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qemu/dump/dump.c
Yao Xingtao 1aef44805d dump: make range overlap check more readable 
use ranges_overlap() instead of open-coding the overlap check to improve
the readability of the code.

Signed-off-by: Yao Xingtao <yaoxt.fnst@fujitsu.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-ID: <20240722040742.11513-13-yaoxt.fnst@fujitsu.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
2024-07-23 20:30:36 +02:00

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/*
* 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/osdep.h"
#include "qemu/cutils.h"
#include "elf.h"
#include "qemu/bswap.h"
#include "exec/target_page.h"
#include "monitor/monitor.h"
#include "sysemu/dump.h"
#include "sysemu/runstate.h"
#include "sysemu/cpus.h"
#include "qapi/error.h"
#include "qapi/qapi-commands-dump.h"
#include "qapi/qapi-events-dump.h"
#include "qapi/qmp/qerror.h"
#include "qemu/error-report.h"
#include "qemu/main-loop.h"
#include "hw/misc/vmcoreinfo.h"
#include "migration/blocker.h"
#include "hw/core/cpu.h"
#include "win_dump.h"
#include "qemu/range.h"
#include <zlib.h>
#ifdef CONFIG_LZO
#include <lzo/lzo1x.h>
#endif
#ifdef CONFIG_SNAPPY
#include <snappy-c.h>
#endif
#ifndef ELF_MACHINE_UNAME
#define ELF_MACHINE_UNAME "Unknown"
#endif
#define MAX_GUEST_NOTE_SIZE (1 << 20) /* 1MB should be enough */
static Error *dump_migration_blocker;
#define ELF_NOTE_SIZE(hdr_size, name_size, desc_size) \
((DIV_ROUND_UP((hdr_size), 4) + \
DIV_ROUND_UP((name_size), 4) + \
DIV_ROUND_UP((desc_size), 4)) * 4)
static inline bool dump_is_64bit(DumpState *s)
{
return s->dump_info.d_class == ELFCLASS64;
}
static inline bool dump_has_filter(DumpState *s)
{
return s->filter_area_length > 0;
}
uint16_t cpu_to_dump16(DumpState *s, uint16_t val)
{
if (s->dump_info.d_endian == ELFDATA2LSB) {
val = cpu_to_le16(val);
} else {
val = cpu_to_be16(val);
}
return val;
}
uint32_t cpu_to_dump32(DumpState *s, uint32_t val)
{
if (s->dump_info.d_endian == ELFDATA2LSB) {
val = cpu_to_le32(val);
} else {
val = cpu_to_be32(val);
}
return val;
}
uint64_t cpu_to_dump64(DumpState *s, uint64_t val)
{
if (s->dump_info.d_endian == ELFDATA2LSB) {
val = cpu_to_le64(val);
} else {
val = cpu_to_be64(val);
}
return val;
}
static int dump_cleanup(DumpState *s)
{
if (s->dump_info.arch_cleanup_fn) {
s->dump_info.arch_cleanup_fn(s);
}
guest_phys_blocks_free(&s->guest_phys_blocks);
memory_mapping_list_free(&s->list);
close(s->fd);
g_free(s->guest_note);
g_clear_pointer(&s->string_table_buf, g_array_unref);
s->guest_note = NULL;
if (s->resume) {
if (s->detached) {
bql_lock();
}
vm_start();
if (s->detached) {
bql_unlock();
}
}
migrate_del_blocker(&dump_migration_blocker);
return 0;
}
static int fd_write_vmcore(const void *buf, size_t size, void *opaque)
{
DumpState *s = opaque;
size_t written_size;
written_size = qemu_write_full(s->fd, buf, size);
if (written_size != size) {
return -errno;
}
return 0;
}
static void prepare_elf64_header(DumpState *s, Elf64_Ehdr *elf_header)
{
/*
* phnum in the elf header is 16 bit, if we have more segments we
* set phnum to PN_XNUM and write the real number of segments to a
* special section.
*/
uint16_t phnum = MIN(s->phdr_num, PN_XNUM);
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_to_dump16(s, ET_CORE);
elf_header->e_machine = cpu_to_dump16(s, s->dump_info.d_machine);
elf_header->e_version = cpu_to_dump32(s, EV_CURRENT);
elf_header->e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
elf_header->e_phoff = cpu_to_dump64(s, s->phdr_offset);
elf_header->e_phentsize = cpu_to_dump16(s, sizeof(Elf64_Phdr));
elf_header->e_phnum = cpu_to_dump16(s, phnum);
elf_header->e_shoff = cpu_to_dump64(s, s->shdr_offset);
elf_header->e_shentsize = cpu_to_dump16(s, sizeof(Elf64_Shdr));
elf_header->e_shnum = cpu_to_dump16(s, s->shdr_num);
elf_header->e_shstrndx = cpu_to_dump16(s, s->shdr_num - 1);
}
static void prepare_elf32_header(DumpState *s, Elf32_Ehdr *elf_header)
{
/*
* phnum in the elf header is 16 bit, if we have more segments we
* set phnum to PN_XNUM and write the real number of segments to a
* special section.
*/
uint16_t phnum = MIN(s->phdr_num, PN_XNUM);
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] = s->dump_info.d_endian;
elf_header->e_ident[EI_VERSION] = EV_CURRENT;
elf_header->e_type = cpu_to_dump16(s, ET_CORE);
elf_header->e_machine = cpu_to_dump16(s, s->dump_info.d_machine);
elf_header->e_version = cpu_to_dump32(s, EV_CURRENT);
elf_header->e_ehsize = cpu_to_dump16(s, sizeof(elf_header));
elf_header->e_phoff = cpu_to_dump32(s, s->phdr_offset);
elf_header->e_phentsize = cpu_to_dump16(s, sizeof(Elf32_Phdr));
elf_header->e_phnum = cpu_to_dump16(s, phnum);
elf_header->e_shoff = cpu_to_dump32(s, s->shdr_offset);
elf_header->e_shentsize = cpu_to_dump16(s, sizeof(Elf32_Shdr));
elf_header->e_shnum = cpu_to_dump16(s, s->shdr_num);
elf_header->e_shstrndx = cpu_to_dump16(s, s->shdr_num - 1);
}
static void write_elf_header(DumpState *s, Error **errp)
{
Elf32_Ehdr elf32_header;
Elf64_Ehdr elf64_header;
size_t header_size;
void *header_ptr;
int ret;
/* The NULL header and the shstrtab are always defined */
assert(s->shdr_num >= 2);
if (dump_is_64bit(s)) {
prepare_elf64_header(s, &elf64_header);
header_size = sizeof(elf64_header);
header_ptr = &elf64_header;
} else {
prepare_elf32_header(s, &elf32_header);
header_size = sizeof(elf32_header);
header_ptr = &elf32_header;
}
ret = fd_write_vmcore(header_ptr, header_size, s);
if (ret < 0) {
error_setg_errno(errp, -ret, "dump: failed to write elf header");
}
}
static void write_elf64_load(DumpState *s, MemoryMapping *memory_mapping,
int phdr_index, hwaddr offset,
hwaddr filesz, Error **errp)
{
Elf64_Phdr phdr;
int ret;
memset(&phdr, 0, sizeof(Elf64_Phdr));
phdr.p_type = cpu_to_dump32(s, PT_LOAD);
