On Sun, Feb 09, 2020 at 01:37:35PM +0100, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 55680890ea78be0df5e1384989f1be835043c084 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger borntraeger@de.ibm.com Date: Fri, 31 Jan 2020 05:02:00 -0500 Subject: [PATCH] KVM: s390: do not clobber registers during guest reset/store status
The initial CPU reset clobbers the userspace fpc and the store status ioctl clobbers the guest acrs + fpr. As these calls are only done via ioctl (and not via vcpu_run), no CPU context is loaded, so we can (and must) act directly on the sync regs, not on the thread context.
Cc: stable@kernel.org Fixes: e1788bb995be ("KVM: s390: handle floating point registers in the run ioctl not in vcpu_put/load") Fixes: 31d8b8d41a7e ("KVM: s390: handle access registers in the run ioctl not in vcpu_put/load") Signed-off-by: Christian Borntraeger borntraeger@de.ibm.com Reviewed-by: David Hildenbrand david@redhat.com Reviewed-by: Cornelia Huck cohuck@redhat.com Signed-off-by: Janosch Frank frankja@linux.ibm.com Link: https://lore.kernel.org/r/20200131100205.74720-2-frankja@linux.ibm.com Signed-off-by: Christian Borntraeger borntraeger@de.ibm.com
This was a context conflict because we don't have b9224cd7381a ("KVM: s390: introduce defines for control registers") on 4.14. I've fixed it and queued it up on 4.14.