From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH] virtio: Define and use per-architecture "pfn shift" constants Date: Thu, 06 Nov 2008 10:22:05 -0600 Message-ID: <491319AD.5070501@codemonkey.ws> References: <1225968591.7284.9.camel@blaa> <1225986626.8620.28.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Mark McLoughlin , rusty-8n+1lVoiYb80n/F98K4Iww@public.gmane.org, kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kvm-ppc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, kvm-ia64-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Hollis Blanchard Return-path: In-Reply-To: <1225986626.8620.28.camel-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org> Sender: kvm-ppc-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: kvm.vger.kernel.org Hollis Blanchard wrote: > On Thu, 2008-11-06 at 10:49 +0000, Mark McLoughlin wrote: > >> But actually, why do we align the size anyway? >> > > I assume it's so that the last page in the ring (containing the "used" > fields) could be safely mapped into another guest's address space, > without fear of exposing other data. > > I don't know how valuable that is, but that's not really my concern so I > preserved the behavior. > > >> Also might make sense for vring_init() and vring_size() not to take a >> pagesize argument and hard-code them to use VRING_PAGE_SIZE. >> > > I think that's a good idea. Anthony mentioned earlier the code was done > this way so it could be copied to userspace, where PAGE_SIZE is > unavailable, but that isn't an issue if we switch to VRING_PAGE_SIZE. > Agreed. Regards, Anthony Liguori -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html