From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755742Ab2GXI0t (ORCPT ); Tue, 24 Jul 2012 04:26:49 -0400 Received: from mx1.redhat.com ([209.132.183.28]:4116 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755713Ab2GXI0p (ORCPT ); Tue, 24 Jul 2012 04:26:45 -0400 Message-ID: <500E5C36.2070601@redhat.com> Date: Tue, 24 Jul 2012 11:26:30 +0300 From: Dor Laor Reply-To: dlaor@redhat.com User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120615 Thunderbird/13.0.1 MIME-Version: 1.0 To: Rusty Russell CC: Sasha Levin , mst@redhat.com, penberg@kernel.org, asias.hejun@gmail.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, avi@redhat.com, anthony@codemonkey.ws, wency@cn.fujitsu.com Subject: Re: [RFC 0/2] virtio: provide a way for host to monitor critical events in the device References: <1343075561-29316-1-git-send-email-levinsasha928@gmail.com> <87a9yprc4v.fsf@rustcorp.com.au> In-Reply-To: <87a9yprc4v.fsf@rustcorp.com.au> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/24/2012 07:55 AM, Rusty Russell wrote: > On Mon, 23 Jul 2012 22:32:39 +0200, Sasha Levin wrote: >> As it was discussed recently, there's currently no way for the guest to notify >> the host about panics. Further more, there's no reasonable way to notify the >> host of other critical events such as an OOM kill. > > I clearly missed the discussion. Is this actually useful? In practice, Admit this is not a killer feature.. > won't you want the log from the guest? What makes a virtual guest > different from a physical guest? Most times virt guest can do better than a physical OS. In that sense, this is where virtualization shines (live migration, hotplug for any virtual resource including net/block/cpu/memory/..). There are plenty of niche but worth while small features such as the virtio-trace series and other that allow the host/virt-mgmt to get more insight into the guest w/o a need to configure the guest. In theory guest OOM can trigger a host memory hot plug action. Again, I don't see it as a key feature.. > > Guest watchdog functionality might be useful, but that's simpler to There is already a fully emulated watchdog device in qemu. Cheers, Dor > implement via a virtio watchdog device, and more effective to implement > via a host facility that actually pings guest functionality (rather than > the kernel). > > Cheers, > Rusty. > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >