From mboxrd@z Thu Jan 1 00:00:00 1970 From: Balbir Singh Subject: Re: [PATCH v4 1/2] KVM: PPC: Add new capability to control MCE behaviour Date: Tue, 10 Jan 2017 07:54:28 +0530 Message-ID: <20170110022428.GA7781@localhost.localdomain> References: <148396203530.1471.16105350692124392705.stgit@aravinda> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: gleb@kernel.org, agraf@suse.de, kvm-ppc@vger.kernel.org, paulus@ozlabs.org, linuxppc-dev@ozlabs.org, pbonzini@redhat.com, mahesh@linux.vnet.ibm.com, david@gibson.dropbear.id.au, kvm@vger.kernel.org To: Aravinda Prasad Return-path: Received: from mail-pf0-f195.google.com ([209.85.192.195]:33357 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031246AbdAJCYh (ORCPT ); Mon, 9 Jan 2017 21:24:37 -0500 Content-Disposition: inline In-Reply-To: <148396203530.1471.16105350692124392705.stgit@aravinda> Sender: kvm-owner@vger.kernel.org List-ID: On Mon, Jan 09, 2017 at 05:10:35PM +0530, Aravinda Prasad wrote: > This patch introduces a new KVM capability to control > how KVM behaves on machine check exception (MCE). > Without this capability, KVM redirects machine check > exceptions to guest's 0x200 vector, if the address in > error belongs to the guest. With this capability KVM > causes a guest exit with NMI exit reason. > > The new capability is required to avoid problems if > a new kernel/KVM is used with an old QEMU for guests > that don't issue "ibm,nmi-register". As old QEMU does > not understand the NMI exit type, it treats it as a > fatal error. However, the guest could have handled > the machine check error if the exception was delivered > to guest's 0x200 interrupt vector instead of NMI exit > in case of old QEMU. > Can you move these to a cover letter, the description here does not match the changes > QEMU part can be found at: > http://lists.nongnu.org/archive/html/qemu-ppc/2015-12/msg00199.html > Balbir Singh.