From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@bugzilla.kernel.org Subject: [Bug 196527] Terrible KVM USB passthrough performance Date: Thu, 10 Aug 2017 12:34:25 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT To: kvm@kernel.org Return-path: Received: from mail.wl.linuxfoundation.org ([198.145.29.98]:56972 "EHLO mail.wl.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751387AbdHJMe1 (ORCPT ); Thu, 10 Aug 2017 08:34:27 -0400 Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 59C2328A10 for ; Thu, 10 Aug 2017 12:34:27 +0000 (UTC) In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: https://bugzilla.kernel.org/show_bug.cgi?id=196527 heyark (kvm-usb@suremail.info) changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |kvm-usb@suremail.info --- Comment #1 from heyark (kvm-usb@suremail.info) --- I have to agree here. In my case, I tried to use two USB devices inside a KVM VM - and failed with both due to timeout issues. I pass them through to the VM using kvm parameters -usb -usbdevice host:[vendorId]:[deviceId]. They are visible inside using lsusb. But trying to access them, both cannot be used, while there is no problem using them directly on the host machine (current Ubuntu 16.04.3 on a Core i5 7500). One is a HomeMatic USB-sender (http://www.fhemwiki.de/wiki/HM-CFG-USB_USB_Konfigurations-Adapter), the other one is a smartcard reader. In case of the Homematic, the driver (hmland) always says: usb-transfer took more than 100ms (125ms), this may lead to timing problems! And the warning is right: nothing works, nothing gets received (using the stick outside the VM works great). Maybe the usb passthrough works generally with less sensible devices (did not try an USB stick or something), but obviously the performance in handling this is so bad, that any device that needs a proper timing is not usable. Probably USB devices at servers are rare in the professional environments where kvm is heavily used, nonetheless this is very disappointing. It definitely limits the use of KVM virtualization. Probably not a good sign too, that the following page is empty: https://www.linux-kvm.org/page/UsbPassthrough Is there any chance this will be cared for soon? Some kind of higher priority for handling the USB passthrough? Thanks! -- You are receiving this mail because: You are watching the assignee of the bug.