Add io.bus=usb for disks

doc/api-extensions.md

@@ -2756,3 +2756,7 @@ This adds an `allocated_time` field below `CPU` in the instance state API.
 ## `network_io_bus`
 
 This introduces a new `io.bus` property for compatible network devices allowing to choose between `virtio` (default) and `usb`.
+
+## `disk_io_bus_usb`
+
+Adds a new `usb` value for `io.bus` on `disk` devices.

doc/config_options.txt

@@ -83,6 +83,7 @@ For block devices (disks), this is one of:
 - `nvme`
 - `virtio-blk`
 - `virtio-scsi` (default)
+- `usb`
 
 For file systems (shared directories or custom volumes), this is one of:
 - `9p`

internal/server/device/disk.go

@@ -351,6 +351,7 @@ func (d *disk) validateConfig(instConf instance.ConfigReader) error {
 		// - `nvme`
 		// - `virtio-blk`
 		// - `virtio-scsi` (default)
+		// - `usb`
 		//
 		// For file systems (shared directories or custom volumes), this is one of:
 		// - `9p`
@@ -361,7 +362,7 @@ func (d *disk) validateConfig(instConf instance.ConfigReader) error {
 		//  default: `virtio-scsi` for block, `auto` for file system
 		//  required: no
 		//  shortdesc: Only for VMs: Override the bus for the device
-		"io.bus": validate.Optional(validate.IsOneOf("nvme", "virtio-blk", "virtio-scsi", "auto", "9p", "virtiofs")),
+		"io.bus": validate.Optional(validate.IsOneOf("nvme", "virtio-blk", "virtio-scsi", "auto", "9p", "virtiofs", "usb")),
 	}
 
 	err := d.config.Validate(rules)
@@ -1350,7 +1351,7 @@ func (d *disk) startVM() (*deviceConfig.RunConfig, error) {
 				}
 			} else {
 				// Confirm we're dealing with block options.
-				err := validate.Optional(validate.IsOneOf("nvme", "virtio-blk", "virtio-scsi"))(d.config["io.bus"])
+				err := validate.Optional(validate.IsOneOf("nvme", "virtio-blk", "virtio-scsi", "usb"))(d.config["io.bus"])
 				if err != nil {
 					return nil, err
 				}

internal/server/instance/drivers/driver_qemu.go

@@ -4366,6 +4366,9 @@ func (d *qemu) addDriveConfig(qemuDev map[string]any, bootIndexes map[string]int
 		}
 
 		qemuDev["driver"] = bus
+	} else if bus == "usb" {
+		qemuDev["driver"] = "usb-storage"
+		qemuDev["bus"] = "qemu_usb.0"
 	}
 
 	if bootIndexes != nil {

internal/server/metadata/configuration.json

@@ -88,7 +88,7 @@
 					{
 						"io.bus": {
 							"default": "`virtio-scsi` for block, `auto` for file system",
-							"longdesc": "This controls what bus a disk device should be attached to.\n\nFor block devices (disks), this is one of:\n- `nvme`\n- `virtio-blk`\n- `virtio-scsi` (default)\n\nFor file systems (shared directories or custom volumes), this is one of:\n- `9p`\n- `auto` (default) (`virtiofs` + `9p`, just `9p` if `virtiofsd` is missing)\n- `virtiofs`",
+							"longdesc": "This controls what bus a disk device should be attached to.\n\nFor block devices (disks), this is one of:\n- `nvme`\n- `virtio-blk`\n- `virtio-scsi` (default)\n- `usb`\n\nFor file systems (shared directories or custom volumes), this is one of:\n- `9p`\n- `auto` (default) (`virtiofs` + `9p`, just `9p` if `virtiofsd` is missing)\n- `virtiofs`",
 							"required": "no",
 							"shortdesc": "Only for VMs: Override the bus for the device",
 							"type": "string"

internal/version/api.go

@@ -473,6 +473,7 @@ var APIExtensions = []string{
 	"network_ovn_ipv4_dhcp_expiry",
 	"instance_state_cpu_time",
 	"network_io_bus",
+	"disk_io_bus_usb",
 }
 
 // APIExtensionsCount returns the number of available API extensions.