From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: FreeBSD image hangs during boot Date: Sat, 06 Oct 2007 21:31:26 +0200 Message-ID: <4707E28E.3040609@qumranet.com> References: <47022E7E.3030509@aurel32.net> <47063B31.6000001@bull.net> <20071005135122.GA17767@hall.aurel32.net> <47066153.2040406@qumranet.com> <47074989.9080100@bull.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel , Aurelien Jarno To: Laurent Vivier Return-path: In-Reply-To: <47074989.9080100-6ktuUTfB/bM@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org Laurent Vivier wrote: >> >> Edge-triggered means we can't share interrupt lines. Since we have only >> two or three that limits the number of devices we can have. >> >> So I'd like to try moving to active low pci interrupts, and implementing >> polarity in the qemu ioapic. It's probably closer to real hardware anyway. >> >> > > Avi, > > I've two questions: > > - why, when you implemented the ioapic polarity bit in kvm (commit > 0203e2d5d0d0cea6eed6e437d9456aad71135913, kvm_ioapic_set_irq()), you > didn't implement it in qemu (in qemu/hw/apic.c ioapic_set_irq()) ? > Laziness > - why implementing polarity changes active level in ACPI ? > Qemu has two bugs: - ACPI (and MP-BIOS) advertises the PCI interrupts as active low - IOAPIC polarity is not implemented The bugs cancel each other out. I fixed one by implementing polarity, now we have to fix the other. -- Any sufficiently difficult bug is indistinguishable from a feature. ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/