From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:36604)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <mtosatti@redhat.com>) id 1Vbb3r-0003mc-2V
	for qemu-devel@nongnu.org; Wed, 30 Oct 2013 15:04:17 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <mtosatti@redhat.com>) id 1Vbb3l-0000XG-3O
	for qemu-devel@nongnu.org; Wed, 30 Oct 2013 15:04:11 -0400
Received: from mx1.redhat.com ([209.132.183.28]:50313)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <mtosatti@redhat.com>) id 1Vbb3k-0000Ww-Qp
	for qemu-devel@nongnu.org; Wed, 30 Oct 2013 15:04:05 -0400
Date: Wed, 30 Oct 2013 17:03:46 -0200
From: Marcelo Tosatti <mtosatti@redhat.com>
Message-ID: <20131030190346.GA19287@amt.cnet>
References: <20131028140406.GA18025@amt.cnet>
	<1383070729-19427-1-git-send-email-imammedo@redhat.com>
	<20131029213844.GB32615@amt.cnet>
	<20131030174949.2fb0d2c2@nial.usersys.redhat.com>
	<20131030185129.GB18378@amt.cnet>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20131030185129.GB18378@amt.cnet>
Subject: Re: [Qemu-devel] [RFC PATCH] pc: align gpa<->hpa on 1GB boundary by
 splitting RAM on several regions
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Igor Mammedov <imammedo@redhat.com>
Cc: aarcange@redhat.com, peter.maydell@linaro.org, gleb@redhat.com, quintela@redhat.com, jan.kiszka@siemens.com, qemu-devel@nongnu.org, aliguori@amazon.com, pbonzini@redhat.com, afaerber@suse.de, rth@twiddle.net

On Wed, Oct 30, 2013 at 04:51:29PM -0200, Marcelo Tosatti wrote:
> On Wed, Oct 30, 2013 at 05:49:49PM +0100, Igor Mammedov wrote:
> > On Tue, 29 Oct 2013 19:38:44 -0200
> > Marcelo Tosatti <mtosatti@redhat.com> wrote:
> > 
> > > On Tue, Oct 29, 2013 at 07:18:49PM +0100, Igor Mammedov wrote:
> > > > Otherwise 1GB TLBs cannot be cached for the range.
> > > 
> > > This fails to back non-1GB-aligned gpas, but 2MB aligned, with 2MB large
> > > pages.
> > With current command line only one hugetlbfs mount point is possible, so it
> > will back with whatever alignment specified hugetlbfs mount point has.
> > Anything that doesn't fit into page aligned region goes to tail using
> > non hugepage baked phys_mem_set_alloc()=qemu_anon_ram_alloc() allocator.
> 
> The patch you propose allocates the non-1GB aligned tail of RAM with 4k
> pages. As mentioned, this is not acceptable (2MB pages should be used
> whenever 1GB alignment is not possible).

Tail and 3-4GB region.