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From: Tony Krowiak <akrowiak@linux.ibm.com>
To: David Hildenbrand <david@redhat.com>,
	Tony Krowiak <akrowiak@linux.vnet.ibm.com>,
	linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org
Cc: freude@de.ibm.com, schwidefsky@de.ibm.com,
	heiko.carstens@de.ibm.com, borntraeger@de.ibm.com,
	cohuck@redhat.com, kwankhede@nvidia.com,
	bjsdjshi@linux.vnet.ibm.com, pbonzini@redhat.com,
	alex.williamson@redhat.com, pmorel@linux.vnet.ibm.com,
	alifm@linux.vnet.ibm.com, mjrosato@linux.vnet.ibm.com,
	jjherne@linux.vnet.ibm.com, thuth@redhat.com,
	pasic@linux.vnet.ibm.com, berrange@redhat.com,
	fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com,
	frankja@linux.ibm.com
Subject: Re: [PATCH v8 21/22] KVM: s390: CPU model support for AP virtualization
Date: Thu, 9 Aug 2018 16:27:38 -0400
Message-ID: <b1094c57-18dd-f4fd-b528-f1682b8fc078@linux.ibm.com> (raw)
In-Reply-To: <58eed530-31b3-49fe-cbd7-4d101b94daa0@redhat.com>

On 08/09/2018 04:17 AM, David Hildenbrand wrote:
> On 08.08.2018 16:44, Tony Krowiak wrote:
>> From: Tony Krowiak <akrowiak@linux.ibm.com>
>>
>> Introduces a new CPU model feature and two CPU model
>> facilities to support AP virtualization for KVM guests.
>>
>> CPU model feature:
>>
>> The KVM_S390_VM_CPU_FEAT_AP feature indicates that
>> AP instructions are available on the guest. This
>> feature will be enabled by the kernel only if the AP
>> instructions are installed on the linux host. This feature
>> must be specifically turned on for the KVM guest from
>> userspace to use the VFIO AP device driver for guest
>> access to AP devices.
>>
>> CPU model facilities:
>>
>> 1. AP Query Configuration Information (QCI) facility is installed.
>>
>>     This is indicated by setting facilities bit 12 for
>>     the guest. The kernel will not enable this facility
>>     for the guest if it is not set on the host. This facility
>>     must not be set by userspace if the KVM_S390_VM_CPU_FEAT_AP
>>     feature is not installed.
> Could it happen on real HW (not frankenstein CPU models), that
>
> !AP, but STFL 12 or 15  are indicated?

I suspect that if AP instructions are not installed, then neither
STFLE.12 nor STFLE.15 would be set in the real hardware. This
comment, however, is talking about an administrator setting the
facility for a guest, not real hardware. Having said that and after
thinking about it a little more, I am going to remove that last sentence
because the CPU model configuration (e.g., as specified on the qemu
command line) will fail if the QCI or APFT facility is enabled when the
CPU model feature KVM_S390_VM_CPU_FEAT_AP is not.

>
>>     If this facility is not set for the KVM guest, then only
>>     APQNs with an APQI less than 16 will be used by a Linux
>>     guest regardless of the matrix configuration for the virtual
>>     machine. This is a limitation of the Linux AP bus.
>>
>> 2. AP Facilities Test facility (APFT) is installed.
>>
>>     This is indicated by setting facilities bit 15 for
>>     the guest. The kernel will not enable this facility for
>>     the guest if it is not set on the host. This facility
>>     must not be set by userspace if the KVM_S390_VM_CPU_FEAT_AP
>>     feature is not installed.
>>
>>     If this facility is not set for the KVM guest, then no
>>     AP devices will be available to the guest regardless of
>>     the guest's matrix configuration for the virtual
>>     machine. This is a limitation of the Linux AP bus.
>>
>> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com>
>> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
>> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
>> Tested-by: Michael Mueller <mimu@linux.ibm.com>
>> Tested-by: Farhan Ali <alifm@linux.ibm.com>
>> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
>> ---
>>   arch/s390/kvm/kvm-s390.c         |    7 +++++++
>>   arch/s390/tools/gen_facilities.c |    2 ++
>>   2 files changed, 9 insertions(+), 0 deletions(-)
>>
>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
>> index 9203f0b..7d4fe9b 100644
>> --- a/arch/s390/kvm/kvm-s390.c
>> +++ b/arch/s390/kvm/kvm-s390.c
>> @@ -367,6 +367,13 @@ static void kvm_s390_cpu_feat_init(void)
>>   
>>   	if (MACHINE_HAS_ESOP)
>>   		allow_cpu_feat(KVM_S390_VM_CPU_FEAT_ESOP);
>> +
>> +	/*
>> +	 * Check if AP instructions installed on host
>> +	 */
> Make this a one-line comment, please.