phdr.p_offset = cpu_to_dump64(s, offset);
phdr.p_paddr = cpu_to_dump64(s, memory_mapping->phys_addr);
phdr.p_filesz = cpu_to_dump64(s, filesz);
phdr.p_memsz = cpu_to_dump64(s, memory_mapping->length);
phdr.p_vaddr = cpu_to_dump64(s, memory_mapping->virt_addr) ?: phdr.p_paddr;
assert(memory_mapping->length >= filesz);
ret = fd_write_vmcore(&phdr, sizeof(Elf64_Phdr), s);
if (ret < 0) {
error_setg_errno(errp, -ret,
"dump: failed to write program header table");
}
}
static void write_elf32_load(DumpState *s, MemoryMapping *memory_mapping,
int phdr_index, hwaddr offset,
hwaddr filesz, Error **errp)
{
Elf32_Phdr phdr;
int ret;
memset(&phdr, 0, sizeof(Elf32_Phdr));
phdr.p_type = cpu_to_dump32(s, PT_LOAD);
phdr.p_offset = cpu_to_dump32(s, offset);
phdr.p_paddr = cpu_to_dump32(s, memory_mapping->phys_addr);
phdr.p_filesz = cpu_to_dump32(s, filesz);
phdr.p_memsz = cpu_to_dump32(s, memory_mapping->length);
phdr.p_vaddr =
cpu_to_dump32(s, memory_mapping->virt_addr) ?: phdr.p_paddr;
assert(memory_mapping->length >= filesz);
ret = fd_write_vmcore(&phdr, sizeof(Elf32_Phdr), s);
if (ret < 0) {
error_setg_errno(errp, -ret,
"dump: failed to write program header table");
}
}
static void prepare_elf64_phdr_note(DumpState *s, Elf64_Phdr *phdr)
{
memset(phdr, 0, sizeof(*phdr));
phdr->p_type = cpu_to_dump32(s, PT_NOTE);
phdr->p_offset = cpu_to_dump64(s, s->note_offset);
phdr->p_paddr = 0;
phdr->p_filesz = cpu_to_dump64(s, s->note_size);
phdr->p_memsz = cpu_to_dump64(s, s->note_size);
phdr->p_vaddr = 0;
}
static inline int cpu_index(CPUState *cpu)
{
return cpu->cpu_index + 1;
}
static void write_guest_note(WriteCoreDumpFunction f, DumpState *s,
Error **errp)
{
int ret;
if (s->guest_note) {
ret = f(s->guest_note, s->guest_note_size, s);
if (ret < 0) {
error_setg(errp, "dump: failed to write guest note");
}
}
}
static void write_elf64_notes(WriteCoreDumpFunction f, DumpState *s,
Error **errp)
{
CPUState *cpu;
int ret;
int id;
CPU_FOREACH(cpu) {
id = cpu_index(cpu);
ret = cpu_write_elf64_note(f, cpu, id, s);
if (ret < 0) {
error_setg(errp, "dump: failed to write elf notes");
return;
}
}
CPU_FOREACH(cpu) {
ret = cpu_write_elf64_qemunote(f, cpu, s);
if (ret < 0) {
error_setg(errp, "dump: failed to write CPU status");
return;
}
}
write_guest_note(f, s, errp);
}
static void prepare_elf32_phdr_note(DumpState *s, Elf32_Phdr *phdr)
{
memset(phdr, 0, sizeof(*phdr));
phdr->p_type = cpu_to_dump32(s, PT_NOTE);
phdr->p_offset = cpu_to_dump32(s, s->note_offset);
phdr->p_paddr = 0;
phdr->p_filesz = cpu_to_dump32(s, s->note_size);
phdr->p_memsz = cpu_to_dump32(s, s->note_size);
phdr->p_vaddr = 0;
}
static void write_elf32_notes(WriteCoreDumpFunction f, DumpState *s,
Error **errp)
{
CPUState *cpu;
int ret;
int id;
CPU_FOREACH(cpu) {
id = cpu_index(cpu);
ret = cpu_write_elf32_note(f, cpu, id, s);
if (ret < 0) {
error_setg(errp, "dump: failed to write elf notes");
return;
}
}
CPU_FOREACH(cpu) {
ret = cpu_write_elf32_qemunote(f, cpu, s);
if (ret < 0) {
error_setg(errp, "dump: failed to write CPU status");
return;
}
}
write_guest_note(f, s, errp);
}
static void write_elf_phdr_note(DumpState *s, Error **errp)
{
Elf32_Phdr phdr32;
Elf64_Phdr phdr64;
void *phdr;
size_t size;
int ret;
if (dump_is_64bit(s)) {
prepare_elf64_phdr_note(s, &phdr64);
size = sizeof(phdr64);
phdr = &phdr64;
} else {
prepare_elf32_phdr_note(s, &phdr32);
size = sizeof(phdr32);
phdr = &phdr32;
}
ret = fd_write_vmcore(phdr, size, s);
if (ret < 0) {
error_setg_errno(errp, -ret,
"dump: failed to write program header table");
}
}
static void prepare_elf_section_hdr_zero(DumpState *s)
{
if (dump_is_64bit(s)) {
Elf64_Shdr *shdr64 = s->elf_section_hdrs;
shdr64->sh_info = cpu_to_dump32(s, s->phdr_num);
} else {
Elf32_Shdr *shdr32 = s->elf_section_hdrs;
shdr32->sh_info = cpu_to_dump32(s, s->phdr_num);
}
}
static void prepare_elf_section_hdr_string(DumpState *s, void *buff)
{
uint64_t index = s->string_table_buf->len;
const char strtab[] = ".shstrtab";
Elf32_Shdr shdr32 = {};
Elf64_Shdr shdr64 = {};
int shdr_size;
void *shdr;
g_array_append_vals(s->string_table_buf, strtab, sizeof(strtab));
if (dump_is_64bit(s)) {
shdr_size = sizeof(Elf64_Shdr);
shdr64.sh_type = SHT_STRTAB;
shdr64.sh_offset = s->section_offset + s->elf_section_data_size;
shdr64.sh_name = index;
shdr64.sh_size = s->string_table_buf->len;
shdr = &shdr64;
} else {
shdr_size = sizeof(Elf32_Shdr);
shdr32.sh_type = SHT_STRTAB;
shdr32.sh_offset = s->section_offset + s->elf_section_data_size;
shdr32.sh_name = index;
shdr32.sh_size = s->string_table_buf->len;
shdr = &shdr32;
}
memcpy(buff, shdr, shdr_size);
}
static bool prepare_elf_section_hdrs(DumpState *s, Error **errp)
{
size_t len, sizeof_shdr;
void *buff_hdr;
/*
* Section ordering:
* - HDR zero
* - Arch section hdrs
* - String table hdr
*/
sizeof_shdr = dump_is_64bit(s) ? sizeof(Elf64_Shdr) : sizeof(Elf32_Shdr);
len = sizeof_shdr * s->shdr_num;
s->elf_section_hdrs = g_malloc0(len);
buff_hdr = s->elf_section_hdrs;
/*
* The first section header is ALWAYS a special initial section
* header.
*
* The header should be 0 with one exception being that if
* phdr_num is PN_XNUM then the sh_info field contains the real
* number of segment entries.
*
* As we zero allocate the buffer we will only need to modify
* sh_info for the PN_XNUM case.
*/
if (s->phdr_num >= PN_XNUM) {
prepare_elf_section_hdr_zero(s);
}
buff_hdr += sizeof_shdr;
/* Add architecture defined section headers */
if (s->dump_info.arch_sections_write_hdr_fn
&& s->shdr_num > 2) {
buff_hdr += s->dump_info.arch_sections_write_hdr_fn(s, buff_hdr);
if (s->shdr_num >= SHN_LORESERVE) {
error_setg_errno(errp, EINVAL,
"dump: too many architecture defined sections");
return false;
}
}
/*
* String table is the last section since strings are added via
* arch_sections_write_hdr().
