From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:51559) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RIU85-0002eh-Oa for qemu-devel@nongnu.org; Mon, 24 Oct 2011 19:40:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RIU83-00021w-9Z for qemu-devel@nongnu.org; Mon, 24 Oct 2011 19:40:29 -0400 Date: Tue, 25 Oct 2011 10:11:40 +1100 From: David Gibson Message-ID: <20111024231140.GC4191@truffala.fritz.box> References: <1318911341-10890-1-git-send-email-david@gibson.dropbear.id.au> <4FD80D1B-D83A-4FD6-ABC8-3FEE985B7D57@suse.de> <20111021004114.GB3852@truffala.fritz.box> <2B3B4C66-9DF4-4CB1-876D-AF917D716D42@suse.de> <20111021050614.GA24434@truffala.fritz.box> <4CD82990-0A3D-41E4-B40D-E98607CE276A@suse.de> <20111024052951.GE4157@truffala.fritz.box> <8DEA1BBB-904C-457E-8269-3A4C98092EC3@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8DEA1BBB-904C-457E-8269-3A4C98092EC3@suse.de> Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH] pseries: Correct vmx/dfp handling in both KVM and TCG cases List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexander Graf Cc: "qemu-ppc@nongnu.org" , "qemu-devel@nongnu.org" On Mon, Oct 24, 2011 at 10:25:26AM -0700, Alexander Graf wrote: > On 23.10.2011, at 22:29, David Gibson wrote: > > On Thu, Oct 20, 2011 at 11:49:40PM -0700, Alexander Graf wrote: [snip] > >>> This gets further complicated in the case of the w-i-p patch I have to > >>> properly advertise page sizes, where it's not just presence or absence > >>> of a feature, but the specific SLB and HPTE encodings must be > >>> advertised to the guest. > >> > >> Yup, so we'd read out the host dt to find the host possible > >> encodings (probably a bad idea, but that's a different story) > > > > Um, a different story perhaps, but one I kind of need an answer to in > > the near future... I can query the host cpu's page sizes easily > > enough, but I'm really not sure where this should be stashed before > > filtering as suggested below. > > Page sizes are usually powers of 2, so we should be ok with just > having a bitmap there with each bit meaning 1 << (n + 12). Not sufficient. Again, it's not just the presence/absence of page sizes I need, but the SLB and HPTE bit encodings. And even if it weren't for that, we need which base page size versus actual page sizes combinations are supported, not just whether a given page size is supported somehow. I did have a draft patch adding more generalized multiple page size support to TCG, which would have provided a solution except that a) I don't really want to finish tha off - still a fair bit of work - just in order to pass through host page sizes and b) I lost the draft in an unfortunate encfs+git corruption incident :(. -- David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson