From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48010) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V1Hik-0001jc-84 for qemu-devel@nongnu.org; Mon, 22 Jul 2013 11:08:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1V1Hij-0000CU-2k for qemu-devel@nongnu.org; Mon, 22 Jul 2013 11:08:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:7718) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1V1Hii-0000CM-SQ for qemu-devel@nongnu.org; Mon, 22 Jul 2013 11:08:17 -0400 Message-ID: <51ED4AC5.5030501@redhat.com> Date: Mon, 22 Jul 2013 17:07:49 +0200 From: Paolo Bonzini MIME-Version: 1.0 References: <1374501278-31549-1-git-send-email-pbonzini@redhat.com> <51ED4362.8060709@redhat.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 00/28] Memory API for 1.6: fix I/O port endianness mess List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell Cc: aliguori@us.ibm.com, aik@ozlabs.ru, jan.kiszka@siemens.com, qemu-devel@nongnu.org, agraf@suse.de, hpoussin@reactos.org, aurelien@aurel32.net Il 22/07/2013 17:04, Peter Maydell ha scritto: > On 22 July 2013 15:36, Paolo Bonzini wrote: >> Il 22/07/2013 16:32, Peter Maydell ha scritto: >>> In the long term it would be good to identify which boards >>> were using isa_mmio purely for the benefit of old_portio >>> (which I think is basically "boards where the CPU has no >>> concept of port I/O instructions"). >> >> All of them. Only i386/x86_64 has I/O space, as far as I know. > > Sounds plausible. I had wondered if our ISA bus infrastructure > assumed that ISA device IO ports live in the system IO space, > but it doesn't. No, luckily it doesn't, and neither should the PCI-to-ISA bridges as you found out---they do not after these patches. PReP is an exception, but I think it could be rewritten to use an IOMMU memory region. > Side question: should the ICH9 emulation ich9_lpc_initfn() > really put its ISA bus in the system IO space rather than > in the pci_address_space_io() ? No, I think it should use pci_address_space_io(). PCI devices (the ISA bridge is one) should not know that a system IO space exists, only the PCI host bridge has that knowledge. Paolo