From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [RFC][PATCH 14/16] kvm: x86: Add user space part for in-kernel i8259 Date: Sun, 04 Dec 2011 15:31:24 +0200 Message-ID: <4EDB762C.7090909@redhat.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , kvm@vger.kernel.org, qemu-devel , Anthony Liguori , "Michael S. Tsirkin" , Blue Swirl To: Jan Kiszka Return-path: Received: from mx1.redhat.com ([209.132.183.28]:34484 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752928Ab1LDNba (ORCPT ); Sun, 4 Dec 2011 08:31:30 -0500 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 12/03/2011 01:17 PM, Jan Kiszka wrote: > From: Jan Kiszka > > Introduce the alternative 'kvm-i8259' device model that exploits KVM > in-kernel acceleration. > > The PIIX3 initialization code is furthermore extended by KVM specific > IRQ route setup. Moreover, GSI injection differs in KVM mode from the > user space model. As we can dispatch ISA-range IRQs to both IOAPIC and > PIC inside the kernel, we do not need to inject them separately. This is > reflected by a KVM-specific GSI handler. > > + > +qemu_irq *kvm_i8259_init(void) > +{ > + ISADevice *dev; > + > + dev = isa_create("kvm-i8259"); > Same issue. Is this a different device, or an different implementation of the same device? We're forcing migration from 1.0 to 1.1 to disable in-kernel irqchip on the target. For qemu itself, that's no issue. But for qemu-kvm, it will result in loss of performance, or hacks to alias the two back together. -- error compiling committee.c: too many arguments to function From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:34810) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RXCAE-0006Op-Rm for qemu-devel@nongnu.org; Sun, 04 Dec 2011 08:31:31 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RXCAD-0007a1-Bl for qemu-devel@nongnu.org; Sun, 04 Dec 2011 08:31:30 -0500 Received: from mx1.redhat.com ([209.132.183.28]:9271) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RXCAD-0007Zw-4j for qemu-devel@nongnu.org; Sun, 04 Dec 2011 08:31:29 -0500 Message-ID: <4EDB762C.7090909@redhat.com> Date: Sun, 04 Dec 2011 15:31:24 +0200 From: Avi Kivity MIME-Version: 1.0 References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [RFC][PATCH 14/16] kvm: x86: Add user space part for in-kernel i8259 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Anthony Liguori , kvm@vger.kernel.org, "Michael S. Tsirkin" , Marcelo Tosatti , qemu-devel , Blue Swirl On 12/03/2011 01:17 PM, Jan Kiszka wrote: > From: Jan Kiszka > > Introduce the alternative 'kvm-i8259' device model that exploits KVM > in-kernel acceleration. > > The PIIX3 initialization code is furthermore extended by KVM specific > IRQ route setup. Moreover, GSI injection differs in KVM mode from the > user space model. As we can dispatch ISA-range IRQs to both IOAPIC and > PIC inside the kernel, we do not need to inject them separately. This is > reflected by a KVM-specific GSI handler. > > + > +qemu_irq *kvm_i8259_init(void) > +{ > + ISADevice *dev; > + > + dev = isa_create("kvm-i8259"); > Same issue. Is this a different device, or an different implementation of the same device? We're forcing migration from 1.0 to 1.1 to disable in-kernel irqchip on the target. For qemu itself, that's no issue. But for qemu-kvm, it will result in loss of performance, or hacks to alias the two back together. -- error compiling committee.c: too many arguments to function