dump: make kdump-compressed format available for 'dump-guest-memory'
Make monitor command 'dump-guest-memory' be able to dump in kdump-compressed
format. The command's usage:
dump [-p] protocol [begin] [length] [format]
'format' is used to specified the format of vmcore and can be:
1. 'elf': ELF format, without compression
2. 'kdump-zlib': kdump-compressed format, with zlib-compressed
3. 'kdump-lzo': kdump-compressed format, with lzo-compressed
4. 'kdump-snappy': kdump-compressed format, with snappy-compressed
Without 'format' being set, it is same as 'elf'. And if non-elf format is
specified, paging and filter is not allowed.
Note:
1. The kdump-compressed format is readable only with the crash utility and
makedumpfile, and it can be smaller than the ELF format because of the
compression support.
2. The kdump-compressed format is the 6th edition.
Signed-off-by: Qiao Nuohan <qiaonuohan@cn.fujitsu.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
diff --git a/dump.c b/dump.c
index a7b5117..fb0c896 100644
--- a/dump.c
+++ b/dump.c
@@ -1443,6 +1443,64 @@
return ret;
}
+static int create_kdump_vmcore(DumpState *s)
+{
+ int ret;
+
+ /*
+ * the kdump-compressed format is:
+ * File offset
+ * +------------------------------------------+ 0x0
+ * | main header (struct disk_dump_header) |
+ * |------------------------------------------+ block 1
+ * | sub header (struct kdump_sub_header) |
+ * |------------------------------------------+ block 2
+ * | 1st-dump_bitmap |
+ * |------------------------------------------+ block 2 + X blocks
+ * | 2nd-dump_bitmap | (aligned by block)
+ * |------------------------------------------+ block 2 + 2 * X blocks
+ * | page desc for pfn 0 (struct page_desc) | (aligned by block)
+ * | page desc for pfn 1 (struct page_desc) |
+ * | : |
+ * |------------------------------------------| (not aligned by block)
+ * | page data (pfn 0) |
+ * | page data (pfn 1) |
+ * | : |
+ * +------------------------------------------+
+ */
+
+ ret = write_start_flat_header(s->fd);
+ if (ret < 0) {
+ dump_error(s, "dump: failed to write start flat header.\n");
+ return -1;
+ }
+
+ ret = write_dump_header(s);
+ if (ret < 0) {
+ return -1;
+ }
+
+ ret = write_dump_bitmap(s);
+ if (ret < 0) {
+ return -1;
+ }
+
+ ret = write_dump_pages(s);
+ if (ret < 0) {
+ return -1;
+ }
+
+ ret = write_end_flat_header(s->fd);
+ if (ret < 0) {
+ dump_error(s, "dump: failed to write end flat header.\n");
+ return -1;
+ }
+
+ dump_completed(s);
+
+ return 0;
+}
+
static ram_addr_t get_start_block(DumpState *s)
{
GuestPhysBlock *block;
@@ -1479,7 +1537,8 @@
s->max_mapnr = paddr_to_pfn(last_block->target_end, s->page_shift);
}
-static int dump_init(DumpState *s, int fd, bool paging, bool has_filter,
+static int dump_init(DumpState *s, int fd, bool has_format,
+ DumpGuestMemoryFormat format, bool paging, bool has_filter,
int64_t begin, int64_t length, Error **errp)
{
CPUState *cpu;
@@ -1487,6 +1546,11 @@
Error *err = NULL;
int ret;
+ /* kdump-compressed is conflict with paging and filter */
+ if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
+ assert(!paging && !has_filter);
+ }
+
if (runstate_is_running()) {
vm_stop(RUN_STATE_SAVE_VM);
s->resume = true;
@@ -1557,6 +1621,28 @@
tmp = DIV_ROUND_UP(DIV_ROUND_UP(s->max_mapnr, CHAR_BIT), s->page_size);
s->len_dump_bitmap = tmp * s->page_size;
+ /* init for kdump-compressed format */
+ if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
+ switch (format) {
+ case DUMP_GUEST_MEMORY_FORMAT_KDUMP_ZLIB:
+ s->flag_compress = DUMP_DH_COMPRESSED_ZLIB;
+ break;
+
+ case DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO:
+ s->flag_compress = DUMP_DH_COMPRESSED_LZO;
+ break;
+
+ case DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY:
+ s->flag_compress = DUMP_DH_COMPRESSED_SNAPPY;
+ break;
+
+ default:
+ s->flag_compress = 0;
+ }
+
+ return 0;
+ }
+
if (s->has_filter) {
memory_mapping_filter(&s->list, s->begin, s->length);
}
@@ -1616,14 +1702,25 @@
}
void qmp_dump_guest_memory(bool paging, const char *file, bool has_begin,
- int64_t begin, bool has_length, int64_t length,
- Error **errp)
+ int64_t begin, bool has_length,
+ int64_t length, bool has_format,
+ DumpGuestMemoryFormat format, Error **errp)
{
const char *p;
int fd = -1;
DumpState *s;
int ret;
+ /*
+ * kdump-compressed format need the whole memory dumped, so paging or
+ * filter is not supported here.
+ */
+ if ((has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) &&
+ (paging || has_begin || has_length)) {
+ error_setg(errp, "kdump-compressed format doesn't support paging or "
+ "filter");
+ return;
+ }
if (has_begin && !has_length) {
error_set(errp, QERR_MISSING_PARAMETER, "length");
return;
@@ -1633,6 +1730,21 @@
return;
}
+ /* check whether lzo/snappy is supported */
+#ifndef CONFIG_LZO
+ if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_LZO) {
+ error_setg(errp, "kdump-lzo is not available now");
+ return;
+ }
+#endif
+
+#ifndef CONFIG_SNAPPY
+ if (has_format && format == DUMP_GUEST_MEMORY_FORMAT_KDUMP_SNAPPY) {
+ error_setg(errp, "kdump-snappy is not available now");
+ return;
+ }
+#endif
+
#if !defined(WIN32)
if (strstart(file, "fd:", &p)) {
fd = monitor_get_fd(cur_mon, p, errp);
@@ -1657,14 +1769,21 @@
s = g_malloc0(sizeof(DumpState));
- ret = dump_init(s, fd, paging, has_begin, begin, length, errp);
+ ret = dump_init(s, fd, has_format, format, paging, has_begin,
+ begin, length, errp);
if (ret < 0) {
g_free(s);
return;
}
- if (create_vmcore(s) < 0 && !error_is_set(s->errp)) {
- error_set(errp, QERR_IO_ERROR);
+ if (has_format && format != DUMP_GUEST_MEMORY_FORMAT_ELF) {
+ if (create_kdump_vmcore(s) < 0 && !error_is_set(s->errp)) {
+ error_set(errp, QERR_IO_ERROR);
+ }
+ } else {
+ if (create_vmcore(s) < 0 && !error_is_set(s->errp)) {
+ error_set(errp, QERR_IO_ERROR);
+ }
}
g_free(s);