*/
prepare_elf_section_hdr_string(s, buff_hdr);
return true;
}
static void write_elf_section_headers(DumpState *s, Error **errp)
{
size_t sizeof_shdr = dump_is_64bit(s) ? sizeof(Elf64_Shdr) : sizeof(Elf32_Shdr);
int ret;
if (!prepare_elf_section_hdrs(s, errp)) {
return;
}
ret = fd_write_vmcore(s->elf_section_hdrs, s->shdr_num * sizeof_shdr, s);
if (ret < 0) {
error_setg_errno(errp, -ret, "dump: failed to write section headers");
}
g_free(s->elf_section_hdrs);
}
static void write_elf_sections(DumpState *s, Error **errp)
{
int ret;
if (s->elf_section_data_size) {
/* Write architecture section data */
ret = fd_write_vmcore(s->elf_section_data,
s->elf_section_data_size, s);
if (ret < 0) {
error_setg_errno(errp, -ret,
"dump: failed to write architecture section data");
return;
}
}
/* Write string table */
ret = fd_write_vmcore(s->string_table_buf->data,
s->string_table_buf->len, s);
if (ret < 0) {
error_setg_errno(errp, -ret, "dump: failed to write string table data");
}
}
static void write_data(DumpState *s, void *buf, int length, Error **errp)
{
int ret;
ret = fd_write_vmcore(buf, length, s);
if (ret < 0) {
error_setg_errno(errp, -ret, "dump: failed to save memory");
} else {
s->written_size += length;
}
}
/* write the memory to vmcore. 1 page per I/O. */
static void write_memory(DumpState *s, GuestPhysBlock *block, ram_addr_t start,
int64_t size, Error **errp)
{
ERRP_GUARD();
int64_t i;
for (i = 0; i < size / s->dump_info.page_size; i++) {
write_data(s, block->host_addr + start + i * s->dump_info.page_size,
s->dump_info.page_size, errp);
if (*errp) {
return;
}
}
if ((size % s->dump_info.page_size) != 0) {
write_data(s, block->host_addr + start + i * s->dump_info.page_size,
size % s->dump_info.page_size, errp);
if (*errp) {
return;
}
}
}
/* get the memory's offset and size in the vmcore */
static void get_offset_range(hwaddr phys_addr,
ram_addr_t mapping_length,
DumpState *s,
hwaddr *p_offset,
hwaddr *p_filesz)
{
GuestPhysBlock *block;
hwaddr offset = s->memory_offset;
int64_t size_in_block, start;
/* When the memory is not stored into vmcore, offset will be -1 */
*p_offset = -1;
*p_filesz = 0;
if (dump_has_filter(s)) {
if (phys_addr < s->filter_area_begin ||
phys_addr >= s->filter_area_begin + s->filter_area_length) {
return;
}
}
QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
if (dump_has_filter(s)) {
if (!ranges_overlap(block->target_start,
block->target_end - block->target_start,
s->filter_area_begin,
s->filter_area_length)) {
/* This block is out of the range */
continue;
}
if (s->filter_area_begin <= block->target_start) {
start = block->target_start;
} else {
start = s->filter_area_begin;
}
size_in_block = block->target_end - start;
if (s->filter_area_begin + s->filter_area_length < block->target_end) {
size_in_block -= block->target_end - (s->filter_area_begin + s->filter_area_length);
}
} else {
start = block->target_start;
size_in_block = block->target_end - block->target_start;
}
if (phys_addr >= start && phys_addr < start + size_in_block) {
*p_offset = phys_addr - start + offset;
/* The offset range mapped from the vmcore file must not spill over
* the GuestPhysBlock, clamp it. The rest of the mapping will be
* zero-filled in memory at load time; see
* <http://refspecs.linuxbase.org/elf/gabi4+/ch5.pheader.html>.
*/
*p_filesz = phys_addr + mapping_length <= start + size_in_block ?
mapping_length :
size_in_block - (phys_addr - start);
return;
}
offset += size_in_block;
}
}
static void write_elf_phdr_loads(DumpState *s, Error **errp)
{
ERRP_GUARD();
hwaddr offset, filesz;
MemoryMapping *memory_mapping;
uint32_t phdr_index = 1;
QTAILQ_FOREACH(memory_mapping, &s->list.head, next) {
get_offset_range(memory_mapping->phys_addr,
memory_mapping->length,
s, &offset, &filesz);
if (dump_is_64bit(s)) {
write_elf64_load(s, memory_mapping, phdr_index++, offset,
filesz, errp);
} else {
write_elf32_load(s, memory_mapping, phdr_index++, offset,
filesz, errp);
}
if (*errp) {
return;
}
if (phdr_index >= s->phdr_num) {
break;
}
}
}
static void write_elf_notes(DumpState *s, Error **errp)
{
if (dump_is_64bit(s)) {
write_elf64_notes(fd_write_vmcore, s, errp);
} else {
write_elf32_notes(fd_write_vmcore, s, errp);
}
}
/* write elf header, PT_NOTE and elf note to vmcore. */
static void dump_begin(DumpState *s, Error **errp)
{
ERRP_GUARD();
/*
* the vmcore's format is:
* --------------
* | elf header |
* --------------
* | sctn_hdr |
* --------------
* | PT_NOTE |
* --------------
* | PT_LOAD |
* --------------
* | ...... |
* --------------
* | PT_LOAD |
* --------------
* | elf note |
* --------------
* | memory |
* --------------
*
* we only know where the memory is saved after we write elf note into
* vmcore.
*/
/* write elf header to vmcore */
write_elf_header(s, errp);
if (*errp) {
return;
}
/* write section headers to vmcore */
write_elf_section_headers(s, errp);
if (*errp) {
return;
}
/* write PT_NOTE to vmcore */
write_elf_phdr_note(s, errp);
if (*errp) {
return;
}
/* write all PT_LOADs to vmcore */
write_elf_phdr_loads(s, errp);
if (*errp) {
return;
}
/* write notes to vmcore */
write_elf_notes(s, errp);
}
int64_t dump_filtered_memblock_size(GuestPhysBlock *block,
int64_t filter_area_start,
int64_t filter_area_length)
{
int64_t size, left, right;
/* No filter, return full size */
if (!filter_area_length) {
return block->target_end - block->target_start;
}
/* calculate the overlapped region. */
left = MAX(filter_area_start, block->target_start);
right = MIN(filter_area_start + filter_area_length, block->target_end);
size = right - left;
size = size > 0 ? size : 0;
return size;
}
int64_t dump_filtered_memblock_start(GuestPhysBlock *block,
int64_t filter_area_start,
int64_t filter_area_length)
{
if (filter_area_length) {
/* return -1 if the block is not within filter area */
if (!ranges_overlap(block->target_start,
block->target_end - block->target_start,
filter_area_start, filter_area_length)) {
return -1;
}
if (filter_area_start > block->target_start) {
return filter_area_start - block->target_start;
}
}
return 0;
}
/* write all memory to vmcore */
static void dump_iterate(DumpState *s, Error **errp)
{
ERRP_GUARD();
GuestPhysBlock *block;
int64_t memblock_size, memblock_start;
QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
memblock_start = dump_filtered_memblock_start(block, s->filter_area_begin, s->filter_area_length);
if (memblock_start == -1) {
continue;
}
memblock_size = dump_filtered_memblock_size(block, s->filter_area_begin, s->filter_area_length);
/* Write the memory to file */
write_memory(s, block, memblock_start, memblock_size, errp);
if (*errp) {
return;
}
}
}
static void dump_end(DumpState *s, Error **errp)
{
int rc;
if (s->elf_section_data_size) {
s->elf_section_data = g_malloc0(s->elf_section_data_size);
}
/* Adds the architecture defined section data to s->elf_section_data */
if (s->dump_info.arch_sections_write_fn &&
s->elf_section_data_size) {
rc = s->dump_info.arch_sections_write_fn(s, s->elf_section_data);
if (rc) {
error_setg_errno(errp, rc,
"dump: failed to get arch section data");
g_free(s->elf_section_data);
return;
}
}
/* write sections to vmcore */
write_elf_sections(s, errp);
}
static void create_vmcore(DumpState *s, Error **errp)
{
ERRP_GUARD();
dump_begin(s, errp);
if (*errp) {
return;
}
/* Iterate over memory and dump it to file */
dump_iterate(s, errp);
if (*errp) {
return;
}
/* Write the section data */
dump_end(s, errp);
}
static int write_start_flat_header(DumpState *s)
{
MakedumpfileHeader *mh;
int ret = 0;
if (s->kdump_raw) {
return 0;
}
QEMU_BUILD_BUG_ON(sizeof *mh > MAX_SIZE_MDF_HEADER);
mh = g_malloc0(MAX_SIZE_MDF_HEADER);
memcpy(mh->signature, MAKEDUMPFILE_SIGNATURE,
MIN(sizeof mh->signature, sizeof MAKEDUMPFILE_SIGNATURE));
mh->type = cpu_to_be64(TYPE_FLAT_HEADER);
mh->version = cpu_to_be64(VERSION_FLAT_HEADER);
size_t written_size;
written_size = qemu_write_full(s->fd, mh, MAX_SIZE_MDF_HEADER);
if (written_size != MAX_SIZE_MDF_HEADER) {
ret = -1;
}
g_free(mh);
return ret;
}
static int write_end_flat_header(DumpState *s)
{
MakedumpfileDataHeader mdh;
if (s->kdump_raw) {
return 0;
}
mdh.offset = END_FLAG_FLAT_HEADER;
mdh.buf_size = END_FLAG_FLAT_HEADER;
size_t written_size;
written_size = qemu_write_full(s->fd, &mdh, sizeof(mdh));
if (written_size != sizeof(mdh)) {
return -1;
}
return 0;
}
static int write_buffer(DumpState *s, off_t offset, const void *buf, size_t size)
{
size_t written_size;
MakedumpfileDataHeader mdh;
off_t seek_loc;
if (s->kdump_raw) {
seek_loc = lseek(s->fd, offset, SEEK_SET);
if (seek_loc == (off_t) -1) {
return -1;
}
} else {
mdh.offset = cpu_to_be64(offset);
mdh.buf_size = cpu_to_be64(size);
written_size = qemu_write_full(s->fd, &mdh, sizeof(mdh));
if (written_size != sizeof(mdh)) {
return -1;
}
}
written_size = qemu_write_full(s->fd, buf, size);
if (written_size != size) {
return -1;
}
return 0;
}
static int buf_write_note(const void *buf, size_t size, void *opaque)
{
DumpState *s = opaque;
/* note_buf is not enough */
if (s->note_buf_offset + size > s->note_size) {
return -1;
}
memcpy(s->note_buf + s->note_buf_offset, buf, size);
s->note_buf_offset += size;
return 0;
}
/*
* This function retrieves various sizes from an elf header.
