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Re: [Qemu-devel] [PATCH 11/11 v10] introduce a new monitor command 'dump
|
From: |
Luiz Capitulino |
|
Subject: |
Re: [Qemu-devel] [PATCH 11/11 v10] introduce a new monitor command 'dump-guest-memory' to dump guest's memory |
|
Date: |
Fri, 23 Mar 2012 14:19:08 -0300 |
On Tue, 20 Mar 2012 11:57:43 +0800
Wen Congyang <address@hidden> wrote:
> The command's usage:
> dump [-p] protocol [begin] [length]
> The supported protocol can be file or fd:
> 1. file: the protocol starts with "file:", and the following string is
> the file's path.
> 2. fd: the protocol starts with "fd:", and the following string is the
> fd's name.
>
> Note:
> 1. If you want to use gdb to process the core, please specify -p option.
> The reason why the -p option is not default is: guest machine in a
> catastrophic state can have corrupted memory, which we cannot trust.
> 2. This command doesn't support the fd that is is associated with a pipe,
> socket, or FIFO(lseek will fail with such fd).
> 3. If you don't want to dump all guest's memory, please specify the start
> physical address and the length.
All the explanation above (except the HMP command-line) pertains to the
qapi-schema.json file.
>
> Signed-off-by: Wen Congyang <address@hidden>
> ---
> Makefile.target | 2 +-
> dump.c | 841
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> elf.h | 5 +
> hmp-commands.hx | 28 ++
> hmp.c | 22 ++
> hmp.h | 1 +
> memory_mapping.c | 27 ++
> memory_mapping.h | 3 +
> qapi-schema.json | 18 ++
> qmp-commands.hx | 38 +++
> 10 files changed, 984 insertions(+), 1 deletions(-)
> create mode 100644 dump.c
>
> diff --git a/Makefile.target b/Makefile.target
> index c3aa5d7..0e179c9 100644
> --- a/Makefile.target
> +++ b/Makefile.target
> @@ -219,7 +219,7 @@ 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
> diff --git a/dump.c b/dump.c
> new file mode 100644
> index 0000000..917bccc
> --- /dev/null
> +++ b/dump.c
> @@ -0,0 +1,841 @@
> +/*
> + * QEMU dump
> + *
> + * Copyright Fujitsu, Corp. 2011, 2012
> + *
> + * Authors:
> + * Wen Congyang <address@hidden>
> + *
> + * 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;
> +}
Nitpick: I personally, wouldn't make these functions inline.
> +
> +typedef struct DumpState {
> + ArchDumpInfo dump_info;
> + MemoryMappingList list;
> + uint16_t phdr_num;
> + uint32_t sh_info;
> + bool have_section;
> + bool resume;
> + target_phys_addr_t memory_offset;
> + write_core_dump_function f;
> + void (*cleanup)(void *opaque);
> + void *opaque;
> +
> + RAMBlock *block;
> + ram_addr_t start;
> + bool has_filter;
> + int64_t begin;
> + int64_t length;
> +} DumpState;
> +
> +static DumpState *dump_get_current(void)
> +{
> + static DumpState current_dump;
> +
> + return ¤t_dump;
> +}
You can drop this function if you allocate DumpState in the stack in
qmp_dump_guest_memory().
