Linux Virtualization - May 2015 - Trying to make VHOST-BLK to work

Hi Kernel KVM folks and Michael,

I am trying to make VHOST-BLK to work by myself since I did not hear from
Asias on my personal mail to him. I will be grateful to you for your time
and response.

The problem I am seeing is there is no response seen by the VM through the
HOST has executed the IO successfully and issued
vhost_add_used_and_signal.  Here is my question. Which code in QEMU issues
virtio_notify() when the VHOST completes the IO in kernel?

I have some related questions. Could I connect a iscsi LUN to a VM via
vhost-scsi? Could you please point me to some documents if there are any?

Thanks and Regards

Sudheer
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.linuxfoundation.org/pipermail/virtualization/attachments/20150519/f57b115c/attachment.html>

There is no code in >>QEMU<< that actually triggers notifications to
the
guest when using vhost.
When you are using vhost, interrupts are triggered directly to the guest.
The interrupt lines are mapped as a shared memory, that don't pass 
through QEMU, if they don't have to.
Indeed, there is an initial setup in QEMU that makes this configuration.

Note:
The things that I am saying are somewhat deductions from what I've 
studied from the code myself and some answers
from qemu-devel (so I cannot assure you on the correctness of this 
answer), as the kvm and virtualization community themselves
aren't very active.

On 19.05.2015 14:13, Sudheer K wrote:
> Hi Kernel KVM folks and Michael,
>
> I am trying to make VHOST-BLK to work by myself since I did not hear 
> from Asias on my personal mail to him. I will be grateful to you for 
> your time and response.
>
> The problem I am seeing is there is no response seen by the VM through 
> the HOST has executed the IO successfully and issued 
> vhost_add_used_and_signal.  Here is my question. Which code in QEMU 
> issues virtio_notify() when the VHOST completes the IO in kernel?
>
> I have some related questions. Could I connect a iscsi LUN to a VM via 
> vhost-scsi? Could you please point me to some documents if there are any?
>
> Thanks and Regards
>
> Sudheer
>
>
> _______________________________________________
> Virtualization mailing list
> Virtualization at lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/virtualization
-- 

CatalinVasile

Intern, DN-Software

FreescaleSemiconductor, Inc.

www.freescale.com

phone: 073-021-1938

e-mail: catalin.vasile at freescale.com <mailto:your.name at
freescale.com>

*Freescale_Logo-nosemi_Lh_4c***

This e-mail, and any associated attachments have been classified as:

[ ] Public

[ ] Freescale Semiconductor Internal Use Only

[ ] Freescale Semiconductor Confidential Proprietary

-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.linuxfoundation.org/pipermail/virtualization/attachments/20150520/47cd2984/attachment-0001.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: image002.gif
Type: image/gif
Size: 1979 bytes
Desc: not available
URL:
<http://lists.linuxfoundation.org/pipermail/virtualization/attachments/20150520/47cd2984/attachment-0001.gif>