From: Nikolay Borisov <nbori...@suse.com>
Add the necessary code to parse the format changes for the 'fixed-ram'
capability.
One of the more notable changes in behavior is that in the 'fixed-ram'
case ram pages are restored in one go rather than constantly looping
through the migration stream.
Signed-off-by: Nikolay Borisov <nbori...@suse.com>
Signed-off-by: Fabiano Rosas <faro...@suse.de>
---
(farosas) reused more of the common code by making the fixed-ram
function take only one ramblock and calling it from inside
parse_ramblock.
---
migration/ram.c | 93 +++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 93 insertions(+)
diff --git a/migration/ram.c b/migration/ram.c
index 152a03604f..cea6971ab2 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -3032,6 +3032,32 @@ static void fixed_ram_insert_header(QEMUFile *file,
RAMBlock *block)
qemu_put_buffer(file, (uint8_t *) header, header_size);
}
+static int fixed_ram_read_header(QEMUFile *file, struct FixedRamHeader *header)
+{
+ size_t ret, header_size = sizeof(struct FixedRamHeader);
+
+ ret = qemu_get_buffer(file, (uint8_t *)header, header_size);
+ if (ret != header_size) {
+ return -1;
+ }
+
+ /* migration stream is big-endian */
+ be32_to_cpus(&header->version);
+
+ if (header->version > FIXED_RAM_HDR_VERSION) {
+ error_report("Migration fixed-ram capability version mismatch
(expected %d, got %d)",
+ FIXED_RAM_HDR_VERSION, header->version);
+ return -1;
+ }
+
+ be64_to_cpus(&header->page_size);
+ be64_to_cpus(&header->bitmap_offset);
+ be64_to_cpus(&header->pages_offset);
+
+
+ return 0;
+}
+
/*
* Each of ram_save_setup, ram_save_iterate and ram_save_complete has
* long-running RCU critical section. When rcu-reclaims in the code
@@ -3932,6 +3958,68 @@ void colo_flush_ram_cache(void)
trace_colo_flush_ram_cache_end();
}
+static void read_ramblock_fixed_ram(QEMUFile *f, RAMBlock *block,
+ long num_pages, unsigned long *bitmap)
+{
+ unsigned long set_bit_idx, clear_bit_idx;
+ unsigned long len;
+ ram_addr_t offset;
+ void *host;
+ size_t read, completed, read_len;
+
+ for (set_bit_idx = find_first_bit(bitmap, num_pages);
+ set_bit_idx < num_pages;
+ set_bit_idx = find_next_bit(bitmap, num_pages, clear_bit_idx + 1)) {
+
+ clear_bit_idx = find_next_zero_bit(bitmap, num_pages, set_bit_idx + 1);
+
+ len = TARGET_PAGE_SIZE * (clear_bit_idx - set_bit_idx);
+ offset = set_bit_idx << TARGET_PAGE_BITS;
+
+ for (read = 0, completed = 0; completed < len; offset += read) {
+ host = host_from_ram_block_offset(block, offset);
+ read_len = MIN(len, TARGET_PAGE_SIZE);
+
+ read = qemu_get_buffer_at(f, host, read_len,
+ block->pages_offset + offset);
+ completed += read;
+ }
+ }
+}
+
+static int parse_ramblock_fixed_ram(QEMUFile *f, RAMBlock *block, ram_addr_t
length)
+{
+ g_autofree unsigned long *bitmap = NULL;
+ struct FixedRamHeader header;
+ size_t bitmap_size;
+ long num_pages;
+ int ret = 0;
+
+ ret = fixed_ram_read_header(f, &header);
+ if (ret < 0) {
+ error_report("Error reading fixed-ram header");
+ return -EINVAL;
+ }
+
+ block->pages_offset = header.pages_offset;
+ num_pages = length / header.page_size;
+ bitmap_size = BITS_TO_LONGS(num_pages) * sizeof(unsigned long);
+
+ bitmap = g_malloc0(bitmap_size);
+ if (qemu_get_buffer_at(f, (uint8_t *)bitmap, bitmap_size,
+ header.bitmap_offset) != bitmap_size) {
+ error_report("Error parsing dirty bitmap");
+ return -EINVAL;
+ }
+
+ read_ramblock_fixed_ram(f, block, num_pages, bitmap);
+
+ /* Skip pages array */
+ qemu_set_offset(f, block->pages_offset + length, SEEK_SET);
+
+ return ret;
+}
+
static int parse_ramblock(QEMUFile *f, RAMBlock *block, ram_addr_t length)
{
int ret = 0;
@@ -3940,6 +4028,10 @@ static int parse_ramblock(QEMUFile *f, RAMBlock *block,
ram_addr_t length)
assert(block);
+ if (migrate_fixed_ram()) {
+ return parse_ramblock_fixed_ram(f, block, length);
+ }
+
if (!qemu_ram_is_migratable(block)) {
error_report("block %s should not be migrated !", block->idstr);
return -EINVAL;
@@ -4142,6 +4234,7 @@ static int ram_load_precopy(QEMUFile *f)
migrate_multifd_flush_after_each_section()) {
multifd_recv_sync_main();
}
+
break;
case RAM_SAVE_FLAG_HOOK:
ret = rdma_registration_handle(f);
--
2.35.3
