Re: [Qemu-devel] Re: A new direction for vmchannel?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 







On 24.01.2009, at 01:02, Dor Laor <dlaor@xxxxxxxxxx> wrote:

Anthony Liguori wrote:
Gleb Natapov wrote:
On Fri, Jan 23, 2009 at 08:45:33AM -0600, Anthony Liguori wrote:

Thoughts?


Looks good, but I am not to much familiar with p9. Will it provide us
with stream semantics?

Sure. It has read and write operations. You just have to implement them in the same sort of way you'd implement them for a character device.

So why not having a virtio pv-serial device.
Above this device/driver users can have several implementations/ semantics:
  - raw messages
  - 9p
  - userspace tcp/ip
     - We already used the host part of it.
     - It provides reliability and handles migration too.
     - Since its userspace, there is no routing/addressing involved.
The above will make windows and other OSs happy and users can still get 9p or tcp or raw. Maybe even the virtio console can be based over it (Don't really know nothing about it )

I don't see where there's any benefit here. You need a driver in the guest for virtio either way - and what exactly goes to userspace ( fs or datagram protocol ) is an implementation detail, no?

Alex



btw: I do suggest to keep the former work of nic based vmchannel. Except for the cmdline, every thing else is committed. It might be good for older OSs and just work out of the box.



How much work is needed to support this in
Windows (what is your estimation)?

If you structure your guest applications to use a library, sort of like libsysfs, then on Windows, you could implement a 9P client in userspace. I have a 9P client that can be used for this. You just need some way to get the stream to userspace. You could write a virtio windows driver that exposed the stream down to userspace. You could also use an alternative transport for Windows (like a serial port).

Will migration be transparent to
in guest users?


There's no better migration story for vmchannel backends implemented outside of QEMU. For the ones in QEMU, migration should be transparent.

Regards,

Anthony Liguori

--
           Gleb.





--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [KVM ARM]     [KVM ia64]     [KVM ppc]     [Virtualization Tools]     [Spice Development]     [Libvirt]     [Libvirt Users]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite Questions]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux