1.\" 2.\" This file and its contents are supplied under the terms of the 3.\" Common Development and Distribution License ("CDDL"), version 1.0. 4.\" You may only use this file in accordance with the terms of version 5.\" 1.0 of the CDDL. 6.\" 7.\" A full copy of the text of the CDDL should have accompanied this 8.\" source. A copy of the CDDL is also available via the Internet at 9.\" http://www.illumos.org/license/CDDL. 10.\" 11.\" 12.\" Copyright 2020 Oxide Computer Company 13.\" 14.Dd August 28, 2021 15.Dt VIOBLK 4D 16.Os 17.Sh NAME 18.Nm vioblk 19.Nd virtio block device 20.Sh SYNOPSIS 21.Pa /dev/dsk/cXt0d0 22.Pa /dev/rdsk/cXt0d0 23.Sh DESCRIPTION 24The 25.Nm 26driver is a 27.Xr blkdev 4D 28based device that supports the virtio para-virtualization block device 29specification which is commonly used by many hypervisors and emulators. 30The device supports what the specification calls the more commonly found 31.Sq legacy 32interface for devices. 33.Pp 34The driver supports the following features, if offered by the device: 35.Bl -dash 36.It 37Volatile write-cache 38.It 39Discarding unused sectors 40.Pq ala TRIM, UNMAP 41.It 42Read-only device support 43.It 44Physical block sizes that are distinct from logical 512-byte blocks 45.It 46Synthesized disk geometry 47.El 48.Sh APPLICATION PROGRAMMING INTERFACE 49For each device instance, a 50.Xr blkdev 4D 51instance is created and treated as an independent controller with a 52single device, meaning that the 53.Em cX 54part of 55.Em cXt0d0 56will vary for each device. 57Because the driver leverages the 58.Xr blkdev 4D 59framework, most standard disk manipulation utilities will function such 60as 61.Xr diskinfo 8 62for discovering devices, 63.Xr format 8 64for manipulating partition tables, 65.Xr iostat 8 66for seeing device I/O statistics, and a subset of the 67.Xr dkio 4I 68ioctl requests to retrieve information about the device. 69.Sh ARCHITECTURE 70The 71.Nm 72driver is only supported on 73.Sy x86 . 74.Sh FILES 75.Bl -tag -width Pa 76.It Pa /dev/dsk/cXt0d0 77Block device minor node. 78.It Pa /dev/rdsk/cXt0d0 79Character device minor node. 80.It Pa /kernel/drv/amd64/vioblk 81x86 device driver. 82.El 83.Sh SEE ALSO 84.Xr blkdev 4D , 85.Xr virtio 4D , 86.Xr dkio 4I , 87.Xr diskinfo 8 88.Rs 89.%T Virtual I/O Device (VIRTIO) Version 1.1 90.%D April, 2019 91.%U https://docs.oasis-open.org/virtio/virtio/v1.1/virtio-v1.1.html 92.Re 93