From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57864) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fazAJ-0005ka-NZ for qemu-devel@nongnu.org; Thu, 05 Jul 2018 03:59:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fazAF-0004CC-En for qemu-devel@nongnu.org; Thu, 05 Jul 2018 03:58:59 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:35710 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fazAF-00048X-90 for qemu-devel@nongnu.org; Thu, 05 Jul 2018 03:58:55 -0400 References: <1530270944-11351-1-git-send-email-suzuki.poulose@arm.com> <1530270944-11351-25-git-send-email-suzuki.poulose@arm.com> <20180704142241.GG4828@arm.com> <8636wzysfl.wl-marc.zyngier@arm.com> <20180704155123.GO4828@arm.com> From: Auger Eric Message-ID: Date: Thu, 5 Jul 2018 09:58:50 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [kvmtool test PATCH 24/24] kvmtool: arm: Add support for creating VM with PA size List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell , Will Deacon Cc: Christoffer Dall , kvm-devel , Marc Zyngier , Catalin Marinas , Punit Agrawal , lkml - Kernel Mailing List , QEMU Developers , kvmarm@lists.cs.columbia.edu, arm-mail-list Hi, On 07/05/2018 09:51 AM, Peter Maydell wrote: > On 4 July 2018 at 16:51, Will Deacon wrote: >> On Wed, Jul 04, 2018 at 03:41:18PM +0100, Marc Zyngier wrote: >>> Not really. Let's say I want my IPA space split in two: memory covers >>> the low 47 bit, and I want MMIO spanning the top 47 bit. With your >>> scheme, you'd end-up with a 47bit IPA space, while you really want 48 >>> bits (MMIO space implemented by userspace isn't registered to the >>> kernel). >> >> That still sounds quite niche for a VM. Does QEMU do that? > > Not at 47 bits, but we have RAM up to the 256GB mark, and > MMIO above that (including a large PCI window), so the general > arrangement of having the top end of the IPA space not > necessarily be things we've told the kernel about definitely > exists. Is this document (2012) still a reference document? http://infocenter.arm.com/help/topic/com.arm.doc.den0001c/DEN0001C_principles_of_arm_memory_maps.pdf (especially Fig 5?) Peter, comments in QEMU hw/arm/virt.c suggested next RAM chunk should be added at 2TB. This doc suggests to put it at 8TB. I understand the PA memory map only is suggested but shouldn't we align? Thanks Eric > > thanks > -- PMM > _______________________________________________ > kvmarm mailing list > kvmarm@lists.cs.columbia.edu > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm >