From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anthony Liguori Subject: Re: [PATCH kvm-unit-tests 2/4] Introduce a C++ wrapper for the kvm APIs Date: Wed, 24 Nov 2010 10:56:15 -0600 Message-ID: <4CED43AF.9080802@codemonkey.ws> References: <1290595933-13122-1-git-send-email-avi@redhat.com> <1290595933-13122-3-git-send-email-avi@redhat.com> <50DD1E97-0ECD-41E6-B6F8-1D78AA4A4876@suse.de> <4CED2416.1040102@codemonkey.ws> <20101124154006.GE15111@redhat.com> <4CED344B.3030000@codemonkey.ws> <20101124161204.GF15111@redhat.com> <4CED39DE.3030207@redhat.com> <20101124162153.GA20014@redhat.com> <4CED40CD.8030503@codemonkey.ws> <20101124164845.GC20014@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Avi Kivity , Alexander Graf , Marcelo Tosatti , kvm@vger.kernel.org To: Gleb Natapov Return-path: Received: from mail-iw0-f174.google.com ([209.85.214.174]:45956 "EHLO mail-iw0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755733Ab0KXQ4t (ORCPT ); Wed, 24 Nov 2010 11:56:49 -0500 Received: by iwn38 with SMTP id 38so24018iwn.19 for ; Wed, 24 Nov 2010 08:56:49 -0800 (PST) In-Reply-To: <20101124164845.GC20014@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 11/24/2010 10:48 AM, Gleb Natapov wrote: >> They *aren't* ISA devices. Look at the PIIX3 spec. All of the >> ports for these devices are positively decoded and not sent over the >> ISA bus. >> >> > Over the external ISA bus you mean? > There is no internal ISA bus. The reality is that the PIIX3 is a microcontroller and most of the platform devices are probably written in microcode. That's certainly the case with modern SuperIO chips. Very specifically, the PIIX3 has a white list of addresses that when it sees the a PCI bus transaction for those addresses, it asserts DEVSEL# and then routes the request to the write part of the chip to handle it. For unhandled transactions, it then forwards them to the ISA bus. Regards, Anthony Liguori