Re: [PATCH v5 01/13] KVM: s390: Interface to test whether APXA installed

Cornelia Huck
2018-05-16T10:21:16Z

On Mon, 7 May 2018 11:11:40 -0400
Tony Krowiak <akrowiak@linux.vnet.ibm.com> wrote:

> Relocates an existing static function that tests whether
> the AP extended addressing facility (APXA) is installed on
> the linux host. The primary reason for relocating this
> function is because a new compilation unit (arch/s390/kvm/kvm-ap.c)
> is being created to contain all of the interfaces and logic
> for configuring an AP matrix for a KVM guest. Some of its
> functions will also need to determine whether APXA is installed,
> so, let's go ahead and relocate this static function as a
> public interface in kvm-ap.c.
>
> Notes:
> ----
> 1. The interface to determine whether APXA is installed on the linux
> host the information returned from the AP Query Configuration
> Information (QCI) function. This function will not be available
> if the AP instructions are not installed on the linux host, so a check
> will be included to verify that.
>
> 2. Currently, the AP bus interfaces accessing the AP instructions will
> not be accessible if CONFIG_ZCRYPT=n, so the relevant code will be
> temporarily contained in the new arch/s390/kvm/kvm-ap.c file until
> the patch(es) to statically build the required AP bus interfaces are
> available.

Any ETA for those interfaces? Would be nice if we could avoid
introducing temporary interfaces (but I'm certainly not opposing this
patch).

>
> Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
> ---
> MAINTAINERS | 1 +
> arch/s390/include/asm/kvm-ap.h | 60 +++++++++++++++++++++++++++++
> arch/s390/kvm/Makefile | 2 +-
> arch/s390/kvm/kvm-ap.c | 83 ++++++++++++++++++++++++++++++++++++++++
> arch/s390/kvm/kvm-s390.c | 42 +-------------------
> 5 files changed, 147 insertions(+), 41 deletions(-)
> create mode 100644 arch/s390/include/asm/kvm-ap.h
> create mode 100644 arch/s390/kvm/kvm-ap.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index eab763f..224e97b 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -7792,6 +7792,7 @@ M: Christian Borntraeger <borntraeger@de.ibm.com>
> M: Janosch Frank <frankja@linux.ibm.com>
> R: David Hildenbrand <david@redhat.com>
> R: Cornelia Huck <cohuck@redhat.com>
> +R: Tony Krowiak <akrowiak@linux.vnet.ibm.com>

Don't you want to drop the 'vnet' from your address, as the vnet-less
form seems to be the one that will continue working from what I've
heard?

> L: linux-s390@vger.kernel.org
> W: http://www.ibm.com/developerworks/linux/linux390/
> T: git git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux.git

No objection against this patch, although I still hope it will not be
needed :)