Re: [Xen-devel] [PATCH] xen/grant-table: Force to use v1 of grants.

Konrad Rzeszutek Wilk
2014-01-02T19:17:39Z

On Thu, Jan 02, 2014 at 02:54:18PM +0000, David Vrabel wrote:
> On 31/12/13 15:15, Konrad Rzeszutek Wilk wrote:
> > We have the framework to use v2, but there are no backends that
> > actually use it. The end result is that on PV we use v2 grants
> > and on PVHVM v1. The v1 has a capacity of 512 grants per page while
> > the v2 has 256 grants per page. This means we lose about 50%
> > capacity - and if we want more than 16 VIFs (each VIF takes
> > 512 grants), then we are hitting the max per guest of 32.
> >
> > Oracle-bug: 16039922
> > CC: annie.li@oracle.com
> > CC: msw@amazon.com
> > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
>
> Reviewed-by: David Vrabel <david.vrabel@citrix.com>
>
> What does v2 add anyway? Do we want to remove all v2 related code or are

Better status reporting page and two extra types of grants.

> we expecting to make use of it in the near future?

Yes, that is my understanding.
>
> David