*
* @note has to be a valid ELF note. The return sizes are unmodified
* (not padded or rounded up to be multiple of 4).
*/
static void get_note_sizes(DumpState *s, const void *note,
uint64_t *note_head_size,
uint64_t *name_size,
uint64_t *desc_size)
{
uint64_t note_head_sz;
uint64_t name_sz;
uint64_t desc_sz;
if (dump_is_64bit(s)) {
const Elf64_Nhdr *hdr = note;
note_head_sz = sizeof(Elf64_Nhdr);
name_sz = cpu_to_dump64(s, hdr->n_namesz);
desc_sz = cpu_to_dump64(s, hdr->n_descsz);
} else {
const Elf32_Nhdr *hdr = note;
note_head_sz = sizeof(Elf32_Nhdr);
name_sz = cpu_to_dump32(s, hdr->n_namesz);
desc_sz = cpu_to_dump32(s, hdr->n_descsz);
}
if (note_head_size) {
*note_head_size = note_head_sz;
}
if (name_size) {
*name_size = name_sz;
}
if (desc_size) {
*desc_size = desc_sz;
}
}
static bool note_name_equal(DumpState *s,
const uint8_t *note, const char *name)
{
int len = strlen(name) + 1;
uint64_t head_size, name_size;
get_note_sizes(s, note, &head_size, &name_size, NULL);
head_size = ROUND_UP(head_size, 4);
return name_size == len && memcmp(note + head_size, name, len) == 0;
}
/* write common header, sub header and elf note to vmcore */
static void create_header32(DumpState *s, Error **errp)
{
ERRP_GUARD();
DiskDumpHeader32 *dh = NULL;
KdumpSubHeader32 *kh = NULL;
size_t size;
uint32_t block_size;
uint32_t sub_hdr_size;
uint32_t bitmap_blocks;
uint32_t status = 0;
uint64_t offset_note;
/* write common header, the version of kdump-compressed format is 6th */
size = sizeof(DiskDumpHeader32);
dh = g_malloc0(size);
memcpy(dh->signature, KDUMP_SIGNATURE, SIG_LEN);
dh->header_version = cpu_to_dump32(s, 6);
block_size = s->dump_info.page_size;
dh->block_size = cpu_to_dump32(s, block_size);
sub_hdr_size = sizeof(struct KdumpSubHeader32) + s->note_size;
sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
dh->sub_hdr_size = cpu_to_dump32(s, sub_hdr_size);
/* dh->max_mapnr may be truncated, full 64bit is in kh.max_mapnr_64 */
dh->max_mapnr = cpu_to_dump32(s, MIN(s->max_mapnr, UINT_MAX));
dh->nr_cpus = cpu_to_dump32(s, s->nr_cpus);
bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
dh->bitmap_blocks = cpu_to_dump32(s, bitmap_blocks);
strncpy(dh->utsname.machine, ELF_MACHINE_UNAME, sizeof(dh->utsname.machine));
if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
status |= DUMP_DH_COMPRESSED_ZLIB;
}
#ifdef CONFIG_LZO
if (s->flag_compress & DUMP_DH_COMPRESSED_LZO) {
status |= DUMP_DH_COMPRESSED_LZO;
}
#endif
#ifdef CONFIG_SNAPPY
if (s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) {
status |= DUMP_DH_COMPRESSED_SNAPPY;
}
#endif
dh->status = cpu_to_dump32(s, status);
if (write_buffer(s, 0, dh, size) < 0) {
error_setg(errp, "dump: failed to write disk dump header");
goto out;
}
/* write sub header */
size = sizeof(KdumpSubHeader32);
kh = g_malloc0(size);
/* 64bit max_mapnr_64 */
kh->max_mapnr_64 = cpu_to_dump64(s, s->max_mapnr);
kh->phys_base = cpu_to_dump32(s, s->dump_info.phys_base);
kh->dump_level = cpu_to_dump32(s, DUMP_LEVEL);
offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size;
if (s->guest_note &&
note_name_equal(s, s->guest_note, "VMCOREINFO")) {
uint64_t hsize, name_size, size_vmcoreinfo_desc, offset_vmcoreinfo;
get_note_sizes(s, s->guest_note,
&hsize, &name_size, &size_vmcoreinfo_desc);
offset_vmcoreinfo = offset_note + s->note_size - s->guest_note_size +
(DIV_ROUND_UP(hsize, 4) + DIV_ROUND_UP(name_size, 4)) * 4;
kh->offset_vmcoreinfo = cpu_to_dump64(s, offset_vmcoreinfo);
kh->size_vmcoreinfo = cpu_to_dump32(s, size_vmcoreinfo_desc);
}
kh->offset_note = cpu_to_dump64(s, offset_note);
kh->note_size = cpu_to_dump32(s, s->note_size);
if (write_buffer(s, DISKDUMP_HEADER_BLOCKS *
block_size, kh, size) < 0) {
error_setg(errp, "dump: failed to write kdump sub header");
goto out;
}
/* write note */
s->note_buf = g_malloc0(s->note_size);
s->note_buf_offset = 0;
/* use s->note_buf to store notes temporarily */
write_elf32_notes(buf_write_note, s, errp);
if (*errp) {
goto out;
}
if (write_buffer(s, offset_note, s->note_buf,
s->note_size) < 0) {
error_setg(errp, "dump: failed to write notes");
goto out;
}
/* get offset of dump_bitmap */
s->offset_dump_bitmap = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size) *
block_size;
/* get offset of page */
s->offset_page = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size + bitmap_blocks) *
block_size;
out:
g_free(dh);
g_free(kh);
g_free(s->note_buf);
}
/* write common header, sub header and elf note to vmcore */
static void create_header64(DumpState *s, Error **errp)
{
ERRP_GUARD();
DiskDumpHeader64 *dh = NULL;
KdumpSubHeader64 *kh = NULL;
size_t size;
uint32_t block_size;
uint32_t sub_hdr_size;
uint32_t bitmap_blocks;
uint32_t status = 0;
uint64_t offset_note;
/* write common header, the version of kdump-compressed format is 6th */
size = sizeof(DiskDumpHeader64);
dh = g_malloc0(size);
memcpy(dh->signature, KDUMP_SIGNATURE, SIG_LEN);
dh->header_version = cpu_to_dump32(s, 6);
block_size = s->dump_info.page_size;
dh->block_size = cpu_to_dump32(s, block_size);
sub_hdr_size = sizeof(struct KdumpSubHeader64) + s->note_size;
sub_hdr_size = DIV_ROUND_UP(sub_hdr_size, block_size);
dh->sub_hdr_size = cpu_to_dump32(s, sub_hdr_size);
/* dh->max_mapnr may be truncated, full 64bit is in kh.max_mapnr_64 */
dh->max_mapnr = cpu_to_dump32(s, MIN(s->max_mapnr, UINT_MAX));
dh->nr_cpus = cpu_to_dump32(s, s->nr_cpus);
bitmap_blocks = DIV_ROUND_UP(s->len_dump_bitmap, block_size) * 2;
dh->bitmap_blocks = cpu_to_dump32(s, bitmap_blocks);
strncpy(dh->utsname.machine, ELF_MACHINE_UNAME, sizeof(dh->utsname.machine));
if (s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) {
status |= DUMP_DH_COMPRESSED_ZLIB;
}
#ifdef CONFIG_LZO
if (s->flag_compress & DUMP_DH_COMPRESSED_LZO) {
status |= DUMP_DH_COMPRESSED_LZO;
}
#endif
#ifdef CONFIG_SNAPPY
if (s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) {
status |= DUMP_DH_COMPRESSED_SNAPPY;
}
#endif
dh->status = cpu_to_dump32(s, status);
if (write_buffer(s, 0, dh, size) < 0) {
error_setg(errp, "dump: failed to write disk dump header");
goto out;
}
/* write sub header */
size = sizeof(KdumpSubHeader64);
kh = g_malloc0(size);
/* 64bit max_mapnr_64 */
kh->max_mapnr_64 = cpu_to_dump64(s, s->max_mapnr);
kh->phys_base = cpu_to_dump64(s, s->dump_info.phys_base);
kh->dump_level = cpu_to_dump32(s, DUMP_LEVEL);
offset_note = DISKDUMP_HEADER_BLOCKS * block_size + size;
if (s->guest_note &&
