From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-1.mimecast.com ([205.139.110.61]:46455 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729043AbgCPLph (ORCPT ); Mon, 16 Mar 2020 07:45:37 -0400 Date: Mon, 16 Mar 2020 12:45:25 +0100 From: Cornelia Huck Subject: Re: [PATCH v2] KVM: s390: Also reset registers in sync regs for initial cpu reset Message-ID: <20200316124525.3bc099f9.cohuck@redhat.com> In-Reply-To: <8bdef3aa-01b5-93a1-c54a-46768d47dfa4@redhat.com> References: <20200310131223.10287-1-borntraeger@de.ibm.com> <8bdef3aa-01b5-93a1-c54a-46768d47dfa4@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-s390-owner@vger.kernel.org List-ID: To: David Hildenbrand Cc: Christian Borntraeger , Janosch Frank , KVM , linux-s390 , stable@vger.kernel.org On Tue, 10 Mar 2020 14:21:23 +0100 David Hildenbrand wrote: > On 10.03.20 14:12, Christian Borntraeger wrote: > > When we do the initial CPU reset we must not only clear the registers > > in the internal data structures but also in kvm_run sync_regs. For > > modern userspace sync_regs is the only place that it looks at. > > > > Cc: stable@vger.kernel.org > > # v? > > > Signed-off-by: Christian Borntraeger > > --- > > arch/s390/kvm/kvm-s390.c | 18 +++++++++++++++++- > > 1 file changed, 17 insertions(+), 1 deletion(-) > However, I do wonder if that ioctl *originally* was designed for that - > IOW if this is rally a stable patch or just some change that makes > sense. IIRC, userspace/QEMU always did the right thing, no? There was no > documentation about the guarantees AFAIK. The documentation only refers to the PoP for what is actually reset... should it also mention the sync regs?