Re: [Qemu-devel] [PATCH V2 0/5] hw/pvrdma: PVRDMA device implementation

[Michael S. Tsirkin]

On Thu, Dec 21, 2017 at 09:27:51AM +0200, Yuval Shaia wrote:
> > > 
> > > > What happens if guest attempts to register all its memory?
> > > > 
> > > 
> > > Then we loose, is not different from bare metal, reg_mr will pin all the 
> > > RAM.
> > 
> > We need to find a way to communicate to guests about amount
> > of memory they can pin.
> 
> dev_caps.max_mr_size is the way device limits guest driver.
> This value is controlled by the command line argument dev-caps-max-mr-size
> so we should be fine (btw, default value is 1<<32).

Isn't that still leaving the option for guest to register all memory,
just in chunks?

> > 
> > > However this is only one scenario, and hopefully not much used
> > > for RoCE. (I know IPoIB does that, but it doesn't make sense to use it 
> > > with RoCE).
> > 
> > SRP does it too AFAIK.
> >