note_name_equal(s, s->guest_note, "VMCOREINFO")) {
uint64_t hsize, name_size, size_vmcoreinfo_desc, offset_vmcoreinfo;
get_note_sizes(s, s->guest_note,
&hsize, &name_size, &size_vmcoreinfo_desc);
offset_vmcoreinfo = offset_note + s->note_size - s->guest_note_size +
(DIV_ROUND_UP(hsize, 4) + DIV_ROUND_UP(name_size, 4)) * 4;
kh->offset_vmcoreinfo = cpu_to_dump64(s, offset_vmcoreinfo);
kh->size_vmcoreinfo = cpu_to_dump64(s, size_vmcoreinfo_desc);
}
kh->offset_note = cpu_to_dump64(s, offset_note);
kh->note_size = cpu_to_dump64(s, s->note_size);
if (write_buffer(s, DISKDUMP_HEADER_BLOCKS *
block_size, kh, size) < 0) {
error_setg(errp, "dump: failed to write kdump sub header");
goto out;
}
/* write note */
s->note_buf = g_malloc0(s->note_size);
s->note_buf_offset = 0;
/* use s->note_buf to store notes temporarily */
write_elf64_notes(buf_write_note, s, errp);
if (*errp) {
goto out;
}
if (write_buffer(s, offset_note, s->note_buf,
s->note_size) < 0) {
error_setg(errp, "dump: failed to write notes");
goto out;
}
/* get offset of dump_bitmap */
s->offset_dump_bitmap = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size) *
block_size;
/* get offset of page */
s->offset_page = (DISKDUMP_HEADER_BLOCKS + sub_hdr_size + bitmap_blocks) *
block_size;
out:
g_free(dh);
g_free(kh);
g_free(s->note_buf);
}
static void write_dump_header(DumpState *s, Error **errp)
{
if (dump_is_64bit(s)) {
create_header64(s, errp);
} else {
create_header32(s, errp);
}
}
static size_t dump_bitmap_get_bufsize(DumpState *s)
{
return s->dump_info.page_size;
}
/*
* set dump_bitmap sequencely. the bit before last_pfn is not allowed to be
* rewritten, so if need to set the first bit, set last_pfn and pfn to 0.
* set_dump_bitmap will always leave the recently set bit un-sync. And setting
* (last bit + sizeof(buf) * 8) to 0 will do flushing the content in buf into
* vmcore, ie. synchronizing un-sync bit into vmcore.
*/
static int set_dump_bitmap(uint64_t last_pfn, uint64_t pfn, bool value,
uint8_t *buf, DumpState *s)
{
off_t old_offset, new_offset;
off_t offset_bitmap1, offset_bitmap2;
uint32_t byte, bit;
size_t bitmap_bufsize = dump_bitmap_get_bufsize(s);
size_t bits_per_buf = bitmap_bufsize * CHAR_BIT;
/* should not set the previous place */
assert(last_pfn <= pfn);
/*
* if the bit needed to be set is not cached in buf, flush the data in buf
* to vmcore firstly.
* making new_offset be bigger than old_offset can also sync remained data
* into vmcore.
*/
old_offset = bitmap_bufsize * (last_pfn / bits_per_buf);
new_offset = bitmap_bufsize * (pfn / bits_per_buf);
while (old_offset < new_offset) {
/* calculate the offset and write dump_bitmap */
offset_bitmap1 = s->offset_dump_bitmap + old_offset;
if (write_buffer(s, offset_bitmap1, buf,
bitmap_bufsize) < 0) {
return -1;
}
/* dump level 1 is chosen, so 1st and 2nd bitmap are same */
offset_bitmap2 = s->offset_dump_bitmap + s->len_dump_bitmap +
old_offset;
if (write_buffer(s, offset_bitmap2, buf,
bitmap_bufsize) < 0) {
return -1;
}
memset(buf, 0, bitmap_bufsize);
old_offset += bitmap_bufsize;
}
/* get the exact place of the bit in the buf, and set it */
byte = (pfn % bits_per_buf) / CHAR_BIT;
bit = (pfn % bits_per_buf) % CHAR_BIT;
if (value) {
buf[byte] |= 1u << bit;
} else {
buf[byte] &= ~(1u << bit);
}
return 0;
}
static uint64_t dump_paddr_to_pfn(DumpState *s, uint64_t addr)
{
int target_page_shift = ctz32(s->dump_info.page_size);
return (addr >> target_page_shift) - ARCH_PFN_OFFSET;
}
static uint64_t dump_pfn_to_paddr(DumpState *s, uint64_t pfn)
{
int target_page_shift = ctz32(s->dump_info.page_size);
return (pfn + ARCH_PFN_OFFSET) << target_page_shift;
}
/*
* Return the page frame number and the page content in *bufptr. bufptr can be
* NULL. If not NULL, *bufptr must contains a target page size of pre-allocated
* memory. This is not necessarily the memory returned.
*/
static bool get_next_page(GuestPhysBlock **blockptr, uint64_t *pfnptr,
uint8_t **bufptr, DumpState *s)
{
GuestPhysBlock *block = *blockptr;
uint32_t page_size = s->dump_info.page_size;
uint8_t *buf = NULL, *hbuf;
hwaddr addr;
/* block == NULL means the start of the iteration */
if (!block) {
block = QTAILQ_FIRST(&s->guest_phys_blocks.head);
*blockptr = block;
addr = block->target_start;
*pfnptr = dump_paddr_to_pfn(s, addr);
} else {
*pfnptr += 1;
addr = dump_pfn_to_paddr(s, *pfnptr);
}
assert(block != NULL);
while (1) {
if (addr >= block->target_start && addr < block->target_end) {
size_t n = MIN(block->target_end - addr, page_size - addr % page_size);
hbuf = block->host_addr + (addr - block->target_start);
if (!buf) {
if (n == page_size) {
/* this is a whole target page, go for it */
assert(addr % page_size == 0);
buf = hbuf;
break;
} else if (bufptr) {
assert(*bufptr);
buf = *bufptr;
memset(buf, 0, page_size);
} else {
return true;
}
}
memcpy(buf + addr % page_size, hbuf, n);
addr += n;
if (addr % page_size == 0 || addr >= block->target_end) {
/* we filled up the page or the current block is finished */
break;
}
} else {
/* the next page is in the next block */
*blockptr = block = QTAILQ_NEXT(block, next);
if (!block) {
break;
}
addr = block->target_start;
/* are we still in the same page? */
if (dump_paddr_to_pfn(s, addr) != *pfnptr) {
if (buf) {
/* no, but we already filled something earlier, return it */
break;
} else {
/* else continue from there */
*pfnptr = dump_paddr_to_pfn(s, addr);
}
}
}
}
if (bufptr) {
*bufptr = buf;
}
return buf != NULL;
}
static void write_dump_bitmap(DumpState *s, Error **errp)
{
int ret = 0;
uint64_t last_pfn, pfn;
void *dump_bitmap_buf;
size_t num_dumpable;
GuestPhysBlock *block_iter = NULL;
size_t bitmap_bufsize = dump_bitmap_get_bufsize(s);
size_t bits_per_buf = bitmap_bufsize * CHAR_BIT;
/* dump_bitmap_buf is used to store dump_bitmap temporarily */
dump_bitmap_buf = g_malloc0(bitmap_bufsize);
num_dumpable = 0;
last_pfn = 0;
/*
* exam memory page by page, and set the bit in dump_bitmap corresponded
* to the existing page.
*/
while (get_next_page(&block_iter, &pfn, NULL, s)) {
ret = set_dump_bitmap(last_pfn, pfn, true, dump_bitmap_buf, s);
if (ret < 0) {
error_setg(errp, "dump: failed to set dump_bitmap");
goto out;
}
last_pfn = pfn;
num_dumpable++;
}
/*
* set_dump_bitmap will always leave the recently set bit un-sync. Here we
* set the remaining bits from last_pfn to the end of the bitmap buffer to
* 0. With those set, the un-sync bit will be synchronized into the vmcore.
