From mboxrd@z Thu Jan  1 00:00:00 1970
From: Pierre Morel <pmorel@linux.ibm.com>
Subject: Re: [PATCH 1/3] vfio-ccw: add capabilities chain
Date: Fri, 23 Nov 2018 13:28:25 +0100
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	<20181122165432.4437-2-cohuck@redhat.com>
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Cc: linux-s390@vger.kernel.org, qemu-s390x@nongnu.org,
	Alex Williamson <alex.williamson@redhat.com>,
	qemu-devel@nongnu.org, kvm@vger.kernel.org
To: Cornelia Huck <cohuck@redhat.com>, Halil Pasic <pasic@linux.ibm.com>,
	Eric Farman <farman@linux.ibm.com>, Farhan Ali <alifm@linux.ibm.com>
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On 22/11/2018 17:54, Cornelia Huck wrote:
> Allow to extend the regions used by vfio-ccw. The first user will be
> handling of halt and clear subchannel.
>=20
> Signed-off-by: Cornelia Huck <cohuck@redhat.com>
> ---
>   drivers/s390/cio/vfio_ccw_ops.c     | 182 ++++++++++++++++++++++++---=
-
>   drivers/s390/cio/vfio_ccw_private.h |  38 ++++++
>   include/uapi/linux/vfio.h           |   1 +
>   3 files changed, 195 insertions(+), 26 deletions(-)
>=20

Halt and clear have no parameters (the sub-channel ID is obviously the=20
one of the mediated device).

Isn't adding a new sub-region for the purpose of handling halt and clear=20
superfluous?

What is the reason not to use simple ioctls ?

Regards,
Pierre

--=20
Pierre Morel
Linux/KVM/QEMU in B=C3=B6blingen - Germany