From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eduardo Habkost Subject: Re: 2.6.27.5 guest boot failure using in-kernel PIT Date: Thu, 20 Nov 2008 20:05:17 -0200 Message-ID: <20081120220517.GB30825@blackpad> References: <20081120142253.GA30825@blackpad> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: kvm@vger.kernel.org Return-path: Received: from mx2.redhat.com ([66.187.237.31]:60200 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755490AbYKTWFy (ORCPT ); Thu, 20 Nov 2008 17:05:54 -0500 Received: from int-mx2.corp.redhat.com (int-mx2.corp.redhat.com [172.16.27.26]) by mx2.redhat.com (8.13.8/8.13.8) with ESMTP id mAKM5mSD000415 for ; Thu, 20 Nov 2008 17:05:48 -0500 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx2.corp.redhat.com (8.13.1/8.13.1) with ESMTP id mAKM5mBu027488 for ; Thu, 20 Nov 2008 17:05:48 -0500 Received: from blackpad.localdomain (vpn-10-24.str.redhat.com [10.32.10.24]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id mAKM5kX0022750 for ; Thu, 20 Nov 2008 17:05:47 -0500 Content-Disposition: inline In-Reply-To: <20081120142253.GA30825@blackpad> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Nov 20, 2008 at 12:22:53PM -0200, Eduardo Habkost wrote: > > Hi, > > When using a kvm.git kernel as host, I am getting guest boot failures > when booting Fedora Rawhide kernel (2.6.27.5-117.fc10.x86_64). Guest > stops booting at: > > ENABLING IO-APIC IRQs > ..TIMER: vector=0x30 apic1=0 pin1=0 apic2=-1 pin2=-1 > ..MP-BIOS bug: 8254 timer not connected to IO-APIC > ...trying to set up timer (IRQ0) through the 8259A ... > ..... (found apic 0 pin 0) ... > ....... failed. > ...trying to set up timer as Virtual Wire IRQ... > ..... failed. > ...trying to set up timer as ExtINT IRQ... I've just found out this problem happens because the guest has HZ=1000 and the host had HZ=250 and no CONFIG_HIGH_RES_TIMERS. With this setup, the host is not managing to inject enough timer interrupts during the mdelay() loop on timer_irq_works(). -- Eduardo