From 12a521b56d0538ca0363dd79db8f359cef40da69 Mon Sep 17 00:00:00 2001 From: Akihiko Odaki Date: Mon, 5 Jul 2021 22:04:57 +0900 Subject: block: Add backend_defaults property backend_defaults property allow users to control if default block properties should be decided with backend information. If it is off, any backend information will be discarded, which is suitable if you plan to perform live migration to a different disk backend. If it is on, a block device may utilize backend information more aggressively. By default, it is auto, which uses backend information for block sizes and ignores the others, which is consistent with the older versions. Signed-off-by: Akihiko Odaki Message-id: 20210705130458.97642-2-akihiko.odaki@gmail.com Signed-off-by: Stefan Hajnoczi --- hw/block/block.c | 42 ++++++++++++++++++++++++++++++++++++++---- 1 file changed, 38 insertions(+), 4 deletions(-) (limited to 'hw') diff --git a/hw/block/block.c b/hw/block/block.c index 1e34573da7..d47ebf005a 100644 --- a/hw/block/block.c +++ b/hw/block/block.c @@ -65,24 +65,58 @@ bool blkconf_blocksizes(BlockConf *conf, Error **errp) { BlockBackend *blk = conf->blk; BlockSizes blocksizes; - int backend_ret; + BlockDriverState *bs; + bool use_blocksizes; + bool use_bs; + + switch (conf->backend_defaults) { + case ON_OFF_AUTO_AUTO: + use_blocksizes = !blk_probe_blocksizes(blk, &blocksizes); + use_bs = false; + break; + + case ON_OFF_AUTO_ON: + use_blocksizes = !blk_probe_blocksizes(blk, &blocksizes); + bs = blk_bs(blk); + use_bs = bs; + break; + + case ON_OFF_AUTO_OFF: + use_blocksizes = false; + use_bs = false; + break; + + default: + abort(); + } - backend_ret = blk_probe_blocksizes(blk, &blocksizes); /* fill in detected values if they are not defined via qemu command line */ if (!conf->physical_block_size) { - if (!backend_ret) { + if (use_blocksizes) { conf->physical_block_size = blocksizes.phys; } else { conf->physical_block_size = BDRV_SECTOR_SIZE; } } if (!conf->logical_block_size) { - if (!backend_ret) { + if (use_blocksizes) { conf->logical_block_size = blocksizes.log; } else { conf->logical_block_size = BDRV_SECTOR_SIZE; } } + if (use_bs) { + if (!conf->opt_io_size) { + conf->opt_io_size = bs->bl.opt_transfer; + } + if (conf->discard_granularity == -1) { + if (bs->bl.pdiscard_alignment) { + conf->discard_granularity = bs->bl.pdiscard_alignment; + } else if (bs->bl.request_alignment != 1) { + conf->discard_granularity = bs->bl.request_alignment; + } + } + } if (conf->logical_block_size > conf->physical_block_size) { error_setg(errp, -- cgit v1.2.3