[Qemu-devel] USB support

[Qemu-devel] USB support

[Fabrice Bellard]

Hi,

I just commited an initial USB support for QEMU. This USB layer will 
ultimately enable QEMU to use some host USB devices and to simulate USB 
devices.

WARNING: the current USB support is for USB hackers only - it is not 
meant to be fully usable yet.

The following features are implemented:

- PCI UHCI USB controller (I finally decided to implement UHCI because I 
know it better than OHCI and because Bochs has a similar driver. Of 
course it would still be very interesting to have an equivalent OHCI 
controller for non PC targets and an EHCI controller for USB 2.0 devices).

- Virtual USB 1.1 hub.

- Linux host USB redirector to use the USB 1.1 host devices which are 
not requested by the host OS (i.e. no host driver is loaded for them). 
It is *very* limited and buggy at the moment, but I was able (once !) to 
mount a disk-on-key flash device.

I plan to implement a USB mouse device as in Bochs just to have at least 
one "useful" virtual USB device to play with. Anyone is free to 
implement other devices by looking at the USB hub implementation in usb.c.

Fabrice.

Re: [Qemu-devel] USB support

[Volker Ruppert]

Hi,

> The following features are implemented:
>
> - PCI UHCI USB controller (I finally decided to implement UHCI because I
> know it better than OHCI and because Bochs has a similar driver. Of
> course it would still be very interesting to have an equivalent OHCI
> controller for non PC targets and an EHCI controller for USB 2.0 devices).

I compared the Qemu USB controller with the Bochs one using Ralph Brown's 
pcifg utility and found two different things.
- Bochs USB appears at function 2 of the PIIX3
- Bochs USB uses PIRQ line INTD
You can find both things in the PIIX3 documentation.

I tried the Qemu USB implementation with Win98 here. The hubs are detected 
correctly, but it makes Win98 hang on shutdown.

> - Linux host USB redirector to use the USB 1.1 host devices which are
> not requested by the host OS (i.e. no host driver is loaded for them).
> It is *very* limited and buggy at the moment, but I was able (once !) to
> mount a disk-on-key flash device.

I guess the host OS doesn't like modifing data on a mounted devices. It might 
be okay for input-only devices. I cannot try it here, since it requires root 
permissions.

--
Bye

Volker

Re: [Qemu-devel] USB support

[Fabrice Bellard]

Volker Ruppert wrote:
> Hi,
> 
> 
>>The following features are implemented:
>>
>>- PCI UHCI USB controller (I finally decided to implement UHCI because I
>>know it better than OHCI and because Bochs has a similar driver. Of
>>course it would still be very interesting to have an equivalent OHCI
>>controller for non PC targets and an EHCI controller for USB 2.0 devices).
> 
> 
> I compared the Qemu USB controller with the Bochs one using Ralph Brown's 
> pcifg utility and found two different things.
> - Bochs USB appears at function 2 of the PIIX3
> - Bochs USB uses PIRQ line INTD
> You can find both things in the PIIX3 documentation.

I'll try to update that.

> I tried the Qemu USB implementation with Win98 here. The hubs are detected 
> correctly, but it makes Win98 hang on shutdown.

I only tested with a Linux 2.4 guest OS. The USB mouse is working in X11 
and the USB hubs seem to work too.

>>- Linux host USB redirector to use the USB 1.1 host devices which are
>>not requested by the host OS (i.e. no host driver is loaded for them).
>>It is *very* limited and buggy at the moment, but I was able (once !) to
>>mount a disk-on-key flash device.
> 
> 
> I guess the host OS doesn't like modifing data on a mounted devices. It might 
> be okay for input-only devices. I cannot try it here, since it requires root 
> permissions.

I will add a documentation once it works better, but here are some 
information :

1) The host OS must not use the USB device. It means in particular that 
no host OS driver must be present for that device. The solution I am 
using is to rename the host kernel module "usb-storage.o" to 
"usb-storage.o.disabled" so that it is not loaded by Linux. Then QEMU 
can exclusively access to the corresponding host storage USB device. The 
same apply to every other type of USB devices.

