Pierre Riteau wrote: > On 30 nov. 2009, at 19:50, Pierre Riteau wrote: > >> I'm currently testing these patches. Here are a few issues I noticed, before I forget about them. >> >> - "migrate -d -b tcp:dest:port" works, but "migrate -b -d tcp:dest:port" doesn't, although "help migrate" doesn't really specify ordering as important. But anyway I think Liran is working on a new version of the command. >> - We use bdrv_aio_readv() to read blocks from the disk. This function increments rd_bytes and rd_ops, which are reported by "info blockstats". I don't think this read operations should appear in VM activity, especially if this interface is used by libvirt to report VM stats (and draw graphs in virt-manager, etc.). Same for write stats. >> - We may need to call bdrv_reset_dirty() _before_ sending the data, to be sure the block is not rewritten in the meantime (maybe it's an issue only with kvm?) >> - I seem to remember that disk images with 0 size are now possible. I'm afraid we will hit a divide by zero in this case: "progress = completed_sector_sum * 100 / block_mig_state.total_sector_sum;" >> >> Apart from that, it works quite fine. Still a few things to cleanup (e.g. unused constants) but much better than before. >> However, I haven't tested the incremental transfer support at all yet. It's on my todo list. > > BTW, of these four issues, only the last one is related to Jan changes. The others were there before. > This is for saying that I strongly agree with the patch series. > That should catch it (yet untested, though). Jan -----> block migration: Skip zero-sized disks No need to migrate emptiness (risking divide by zero later on). Signed-off-by: Jan Kiszka --- block-migration.c | 10 ++++++++-- 1 files changed, 8 insertions(+), 2 deletions(-) diff --git a/block-migration.c b/block-migration.c index a5735b7..98f36a4 100644 --- a/block-migration.c +++ b/block-migration.c @@ -222,6 +222,7 @@ static void init_blk_migration(Monitor *mon, QEMUFile *f) { BlkMigDevState *bmds; BlockDriverState *bs; + int64_t sectors; block_mig_state.submitted = 0; block_mig_state.read_done = 0; @@ -231,14 +232,19 @@ static void init_blk_migration(Monitor *mon, QEMUFile *f) for (bs = bdrv_first; bs != NULL; bs = bs->next) { if (bs->type == BDRV_TYPE_HD) { + sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS; + if (sectors == 0) { + continue; + } + bmds = qemu_mallocz(sizeof(BlkMigDevState)); bmds->bs = bs; bmds->bulk_completed = 0; - bmds->total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS; + bmds->total_sectors = sectors; bmds->completed_sectors = 0; bmds->shared_base = block_mig_state.shared_base; - block_mig_state.total_sector_sum += bmds->total_sectors; + block_mig_state.total_sector_sum += sectors; if (bmds->shared_base) { monitor_printf(mon, "Start migration for %s with shared base "