*/
if (num_dumpable > 0) {
ret = set_dump_bitmap(last_pfn, last_pfn + bits_per_buf, false,
dump_bitmap_buf, s);
if (ret < 0) {
error_setg(errp, "dump: failed to sync dump_bitmap");
goto out;
}
}
/* number of dumpable pages that will be dumped later */
s->num_dumpable = num_dumpable;
out:
g_free(dump_bitmap_buf);
}
static void prepare_data_cache(DataCache *data_cache, DumpState *s,
off_t offset)
{
data_cache->state = s;
data_cache->data_size = 0;
data_cache->buf_size = 4 * dump_bitmap_get_bufsize(s);
data_cache->buf = g_malloc0(data_cache->buf_size);
data_cache->offset = offset;
}
static int write_cache(DataCache *dc, const void *buf, size_t size,
bool flag_sync)
{
/*
* dc->buf_size should not be less than size, otherwise dc will never be
* enough
*/
assert(size <= dc->buf_size);
/*
* if flag_sync is set, synchronize data in dc->buf into vmcore.
* otherwise check if the space is enough for caching data in buf, if not,
* write the data in dc->buf to dc->state->fd and reset dc->buf
*/
if ((!flag_sync && dc->data_size + size > dc->buf_size) ||
(flag_sync && dc->data_size > 0)) {
if (write_buffer(dc->state, dc->offset, dc->buf, dc->data_size) < 0) {
return -1;
}
dc->offset += dc->data_size;
dc->data_size = 0;
}
if (!flag_sync) {
memcpy(dc->buf + dc->data_size, buf, size);
dc->data_size += size;
}
return 0;
}
static void free_data_cache(DataCache *data_cache)
{
g_free(data_cache->buf);
}
static size_t get_len_buf_out(size_t page_size, uint32_t flag_compress)
{
switch (flag_compress) {
case DUMP_DH_COMPRESSED_ZLIB:
return compressBound(page_size);
case DUMP_DH_COMPRESSED_LZO:
/*
* LZO will expand incompressible data by a little amount. Please check
* the following URL to see the expansion calculation:
* http://www.oberhumer.com/opensource/lzo/lzofaq.php
*/
return page_size + page_size / 16 + 64 + 3;
#ifdef CONFIG_SNAPPY
case DUMP_DH_COMPRESSED_SNAPPY:
return snappy_max_compressed_length(page_size);
#endif
}
return 0;
}
static void write_dump_pages(DumpState *s, Error **errp)
{
int ret = 0;
DataCache page_desc, page_data;
size_t len_buf_out, size_out;
#ifdef CONFIG_LZO
lzo_bytep wrkmem = NULL;
#endif
uint8_t *buf_out = NULL;
off_t offset_desc, offset_data;
PageDescriptor pd, pd_zero;
uint8_t *buf;
GuestPhysBlock *block_iter = NULL;
uint64_t pfn_iter;
g_autofree uint8_t *page = NULL;
/* get offset of page_desc and page_data in dump file */
offset_desc = s->offset_page;
offset_data = offset_desc + sizeof(PageDescriptor) * s->num_dumpable;
prepare_data_cache(&page_desc, s, offset_desc);
prepare_data_cache(&page_data, s, offset_data);
/* prepare buffer to store compressed data */
len_buf_out = get_len_buf_out(s->dump_info.page_size, s->flag_compress);
assert(len_buf_out != 0);
#ifdef CONFIG_LZO
wrkmem = g_malloc(LZO1X_1_MEM_COMPRESS);
#endif
buf_out = g_malloc(len_buf_out);
/*
* init zero page's page_desc and page_data, because every zero page
* uses the same page_data
*/
pd_zero.size = cpu_to_dump32(s, s->dump_info.page_size);
pd_zero.flags = cpu_to_dump32(s, 0);
pd_zero.offset = cpu_to_dump64(s, offset_data);
pd_zero.page_flags = cpu_to_dump64(s, 0);
buf = g_malloc0(s->dump_info.page_size);
ret = write_cache(&page_data, buf, s->dump_info.page_size, false);
g_free(buf);
if (ret < 0) {
error_setg(errp, "dump: failed to write page data (zero page)");
goto out;
}
offset_data += s->dump_info.page_size;
page = g_malloc(s->dump_info.page_size);
/*
* dump memory to vmcore page by page. zero page will all be resided in the
* first page of page section
*/
for (buf = page; get_next_page(&block_iter, &pfn_iter, &buf, s); buf = page) {
/* check zero page */
if (buffer_is_zero(buf, s->dump_info.page_size)) {
ret = write_cache(&page_desc, &pd_zero, sizeof(PageDescriptor),
false);
if (ret < 0) {
error_setg(errp, "dump: failed to write page desc");
goto out;
}
} else {
/*
* not zero page, then:
* 1. compress the page
* 2. write the compressed page into the cache of page_data
* 3. get page desc of the compressed page and write it into the
* cache of page_desc
*
* only one compression format will be used here, for
* s->flag_compress is set. But when compression fails to work,
* we fall back to save in plaintext.
*/
size_out = len_buf_out;
if ((s->flag_compress & DUMP_DH_COMPRESSED_ZLIB) &&
(compress2(buf_out, (uLongf *)&size_out, buf,
s->dump_info.page_size, Z_BEST_SPEED) == Z_OK) &&
(size_out < s->dump_info.page_size)) {
pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_ZLIB);
pd.size = cpu_to_dump32(s, size_out);
ret = write_cache(&page_data, buf_out, size_out, false);
if (ret < 0) {
error_setg(errp, "dump: failed to write page data");
goto out;
}
#ifdef CONFIG_LZO
} else if ((s->flag_compress & DUMP_DH_COMPRESSED_LZO) &&
(lzo1x_1_compress(buf, s->dump_info.page_size, buf_out,
(lzo_uint *)&size_out, wrkmem) == LZO_E_OK) &&
(size_out < s->dump_info.page_size)) {
pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_LZO);
pd.size = cpu_to_dump32(s, size_out);
ret = write_cache(&page_data, buf_out, size_out, false);
if (ret < 0) {
error_setg(errp, "dump: failed to write page data");
goto out;
}
#endif
#ifdef CONFIG_SNAPPY
} else if ((s->flag_compress & DUMP_DH_COMPRESSED_SNAPPY) &&
(snappy_compress((char *)buf, s->dump_info.page_size,
(char *)buf_out, &size_out) == SNAPPY_OK) &&
(size_out < s->dump_info.page_size)) {
pd.flags = cpu_to_dump32(s, DUMP_DH_COMPRESSED_SNAPPY);
pd.size = cpu_to_dump32(s, size_out);
ret = write_cache(&page_data, buf_out, size_out, false);
if (ret < 0) {
error_setg(errp, "dump: failed to write page data");
goto out;
}
#endif
} else {
/*
* fall back to save in plaintext, size_out should be
* assigned the target's page size
*/
pd.flags = cpu_to_dump32(s, 0);
size_out = s->dump_info.page_size;
pd.size = cpu_to_dump32(s, size_out);
ret = write_cache(&page_data, buf,
s->dump_info.page_size, false);
if (ret < 0) {
error_setg(errp, "dump: failed to write page data");
goto out;
}
}
/* get and write page desc here */
pd.page_flags = cpu_to_dump64(s, 0);
pd.offset = cpu_to_dump64(s, offset_data);
offset_data += size_out;
ret = write_cache(&page_desc, &pd, sizeof(PageDescriptor), false);
if (ret < 0) {
error_setg(errp, "dump: failed to write page desc");
goto out;
}
}
s->written_size += s->dump_info.page_size;
}
ret = write_cache(&page_desc, NULL, 0, true);
if (ret < 0) {
error_setg(errp, "dump: failed to sync cache for page_desc");
goto out;
}
ret = write_cache(&page_data, NULL, 0, true);
if (ret < 0) {
error_setg(errp, "dump: failed to sync cache for page_data");
goto out;
}
out:
free_data_cache(&page_desc);
free_data_cache(&page_data);
#ifdef CONFIG_LZO
g_free(wrkmem);
#endif
g_free(buf_out);
}
static void create_kdump_vmcore(DumpState *s, Error **errp)
{
ERRP_GUARD();
int ret;
/*
* the kdump-compressed format is:
* File offset
* +------------------------------------------+ 0x0
* | main header (struct disk_dump_header) |
* |------------------------------------------+ block 1
* | sub header (struct kdump_sub_header) |
* |------------------------------------------+ block 2
* | 1st-dump_bitmap |
* |------------------------------------------+ block 2 + X blocks
* | 2nd-dump_bitmap | (aligned by block)
* |------------------------------------------+ block 2 + 2 * X blocks
* | page desc for pfn 0 (struct page_desc) | (aligned by block)
* | page desc for pfn 1 (struct page_desc) |
* | : |
* |------------------------------------------| (not aligned by block)
* | page data (pfn 0) |
* | page data (pfn 1) |
* | : |
* +------------------------------------------+
*/
ret = write_start_flat_header(s);
if (ret < 0) {
error_setg(errp, "dump: failed to write start flat header");
return;
}
write_dump_header(s, errp);
if (*errp) {
return;
}
write_dump_bitmap(s, errp);
if (*errp) {
return;
}
write_dump_pages(s, errp);
if (*errp) {
return;
}
ret = write_end_flat_header(s);
if (ret < 0) {
error_setg(errp, "dump: failed to write end flat header");
return;
}
}
static void get_max_mapnr(DumpState *s)
{
GuestPhysBlock *last_block;
last_block = QTAILQ_LAST(&s->guest_phys_blocks.head);
s->max_mapnr = dump_paddr_to_pfn(s, last_block->target_end);
}
static DumpState dump_state_global = { .status = DUMP_STATUS_NONE };
static void dump_state_prepare(DumpState *s)
{
/* zero the struct, setting status to active */
*s = (DumpState) { .status = DUMP_STATUS_ACTIVE };
}
bool qemu_system_dump_in_progress(void)
{
DumpState *state = &dump_state_global;
return (qatomic_read(&state->status) == DUMP_STATUS_ACTIVE);
}
/*
* calculate total size of memory to be dumped (taking filter into
* account.)
