From b91e013982e8bd44833974128f1581e427082880 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Thu, 23 Jun 2016 09:45:01 +0200 Subject: [PATCH] usb: add storage hotplug documentation Suggested-by: Paolo Bonzini Signed-off-by: Gerd Hoffmann Message-id: 1466667901-1341-1-git-send-email-kraxel@redhat.com --- docs/usb-storage.txt | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/docs/usb-storage.txt b/docs/usb-storage.txt index c5a3866eeb..fbc1f2edd8 100644 --- a/docs/usb-storage.txt +++ b/docs/usb-storage.txt @@ -40,6 +40,18 @@ numbers must be continuous, i.e. for three devices you must use 0+1+2. The 0+1+5 numbering from the "usb-uas" example isn't going to work with "usb-bot". +Starting with qemu version 2.7 usb-bot and usb-uas devices can be +hotplugged. In the hotplug case they are added with "attached = +false" so the guest will not see the device until the "attached" +property is explicitly set to true. That allows to attach one or more +scsi devices before making the device visible to the guest, i.e. the +workflow looks like this: + + (1) device-add usb-bot,id=foo + (2) device-add scsi-{hd,cd},bus=foo.0,lun=0 + (2b) optionally add more devices (luns 1 ... 15). + (3) scripts/qmp/qom-set foo.attached = true + enjoy, Gerd