Yeah I see. In virt-manager ,aarch64 can realize hotplug by virtio-scsi . Thanks Cole ~ On Mon, 13 Jun 2016 at 22:07 Cole Robinson <crobinso@redhat.com> wrote:
Hi Cole, Thanks for your kindly help.
On 13 June 2016 at 06:21, Cole Robinson <crobinso@redhat.com <mailto:crobinso@redhat.com>> wrote:
On 06/12/2016 10:29 AM, Kevin Zhao wrote: > Hi Cole && All, > Nice meeting you in the libvirt mail-list. Greetings from Linaro !!! > I am Kevin Zhao from Linaro and working for OpenStack on Aarch64. > Nowadays I find that the default "virtio" bus is "virtio-mmio" , not > "virtio-pci". Since virtio-mmio do not has the host plugged function , > something is wrong with the function in OpenStack Nova. > > Then I search and find some mail information as belows by Cole :-) > 1) https://www.redhat.com/archives/libvir-list/2015-December/msg00217.html > 2) https://www.redhat.com/archives/libvir-list/2016-March/msg00167.html > > I see some efforts have been doing by you. Really thanks for your > efforts for Aarch64. And I have some small questions. > 1. Is Libvirt planning to replace the default virtio-mmio to virtio-pci > for Aarch64?
We have vague plans to maybe change the virtio-mmio default to virtio-pci at some future point, based on some new enough qemu machine type. But
On 06/12/2016 10:08 PM, Kevin Zhao wrote: the main
blocker is that most linux distributions currently don't work out of
the box
with virtio-pci, at least Fedora doesn't as far as I know. So
changing the
default now is pre-mature
OK . Hope it will be true in the future.
> 2. If not , how can I change the xml file(generated by
Virsh) for
> virtio-pci so that Qemu can recognize it ? >
The latest libvirt-1.3.5 release accepts device XML containing
<address
type='pci'/> . The address block is an explicit request to libvirt to 'allocate a PCI address' rather than the default virtio-mmio. So for
example
if you want to specify a virtio nic, but have it use virtio-pci
rather than
virtio-mmio, you can do something like:
<interface type='network'> <source network='default'/> <model type='virtio'/> <address type='pci'/> </interface>
But there isn't currently any switch to say 'always give me
virtio-pci instead
of virtio-mmio'
In my opinion, that is to say, when I want to attach a block device to a
guest
and hope it take effects soon,*the only way is using 'scsi' instead of 'virtio'* in Aarch64 just like what virt-manager does since scsi supports hot plugged. Am I right?
On x86 at least virtio-blk + pci supports hotplug, but I don't know if that combo works for aarch64 at the moment. However disk=scsi hotplug should currently work on aarch64 with controller=virtio-scsi, I've tested that before
Thanks, Cole