From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [Qemu-devel] Announcing qboot, a minimal x86 firmware for QEMU Date: Wed, 27 May 2015 11:30:19 +0200 Message-ID: <55658EAB.3010107@redhat.com> References: <555DE2EF.1000509@redhat.com> <20150522110136.GF14428@redhat.com> <20150522111259.GG14428@redhat.com> <55631B3A.7080803@redhat.com> <5564E4C9.8010906@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: qemu-devel , KVM list To: Christopher Covington , "Daniel P. Berrange" , Peter Maydell Return-path: Received: from mx1.redhat.com ([209.132.183.28]:33494 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752576AbbE0Ja1 (ORCPT ); Wed, 27 May 2015 05:30:27 -0400 In-Reply-To: <5564E4C9.8010906@codeaurora.org> Sender: kvm-owner@vger.kernel.org List-ID: On 26/05/2015 23:25, Christopher Covington wrote: > On 05/25/2015 08:53 AM, Paolo Bonzini wrote: >> >> On 22/05/2015 13:12, Daniel P. Berrange wrote: >>> In >>> particular I don't see why we need to have a SATA controller and ISA/LPC >>> bridge in every virt machine - root PCI bus only should be possible, as you >>> can provide disks via virtio-blk or virtio-scsi and serial, parallel, mouse, >>> floppy via PCI devices and/or by adding a USB bus in the cases where you >>> really need one. >> >> I think removing the ISA/LPC bridge is hard. It includes the real-time >> clock and fw_cfg, for example. > > Could VirtIO specified replacements make sense for these peripherals? Not really. virtio is too heavyweight and you'd be reinventing the wheel unnecessarily. For example, ARM's "-M virt" uses a pl011 block for the RTC, and also uses fw_cfg. Another commonly used ISA device is the UART, for which again -M virt uses a pl031. Paolo