vhost_blk is a host-side kernel mode accelerator for virtio-blk. The driver allows VM to reach a near bare-metal disk performance. See IOPS numbers below (fio --rw=randread --bs=4k). This implementation uses kiocb interface. It is slightly slower than going directly through bio, but is simpler and also works with disk images placed on a file system. # fio num-jobs # A: bare metal over block # B: bare metal over file # C: virtio-blk over block # D: virtio-blk over file # E: vhost-blk bio over block # F: vhost-blk kiocb over block # G: vhost-blk kiocb over file # # A B C D E F G 1 171k 151k 148k 151k 195k 187k 175k 2 328k 302k 249k 241k 349k 334k 296k 3 479k 437k 179k 174k 501k 464k 404k 4 622k 568k 143k 183k 620k 580k 492k 5 755k 697k 136k 128k 737k 693k 579k 6 887k 808k 131k 120k 830k 782k 640k 7 1004k 926k 126k 131k 926k 863k 693k 8 1099k 1015k 117k 115k 1001k 931k 712k 9 1194k 1119k 115k 111k 1055k 991k 711k 10 1278k 1207k 109k 114k 1130k 1046k 695k 11 1345k 1280k 110k 108k 1119k 1091k 663k 12 1411k 1356k 104k 106k 1201k 1142k 629k 13 1466k 1423k 106k 106k 1260k 1170k 607k 14 1517k 1486k 103k 106k 1296k 1179k 589k 15 1552k 1543k 102k 102k 1322k 1191k 571k 16 1480k 1506k 101k 102k 1346k 1202k 566k Vitaly Mayatskikh (1): Add vhost_blk driver drivers/vhost/Kconfig | 13 ++ drivers/vhost/Makefile | 3 + drivers/vhost/blk.c | 510 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 526 insertions(+) create mode 100644 drivers/vhost/blk.c -- 2.17.1
