From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43998) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aLwVW-000838-DR for qemu-devel@nongnu.org; Wed, 20 Jan 2016 12:25:23 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aLwVT-0003t5-5u for qemu-devel@nongnu.org; Wed, 20 Jan 2016 12:25:22 -0500 Received: from mx1.redhat.com ([209.132.183.28]:47226) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aLwVT-0003qS-0O for qemu-devel@nongnu.org; Wed, 20 Jan 2016 12:25:19 -0500 Date: Wed, 20 Jan 2016 19:25:13 +0200 From: "Michael S. Tsirkin" Message-ID: <20160120192229-mutt-send-email-mst@redhat.com> References: <1452257883-19549-1-git-send-email-kraxel@redhat.com> <20160119123739.GA27855@thinpad.lan.raisama.net> <1453301733.11804.142.camel@redhat.com> <20160120153429.GA4218@thinpad.lan.raisama.net> <20160120171504.GB4218@thinpad.lan.raisama.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160120171504.GB4218@thinpad.lan.raisama.net> Subject: Re: [Qemu-devel] [PATCH v2] pc: allow raising low memory via max-ram-below-4g option List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: Paolo Bonzini , Richard Henderson , Gerd Hoffmann , qemu-devel@nongnu.org On Wed, Jan 20, 2016 at 03:15:04PM -0200, Eduardo Habkost wrote: > On Wed, Jan 20, 2016 at 01:34:29PM -0200, Eduardo Habkost wrote: > [...] > > Considering that we never supported > > gigabyte_align && max_ram_below_4g > 3G || > > max_ram_below_4g > 3.5G > > before, we could simply remove the MachineClass::gigabyte_align > > field from pc_piix, and just do the following: > > > > * pc > 1.7: max_ram_below_4g = 3G > > (equivalent to gigabyte_align=true) > > * pc <= 1.7: max_ram_below_4g = 3.5G > > (equivalent to gigabyte_align=false) > > Ignore the suggestion above. I forgot that gigabyte_align applies > only if ram_size > 3.5GB (so setting max_ram_below_4g = 3G on > pc > 1.7 wouldn't work). So, unless somebody has a suggestion > that makes this logic simpler: I wonder whether we should just bite the bullet and ask management to maintain the physical memory map for us, instead of trying to give us hints. Thoughts? > Reviewed-by: Eduardo Habkost > > -- > Eduardo