[Qemu-devel] Virtio_PCI device driver code

[Qemu-devel] Virtio_PCI device driver code

[Abhinav Pundir]

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Hello all I am very much new to the world of KVM and Qemu.
I am trying to make a communication possible between the Guest and the Host.
I have studied how Virtio works but I am still confused how exactly the
flow will work.
The front end drivers will communicate to the back end driver by invoking a
kick function, but which back end driver will be involved in that.
Also how the back end driver present in the Hypervisor will pass this
information to the emulated device running in  Qemu.
I am trying to use virtio_pci.c and some suitable modification, so that the
back end driver can take that information and that information will
be available to the Hypervisor.

It will be very useful if somebody can provide me the working code of the
virtio_pci with all the dependencies in the separate directory, so that I
will be able to insert that module and the equivalent back-end driver code
running in the Hypervisor.

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Re: [Qemu-devel] Virtio_PCI device driver code

[Brian Jackson]

On Wed, 14 Mar 2012 08:38:04 -0500, Abhinav Pundir  
<abhinavmasters@gmail.com> wrote:

> Hello all I am very much new to the world of KVM and Qemu.
> I am trying to make a communication possible between the Guest and the  
> Host.


If you just need to communicate, why not just use virtio-serial  
functionality?


> I have studied how Virtio works but I am still confused how exactly the
> flow will work.
> The front end drivers will communicate to the back end driver by  
> invoking a
> kick function, but which back end driver will be involved in that.
> Also how the back end driver present in the Hypervisor will pass this
> information to the emulated device running in  Qemu.
> I am trying to use virtio_pci.c and some suitable modification, so that  
> the
> back end driver can take that information and that information will
> be available to the Hypervisor.
>
> It will be very useful if somebody can provide me the working code of the
> virtio_pci with all the dependencies in the separate directory, so that I
> will be able to insert that module and the equivalent back-end driver  
> code
> running in the Hypervisor.

Re: [Qemu-devel] Virtio_PCI device driver code

[Stefan Hajnoczi]

On Wed, Mar 14, 2012 at 1:38 PM, Abhinav Pundir
<abhinavmasters@gmail.com> wrote:
> Hello all I am very much new to the world of KVM and Qemu.
> I am trying to make a communication possible between the Guest and the Host.
> I have studied how Virtio works but I am still confused how exactly the flow
> will work.
> The front end drivers will communicate to the back end driver by invoking a
> kick function, but which back end driver will be involved in that.
> Also how the back end driver present in the Hypervisor will pass this
> information to the emulated device running in  Qemu.
> I am trying to use virtio_pci.c and some suitable modification, so that the
> back end driver can take that information and that information will
> be available to the Hypervisor.
>
> It will be very useful if somebody can provide me the working code of the
> virtio_pci with all the dependencies in the separate directory, so that I
> will be able to insert that module and the equivalent back-end driver code
> running in the Hypervisor.

Please explain what you are trying to achieve.  Coding a custom virtio
device may not be the best solution - it depends on the specific use
case.

Stefan