From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: Announcing qboot, a minimal x86 firmware for QEMU Date: Wed, 27 May 2015 12:36:16 +0300 Message-ID: <55659010.6010302@cloudius-systems.com> References: <555DE2EF.1000509@redhat.com> <20150522110136.GF14428@redhat.com> <20150522111259.GG14428@redhat.com> <55631B3A.7080803@redhat.com> <5564E4C9.8010906@codeaurora.org> <55658EAB.3010107@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Cc: qemu-devel , KVM list To: Paolo Bonzini , Christopher Covington , "Daniel P. Berrange" , Peter Maydell Return-path: In-Reply-To: <55658EAB.3010107@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org Sender: qemu-devel-bounces+gceq-qemu-devel=gmane.org@nongnu.org List-Id: kvm.vger.kernel.org On 05/27/2015 12:30 PM, Paolo Bonzini wrote: > > 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. > The RTC can be replaced by kvmclock, the keyboard by virtio-console. Maybe we can provide an msr- or pci- based interface to fw_cfg.