From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: IOAPIC doesn't handle byte writes Date: Tue, 22 Nov 2011 16:19:37 +0200 Message-ID: <4ECBAF79.6050000@redhat.com> References: <1321967582.16507.10.camel@tabernacle.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, "udo@hypervisor.org" To: Julian Stecklina Return-path: Received: from mx1.redhat.com ([209.132.183.28]:24406 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754654Ab1KVOTn (ORCPT ); Tue, 22 Nov 2011 09:19:43 -0500 In-Reply-To: <1321967582.16507.10.camel@tabernacle.lan> Sender: kvm-owner@vger.kernel.org List-ID: On 11/22/2011 03:13 PM, Julian Stecklina wrote: > Hello, > > KVM emulates an IOAPIC that doesn't handle byte writes to its > IOAPIC_REG_SELECT register, although for example the ICH10 spec[1] > clearly states that this is an 8-bit register. See > http://www.intel.com/content/dam/doc/datasheet/io-controller-hub-10-family-datasheet.pdf > Table 13-4 on page 433. > > The code in question is: > > http://git.kernel.org/?p=virt/kvm/kvm.git;a=blob;f=virt/kvm/ioapic.c;h=3eed61eb48675a63dd1f31b0095217ab6bc5f646;hb=HEAD#l323 > > This breaks IOAPIC code in OSes that adhere to the spec. Agree, the code is broken. > I would file a bug, but the kernel bugzilla seems to be down at the > moment. Care to post a patch instead? -- error compiling committee.c: too many arguments to function