Archipelago » qemu

/*

 * QEMU dump

 *

 * Copyright Fujitsu, Corp. 2011, 2012

 *

 * Authors:

 *     Wen Congyang <wency@cn.fujitsu.com>

 *

 * This work is licensed under the terms of the GNU GPL, version 2 or later.

 * See the COPYING file in the top-level directory.

 *

 */

#include "qemu-common.h"

#include "elf.h"

#include "cpu.h"

#include "cpu-all.h"

#include "targphys.h"

#include "monitor.h"

#include "kvm.h"

#include "dump.h"

#include "sysemu.h"

#include "memory_mapping.h"

#include "error.h"

#include "qmp-commands.h"

#include "gdbstub.h"

static 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 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 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;

}

typedef struct DumpState {

    ArchDumpInfo dump_info;

    MemoryMappingList list;

    uint16_t phdr_num;

    uint32_t sh_info;

    bool have_section;

    bool resume;

    size_t note_size;

    target_phys_addr_t memory_offset;

    int fd;

    RAMBlock *block;

    ram_addr_t start;

    bool has_filter;

    int64_t begin;

    int64_t length;

    Error **errp;

} DumpState;

static int dump_cleanup(DumpState *s)

{

    int ret = 0;

    memory_mapping_list_free(&s->list);

    if (s->fd != -1) {

        close(s->fd);

    }

    if (s->resume) {

        vm_start();

    }

    return ret;

}

static void dump_error(DumpState *s, const char *reason)

{

    dump_cleanup(s);

}

static int fd_write_vmcore(void *buf, size_t size, void *opaque)

{

    DumpState *s = opaque;

    int fd = s->fd;

    size_t writen_size;

    /* 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 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, SELFMAG);

    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 = fd_write_vmcore(&elf_header, sizeof(elf_header), s);

    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, SELFMAG);

    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 = fd_write_vmcore(&elf_header, sizeof(elf_header), s);

    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;

    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) {

        /* When the memory is not stored into vmcore, offset will be -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);

    ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);

    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;

    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) {

        /* When the memory is not stored into vmcore, offset will be -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);

    ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);

    if (ret < 0) {

        dump_error(s, "dump: failed to write program header table.\n");

        return -1;

    }

    return 0;

}

static int write_elf64_note(DumpState *s)

{

    Elf64_Phdr phdr;

    int endian = s->dump_info.d_endian;

    target_phys_addr_t begin = s->memory_offset - s->note_size;

    int ret;

    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(s->note_size, endian);

    phdr.p_memsz = cpu_convert_to_target64(s->note_size, endian);

    phdr.p_vaddr = 0;

    ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);

    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)

{

    CPUArchState *env;

    int ret;

    int id;

    for (env = first_cpu; env != NULL; env = env->next_cpu) {

        id = cpu_index(env);

        ret = cpu_write_elf64_note(fd_write_vmcore, env, id, s);

        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(fd_write_vmcore, env, s);

        if (ret < 0) {

            dump_error(s, "dump: failed to write CPU status.\n");

            return -1;

        }

    }

    return 0;

}

static int write_elf32_note(DumpState *s)

{

    target_phys_addr_t begin = s->memory_offset - s->note_size;

    Elf32_Phdr phdr;

    int endian = s->dump_info.d_endian;

    int ret;

    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(s->note_size, endian);

    phdr.p_memsz = cpu_convert_to_target32(s->note_size, endian);

    phdr.p_vaddr = 0;

    ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);

    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)

{

    CPUArchState *env;

    int ret;

    int id;

    for (env = first_cpu; env != NULL; env = env->next_cpu) {

        id = cpu_index(env);

        ret = cpu_write_elf32_note(fd_write_vmcore, env, id, s);

        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(fd_write_vmcore, env, s);

        if (ret < 0) {

            dump_error(s, "dump: failed to write CPU status.\n");

            return -1;

        }

    }

    return 0;

}

static int write_elf_section(DumpState *s, 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 = fd_write_vmcore(&shdr, shdr_size, s);

    if (ret < 0) {

        dump_error(s, "dump: failed to write section header table.\n");

        return -1;

    }

    return 0;

}

static int write_data(DumpState *s, void *buf, int length)

{

    int ret;

    ret = fd_write_vmcore(buf, length, s);

    if (ret < 0) {

        dump_error(s, "dump: failed to save memory.\n");

        return -1;

    }

    return 0;

}

/* write the memroy to vmcore. 1 page per I/O. */

static int write_memory(DumpState *s, RAMBlock *block, ram_addr_t start,

                        int64_t size)

{

    int64_t i;

    int ret;

    for (i = 0; i < size / TARGET_PAGE_SIZE; i++) {

        ret = write_data(s, block->host + start + i * TARGET_PAGE_SIZE,

                         TARGET_PAGE_SIZE);

        if (ret < 0) {

            return ret;

