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

[Cornelia Huck]

On Mon,  7 May 2018 11:11:40 -0400
Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxxxx>
> ---
>  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@xxxxxxxxxx>
>  M:	Janosch Frank <frankja@xxxxxxxxxxxxx>
>  R:	David Hildenbrand <david@xxxxxxxxxx>
>  R:	Cornelia Huck <cohuck@xxxxxxxxxx>
> +R:	Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxxx
>  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 :)