*/
static int64_t dump_calculate_size(DumpState *s)
{
GuestPhysBlock *block;
int64_t total = 0;
QTAILQ_FOREACH(block, &s->guest_phys_blocks.head, next) {
total += dump_filtered_memblock_size(block,
s->filter_area_begin,
s->filter_area_length);
}
return total;
}
static void vmcoreinfo_update_phys_base(DumpState *s)
{
uint64_t size, note_head_size, name_size, phys_base;
char **lines;
uint8_t *vmci;
size_t i;
if (!note_name_equal(s, s->guest_note, "VMCOREINFO")) {
return;
}
get_note_sizes(s, s->guest_note, &note_head_size, &name_size, &size);
note_head_size = ROUND_UP(note_head_size, 4);
vmci = s->guest_note + note_head_size + ROUND_UP(name_size, 4);
*(vmci + size) = '\0';
lines = g_strsplit((char *)vmci, "\n", -1);
for (i = 0; lines[i]; i++) {
const char *prefix = NULL;
if (s->dump_info.d_machine == EM_X86_64) {
prefix = "NUMBER(phys_base)=";
} else if (s->dump_info.d_machine == EM_AARCH64) {
prefix = "NUMBER(PHYS_OFFSET)=";
}
if (prefix && g_str_has_prefix(lines[i], prefix)) {
if (qemu_strtou64(lines[i] + strlen(prefix), NULL, 16,
&phys_base) < 0) {
warn_report("Failed to read %s", prefix);
} else {
s->dump_info.phys_base = phys_base;
}
break;
}
}
g_strfreev(lines);
}
static void dump_init(DumpState *s, int fd, bool has_format,
DumpGuestMemoryFormat format, bool paging, bool has_filter,
int64_t begin, int64_t length, bool kdump_raw,
Error **errp)
{
ERRP_GUARD();
VMCoreInfoState *vmci = vmcoreinfo_find();
CPUState *cpu;
int nr_cpus;
int ret;
s->has_format = has_format;
s->format = format;
s->written_size = 0;
s->kdump_raw = kdump_raw;
/* kdump-compressed is conflict with paging and filter */
if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
assert(!paging && !has_filter);
}
if (runstate_is_running()) {
vm_stop(RUN_STATE_SAVE_VM);
s->resume = true;
} else {
s->resume = false;
}
/* If we use KVM, we should synchronize the registers before we get dump
* info or physmap info.
*/
cpu_synchronize_all_states();
nr_cpus = 0;
CPU_FOREACH(cpu) {
nr_cpus++;
}
s->fd = fd;
if (has_filter && !length) {
error_setg(errp, "parameter 'length' expects a non-zero size");
goto cleanup;
}
s->filter_area_begin = begin;
s->filter_area_length = length;
/* First index is 0, it's the special null name */
s->string_table_buf = g_array_new(FALSE, TRUE, 1);
/*
* Allocate the null name, due to the clearing option set to true
* it will be 0.
*/
g_array_set_size(s->string_table_buf, 1);
memory_mapping_list_init(&s->list);
guest_phys_blocks_init(&s->guest_phys_blocks);
guest_phys_blocks_append(&s->guest_phys_blocks);
s->total_size = dump_calculate_size(s);
#ifdef DEBUG_DUMP_GUEST_MEMORY
fprintf(stderr, "DUMP: total memory to dump: %lu\n", s->total_size);
#endif
/* it does not make sense to dump non-existent memory */
if (!s->total_size) {
error_setg(errp, "dump: no guest memory to dump");
goto cleanup;
}
/* get dump info: endian, class and architecture.
* If the target architecture is not supported, cpu_get_dump_info() will
* return -1.
*/
ret = cpu_get_dump_info(&s->dump_info, &s->guest_phys_blocks);
if (ret < 0) {
error_setg(errp,
"dumping guest memory is not supported on this target");
goto cleanup;
}
if (!s->dump_info.page_size) {
s->dump_info.page_size = qemu_target_page_size();
}
s->note_size = cpu_get_note_size(s->dump_info.d_class,
s->dump_info.d_machine, nr_cpus);
assert(s->note_size >= 0);
/*
* The goal of this block is to (a) update the previously guessed
* phys_base, (b) copy the guest note out of the guest.
* Failure to do so is not fatal for dumping.
*/
if (vmci) {
uint64_t addr, note_head_size, name_size, desc_size;
uint32_t size;
uint16_t guest_format;
note_head_size = dump_is_64bit(s) ?
sizeof(Elf64_Nhdr) : sizeof(Elf32_Nhdr);
guest_format = le16_to_cpu(vmci->vmcoreinfo.guest_format);
size = le32_to_cpu(vmci->vmcoreinfo.size);
addr = le64_to_cpu(vmci->vmcoreinfo.paddr);
if (!vmci->has_vmcoreinfo) {
warn_report("guest note is not present");
} else if (size < note_head_size || size > MAX_GUEST_NOTE_SIZE) {
warn_report("guest note size is invalid: %" PRIu32, size);
} else if (guest_format != FW_CFG_VMCOREINFO_FORMAT_ELF) {
warn_report("guest note format is unsupported: %" PRIu16, guest_format);
} else {
s->guest_note = g_malloc(size + 1); /* +1 for adding \0 */
cpu_physical_memory_read(addr, s->guest_note, size);
get_note_sizes(s, s->guest_note, NULL, &name_size, &desc_size);
s->guest_note_size = ELF_NOTE_SIZE(note_head_size, name_size,
desc_size);
if (name_size > MAX_GUEST_NOTE_SIZE ||
desc_size > MAX_GUEST_NOTE_SIZE ||
s->guest_note_size > size) {
warn_report("Invalid guest note header");
g_free(s->guest_note);
s->guest_note = NULL;
} else {
vmcoreinfo_update_phys_base(s);
s->note_size += s->guest_note_size;
}
}
}
/* get memory mapping */
if (paging) {
qemu_get_guest_memory_mapping(&s->list, &s->guest_phys_blocks, errp);
if (*errp) {
goto cleanup;
}
} else {
qemu_get_guest_simple_memory_mapping(&s->list, &s->guest_phys_blocks);
}
s->nr_cpus = nr_cpus;
get_max_mapnr(s);
uint64_t tmp;
tmp = DIV_ROUND_UP(DIV_ROUND_UP(s->max_mapnr, CHAR_BIT),
s->dump_info.page_size);
s->len_dump_bitmap = tmp * s->dump_info.page_size;
/* init for kdump-compressed format */
if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
switch (format) {
case DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB:
s->flag_compress = DUMP_DH_COMPRESSED_ZLIB;
break;
case DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO:
#ifdef CONFIG_LZO
if (lzo_init() != LZO_E_OK) {
error_setg(errp, "failed to initialize the LZO library");
goto cleanup;
}
#endif
s->flag_compress = DUMP_DH_COMPRESSED_LZO;
break;
case DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY:
s->flag_compress = DUMP_DH_COMPRESSED_SNAPPY;
break;
default:
s->flag_compress = 0;
}
return;
}
if (dump_has_filter(s)) {
memory_mapping_filter(&s->list, s->filter_area_begin, s->filter_area_length);
}
/*
* The first section header is always a special one in which most
* fields are 0. The section header string table is also always
* set.
