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authorDr. David Alan Gilbert <dgilbert@redhat.com>2017-02-24 18:28:30 +0000
committerDr. David Alan Gilbert <dgilbert@redhat.com>2017-02-28 11:30:23 +0000
commitef08fb389fe4ae4a8f7529ae3ec7b4274b7b5248 (patch)
tree5d8d8a9ba70e62bd676b038cdd0b9fad76e56abf /migration
parente8ca1db29b349e780743c504cb735c8e1d542a8c (diff)
postcopy: Transmit and compare individual page sizes
When using postcopy with hugepages, we require the source and destination page sizes for any RAMBlock to match; note that different RAMBlocks in the same VM can have different page sizes. Transmit them as part of the RAM information header and fail if there's a difference. Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> Reviewed-by: Laurent Vivier <lvivier@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Message-Id: <20170224182844.32452-3-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Diffstat (limited to 'migration')
-rw-r--r--migration/ram.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/migration/ram.c b/migration/ram.c
index 1f6397a26d..fbd987a340 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -2027,6 +2027,9 @@ static int ram_save_setup(QEMUFile *f, void *opaque)
qemu_put_byte(f, strlen(block->idstr));
qemu_put_buffer(f, (uint8_t *)block->idstr, strlen(block->idstr));
qemu_put_be64(f, block->used_length);
+ if (migrate_postcopy_ram() && block->page_size != qemu_host_page_size) {
+ qemu_put_be64(f, block->page_size);
+ }
}
rcu_read_unlock();
@@ -2528,6 +2531,8 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
* be atomic
*/
bool postcopy_running = postcopy_state_get() >= POSTCOPY_INCOMING_LISTENING;
+ /* ADVISE is earlier, it shows the source has the postcopy capability on */
+ bool postcopy_advised = postcopy_state_get() >= POSTCOPY_INCOMING_ADVISE;
seq_iter++;
@@ -2592,6 +2597,18 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
error_report_err(local_err);
}
}
+ /* For postcopy we need to check hugepage sizes match */
+ if (postcopy_advised &&
+ block->page_size != qemu_host_page_size) {
+ uint64_t remote_page_size = qemu_get_be64(f);
+ if (remote_page_size != block->page_size) {
+ error_report("Mismatched RAM page size %s "
+ "(local) %zd != %" PRId64,
+ id, block->page_size,
+ remote_page_size);
+ ret = -EINVAL;
+ }
+ }
ram_control_load_hook(f, RAM_CONTROL_BLOCK_REG,
block->idstr);
} else {