<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv="Content-Type" content="text/html; charset=gb2312"> <meta name="Generator" content="Microsoft Word 14 (filtered medium)"> <style></style> </head> <body lang="ZH-CN" link="blue" vlink="purple"> <div class="WordSection1"> Can you see the USB device in the lxc?<o:p></o:p> My answering assumes you cannot see the USB device in the container. If you can see it, please ignore my answer.<o:p></o:p> According to my understanding, “hostdev mode='subsystem' “ is used with KVM only. We use this if we want to passthrough a device to a KVM virtual machine. After doing that, the host machine will lose control of the device. If container is used, the container is not a real virtual machine, it’s just a group of processes and it shares the OS kernel with the host. If a device cannot be seen by the host machine, I guess it also cannot been seen by the container.<o:p></o:p> I used the following XML scripts to expose a third-party PCIe card to the container successfully, and I can access the card in the lxc.<o:p></o:p> <hostdev mode=’capabilities’ type=’misc’><o:p></o:p> <source><o:p></o:p> <char/dev/mydevice</char><o:p></o:p> </source><o:p></o:p> </hostdev><o:p></o:p> Although I am not sure if my card is a char device, but it really works.<o:p></o:p> If I use “ hostdev mode=’subsystem’”, it will fail to expose the PCIe card.<o:p></o:p> <o:p> </o:p> From: Filip Maj [mailto:fil@saucelabs.com] Sent: 2014年4月14日 11:26 To: WANG Cheng D Cc: libvirt-users@redhat.com Subject: RE: [libvirt-users] LXC + USB passthrough = Operation not permitted<o:p></o:p> <o:p> </o:p> Hi Chang Weng,<o:p></o:p> Thanks for answering!<o:p></o:p> Could you explain why subsystem=USB does not make sense? I was simply following the documentation for USB devices (right above the section you linked to).<o:p></o:p> For what it's worth, I've also tried mounting the specific character device related to the appropriate android device into the container in the way you suggest, with no luck; `adb` still does not recognize the device.<o:p></o:p> <div> On Apr 13, 2014 7:10 PM, "WANG Cheng D" <<a href="mailto:Cheng.d.Wang@alcatel-sbell.com.cn">Cheng.d.Wang@alcatel-sbell.com.cn</a>> wrote:<o:p></o:p> <div> <div> Dear Fil,<o:p></o:p> I am not sure if my answer can help you.<o:p></o:p> I had ever asked a similar question to Daniel and I was using a thirty-party card. As a container uses a shared kernel with the host, so hostdev mode='subsystem' doesn’t make sense. Maybe you can try to use hostdev mode='capabilities’. Please see <a href="http://libvirt.org/formatdomain.html#elementsHostDevCaps" target="_blank"> http://libvirt.org/formatdomain.html#elementsHostDevCaps</a><o:p></o:p> Hope this helps<o:p></o:p> Cheng Wang<o:p></o:p> <o:p></o:p> </div> </div> </div> </div> </body> </html>