2) In order not to launch QEMU as root, I changed the permissions in 
/proc/bus/usb : chown -R myuid /proc/bus/usb. I am sure it is possible 
to find a better solution !

3) Isosynchronous USB packets are not redirected yet, so host webcams 
have no chance to work.

Fabrice.

Re: [Qemu-devel] USB support

[Lonnie Mendez]

On Saturday 05 November 2005 11:10 am, Fabrice Bellard wrote: 
> 1) The host OS must not use the USB device. It means in particular that 
> no host OS driver must be present for that device. The solution I am 
> using is to rename the host kernel module "usb-storage.o" to 
> "usb-storage.o.disabled" so that it is not loaded by Linux. Then QEMU 
> can exclusively access to the corresponding host storage USB device. The 
> same apply to every other type of USB devices.

   usb devfs has a disconnect ioctl (USBDEVFS_DISCONNECT) which
allows you to disconnect a single device from a driver.

   A suggestion is to hook the interface up to qemu monitor.  Then you would 
be able to list usb devices and then claim only the ones you want to use.

Re: [Qemu-devel] USB support

[Mark Williamson]

> I just commited an initial USB support for QEMU. This USB layer will
> ultimately enable QEMU to use some host USB devices and to simulate USB
> devices.

Coolness!

> - Linux host USB redirector to use the USB 1.1 host devices which are
> not requested by the host OS (i.e. no host driver is loaded for them).
> It is *very* limited and buggy at the moment, but I was able (once !) to
> mount a disk-on-key flash device.

Had you thought of adding a minimal kernel module to allow "stealing" of host 
drivers for use by QEmu?  When I looked into this, I had the impression that 
the 2.6 USB code ought to be able to support it, although I'm not sure how it 
would interact with the userspace driver layer in your case.

Cheers,
Mark

> I plan to implement a USB mouse device as in Bochs just to have at least
> one "useful" virtual USB device to play with. Anyone is free to
> implement other devices by looking at the USB hub implementation in usb.c.
>
> Fabrice.
>
>
> _______________________________________________
> Qemu-devel mailing list
> Qemu-devel@nongnu.org
> http://lists.nongnu.org/mailman/listinfo/qemu-devel

Re: [Qemu-devel] USB support

[Paul Brook]

> > - Linux host USB redirector to use the USB 1.1 host devices which are
> > not requested by the host OS (i.e. no host driver is loaded for them).
> > It is *very* limited and buggy at the moment, but I was able (once !) to
> > mount a disk-on-key flash device.
>
> Had you thought of adding a minimal kernel module to allow "stealing" of
> host drivers for use by QEmu?  When I looked into this, I had the
> impression that the 2.6 USB code ought to be able to support it, although
> I'm not sure how it would interact with the userspace driver layer in your
> case.

Someone else already pointed out there's a usbdevfs ioctl for this.

Paul

Re: [Qemu-devel] USB support

[Fabrice Bellard]

Lonnie Mendez wrote:
> On Saturday 05 November 2005 11:10 am, Fabrice Bellard wrote: 
> 
>>1) The host OS must not use the USB device. It means in particular that 
>>no host OS driver must be present for that device. The solution I am 
>>using is to rename the host kernel module "usb-storage.o" to 
>>"usb-storage.o.disabled" so that it is not loaded by Linux. Then QEMU 
>>can exclusively access to the corresponding host storage USB device. The 
>>same apply to every other type of USB devices.
> 
> 
>    usb devfs has a disconnect ioctl (USBDEVFS_DISCONNECT) which
> allows you to disconnect a single device from a driver.
> 
>    A suggestion is to hook the interface up to qemu monitor.  Then you would 
> be able to list usb devices and then claim only the ones you want to use.

