David Ahern wrote:
On 03/09/11 14:28, Erik Rull wrote:
David Ahern wrote:
I've tried it long time ago with kvm-88, but there it was working but
extremely slow. (At least the mouse was reacting there)
I thought you tried the EHCI patch against a recent qemu-kvm version --
like December 2010 or January 2011.
Yes, this time I patched against 0.14.0, I misunderstood your question, sorry.
My last attempt before that was kvm-88.
Hm, okay.
As far as I understood it, the auto-add feature should be similar to the
USB 1.1, right? It seems to work basically but not fully - the system is
somehow slowed down, maybe the polling timer is too fast? (I will play a
little bit with that and review and compare as well the auto routine)
And the usb-tablet should be an uhci-emulated component, that should
then not interfere with the ehci-emulation, right?
My proposal from July 2010 was to have emulated devices state their
version and have host devices try EHCI then UHCI. This means that the
tablet device is attached to UHCI and a host USB key is attached to
EHCI. Like this:
info usb
Device 0.1, Port 1, Speed 12 Mb/s, Product QEMU USB Tablet
Device 1.1, Port , Speed 480 Mb/s, Product DT 101 II
(qemu)
That's what the patch I sent does.
EHCI does have a lot higher frame rate and in its current form does have
a noticeable impact on CPU usage when devices are connected and one of
the lists is activated. If the OS deactivates the controller when there
is nothing to do (e.g., not actively talking to the device), cpu usage
goes down.
Thanks for the explanation!
I just tried a few scenarios with the X and V versions of those GUI
based guests and an external key attached to EHCI bus worked fine and
the usb tablet also worked fine.
I did notice some differences in command syntax. For instance, my
scripts still use the older -usbdevice tablet syntax and I did not see
the USB stall message. Switching to '-device usb-tablet' did generate
the message at boot (though overall it seems to be harmless).
Nothing fancy with the setup -- ide drive, virtio or e1000 networking,
ac97 sound, no-hpet and usb tablet devices.
In the time it took to write this response about 900MB was transferred
to the usb key at about 1.7-1.8MB/sec rate.
David
I will give it another try tomorrow. I use
-usb -device usb-tablet -device usb-host
The last parameter for the auto-add to the guest
I will also try the old parameter syntax.
What does the no-hpet option do? Might this be somehow significant
regarding the performance?
Best regards,
Erik
P.S.
When EHCI was active today without tablet and without auto-add I got a
transfer rate of ~5MByte/sec from USB key to the HDD.
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