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>
This commit is contained in:
Fei Li
2017-02-17 17:06:26 +08:00
committed by Christian Borntraeger
parent 08fab50da6
commit 5197839354
6 changed files with 114 additions and 0 deletions

View File

@@ -2152,6 +2152,45 @@ static int clear_io_irq(struct kvm *kvm, struct kvm_device_attr *attr)
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 @@ static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
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 @@ static int flic_has_attr(struct kvm_device *dev,
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;