> +
> +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)
> +{
> + 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)
> +{
> + CPUArchState *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)
> +{
> + CPUArchState *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, ram_addr_t start,
> + target_phys_addr_t *offset, int64_t *size)
> +{
> + int i, ret;
> + int64_t writen_size = 0;
> +
> + *size = block->length - start;
> + for (i = 0; i < *size / TARGET_PAGE_SIZE; i++) {
> + ret = write_data(s, block->host + start + i * TARGET_PAGE_SIZE,
> + TARGET_PAGE_SIZE, offset);
> + if (ret < 0) {
> + *size = writen_size;
> + return ret;
> + }
> +
> + writen_size += TARGET_PAGE_SIZE;
> + }
> +
> + if ((*size % TARGET_PAGE_SIZE) != 0) {
> + ret = write_data(s, block->host + start + i * TARGET_PAGE_SIZE,
> + *size % TARGET_PAGE_SIZE, offset);
> + if (ret < 0) {
> + *size = writen_size;
> + return ret;
> + }
> + }
> +
> + return 0;
> +}
> +
> +/* get the memory's offset in the vmcore */
> +static target_phys_addr_t get_offset(target_phys_addr_t phys_addr,
> + DumpState *s)
> +{
> + RAMBlock *block;
> + target_phys_addr_t offset = s->memory_offset;
> + int64_t size_in_block, start;
> +
> + if (s->has_filter) {
> + if (phys_addr < s->begin || phys_addr >= s->begin + s->length) {
> + return -1;
> + }
> + }
> +
> + QLIST_FOREACH(block, &ram_list.blocks, next) {
> + if (s->has_filter) {
> + if (block->offset >= s->begin + s->length ||
> + block->offset + block->length <= s->begin) {
> + /* This block is out of the range */
> + continue;
> + }
> +
> + if (s->begin <= block->offset) {
> + start = block->offset;
> + } else {
> + start = s->begin;
> + }
> +
> + size_in_block = block->length - (start - block->offset);
> + if (s->begin + s->length < block->offset + block->length) {
> + size_in_block -= block->offset + block->length -
> + (s->begin + s->length);
> + }
> + } else {
> + start = block->offset;
> + size_in_block = block->length;
> + }
> +
> + if (phys_addr >= start && phys_addr < start + size_in_block) {
> + return phys_addr - start + offset;
> + }
> +
> + offset += size_in_block;
> + }
> +
> + 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;
> +
> + /*
> + * 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);
> + 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;
> + }
> + }
> +
> + dump_cleanup(s);
> + return 0;
> +}
> +
> +static int get_next_block(DumpState *s, RAMBlock *block)
> +{
> + while (1) {
> + block = QLIST_NEXT(block, next);
> + if (!block) {
> + /* no more block */
> + return 1;
> + }
> +
> + s->start = 0;
> + s->block = block;
> + if (s->has_filter) {
> + if (block->offset >= s->begin + s->length ||
> + block->offset + block->length <= s->begin) {
> + /* This block is out of the range */
> + continue;
> + }
> +
> + if (s->begin > block->offset) {
> + s->start = s->begin - block->offset;
> + }
> + }
> +
> + return 0;
> + }
> +}
> +
> +/* write all memory to vmcore */
> +static int dump_iterate(DumpState *s)
> +{
> + RAMBlock *block;
> + target_phys_addr_t offset = s->memory_offset;
> + int64_t size;
> + int ret;
> +
> + while(1) {
> + block = s->block;
> + ret = write_memory(s, block, s->start, &offset, &size);
> + if (ret == -1) {
> + return ret;
> + }
> +
> + ret = get_next_block(s, block);
> + if (ret == 1) {
> + dump_completed(s);
> + return 0;
> + }
> + }
> +}
> +
> +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;
> +}
> +
> +static ram_addr_t get_start_block(DumpState *s)
> +{
> + RAMBlock *block;
> +
> + if (!s->has_filter) {
> + s->block = QLIST_FIRST(&ram_list.blocks);
> + return 0;
> + }
> +
> + QLIST_FOREACH(block, &ram_list.blocks, next) {
> + if (block->offset >= s->begin + s->length ||
> + block->offset + block->length <= s->begin) {
> + /* This block is out of the range */
> + continue;
> + }
> +
> + s->block = block;
> + if (s->begin > block->offset ) {
> + s->start = s->begin - block->offset;
> + } else {
> + s->start = 0;
> + }
> + return s->start;
> + }
> +
> + return -1;
> +}
> +
> +static DumpState *dump_init(bool paging, bool has_filter, int64_t begin,
> + int64_t length, Error **errp)
> +{
> + CPUArchState *env;
> + DumpState *s = dump_get_current();
As I said above, you could drop dump_get_current() and pass 's' as a parameter.
