Re: [PATCH v2 07/15] KVM: s390: Interfaces to configure/deconfigure guest's AP matrix

From: Pierre Morel
Date: Wed Feb 28 2018 - 11:16:05 EST


On 27/02/2018 15:28, Tony Krowiak wrote:
Provides interfaces to assign AP adapters, usage domains
and control domains to a KVM guest.

A KVM guest is started by executing the Start Interpretive Execution (SIE)
instruction. The SIE state description is a control block that contains the
state information for a KVM guest and is supplied as input to the SIE
instruction. The SIE state description has a satellite structure called the
Crypto Control Block (CRYCB). The CRYCB contains three bitmask fields
identifying the adapters, queues (domains) and control domains assigned to
the KVM guest:

* The AP Adapter Mask (APM) field identifies the AP adapters assigned to
the KVM guest

* The AP Queue Mask (AQM) field identifies the AP queues assigned to
the KVM guest. Each AP queue is connected to a usage domain within
an AP adapter.

* The AP Domain Mask (ADM) field identifies the control domains
assigned to the KVM guest.

Each adapter, queue (usage domain) and control domain are identified by
a number from 0 to 255. The bits in each mask, from most significant to
least significant bit, correspond to the numbers 0-255. When a bit is
set, the corresponding adapter, queue (usage domain) or control domain
is assigned to the KVM guest.

...snip...

static int kvm_ap_apxa_installed(void)
{
int ret;
@@ -50,3 +170,140 @@ void kvm_ap_set_crycb_format(struct kvm *kvm, __u32 *crycbd)
*crycbd |= CRYCB_FORMAT1;
}
}
+
+static int kvm_ap_matrix_apm_create(struct kvm_ap_matrix *ap_matrix, int apxa)
+{
+ if (apxa)
+ ap_matrix->apm_max = 256;

AFAIK the number of possible bits in the masks for a system is not a generic value but is
returned by the QCI instruction.
Is there a reason to use a fix value?

+ else
+ ap_matrix->apm_max = 64;
+
+ ap_matrix->apm = kzalloc(KVM_AP_MASK_BYTES(ap_matrix->apm_max),
+ GFP_KERNEL);
+ if (!ap_matrix->apm)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static int kvm_ap_matrix_aqm_create(struct kvm_ap_matrix *ap_matrix, int apxa)
+{
+ if (apxa)
+ ap_matrix->aqm_max = 256;

same here

+ else
+ ap_matrix->aqm_max = 16;
+
+ ap_matrix->aqm = kzalloc(KVM_AP_MASK_BYTES(ap_matrix->aqm_max),
+ GFP_KERNEL);
+ if (!ap_matrix->aqm)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static int kvm_ap_matrix_adm_create(struct kvm_ap_matrix *ap_matrix, int apxa)
+{
+ if (apxa)
+ ap_matrix->adm_max = 256;

and here


Pierre

--
Pierre Morel
Linux/KVM/QEMU in BÃblingen - Germany