Re: [virtio-comment] Re: [Qemu-devel] [PATCH] *** Vhost-pci RFC v2 ***

From
Marc-André Lureau <>
Date
2016-09-02T08:15:40+00:00
ID
Thread
Re: [virtio-comment] Re: [Qemu-devel] [PATCH] *** Vhost-pci RFC v2 ***
Hi

On Fri, Sep 2, 2016 at 5:30 AM Wei Wang <> wrote:

On 09/01/2016 09:05 PM, Marc-André Lureau wrote:

> On Thu, Sep 1, 2016 at 4:13 PM Wei Wang <

> <mailto:>> wrote:

> My question is not about the support of various kind of devices (that

> is clearly a worthy goal to me) but to have support simultaneously of

> several frontend/provider devices on the same vhost-pci device: is

> this required or necessary? I think it would simplify things if it was

> 1-1 instead, I would like to understand why you propose a different

> design.

It is not required, but necessary, I think. As mentioned above, those

consumer-side functionalities basically access the same provider VM's

memory, so I think one vhost-pci device is enough to hold that memory.

When it comes to the consumer guest kernel, we only need to ioremap that

memory once. Also, a pair of controlq-s is enough to handle the control

path messages between all those functionalities and the QEMU. I think

the design also looks compact in this way. what do you think?

If it's not required, I would propose to stick to a 1-1 design for now. (1-n support could be added later, even if it means a new device kind) Michael, what do you think?

-- 

Marc-André Lureau