Good idea. I am adding something like that:

In the monitor:

'info usbhost' lists the available host USB devices

'usbhost_add 3.4' or 'usbhost_add 1234:5678' adds the USB host device on 
bus 3 at address 4 or the first one matching the vendor ID 0x1234 and 
product ID 0x5678.

The QEMU option '-usbhost x' can be used to do the same as usbhost_add.

Fabrice.

[Qemu-devel] USB support

[Marek Zelem]

[-- Attachment #1: Type: text/plain, Size: 1102 bytes --]


    Hi

I want to inform you that I successfully attached my Canon MP830
(printer, scanner, fax) to Qemu via USB.
It was not easy, I had to pass though two stoppages.

1. There is no support for multi port/config (do not know proper term
for that) USB devices in Qemu. Meaning that if single USB device
provides multiple functionalities (like printer, scanner, fax) it will
be rejected by Qemu.
Fortunately there is patch for that available on internet page
http://www.wina.at/uni/html/linux-qemu.html
(qemu-0.9.0-usb-multi-configs.patch).

2. When I applied the patch I hit another issue. When the USB device is
not ready it is automatically switched to HALT state (if I understood it
correctly) and additional ioctl USBDEVFS_CLEAR_HALT is required to give
device another chance. Thus, I have written patch for that issue. The
patch I am sending as attachment.

When I applied both patches, everything worked fine. I suggest to
include those two patches in Qemu.

Best regards

Marek Zelem

--
  e-mail: marek@terminus.sk
  web: http://marek.terminus.sk/
  pgp key: http://marek.terminus.sk/gpg.txt


[-- Attachment #2: qemu-0.9.0-usb-clrhalt.patch --]
[-- Type: text/x-patch, Size: 524 bytes --]

--- usb-linux.c.orig	2008-01-12 12:56:09.000000000 +0100
+++ usb-linux.c	2008-01-12 14:02:47.000000000 +0100
@@ -229,12 +229,14 @@
     if (ret < 0) {
         switch(errno) {
         case ETIMEDOUT:
+	    ret = ioctl(s->fd, USBDEVFS_CLEAR_HALT, &(bt.ep));
             return USB_RET_NAK;
         case EPIPE:
         default:
 #ifdef DEBUG
             printf("handle_data: errno=%d\n", errno);
 #endif
+	    ret = ioctl(s->fd, USBDEVFS_CLEAR_HALT, &(bt.ep));
             return USB_RET_STALL;
         }
     } else {

RE: [Qemu-devel] USB support

[Arnon Gilboa]

The multi-config patch is already merged in Qemu 9.1 

-----Original Message-----
From: qemu-devel-bounces+arnong=qumranet.com@nongnu.org
[mailto:qemu-devel-bounces+arnong=qumranet.com@nongnu.org] On Behalf Of
Marek Zelem
Sent: Saturday, February 09, 2008 5:34 PM
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] USB support


    Hi

I want to inform you that I successfully attached my Canon MP830
(printer, scanner, fax) to Qemu via USB.
It was not easy, I had to pass though two stoppages.

1. There is no support for multi port/config (do not know proper term
for that) USB devices in Qemu. Meaning that if single USB device
provides multiple functionalities (like printer, scanner, fax) it will
be rejected by Qemu.
Fortunately there is patch for that available on internet page
http://www.wina.at/uni/html/linux-qemu.html
(qemu-0.9.0-usb-multi-configs.patch).

2. When I applied the patch I hit another issue. When the USB device is
not ready it is automatically switched to HALT state (if I understood it
correctly) and additional ioctl USBDEVFS_CLEAR_HALT is required to give
device another chance. Thus, I have written patch for that issue. The
patch I am sending as attachment.

When I applied both patches, everything worked fine. I suggest to
include those two patches in Qemu.

Best regards

Marek Zelem

--
  e-mail: marek@terminus.sk
  web: http://marek.terminus.sk/
  pgp key: http://marek.terminus.sk/gpg.txt