mon, const QDict *qdict) · line 870

Quoted 2 lines

hmp.c +2 -0

+
+    qmp_dump(!!paging, file, &errp);

Why the double negation on 'paging'?

Quoted 2 lines

+ hmp_handle_error(mon, &errp);

qapi-schema.json line 1668

Quoted 3 lines

qapi-schema.json +3 -0

+
+##
+# @dump

'dump' is too generic, please call this dump-guest-memory-vmcore or something more descriptive.

qapi-schema.json line 1673

Quoted 6 lines

qapi-schema.json +5 -0

+#
+# Dump guest's memory to vmcore.
+#
+# @paging: if true, do paging to get guest's memory mapping
+# @file: the filename or file descriptor of the vmcore.

'file' is not a good name because it can also dump to an fd, maybe 'protocol'?

At 03/15/2012 01:18 AM, Luiz Capitulino Wrote:

Quoted 13 lines

Quoted 10 lines · On Wed, 14 Mar 2012 10:11:35 +0800 Wen Congyang <[email protected]> wrote:

The command's usage:
dump [-p] file
file should be start with "file:"(the file's path) or "fd:"(the fd's name).

Note:
1. If you want to use gdb to analyse the core, please specify -p option.
2. This command doesn't support the fd that is is associated with a pipe, socket, or FIFO(lseek will fail with such fd).

Signed-off-by Wen Congyang <[email protected]>

<cut>

Quoted 7 lines

Quoted 7 lines

dump.c new file +7 -0

+
+static DumpState *dump_init(bool paging, Error **errp)
+{
+    CPUState *env;
+    DumpState *s = dump_get_current();
+    int ret;
+

Quoted 8 lines

dump.c line 574

Quoted 3 lines

dump.c new file +3 -0

+    if (runstate_is_running()) {
+        vm_stop(RUN_STATE_PAUSED);
+        s->resume = true;

Hmm, you actually stop the VM. Seems obvious now, but when people talked about making this asynchronous I automatically assumed that what we didn't want was having the global mutex held for too much time (ie. while this command was running).

Yes, In the earlier version, I add a vm state change handler. If the vm is resumed by the user, qemu dump will be auto cancelled.

Quoted 8 lines

The only disadvantage of having this as a synchronous command is that libvirt won't be able to cancel it and won't be able to run other commands in parallel. Doesn't seem that serious to me.

Btw, RUN_STATE_PAUSED is not a good one. Doesn't matter that much, as this is unlikely to be visible, but you should use RUN_STATE_SAVE_VM or RUN_STATE_DEBUG.

OK, I will use RUN_STATE_SAVE_VM.

Quoted 2 lines

Quoted 2 lines

+ } else {

<cut>

Quoted 5 lines

dump.c line 598

Quoted 3 lines

dump.c new file +3 -0

+    ret = cpu_get_dump_info(&s->dump_info);
+    if (ret < 0) {
+        error_set(errp, QERR_UNSUPPORTED);

This will let the VM paused.

Hmm, in which function the vm is paused?

Quoted 3 lines

Quoted 3 lines

+ return NULL;

<cut>

Quoted 6 lines

dump.c line 648

Quoted 4 lines

dump.c new file +4 -0

+    ret = write(fd, buf, size);
+    if (ret != size) {
+        return -1;
+    }

I think you should use send_all() instead of plain write().

OK, I will use qemu_write_full() you mentioned in anohter mail.

Quoted 4 lines

Quoted 4 lines

dump.c new file +3 -0

+
+    return 0;
+}

<cut>

Quoted 6 lines

dump.c line 672

Quoted 4 lines

dump.c new file +4 -0

+
+    s->f = fd_write_vmcore;
+    s->cleanup = fd_cleanup;
+    s->opaque = (void *)(intptr_t)fd;

Do we really need all these indirections?

At 02/15/2012 01:31 AM, Jan Kiszka Wrote:

Quoted 2 lines

Is writing to file descriptor generic enough? What if we want to dump via QMP, letting the receiver side decide about where to write it?

So I use these indirections.

