From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 1 Mar 2013 11:16:54 -0800 From: Greg Kroah-Hartman To: Jiri Slaby Cc: Christian Borntraeger , linux-kernel@vger.kernel.org, stable@vger.kernel.org, Gleb Natapov Subject: Re: [ 17/53] s390/kvm: Fix store status for ACRS/FPRS Message-ID: <20130301191654.GA30321@kroah.com> References: <20130226235619.844721947@linuxfoundation.org> <20130226235621.622037661@linuxfoundation.org> <512FD9B3.5000304@suse.cz> <51305DC5.7010201@de.ibm.com> <5130734F.6090208@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5130734F.6090208@suse.cz> Sender: linux-kernel-owner@vger.kernel.org List-ID: On Fri, Mar 01, 2013 at 10:22:23AM +0100, Jiri Slaby wrote: > On 03/01/2013 08:50 AM, Christian Borntraeger wrote: > > On 28/02/13 23:26, Jiri Slaby wrote: > >> On 02/27/2013 12:57 AM, Greg Kroah-Hartman wrote: > >>> 3.0-stable review patch. If anyone has any objections, please let me know. > >>> > >>> ------------------ > >>> > >>> From: Christian Borntraeger > >>> > >>> commit 15bc8d8457875f495c59d933b05770ba88d1eacb upstream. > >>> > >>> On store status we need to copy the current state of registers > >>> into a save area. Currently we might save stale versions: > >>> The sie state descriptor doesnt have fields for guest ACRS,FPRS, > >>> those registers are simply stored in the host registers. The host > >>> program must copy these away if needed. We do that in vcpu_put/load. > >>> > >>> If we now do a store status in KVM code between vcpu_put/load, the > >>> saved values are not up-to-date. Lets collect the ACRS/FPRS before > >>> saving them. > >>> > >>> This also fixes some strange problems with hotplug and virtio-ccw, > >>> since the low level machine check handler (on hotplug a machine check > >>> will happen) will revalidate all registers with the content of the > >>> save area. > >>> > >>> Signed-off-by: Christian Borntraeger > >>> Signed-off-by: Gleb Natapov > >>> Signed-off-by: Greg Kroah-Hartman > >>> > >>> --- > >>> arch/s390/kvm/kvm-s390.c | 8 ++++++++ > >>> 1 file changed, 8 insertions(+) > >>> > >>> --- a/arch/s390/kvm/kvm-s390.c > >>> +++ b/arch/s390/kvm/kvm-s390.c > >>> @@ -584,6 +584,14 @@ int kvm_s390_vcpu_store_status(struct kv > >>> } else > >>> prefix = 0; > >>> > >>> + /* > >>> + * The guest FPRS and ACRS are in the host FPRS/ACRS due to the lazy > >>> + * copying in vcpu load/put. Lets update our copies before we save > >>> + * it into the save area > >>> + */ > >>> + save_fp_regs(&vcpu->arch.guest_fpregs); > >>> + save_access_regs(vcpu->run->s.regs.acrs); > >> > >> kvm_run structure does not have kvm_sync_regs in it in 3.0 yet. So this > >> fails with: > >> arch/s390/kvm/kvm-s390.c: In function 'kvm_s390_vcpu_store_status': > >> arch/s390/kvm/kvm-s390.c:593: error: 'struct kvm_run' has no member > >> named 's' > >> > >> I believe the fix is just to remove save_access_regs, right? > > > > Before the sync reg changes, the ACRS were saved in the vcpu->arch. > > So the fix would look like > > > > save_access_regs(vcpu->arch.guest_acrs); > > Fix attached. Thanks, now applied. greg k-h