From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gerd Hoffmann Subject: qemu & xhci mini howto (was: Re: [Qemu-devel] [ANNOUNCE] qemu-kvm-1.1-rc3) Date: Tue, 29 May 2012 10:32:07 +0200 Message-ID: <4FC48987.2060103@redhat.com> References: <4FBCA8EE.1060708@redhat.com> <4FC345D2.3090309@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Veruca Salt , qemu-devel , QEMU-KVM Mailing List To: Avi Kivity Return-path: Received: from mx1.redhat.com ([209.132.183.28]:23397 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751610Ab2E2IcO (ORCPT ); Tue, 29 May 2012 04:32:14 -0400 In-Reply-To: <4FC345D2.3090309@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 05/28/12 11:30, Avi Kivity wrote: > On 05/25/2012 11:36 AM, Veruca Salt wrote: >> >> Avi- would love to test out 1.1, as we are currently using the ehci method >> which has been frozen at 'experimental' for so long. >> >> Is there any user documentation on the xhci methods? > > Copying qemu-devel, where someone may know the answer. There are no docs. But xhci can handle all devices by itself, no need to do all this companion controller stuff you have to do with ehci for usb 1.1 compatibility. Thus it's pretty simple actually: (1) You add the xhci host adapter: qemu $args -device nec-usb-xhci,id=xhci (2) You add usb devices devices as usual: qemu $args -device usb-tablet,bus=xhci.0 (3) There is no third step ;) Advantages of xhci: * higher performance, less cpu overhead (thanks to the virtualization/emulation friendly hardware design). Known issues (for qemu 1.1, list hopefully becomes shorter for 1.2): * Got less testing than ehci. * No usb-hub support yet (i.e. you are limited to the 4 root ports, but as the qemu-emulated usb hub supports usb 1.1 only you probably want avoid it anyway ...). * No usb 3.0 ports yet. * No isochronous transfer support yet. * No seabios support yet (i.e. you can't boot from xhci-connected usbsticks). cheers, Gerd