Quoted 16 lines

Quoted 4 lines

dump.c new file +3 -0

+
+    return s;
+}

dump.c line 685

Quoted 10 lines

dump.c new file +10 -0

+
+void qmp_dump(bool paging, const char *file, Error **errp)
+{
+    const char *p;
+    int fd = -1;
+    DumpState *s;
+
+#if !defined(WIN32)
+    if (strstart(file, "fd:", &p)) {
+        fd = qemu_get_fd(p);

qemu_get_fd() won't be merged, you should use monitor_get_fd(cur_mon, p);

OK

Quoted 12 lines

dump.c line 694

Quoted 10 lines

dump.c new file +9 -0

+        if (fd == -1) {
+            error_set(errp, QERR_FD_NOT_FOUND, p);
+            return;
+        }
+    }
+#endif
+
+    if  (strstart(file, "file:", &p)) {
+        fd = open(p, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR);

This is minor, but I'd use qemu_open() here.

OK

Quoted 2 lines

Quoted 2 lines

+ if (fd < 0) {

<cut>

Quoted 4 lines

hmp.c void hmp_block_job_cancel(Monitor *mon, const QDict *qdict) · line 870

Quoted 2 lines

hmp.c +2 -0

+
+    qmp_dump(!!paging, file, &errp);

Why the double negation on 'paging'?

OK, I will remove double negation.

Quoted 2 lines

Quoted 2 lines

+ hmp_handle_error(mon, &errp);

<cut>

Quoted 6 lines

qapi-schema.json line 1668

Quoted 3 lines

qapi-schema.json +3 -0

+
+##
+# @dump

'dump' is too generic, please call this dump-guest-memory-vmcore or something more descriptive.

Hmm, dump-guest-memory-vmcore is too long. What about dump-guest-memory or dump-memory?

Quoted 8 lines

qapi-schema.json line 1673

Quoted 6 lines

qapi-schema.json +5 -0

+#
+# Dump guest's memory to vmcore.
+#
+# @paging: if true, do paging to get guest's memory mapping
+# @file: the filename or file descriptor of the vmcore.

'file' is not a good name because it can also dump to an fd, maybe 'protocol'?

OK

Thanks for you reviewing
Wen Congyang

Quoted 2 lines

'dump' is too generic, please call this dump-guest-memory-vmcore or something more descriptive.

Hmm, dump-guest-memory-vmcore is too long. What about dump-guest-memory or dump-memory?

+/*
+ * QEMU dump
+ *
+ * Copyright Fujitsu, Corp. 2011
+ *

+ s->sh_info = 0xffffffff;

From: Wen Congyang <[email protected]>
Subject: [RFC][PATCH 11/14 v9] introduce a new monitor command 'dump' to dump guest's memory
Date: Wed, 14 Mar 2012 10:11:35 +0800

Quoted 5 lines

+/*
+ * QEMU dump
+ *
+ * Copyright Fujitsu, Corp. 2011
+ *

Now 2012.

dump.c line 613

Quoted 5 lines

dump.c new file +4 -0

+    /*
+     * calculate phdr_num
+     *
+     * the type of phdr->num is uint16_t, so we should avoid overflow

e_phnum is correct.

dump.c line 616

Quoted 4 lines

dump.c new file +3 -0

+     */
+    s->phdr_num = 1; /* PT_NOTE */
+    if (s->list.num < (1 << 16) - 2) {

s->list.num < UINT16_MAX is better.

dump.c line 624

Quoted 8 lines

dump.c new file +8 -0

+        s->phdr_num += s->list.num;
+        s->have_section = false;
+    } else {
+        s->have_section = true;
+        s->phdr_num = PN_XNUM;
+
+        /* the type of shdr->sh_info is uint32_t, so we should avoid overflow */
+        if (s->list.num > (1ULL << 32) - 2) {

s->list.num < UINT32_MAX is better.

Quoted 1 line

+ s->sh_info = 0xffffffff;

UINT32_MAX is better. Is it rough around here?

dump.c line 629

Quoted 4 lines

dump.c new file +4 -0

+        } else {
+            s->sh_info += s->list.num;
+        }
+    }

Now orders of processings in positive and negative cases for e_phnum and sh_info are different. It's better to make them sorted in the same order.

  if (phdr_num not overflow?) {
    not overflow case;
  } else {
    overflow case;
    if (sh_info not overflow?) {
      not overflow case;
    } else {
      overflow case;
    }
  }

is better.

