From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aravinda Prasad Subject: Re: [PATCH v4 1/2] KVM: PPC: Add new capability to control MCE behaviour Date: Fri, 13 Jan 2017 12:52:27 +0530 Message-ID: References: <148396203530.1471.16105350692124392705.stgit@aravinda> <20170112095628.GA29786@fergus.ozlabs.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, gleb@kernel.org, mahesh@linux.vnet.ibm.com, agraf@suse.de, kvm-ppc@vger.kernel.org, linuxppc-dev@ozlabs.org, pbonzini@redhat.com, david@gibson.dropbear.id.au To: Paul Mackerras Return-path: In-Reply-To: <20170112095628.GA29786@fergus.ozlabs.ibm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" List-Id: kvm.vger.kernel.org On Thursday 12 January 2017 03:26 PM, Paul Mackerras wrote: > 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. > > You need to add a description of the new capability to > Documentation/virtual/kvm/api.txt. sure. > > Paul. > -- Regards, Aravinda