From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefano Stabellini Subject: Re: [hybrid] : mmap pfn space... Date: Mon, 16 Apr 2012 17:22:14 +0100 Message-ID: References: <20120323110144.4b2f1d45@mantra.us.oracle.com> <20120413184705.77b4d316@mantra.us.oracle.com> <1334585643.14560.199.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1334585643.14560.199.camel@zakaz.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Ian Campbell Cc: "Xen-devel@lists.xensource.com" , Stefano Stabellini List-Id: xen-devel@lists.xenproject.org On Mon, 16 Apr 2012, Ian Campbell wrote: > > In a nutshell, I am still trying to figure how to allocate rsvd pfn's > > for privcmd without writing a slab allocator. > > Can't you just use the core get_page function (or > alloc_xenballooned_pages) and move the associated mfn aside temporarily > (or not if using alloc_xenballooned_pages)? I think that is a good suggestion: if we are trying to get in something that works but might not be the best solution, then using alloc_xenballooned_pages to get some pages and then changing the p2m is the best option: it wastes a non-trivial amount of memory in dom0 but at least it is known to work well and it wouldn't be an "hack". Give a look at gntdev_alloc_map, gnttab_map_refs and m2p_add_override for an example.