From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [PATCH] KVM: x86: Don't deliver PIC interrupts to disabled APICs - v2 Date: Wed, 22 Oct 2008 17:12:14 +0200 Message-ID: <48FF42CE.5070503@siemens.com> References: <48FC4671.90409@siemens.com> <48FC7435.4020707@siemens.com> <48FF33C9.40106@redhat.com> <48FF4235.6020908@siemens.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit Cc: kvm-devel , "Yang, Sheng" To: Avi Kivity Return-path: Received: from gecko.sbs.de ([194.138.37.40]:19035 "EHLO gecko.sbs.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751597AbYJVPMb (ORCPT ); Wed, 22 Oct 2008 11:12:31 -0400 In-Reply-To: <48FF4235.6020908@siemens.com> Sender: kvm-owner@vger.kernel.org List-ID: Jan Kiszka wrote: > Avi Kivity wrote: >> Jan Kiszka wrote: >>> [ taking Sheng's comments into account ] >>> >>> The logic of kvm_apic_accept_pic_intr has a minor, practically hardly >>> relevant incorrectness: PIC interrupts are still delivered even if the >>> APIC of VPU0 (BSP) is disabled. This does not comply with the Virtual >>> Wire mode according to the Intel MP spec. >>> >> This breaks Windows XP with the Standard PC HAL, so I am unapplying this >> patch. > > Hmm, this points to either an APIC setup or BIOS bug. To my > understanding, the Standard PC HAL should not fiddle with the APIC, so > what the BIOS leaves behind should counts. But I think I found no traces > of APIC manipulation in rombios32.c. Manipulation on UP systems. There is fiddling for SMP. But I will check again. Jan -- Siemens AG, Corporate Technology, CT SE 2 Corporate Competence Center Embedded Linux