*/
s->shdr_num = 2;
/*
* Adds the number of architecture sections to shdr_num and sets
* elf_section_data_size so we know the offsets and sizes of all
* parts.
*/
if (s->dump_info.arch_sections_add_fn) {
s->dump_info.arch_sections_add_fn(s);
}
/*
* calculate shdr_num so we know the offsets and sizes of all
* parts.
* Calculate phdr_num
*
* The absolute maximum amount of phdrs is UINT32_MAX - 1 as
* sh_info is 32 bit. There's special handling once we go over
* UINT16_MAX - 1 but that is handled in the ehdr and section
* code.
*/
s->phdr_num = 1; /* Reserve PT_NOTE */
if (s->list.num <= UINT32_MAX - 1) {
s->phdr_num += s->list.num;
} else {
s->phdr_num = UINT32_MAX;
}
/*
* Now that the number of section and program headers is known we
* can calculate the offsets of the headers and data.
*/
if (dump_is_64bit(s)) {
s->shdr_offset = sizeof(Elf64_Ehdr);
s->phdr_offset = s->shdr_offset + sizeof(Elf64_Shdr) * s->shdr_num;
s->note_offset = s->phdr_offset + sizeof(Elf64_Phdr) * s->phdr_num;
} else {
s->shdr_offset = sizeof(Elf32_Ehdr);
s->phdr_offset = s->shdr_offset + sizeof(Elf32_Shdr) * s->shdr_num;
s->note_offset = s->phdr_offset + sizeof(Elf32_Phdr) * s->phdr_num;
}
s->memory_offset = s->note_offset + s->note_size;
s->section_offset = s->memory_offset + s->total_size;
return;
cleanup:
dump_cleanup(s);
}
/* this operation might be time consuming. */
static void dump_process(DumpState *s, Error **errp)
{
ERRP_GUARD();
DumpQueryResult *result = NULL;
if (s->has_format && s->format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP) {
create_win_dump(s, errp);
} else if (s->has_format && s->format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
create_kdump_vmcore(s, errp);
} else {
create_vmcore(s, errp);
}
/* make sure status is written after written_size updates */
smp_wmb();
qatomic_set(&s->status,
(*errp ? DUMP_STATUS_FAILED : DUMP_STATUS_COMPLETED));
/* send DUMP_COMPLETED message (unconditionally) */
result = qmp_query_dump(NULL);
/* should never fail */
assert(result);
qapi_event_send_dump_completed(result,
*errp ? error_get_pretty(*errp) : NULL);
qapi_free_DumpQueryResult(result);
dump_cleanup(s);
}
static void *dump_thread(void *data)
{
DumpState *s = (DumpState *)data;
dump_process(s, NULL);
return NULL;
}
DumpQueryResult *qmp_query_dump(Error **errp)
{
DumpQueryResult *result = g_new(DumpQueryResult, 1);
DumpState *state = &dump_state_global;
result->status = qatomic_read(&state->status);
/* make sure we are reading status and written_size in order */
smp_rmb();
result->completed = state->written_size;
result->total = state->total_size;
return result;
}
void qmp_dump_guest_memory(bool paging, const char *protocol,
bool has_detach, bool detach,
bool has_begin, int64_t begin,
bool has_length, int64_t length,
bool has_format, DumpGuestMemoryFormat format,
Error **errp)
{
ERRP_GUARD();
const char *p;
int fd;
DumpState *s;
bool detach_p = false;
bool kdump_raw = false;
if (runstate_check(RUN_STATE_INMIGRATE)) {
error_setg(errp, "Dump not allowed during incoming migration.");
return;
}
/* if there is a dump in background, we should wait until the dump
* finished */
if (qemu_system_dump_in_progress()) {
error_setg(errp, "There is a dump in process, please wait.");
return;
}
/*
* externally, we represent kdump-raw-* as separate formats, but internally
* they are handled the same, except for the "raw" flag
*/
if (has_format) {
switch (format) {
case DUMP_GUEST_MEMORY_FORMAT_KDUMP_RAW_ZLIB:
format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB;
kdump_raw = true;
break;
case DUMP_GUEST_MEMORY_FORMAT_KDUMP_RAW_LZO:
format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO;
kdump_raw = true;
break;
case DUMP_GUEST_MEMORY_FORMAT_KDUMP_RAW_SNAPPY:
format = DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY;
kdump_raw = true;
break;
default:
break;
}
}
/*
* kdump-compressed format need the whole memory dumped, so paging or
* filter is not supported here.
*/
if ((has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) &&
(paging || has_begin || has_length)) {
error_setg(errp, "kdump-compressed format doesn't support paging or "
"filter");
return;
}
if (has_begin && !has_length) {
error_setg(errp, QERR_MISSING_PARAMETER, "length");
return;
}
if (!has_begin && has_length) {
error_setg(errp, QERR_MISSING_PARAMETER, "begin");
return;
}
if (has_detach) {
detach_p = detach;
}
/* check whether lzo/snappy is supported */
#ifndef CONFIG_LZO
if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO) {
error_setg(errp, "kdump-lzo is not available now");
return;
}
#endif
#ifndef CONFIG_SNAPPY
if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY) {
error_setg(errp, "kdump-snappy is not available now");
return;
}
#endif
if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_WIN_DMP
&& !win_dump_available(errp)) {
return;
}
if (strstart(protocol, "fd:", &p)) {
fd = monitor_get_fd(monitor_cur(), p, errp);
if (fd == -1) {
return;
}
} else if (strstart(protocol, "file:", &p)) {
fd = qemu_create(p, O_WRONLY | O_TRUNC | O_BINARY, S_IRUSR, errp);
if (fd < 0) {
return;
}
} else {
error_setg(errp,
"parameter 'protocol' must start with 'file:' or 'fd:'");
return;
}
if (kdump_raw && lseek(fd, 0, SEEK_CUR) == (off_t) -1) {
close(fd);
error_setg(errp, "kdump-raw formats require a seekable file");
return;
}
if (!dump_migration_blocker) {
error_setg(&dump_migration_blocker,
"Live migration disabled: dump-guest-memory in progress");
}
/*
* Allows even for -only-migratable, but forbid migration during the
* process of dump guest memory.
*/
if (migrate_add_blocker_internal(&dump_migration_blocker, errp)) {
/* Remember to release the fd before passing it over to dump state */
close(fd);
return;
}
s = &dump_state_global;
dump_state_prepare(s);
dump_init(s, fd, has_format, format, paging, has_begin,
begin, length, kdump_raw, errp);
if (*errp) {
qatomic_set(&s->status, DUMP_STATUS_FAILED);
return;
}
if (detach_p) {
/* detached dump */
s->detached = true;
qemu_thread_create(&s->dump_thread, "dump_thread", dump_thread,
s, QEMU_THREAD_DETACHED);
} else {
/* sync dump */
dump_process(s, errp);
}
}
DumpGuestMemoryCapability *qmp_query_dump_guest_memory_capability(Error **errp)
{
DumpGuestMemoryCapability *cap =
g_new0(DumpGuestMemoryCapability, 1);
DumpGuestMemoryFormatList **tail = &cap->formats;
/* elf is always available */
QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_ELF);
/* kdump-zlib is always available */
QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB);
QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_RAW_ZLIB);
/* add new item if kdump-lzo is available */
#ifdef CONFIG_LZO
QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO);
QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_RAW_LZO);
#endif
/* add new item if kdump-snappy is available */
#ifdef CONFIG_SNAPPY
QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY);
QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_KDUMP_RAW_SNAPPY);
#endif
if (win_dump_available(NULL)) {
QAPI_LIST_APPEND(tail, DUMP_GUEST_MEMORY_FORMAT_WIN_DMP);
}
return cap;
}
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