Thanks.
HATAYAMA, Daisuke

Add API to allow the user to cancel the current dumping. It can only work after async dumping is supported.

Signed-off-by Wen Congyang <[email protected]>

---
 dump.c           |   12 ++++++++++++
 hmp-commands.hx  |   14 ++++++++++++++
 hmp.c            |    5 +++++
 hmp.h            |    1 +
 qapi-schema.json |   13 +++++++++++++
 qmp-commands.hx  |   21 +++++++++++++++++++++
 6 files changed, 66 insertions(+), 0 deletions(-)

dump.c +12 -0

index 42e1681..dab0c84 100644
@@ -712,3 +712,15 @@ void qmp_dump(bool paging, const char *file, Error **errp)
         error_set(errp, QERR_IO_ERROR);
     }
 }
+
+void qmp_dump_cancel(Error **errp)
+{
+    DumpState *s = dump_get_current();
+
+    if (s->state != DUMP_STATE_ACTIVE) {
+        return;
+    }
+
+    s->state = DUMP_STATE_CANCELLED;
+    dump_cleanup(s);
+}

hmp-commands.hx +14 -0

index d4cf2e5..313f876 100644
@@ -902,6 +902,20 @@ ETEXI
 #endif
 
     {
+        .name       = "dump_cancel",
+        .args_type  = "",
+        .params     = "",
+        .help       = "cancel the current VM dumping",
+        .mhandler.cmd = hmp_dump_cancel,
+    },
+
+STEXI
+@item dump_cancel
+@findex dump_cancel
+Cancel the current VM dumping.
+ETEXI
+
+    {
         .name       = "snapshot_blkdev",
         .args_type  = "reuse:-n,device:B,snapshot-file:s?,format:s?",
         .params     = "[-n] device [new-image-file] [format]",

hmp.c +5 -0

index e13b793..31e85d3 100644
@@ -870,3 +870,8 @@ void hmp_dump(Monitor *mon, const QDict *qdict)
     qmp_dump(!!paging, file, &errp);
     hmp_handle_error(mon, &errp);
 }
+
+void hmp_dump_cancel(Monitor *mon, const QDict *qdict)
+{
+    qmp_dump_cancel(NULL);
+}

hmp.h +1 -0

index b055e50..75c6c1d 100644
@@ -60,5 +60,6 @@ void hmp_block_stream(Monitor *mon, const QDict *qdict);
 void hmp_block_job_set_speed(Monitor *mon, const QDict *qdict);
 void hmp_block_job_cancel(Monitor *mon, const QDict *qdict);
 void hmp_dump(Monitor *mon, const QDict *qdict);
+void hmp_dump_cancel(Monitor *mon, const QDict *qdict);
 
 #endif

qapi-schema.json +13 -0

index 81b8c7c..1fdfee8 100644
@@ -1677,3 +1677,16 @@
 # Since: 1.1
 ##
 { 'command': 'dump', 'data': { 'paging': 'bool', 'file': 'str' } }
+
+##
+# @dump_cancel
+#
+# Cancel the current executing dumping process.
+#
+# Returns: nothing on success
+#
+# Notes: This command succeeds even if there is no dumping process running.
+#
+# Since: 1.1
+##
+{ 'command': 'dump_cancel' }

qmp-commands.hx +21 -0

index 9e39bd9..cbe5b91 100644
@@ -621,6 +621,27 @@ EQMP
 #endif
 
     {
+        .name       = "dump_cancel",
+        .args_type  = "",
+        .mhandler.cmd_new = qmp_marshal_input_dump_cancel,
+    },
+
+SQMP
+dump_cancel
+
+
+Cancel the current dumping.
+
+Arguments: None.
+
+Example:
+
+-> { "execute": "dump_cancel" }
+<- { "return": {} }
+
+EQMP
+
+    {
         .name       = "netdev_add",
         .args_type  = "netdev:O",
         .params     = "[user|tap|socket],id=str[,prop=value][,...]",