From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Bader Subject: Xen 4.x / Linux 3.x (dom0 and HVM domU) and NIC handling Date: Thu, 01 Dec 2011 16:09:38 +0100 Message-ID: <4ED798B2.1040309@canonical.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: "xen-devel@lists.xensource.com" Cc: Ian Campbell , Stefano Stabellini List-Id: xen-devel@lists.xenproject.org Moving to public discussion... This was found with Xen hypervisor version supporting device unplugging and the domU kernel having net-/blkfront and pci platform built-in (or as module). The block device is defined as hda and the NIC type=ioemu (so theoretically guests without pv support would work, too). Since both drivers are present, the kernel tries to unplug the emulated devices and succeeds. The blkfront driver detects the xvda device available in parallel and is working ok. However the network interface does not work. There are entries present under sysfs for the xenbus but trying to bring it up fails with errors. And also there seems to be no mac address set (all zeros in sysfs). When the type=ioemu is removed in the configuration, this works. I have not much more debugging information beyond that, yet. But it sounds a bit like NICs should behave the same as block devices. So if there is an emulated device defined there will be an alternate paravirt interface for it and after unplugging the emulated ones we end up with the pv ones. Is that something that can be seen with newer Xen versions, too (I am using 4.1.1)? -Stefan