From ef08fb389fe4ae4a8f7529ae3ec7b4274b7b5248 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Fri, 24 Feb 2017 18:28:30 +0000 Subject: 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 Reviewed-by: Laurent Vivier Reviewed-by: Juan Quintela Message-Id: <20170224182844.32452-3-dgilbert@redhat.com> Signed-off-by: Dr. David Alan Gilbert --- migration/ram.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) (limited to 'migration/ram.c') 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 { -- cgit v1.2.3