[vfio-users] Q35's default bus ID

[Nu Tiu]

Hello Guys,

I have been playing with qemu-kvm & ovmf with GPU passthrough on my
ubuntu machine.  I got almost everything up and running smoothly,
except one little detail. I am setting up an experimental ubuntu vm
and play around with usb devices.

When I set up a blank q35 machine by:

     -M q35,usb=on -nodefaults \

I find the following USB controllers on lspci:

00:1d.0 USB controller: Intel Corporation 82801I (ICH9 Family) USB
UHCI Controller #1 (rev 03)
00:1d.1 USB controller: Intel Corporation 82801I (ICH9 Family) USB
UHCI Controller #2 (rev 03)
00:1d.2 USB controller: Intel Corporation 82801I (ICH9 Family) USB
UHCI Controller #3 (rev 03)
00:1d.7 USB controller: Intel Corporation 82801I (ICH9 Family) USB2
EHCI Controller #1 (rev 03)

Looks good, and I can attach a device to 0x1d.7 (the USB2 EHCI
controller), by referring to it this way:

    -device usb-storage,drive=disk0,id=usbdisk0,bus=usb-bus.0

But I would like to know how can I attach a USB device to other
controllers? What would their bus name/id be? Currently, I am
attaching the host's keyboard and mouse, but they go on different
controllers because I have no control. The keyboard and mouse are
currently attached with:

   -device usb-host,vendorid=0x0557,productid=0x2221 \
   -device usb-host,vendorid=0x093a,productid=0x2510 \

Your help will be greatly appreciated.  If this is so unrelated to
VFIO, I apologize, and please give me advice on where to find more
information and answer.

Thanks a lot in advance,
-Nu

---------------------------------------------------------------------
PS: I also know that the SATA bus on q35 is ide

My full qemu command line is:

sudo qemu-system-x86_64 \
-m 2048 \
-enable-kvm \
-cpu host \
-M q35,accel=kvm,usb=on,vmport=off \
-bios OVMF-pure-efi.fd \
-nodefaults \
\
-device i82801b11-bridge,id=pci.0,bus=pcie.0,addr=0x1e \
\
-device ide-hd,bus=ide.0,drive=MacOSX,bootindex=2 \
-drive id=MacOSX,if=none,file=disk0-linux.img,format=qcow2  \
\
-device ide-cd,bus=ide.1,drive=sata0-1 \
-drive id=sata0-1,if=none,file=/samba/playground/virtio-win-0.1.112.iso,format=raw,media=cdrom,readonly=on
\
\
-device usb-storage,drive=drive-usb-disk0,id=usb-disk0,bootindex=1,removable=off
\
-drive file=/samba/playground/ubuntu-15.10-desktop-amd64.iso,if=none,media=cdrom,id=drive-usb-disk0,readonly=on,format=raw
\
\
-device usb-host,vendorid=0x0557,productid=0x2221 \
-device usb-host,vendorid=0x093a,productid=0x2510 \
\
-nographic \
-device vfio-pci,host=01:00.0,id=hostdev0,bus=pcie.0,multifunction=on \
-device vfio-pci,host=00:1b.0,id=hostdev1,bus=pcie.0 \
-serial stdio \