On 11/02/2017 11:53 AM, Christian Borntraeger wrote:
On 11/02/2017 04:36 PM, Tony Krowiak wrote:
On 11/02/2017 08:08 AM, Christian Borntraeger wrote:
On 10/16/2017 11:25 AM, Martin Schwidefsky wrote:
On Fri, 13 Oct 2017 13:39:04 -0400
Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx> wrote:
Sets up the following facilities bits to enable the specified AP
facilities for the guest VM:
* STFLE.12: Enables the AP Query Configuration Information
facility. The AP bus running in the guest uses
the information returned from this instruction
to configure AP adapters and domains for the
guest machine.
* STFLE.15: Indicates the AP facilities test is available.
The AP bus running in the guest uses the
information.
Signed-off-by: Tony Krowiak <akrowiak@xxxxxxxxxxxxxxxxxx>
---
arch/s390/tools/gen_facilities.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/arch/s390/tools/gen_facilities.c b/arch/s390/tools/gen_facilities.c
index 70dd8f1..eeaa7db 100644
--- a/arch/s390/tools/gen_facilities.c
+++ b/arch/s390/tools/gen_facilities.c
@@ -74,8 +74,10 @@ struct facility_def {
8, /* enhanced-DAT 1 */
9, /* sense-running-status */
10, /* conditional sske */
+ 12, /* AP query configuration */
13, /* ipte-range */
14, /* nonquiescing key-setting */
+ 15, /* AP special-command facility */
73, /* transactional execution */
75, /* access-exception-fetch/store indication */
76, /* msa extension 3 */
With this all KVM guests will always have the AP instructions available, no?
In principles I like this approach, but it differs from the way z/VM does things,
there the guest will get an exception if it tries to execute an AP instruction
if there are no AP devices assigned to the guest. I wonder if there is a reason
why z/VM does it the way it does.
A good question. For LPAR it seems that you have AP instructions even if you have
no crypto cards.
I don't believe these facilities control whether or not AP instructions will be available
to the guest.
This is actually handled by your patch2 enabling the ECA bit.
I think we must decide if we want to be able to disable these instructions
via the cpu model. If yes we must then couple the facilities with the enablement.
The ECA.28 bit controls whether instructions are intercepted or
interpreted - i.e., handled via hardware
virtualization. If set, as is done in patch2, then instructions will be
interpreted. I don't see how
that affects enabling or disabling AP instructions, unless we don't set
ECA.28, intercept every instruction
and program check. Am I missing something here?
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