Will do

>
>> +	if (ap_instructions_available() == 0)
>> +		allow_cpu_feat(KVM_S390_VM_CPU_FEAT_AP);
>> +
>>   	/*
>>   	 * We need SIE support, ESOP (PROT_READ protection for gmap_shadow),
>>   	 * 64bit SCAO (SCA passthrough) and IDTE (for gmap_shadow unshadowing).
>> diff --git a/arch/s390/tools/gen_facilities.c b/arch/s390/tools/gen_facilities.c
>> index 90a8c9e..a52290b 100644
>> --- a/arch/s390/tools/gen_facilities.c
>> +++ b/arch/s390/tools/gen_facilities.c
>> @@ -106,6 +106,8 @@ struct facility_def {
>>   
>>   		.name = "FACILITIES_KVM_CPUMODEL",
>>   		.bits = (int[]){
>> +			12, /* AP Query Configuration Information */
>> +			15, /* AP Facilities Test */
>>   			-1  /* END */
>>   		}
>>   	},
>>
>


  parent reply index

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-08 14:44 [PATCH v8 00/22] vfio-ap: guest dedicated crypto adapters Tony Krowiak
2018-08-08 14:44 ` [PATCH v8 01/22] s390/zcrypt: Add ZAPQ inline function Tony Krowiak
2018-08-08 14:44 ` [PATCH v8 02/22] s390/zcrypt: Review inline assembler constraints Tony Krowiak
2018-08-08 14:44 ` [PATCH v8 03/22] s390/zcrypt: Show load of cards and queues in sysfs Tony Krowiak
2018-08-08 14:44 ` [PATCH v8 04/22] s390/zcrypt: Integrate ap_asm.h into include/asm/ap.h Tony Krowiak
2018-08-09  9:06   ` Cornelia Huck
2018-08-09  9:17     ` Harald Freudenberger
2018-08-09 13:45       ` Harald Freudenberger
2018-08-09 16:06       ` Tony Krowiak
2018-08-10  8:49         ` Cornelia Huck
2018-08-10  9:37           ` Harald Freudenberger
2018-08-10 15:53             ` Tony Krowiak
2018-08-10 15:50           ` Tony Krowiak
2018-08-09 15:18     ` Tony Krowiak
2018-08-09 15:43       ` Heiko Carstens
2018-08-09 16:55         ` Tony Krowiak
2018-08-13  9:24     ` Harald Freudenberger
2018-08-13  9:34       ` Cornelia Huck
2018-08-08 14:44 ` [PATCH v8 05/22] KVM: s390: vsie: simulate VCPU SIE entry/exit Tony Krowiak
2018-08-08 14:44 ` [PATCH v8 06/22] KVM: s390: introduce and use KVM_REQ_VSIE_RESTART Tony Krowiak
2018-08-08 14:44 ` [PATCH v8 07/22] KVM: s390: refactor crypto initialization Tony Krowiak
2018-08-09  5:58   ` Janosch Frank
2018-08-10 16:13     ` Tony Krowiak
2018-08-09  8:25   ` David Hildenbrand
2018-08-09 19:54     ` Tony Krowiak
2018-08-08 14:44 ` [PATCH v8 08/22] s390: vfio-ap: base implementation of VFIO AP device driver Tony Krowiak
2018-08-09 10:12   ` Cornelia Huck
2018-08-08 14:44 ` [PATCH v8 09/22] s390: vfio-ap: register matrix device with VFIO mdev framework Tony Krowiak
2018-08-09 11:06   ` Cornelia Huck
2018-08-09 16:27     ` Pierre Morel
2018-08-10  8:59       ` Cornelia Huck
2018-08-08 14:44 ` [PATCH v8 10/22] s390: vfio-ap: sysfs interfaces to configure adapters Tony Krowiak
2018-08-08 14:44 ` [PATCH v8 11/22] s390: vfio-ap: sysfs interfaces to configure domains Tony Krowiak
2018-08-08 14:44 ` [PATCH v8 12/22] s390: vfio-ap: sysfs interfaces to configure control domains Tony Krowiak
2018-08-08 14:44 ` [PATCH v8 13/22] s390: vfio-ap: sysfs interface to view matrix mdev matrix Tony Krowiak
2018-08-08 14:44 ` [PATCH v8 14/22] KVM: s390: interfaces to clear CRYCB masks Tony Krowiak
2018-08-08 14:44 ` [PATCH v8 15/22] s390: vfio-ap: implement mediated device open callback Tony Krowiak
2018-08-08 14:44 ` [PATCH v8 16/22] s390: vfio-ap: implement VFIO_DEVICE_GET_INFO ioctl Tony Krowiak
2018-08-08 14:44 ` [PATCH v8 17/22] s390: vfio-ap: zeroize the AP queues Tony Krowiak
2018-08-10  9:14   ` Cornelia Huck
2018-08-10 10:49     ` Pierre Morel
2018-08-10 11:16       ` Cornelia Huck
2018-08-10 16:24         ` Tony Krowiak
2018-08-13  6:57           ` Cornelia Huck
2018-08-08 14:44 ` [PATCH v8 18/22] s390: vfio-ap: implement VFIO_DEVICE_RESET ioctl Tony Krowiak
2018-08-08 14:44 ` [PATCH v8 19/22] KVM: s390: Clear Crypto Control Block when using vSIE Tony Krowiak
2018-08-09  8:10   ` David Hildenbrand
2018-08-09  8:50     ` Pierre Morel
2018-08-09  8:57     ` Pierre Morel
2018-08-08 14:44 ` [PATCH v8 20/22] KVM: s390: Handling of Cypto control block in VSIE Tony Krowiak
2018-08-09  6:20   ` Janosch Frank
2018-08-09  7:33     ` Pierre Morel
2018-08-08 14:44 ` [PATCH v8 21/22] KVM: s390: CPU model support for AP virtualization Tony Krowiak
2018-08-09  8:17   ` David Hildenbrand
2018-08-09  8:34     ` Harald Freudenberger
2018-08-09 20:27     ` Tony Krowiak [this message]
2018-08-08 14:44 ` [PATCH v8 22/22] s390: doc: detailed specifications " Tony Krowiak
2018-08-08 15:06 ` [PATCH v8 00/22] vfio-ap: guest dedicated crypto adapters Janosch Frank
2018-08-08 16:25 ` Cornelia Huck
2018-08-08 22:52   ` Tony Krowiak

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