From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48045) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bEwZO-0004Wq-KQ for qemu-devel@nongnu.org; Mon, 20 Jun 2016 06:36:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bEwZK-0004zH-DO for qemu-devel@nongnu.org; Mon, 20 Jun 2016 06:36:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50808) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bEwZK-0004zC-85 for qemu-devel@nongnu.org; Mon, 20 Jun 2016 06:36:38 -0400 Date: Mon, 20 Jun 2016 11:36:32 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20160620103632.GB2891@work-vm> References: <1466151257-96318-1-git-send-email-chao.p.peng@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [RFC 0/9] Introduce light weight PC platform pc-lite List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini Cc: Chao Peng , qemu-devel@nongnu.org, Haozhong Zhang , Xiao Guangrong , Eduardo Habkost , "Michael S. Tsirkin" , gor Mammedov , Richard Henderson * Paolo Bonzini (pbonzini@redhat.com) wrote: > > > On 17/06/2016 10:14, Chao Peng wrote: > > Basically: > > - it removes old ISA devices and support only PCI devices; > > I think you need to keep at least the RTC, otherwise where does Linux > get the time of day from? > > > - it removes 8259, instead use MSI as much as possible. IOAPIC and PCI > > PIN are still kept to support ACPI SCI; > > - it supports PCIE ( you can use MMFG instead of 0xcf8/0xcfc port > > access); > > - it gets rid of legacy firmware interfaces and supports ACPI tables; > > - it supports CPU/memory/PCI hotplug; > > - it supports Linux-guest only at present; > > - You may need carefully configure guest kernel; > > - You are forced to use virtio-serial-pci, old 8250/16550 is not there; > > It doesn't support PCIe hotplug though, I think? (Because it doesn't > support PCI bridges and PCIe hotplug doesn't work for root complex > devices). So is it ACPI-based hotplug? > > Lack of 8250/16550 means lack of earlyprintk. I know the driver is slow > though, so I understand that. You could always define a different way to get early debug; for example a chunk of RAM at a known address seems fine for a VM. Dave -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK