From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 132DE1A03F5 for ; Thu, 12 Nov 2015 15:58:22 +1100 (AEDT) Received: from mail-pa0-x232.google.com (mail-pa0-x232.google.com [IPv6:2607:f8b0:400e:c03::232]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id EA1121402B3 for ; Thu, 12 Nov 2015 15:58:20 +1100 (AEDT) Received: by padhx2 with SMTP id hx2so53005631pad.1 for ; Wed, 11 Nov 2015 20:58:19 -0800 (PST) From: Daniel Axtens To: David Gibson Cc: Aravinda Prasad , paulus@ozlabs.org, linuxppc-dev@ozlabs.org, kvm-ppc@vger.kernel.org, mahesh@linux.vnet.ibm.com, agraf@suse.de, michaele@au1.ibm.com, kvm@vger.kernel.org Subject: Re: [PATCH] KVM: PPC: Exit guest upon fatal machine check exception In-Reply-To: <20151112033816.GJ5852@voom.redhat.com> References: <20151111165845.3721.98296.stgit@aravindap> <876118ymy4.fsf@gamma.ozlabs.ibm.com> <20151112033816.GJ5852@voom.redhat.com> Date: Thu, 12 Nov 2015 15:58:14 +1100 Message-ID: <87bnazizkp.fsf@gamma.ozlabs.ibm.com> MIME-Version: 1.0 Content-Type: text/plain List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > So, IIUC. Once the qemu pieces are in place as well it shouldn't > change this behaviour: KVM will exit to qemu, qemu will log the error > information (new), then reinject the MC to the guest which can still > handle it as you describe above. Ah, that makes *much* more sense now! Thanks for the explanation: I don't really follow qemu development. > > But, there could be a problem if you have a new kernel with an old > qemu, in that case qemu might not understand the new exit type and > treat it as a fatal error, even though the guest could actually cope > with it. > > Aravinda, do we need to change this so that qemu has to explicitly > enable the new NMI behaviour? Or have I missed something that will > make that case work already. Yeah, it would be good not to break this. Regards, Daniel > -- > David Gibson | I'll have my music baroque, and my code > david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ > | _way_ _around_! > http://www.ozlabs.org/~dgibson