KVM: s390: introduce ais mode modify function
Provide an interface for userspace to modify AIS
(adapter-interruption-suppression) mode state, and add documentation
for the interface. Allowed target modes are ALL-Interruptions mode
and SINGLE-Interruption mode.
We introduce the 'simm' and 'nimm' fields in kvm_s390_float_interrupt
to store interruption modes for each ISC. Each bit in 'simm' and
'nimm' targets to one ISC, and collaboratively indicate three modes:
ALL-Interruptions, SINGLE-Interruption and NO-Interruptions. This
interface can initiate most transitions between the states; transition
from SINGLE-Interruption to NO-Interruptions via adapter interrupt
injection will be introduced in a following patch. The meaningful
combinations are as follows:
interruption mode | simm bit | nimm bit
------------------|----------|----------
ALL | 0 | 0
SINGLE | 1 | 0
NO | 1 | 1
Besides, add tracepoint to track AIS mode transitions.
Co-Authored-By: Yi Min Zhao <zyimin@linux.vnet.ibm.com>
Signed-off-by: Yi Min Zhao <zyimin@linux.vnet.ibm.com>
Signed-off-by: Fei Li <sherrylf@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 499c72c..552c319 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -521,6 +521,12 @@
#define FIRQ_CNTR_PFAULT 3
#define FIRQ_MAX_COUNT 4
+/* mask the AIS mode for a given ISC */
+#define AIS_MODE_MASK(isc) (0x80 >> isc)
+
+#define KVM_S390_AIS_MODE_ALL 0
+#define KVM_S390_AIS_MODE_SINGLE 1
+
struct kvm_s390_float_interrupt {
unsigned long pending_irqs;
spinlock_t lock;
@@ -530,6 +536,10 @@
struct kvm_s390_ext_info srv_signal;
int next_rr_cpu;
unsigned long idle_mask[BITS_TO_LONGS(KVM_MAX_VCPUS)];
+ struct mutex ais_lock;
+ u8 simm;
+ u8 nimm;
+ int ais_enabled;
};
struct kvm_hw_wp_info_arch {
diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
index 5fa144d..50d2a92 100644
--- a/arch/s390/include/uapi/asm/kvm.h
+++ b/arch/s390/include/uapi/asm/kvm.h
@@ -26,6 +26,7 @@
#define KVM_DEV_FLIC_ADAPTER_REGISTER 6
#define KVM_DEV_FLIC_ADAPTER_MODIFY 7
#define KVM_DEV_FLIC_CLEAR_IO_IRQ 8
+#define KVM_DEV_FLIC_AISM 9
/*
* We can have up to 4*64k pending subchannels + 8 adapter interrupts,
* as well as up to ASYNC_PF_PER_VCPU*KVM_MAX_VCPUS pfault done interrupts.
@@ -46,6 +47,11 @@
#define KVM_S390_ADAPTER_SUPPRESSIBLE 0x01
+struct kvm_s390_ais_req {
+ __u8 isc;
+ __u16 mode;
+};
+
#define KVM_S390_IO_ADAPTER_MASK 1
#define KVM_S390_IO_ADAPTER_MAP 2
#define KVM_S390_IO_ADAPTER_UNMAP 3
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index dba51ad..96b689e 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -2152,6 +2152,45 @@
return 0;
}
+static int modify_ais_mode(struct kvm *kvm, struct kvm_device_attr *attr)
+{
+ struct kvm_s390_float_interrupt *fi = &kvm->arch.float_int;
+ struct kvm_s390_ais_req req;
+ int ret = 0;
+
+ if (!fi->ais_enabled)
+ return -ENOTSUPP;
+
+ if (copy_from_user(&req, (void __user *)attr->addr, sizeof(req)))
+ return -EFAULT;
+
+ if (req.isc > MAX_ISC)
+ return -EINVAL;
+
+ trace_kvm_s390_modify_ais_mode(req.isc,
+ (fi->simm & AIS_MODE_MASK(req.isc)) ?
+ (fi->nimm & AIS_MODE_MASK(req.isc)) ?
+ 2 : KVM_S390_AIS_MODE_SINGLE :
+ KVM_S390_AIS_MODE_ALL, req.mode);
+
+ mutex_lock(&fi->ais_lock);
+ switch (req.mode) {
+ case KVM_S390_AIS_MODE_ALL:
+ fi->simm &= ~AIS_MODE_MASK(req.isc);
+ fi->nimm &= ~AIS_MODE_MASK(req.isc);
+ break;
+ case KVM_S390_AIS_MODE_SINGLE:
+ fi->simm |= AIS_MODE_MASK(req.isc);
+ fi->nimm &= ~AIS_MODE_MASK(req.isc);
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ mutex_unlock(&fi->ais_lock);
+
+ return ret;
+}
+
static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
int r = 0;
@@ -2188,6 +2227,9 @@
case KVM_DEV_FLIC_CLEAR_IO_IRQ:
r = clear_io_irq(dev->kvm, attr);
break;
+ case KVM_DEV_FLIC_AISM:
+ r = modify_ais_mode(dev->kvm, attr);
+ break;
default:
r = -EINVAL;
}
@@ -2207,6 +2249,7 @@
case KVM_DEV_FLIC_ADAPTER_REGISTER:
case KVM_DEV_FLIC_ADAPTER_MODIFY:
case KVM_DEV_FLIC_CLEAR_IO_IRQ:
+ case KVM_DEV_FLIC_AISM:
return 0;
}
return -ENXIO;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index f83f18b..977cc16 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -1515,6 +1515,10 @@
kvm_s390_crypto_init(kvm);
+ mutex_init(&kvm->arch.float_int.ais_lock);
+ kvm->arch.float_int.simm = 0;
+ kvm->arch.float_int.nimm = 0;
+ kvm->arch.float_int.ais_enabled = 0;
spin_lock_init(&kvm->arch.float_int.lock);
for (i = 0; i < FIRQ_LIST_COUNT; i++)
INIT_LIST_HEAD(&kvm->arch.float_int.lists[i]);
diff --git a/arch/s390/kvm/trace-s390.h b/arch/s390/kvm/trace-s390.h
index 396485b..b32994d 100644
--- a/arch/s390/kvm/trace-s390.h
+++ b/arch/s390/kvm/trace-s390.h
@@ -280,6 +280,37 @@
__entry->state ? "enabling" : "disabling", __entry->id)
);
+/*
+ * Trace point for modifying ais mode for a given isc.
+ */
+TRACE_EVENT(kvm_s390_modify_ais_mode,
+ TP_PROTO(__u8 isc, __u16 from, __u16 to),
+ TP_ARGS(isc, from, to),
+
+ TP_STRUCT__entry(
+ __field(__u8, isc)
+ __field(__u16, from)
+ __field(__u16, to)
+ ),
+
+ TP_fast_assign(
+ __entry->isc = isc;
+ __entry->from = from;
+ __entry->to = to;
+ ),
+
+ TP_printk("for isc %x, modifying interruption mode from %s to %s",
+ __entry->isc,
+ (__entry->from == KVM_S390_AIS_MODE_ALL) ?
+ "ALL-Interruptions Mode" :
+ (__entry->from == KVM_S390_AIS_MODE_SINGLE) ?
+ "Single-Interruption Mode" : "No-Interruptions Mode",
+ (__entry->to == KVM_S390_AIS_MODE_ALL) ?
+ "ALL-Interruptions Mode" :
+ (__entry->to == KVM_S390_AIS_MODE_SINGLE) ?
+ "Single-Interruption Mode" : "No-Interruptions Mode")
+ );
+
#endif /* _TRACE_KVMS390_H */