Re: [PATCH v2 03/15] s390: zcrypt: externalize AP instructions available function

[Harald Freudenberger]

On 02/28/2018 06:41 PM, Cornelia Huck wrote:
> On Tue, 27 Feb 2018 09:28:01 -0500
> Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> wrote:
>
>> If the AP instructions are not available on the linux host, then
>> AP devices can not be interpreted by the SIE. The AP bus has a
>> function it uses to determine if the AP instructions are
>> available. This patch provides a new function that wraps the
>> AP bus's function to externalize it for use by KVM.
>>
>> Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx>
>> Reviewed-by: Pierre Morel <pmorel@xxxxxxxxxxxxxxxxxx>
>> ---
>>  arch/s390/include/asm/ap.h   |    7 +++++++
>>  drivers/s390/crypto/ap_bus.c |    6 ++++++
>>  2 files changed, 13 insertions(+), 0 deletions(-)
> While I don't see anything wrong with this patch as it stands, you need
> to be careful to call this only from vfio-ap code (which depends on
> CONFIG_ZCRYPT).
>
> Speaking of which: the ap_bus part cannot be a module, but only
> built-in, right? So we don't get additional module complications?
Right, the AP bus is not available as a module but statically build.
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