> + int ret;
> +
> + if (runstate_is_running()) {
> + vm_stop(RUN_STATE_SAVE_VM);
> + s->resume = true;
> + } else {
> + s->resume = false;
> + }
> +
> + s->has_filter = has_filter;
> + s->begin = begin;
> + s->length = length;
> + s->start = get_start_block(s);
> + if (s->start == -1) {
> + error_set(errp, QERR_INVALID_PARAMETER, "begin");
> + goto cleanup;
> + }
> +
> + /*
> + * get dump info: endian, class and architecture.
> + * If the target architecture is not supported, cpu_get_dump_info() will
> + * return -1.
> + *
> + * 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);
> + goto cleanup;
> + }
> +
> + /* 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);
> + }
> +
> + if (s->has_filter) {
> + memory_mapping_filter(&s->list, s->begin, s->length);
> + }
> +
> + /*
> + * calculate phdr_num
> + *
> + * the type of ehdr->e_phnum is uint16_t, so we should avoid overflow
> + */
> + s->phdr_num = 1; /* PT_NOTE */
> + if (s->list.num < UINT16_MAX - 2) {
> + s->phdr_num += s->list.num;
> + s->have_section = false;
> + } else {
> + s->have_section = true;
> + s->phdr_num = PN_XNUM;
> + s->sh_info = 1; /* PT_NOTE */
> +
> + /* the type of shdr->sh_info is uint32_t, so we should avoid
> overflow */
> + if (s->list.num <= UINT32_MAX -1) {
> + s->sh_info += s->list.num;
> + } else {
> + s->sh_info = UINT32_MAX;
> + }
> + }
> +
> + return s;
> +
> +cleanup:
> + if (s->resume) {
> + vm_start();
> + }
> +
> + return NULL;
> +}
> +
> +static int fd_write_vmcore(target_phys_addr_t offset, void *buf, size_t size,
> + void *opaque)
> +{
> + int fd = (int)(intptr_t)opaque;
> + off_t ret;
> + size_t writen_size;
> +
> + while(1) {
> + ret = lseek(fd, offset, SEEK_SET);
> + if (ret < 0) {
> + if (errno != EINTR && errno != EAGAIN) {
According to the man page, lseek() doesn't return EINTR nor EAGAIN.
Also, it would be nice to check for ESPIPE and return the proper QMP by
using error_set(). The error doesn't exist yet, maybe it could be called
PipeOrSocketFD (look at qerror.[ch] for more examples).
> + return -1;
> + }
> + continue;
> + }
> + break;
> + }
> +
> + /* The fd may be passed from user, and it can be non-blocked */
> + while(size) {
> + writen_size = qemu_write_full(fd, buf, size);
> + if (writen_size != size && errno != EAGAIN) {
> + return -1;
> + }
> +
> + buf += writen_size;
> + size -= writen_size;
> + }
> +
> + 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, bool has_filter,
> + int64_t begin, int64_t length, Error **errp)
> +{
> + DumpState *s = dump_init(paging, has_filter, begin, length, errp);
> +
> + if (s == NULL) {
> + return NULL;
> + }
> +
> + s->f = fd_write_vmcore;
> + s->cleanup = fd_cleanup;
> + s->opaque = (void *)(intptr_t)fd;
> +
> + return s;
> +}
> +
> +void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
> + int64_t begin, bool has_length, int64_t length,
> + Error **errp)
> +{
> + const char *p;
> + int fd = -1;
> + DumpState *s;
> +
> + if (has_begin && !has_length) {
> + error_set(errp, QERR_MISSING_PARAMETER, "length");
> + return;
> + }
> + if (!has_begin && has_length) {
> + error_set(errp, QERR_MISSING_PARAMETER, "begin");
> + return;
> + }
> +
> +#if !defined(WIN32)
> + if (strstart(file, "fd:", &p)) {
> + fd = monitor_get_fd(cur_mon, p);
> + if (fd == -1) {
> + error_set(errp, QERR_FD_NOT_FOUND, p);
> + return;
> + }
> + }
> +#endif
> +
> + if (strstart(file, "file:", &p)) {
> + fd = qemu_open(p, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, S_IRUSR);
> + if (fd < 0) {
> + error_set(errp, QERR_OPEN_FILE_FAILED, p);
> + return;
> + }
> + }
> +
> + if (fd == -1) {
> + error_set(errp, QERR_INVALID_PARAMETER, "file");
> + return;
> + }
s/file/parameter
> +
> + s = dump_init_fd(fd, paging, has_begin, begin, length, errp);
> + if (!s) {
> + return;
> + }
> +
> + if (create_vmcore(s) < 0) {
> + error_set(errp, QERR_IO_ERROR);
> + }
> +}
> diff --git a/elf.h b/elf.h
> index 2e05d34..6a10657 100644
> --- a/elf.h
> +++ b/elf.h
> @@ -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;
> diff --git a/hmp-commands.hx b/hmp-commands.hx
> index bd35a3e..d270fd1 100644
> --- a/hmp-commands.hx
> +++ b/hmp-commands.hx
> @@ -879,6 +879,34 @@ 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-guest-memory",
> + .args_type = "paging:-p,protocol:s,begin:i?,length:i?",
> + .params = "[-p] protocol [begin] [length]",
> + .help = "dump guest memory to file"
> + "\n\t\t\t begin(optional): the starting physical
> address"
> + "\n\t\t\t length(optional): the memory size, in bytes",
> + .user_print = monitor_user_noop,
> + .mhandler.cmd = hmp_dump_guest_memory,
> + },
> +
> +
> +STEXI
> address@hidden dump-guest-memory [-p] @var{protocol} @var{begin} @var{length}
> address@hidden dump-guest-memory
> +Dump guest memory to @var{protocol}. The file can be processed with crash or
> +gdb.
> + protocol: destination file(started with "file:") or destination file
> + descriptor (started with "fd:")
> + paging: do paging to get guest's memory mapping
> + begin: the starting physical address. It's optional, and should be
> + specified with length together.
> + length: the memory size, in bytes. It's optional, and should be specified
> + with begin together.
> +ETEXI
> +#endif
> +
> {
> .name = "snapshot_blkdev",
> .args_type = "reuse:-n,device:B,snapshot-file:s?,format:s?",
> diff --git a/hmp.c b/hmp.c
> index 9cf2d13..75ec9a9 100644
> --- a/hmp.c
> +++ b/hmp.c
> @@ -934,3 +934,25 @@ void hmp_migrate(Monitor *mon, const QDict *qdict)
> qemu_mod_timer(status->timer, qemu_get_clock_ms(rt_clock));
> }
> }
> +
> +void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict)
> +{
> + Error *errp = NULL;
> + int paging = qdict_get_try_bool(qdict, "paging", 0);
> + const char *file = qdict_get_str(qdict, "protocol");
> + bool has_begin = qdict_haskey(qdict, "begin");
> + bool has_length = qdict_haskey(qdict, "length");
> + int64_t begin = 0;
> + int64_t length = 0;
> +
> + if (has_begin) {
> + begin = qdict_get_int(qdict, "begin");
> + }
> + if (has_length) {
> + length = qdict_get_int(qdict, "length");
> + }
> +
> + qmp_dump_guest_memory(paging, file, has_begin, begin, has_length, length,
> + &errp);
> + hmp_handle_error(mon, &errp);
> +}
> diff --git a/hmp.h b/hmp.h
> index 8807853..36d69c6 100644
> --- a/hmp.h
> +++ b/hmp.h
> @@ -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_migrate(Monitor *mon, const QDict *qdict);
> +void hmp_dump_guest_memory(Monitor *mon, const QDict *qdict);
>
> #endif
> diff --git a/memory_mapping.c b/memory_mapping.c
> index 9a2ffe6..ff52c9d 100644
> --- a/memory_mapping.c
> +++ b/memory_mapping.c
> @@ -207,3 +207,30 @@ void
> qemu_get_guest_simple_memory_mapping(MemoryMappingList *list)
> create_new_memory_mapping(list, block->offset, 0, block->length);