        }

    }

    if ((size % TARGET_PAGE_SIZE) != 0) {

        ret = write_data(s, block->host + start + i * TARGET_PAGE_SIZE,

                         size % TARGET_PAGE_SIZE);

        if (ret < 0) {

            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;

}

static int write_elf_loads(DumpState *s)

{

    target_phys_addr_t offset;

    MemoryMapping *memory_mapping;

    uint32_t phdr_index = 1;

    int ret;

    uint32_t max_index;

    if (s->have_section) {

        max_index = s->sh_info;

    } else {

        max_index = s->phdr_num;

    }

    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;

        }

        if (phdr_index >= max_index) {

            break;

        }

    }

    return 0;

}

/* write elf header, PT_NOTE and elf note to vmcore. */

static int dump_begin(DumpState *s)

{

    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;

    }

    if (s->dump_info.d_class == ELFCLASS64) {

        /* write PT_NOTE to vmcore */

        if (write_elf64_note(s) < 0) {

            return -1;

        }

        /* write all PT_LOAD to vmcore */

        if (write_elf_loads(s) < 0) {

            return -1;

        }

        /* write section to vmcore */

        if (s->have_section) {

            if (write_elf_section(s, 1) < 0) {

                return -1;

            }

        }

        /* write notes to vmcore */

        if (write_elf64_notes(s) < 0) {

            return -1;

        }

    } else {

        /* write PT_NOTE to vmcore */

        if (write_elf32_note(s) < 0) {

            return -1;

        }

        /* write all PT_LOAD to vmcore */

        if (write_elf_loads(s) < 0) {

            return -1;

        }

        /* write section to vmcore */

        if (s->have_section) {

            if (write_elf_section(s, 0) < 0) {

                return -1;

            }

        }

        /* write notes to vmcore */

        if (write_elf32_notes(s) < 0) {

            return -1;

        }

    }

    return 0;

}

/* write PT_LOAD to vmcore */

static int dump_completed(DumpState *s)

{

    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;

    int64_t size;

    int ret;

    while (1) {

        block = s->block;

        size = block->length;

        if (s->has_filter) {

            size -= s->start;

            if (s->begin + s->length < block->offset + block->length) {

                size -= block->offset + block->length - (s->begin + s->length);

            }

        }

        ret = write_memory(s, block, s->start, 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 int dump_init(DumpState *s, int fd, bool paging, bool has_filter,

                     int64_t begin, int64_t length, Error **errp)

{

    CPUArchState *env;

    int nr_cpus;

    int ret;

    if (runstate_is_running()) {

        vm_stop(RUN_STATE_SAVE_VM);

        s->resume = true;

    } else {

        s->resume = false;

    }

    s->errp = errp;

    s->fd = fd;

    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.

     */

    nr_cpus = 0;

    for (env = first_cpu; env != NULL; env = env->next_cpu) {

        cpu_synchronize_state(env);

        nr_cpus++;

    }

    ret = cpu_get_dump_info(&s->dump_info);

    if (ret < 0) {

        error_set(errp, QERR_UNSUPPORTED);

        goto cleanup;

    }

    s->note_size = cpu_get_note_size(s->dump_info.d_class,

                                     s->dump_info.d_machine, nr_cpus);

    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;

        }

    }

    if (s->dump_info.d_class == ELFCLASS64) {

        if (s->have_section) {

            s->memory_offset = sizeof(Elf64_Ehdr) +

                               sizeof(Elf64_Phdr) * s->sh_info +

                               sizeof(Elf64_Shdr) + s->note_size;

        } else {

            s->memory_offset = sizeof(Elf64_Ehdr) +

                               sizeof(Elf64_Phdr) * s->phdr_num + s->note_size;

        }

    } else {

        if (s->have_section) {

            s->memory_offset = sizeof(Elf32_Ehdr) +

                               sizeof(Elf32_Phdr) * s->sh_info +

                               sizeof(Elf32_Shdr) + s->note_size;

        } else {

            s->memory_offset = sizeof(Elf32_Ehdr) +

                               sizeof(Elf32_Phdr) * s->phdr_num + s->note_size;

        }

    }

    return 0;

cleanup:

    if (s->resume) {

        vm_start();

    }

    return -1;

}

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;

    int ret;

    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, "protocol");

        return;

    }

    s = g_malloc(sizeof(DumpState));

    ret = dump_init(s, fd, paging, has_begin, begin, length, errp);

    if (ret < 0) {

        g_free(s);

        return;

    }

    if (create_vmcore(s) < 0 && !error_is_set(s->errp)) {

        error_set(errp, QERR_IO_ERROR);

    }

    g_free(s);

}