From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:53439)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <david@redhat.com>) id 1ebv0q-0006pU-8U
	for qemu-devel@nongnu.org; Wed, 17 Jan 2018 16:12:49 -0500
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <david@redhat.com>) id 1ebv0n-0004fc-3V
	for qemu-devel@nongnu.org; Wed, 17 Jan 2018 16:12:48 -0500
References: <20180117193757.73471-1-borntraeger@de.ibm.com>
	<20180117193757.73471-3-borntraeger@de.ibm.com>
From: David Hildenbrand <david@redhat.com>
Message-ID: <47dbb1aa-76ae-eb3b-8060-b67ff3732dd4@redhat.com>
Date: Wed, 17 Jan 2018 22:12:40 +0100
MIME-Version: 1.0
In-Reply-To: <20180117193757.73471-3-borntraeger@de.ibm.com>
Content-Type: text/plain; charset=utf-8
Content-Language: en-US
Content-Transfer-Encoding: 7bit
Subject: Re: [Qemu-devel] [PATCH v2 2/3] s390x/kvm: Handle bpb feature
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel/>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Christian Borntraeger <borntraeger@de.ibm.com>, Cornelia Huck <cohuck@redhat.com>
Cc: qemu-devel <qemu-devel@nongnu.org>, qemu-s390x <qemu-s390x@nongnu.org>, Alexander Graf <agraf@suse.de>, Thomas Huth <thuth@redhat.com>, Richard Henderson <rth@twiddle.net>, Janosch Frank <frankja@linux.vnet.ibm.com>, Halil Pasic <pasic@linux.vnet.ibm.com>

On 17.01.2018 20:37, Christian Borntraeger wrote:
> We need to handle the bpb control on reset and migration. Normally
> stfle.82 is transparent (and the normal guest part works without
> hypervisor activity). To prevent any issues we require full
> host kernel support for this feature.
> 
> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
> ---
>  target/s390x/cpu.c              |  1 +
>  target/s390x/cpu.h              |  1 +
>  target/s390x/cpu_features.c     |  1 +
>  target/s390x/cpu_features_def.h |  1 +
>  target/s390x/gen-features.c     |  1 +
>  target/s390x/kvm.c              | 14 ++++++++++++++
>  target/s390x/machine.c          | 17 +++++++++++++++++
>  7 files changed, 36 insertions(+)
> 
> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
> index ae3cee9..1577b2c 100644
> --- a/target/s390x/cpu.c
> +++ b/target/s390x/cpu.c
> @@ -89,6 +89,7 @@ static void s390_cpu_reset(CPUState *s)
>      CPUS390XState *env = &cpu->env;
>  
>      env->pfault_token = -1UL;
> +    env->bpbc = 0;

As this is effectively only 1 bit, I wonder if we should also make that
clear in QEMU

bool bpbc, VMSTATE_BOOL ...

Apart from that, looks sane.

-- 

Thanks,

David / dhildenb