> }
> }
> +
> +void memory_mapping_filter(MemoryMappingList *list, int64_t begin,
> + int64_t length)
> +{
> + MemoryMapping *cur, *next;
> +
> + QTAILQ_FOREACH_SAFE(cur, &list->head, next, next) {
> + if (cur->phys_addr >= begin + length ||
> + cur->phys_addr + cur->length <= begin) {
> + QTAILQ_REMOVE(&list->head, cur, next);
> + list->num--;
> + continue;
> + }
> +
> + if (cur->phys_addr < begin) {
> + cur->length -= begin - cur->phys_addr;
> + if (cur->virt_addr) {
> + cur->virt_addr += begin - cur->phys_addr;
> + }
> + cur->phys_addr = begin;
> + }
> +
> + if (cur->phys_addr + cur->length > begin + length) {
> + cur->length -= cur->phys_addr + cur->length - begin - length;
> + }
> + }
> +}
> diff --git a/memory_mapping.h b/memory_mapping.h
> index a583e44..b795678 100644
> --- a/memory_mapping.h
> +++ b/memory_mapping.h
> @@ -62,4 +62,7 @@ static inline int
> qemu_get_guest_memory_mapping(MemoryMappingList *list)
> /* get guest's memory mapping without do paging(virtual address is 0). */
> void qemu_get_guest_simple_memory_mapping(MemoryMappingList *list);
>
> +void memory_mapping_filter(MemoryMappingList *list, int64_t begin,
> + int64_t length);
> +
> #endif
> diff --git a/qapi-schema.json b/qapi-schema.json
> index 0d11d6e..b0d885f 100644
> --- a/qapi-schema.json
> +++ b/qapi-schema.json
> @@ -1701,3 +1701,21 @@
> # Since: 1.1
> ##
> { 'command': 'xen-save-devices-state', 'data': {'filename': 'str'} }
> +
> +##
> +# @dump-guest-memory
> +#
> +# Dump guest's memory to vmcore.
> +#
> +# @paging: if true, do paging to get guest's memory mapping
> +# @protocol: the filename or file descriptor of the vmcore.
> +# @begin: #optional if specified, the starting physical address.
> +# @length: #optional if specified, the memory size, in bytes.
> +#
> +# Returns: nothing on success
> +#
> +# Since: 1.1
> +##
> +{ 'command': 'dump-guest-memory',
> + 'data': { 'paging': 'bool', 'protocol': 'str', '*begin': 'int',
> + '*length': 'int' } }
> diff --git a/qmp-commands.hx b/qmp-commands.hx
> index c626ba8..ca4484b 100644
> --- a/qmp-commands.hx
> +++ b/qmp-commands.hx
> @@ -606,6 +606,44 @@ Example:
>
> EQMP
>
> +#if defined(CONFIG_HAVE_CORE_DUMP)
> + {
> + .name = "dump-guest-memory",
> + .args_type = "paging:-p,protocol:s,begin:i?,end:i?",
Please, use b instead of -p.
> + .params = "[-p] protocol [begin] [length]",
> + .help = "dump guest memory to file",
> + .user_print = monitor_user_noop,
> + .mhandler.cmd_new = qmp_marshal_input_dump_guest_memory,
> + },
> +
> +SQMP
> +dump
> +
> +
> +Dump guest memory to file. The file can be processed with crash or gdb.
> +
> +Arguments:
> +
> +- "paging": do paging to get guest's memory mapping (json-bool)
> +- "protocol": destination file(started with "file:") or destination file
> + descriptor (started with "fd:") (json-string)
> +- "begin": the starting physical address. It's optional, and should be
> specified
> + with length together (json-int)
> +- "length": the memory size, in bytes. It's optional, and should be specified
> + with begin together (json-int)
> +
> +Example:
> +
> +-> { "execute": "dump-guest-memory", "arguments": { "protocol": "fd:dump" } }
> +<- { "return": {} }
> +
> +Notes:
> +
> +(1) All boolean arguments default to false
> +
> +EQMP
> +#endif
> +
> {
> .name = "netdev_add",
> .args_type = "netdev:O",