From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [RFC PATCH 14/17] kvm: add a reset capability Date: Tue, 31 Mar 2009 23:18:35 +0300 Message-ID: <49D27A9B.9030703@redhat.com> References: <20090331184057.28333.77287.stgit@dev.haskins.net> <20090331184400.28333.50396.stgit@dev.haskins.net> <49D26D8B.7020201@redhat.com> <49D276E5.6000000@novell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, agraf@suse.de, pmullaney@novell.com, pmorreale@novell.com, anthony@codemonkey.ws, rusty@rustcorp.com.au, netdev@vger.kernel.org, kvm@vger.kernel.org To: Gregory Haskins Return-path: Received: from mx2.redhat.com ([66.187.237.31]:45463 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754461AbZCaUSH (ORCPT ); Tue, 31 Mar 2009 16:18:07 -0400 In-Reply-To: <49D276E5.6000000@novell.com> Sender: kvm-owner@vger.kernel.org List-ID: Gregory Haskins wrote: > Avi Kivity wrote: > >> Gregory Haskins wrote: >> >>> We need a way to detect if a VM is reset later in the series, so lets >>> add a capability for userspace to signal a VM reset down to the kernel. >>> >>> >> How do you handle the case of a guest calling kexec to load a new >> kernel? Or is that not important for your use case? >> >> > > Hmm..I had not considered this. Any suggestions on ways to detect it? > > Best would be not to detect it; it's tying global events into a device. Instead, have a reset command for your device and have the driver issue it on load and unload. btw, reset itself would be better controlled from userspace; qemu knows about resets and can reset vbus devices directly instead of relying on kvm to reset them. This decouples the two code bases a bit. This is what virtio does. -- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.