KVM: async_pf: Async page fault support on s390
This patch enables async page faults for s390 kvm guests.
It provides the userspace API to enable and disable_wait this feature.
The disable_wait will enforce that the feature is off by waiting on it.
Also it includes the diagnose code, called by the guest to enable async page faults.
The async page faults will use an already existing guest interface for this
purpose, as described in "CP Programming Services (SC24-6084)".
Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 9c9192b..1848080 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -31,7 +31,7 @@
return ((type & 0xfffe0000u) != 0xfffe0000u);
}
-static int psw_extint_disabled(struct kvm_vcpu *vcpu)
+int psw_extint_disabled(struct kvm_vcpu *vcpu)
{
return !(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_EXT);
}
@@ -78,11 +78,8 @@
return 1;
return 0;
case KVM_S390_INT_SERVICE:
- if (psw_extint_disabled(vcpu))
- return 0;
- if (vcpu->arch.sie_block->gcr[0] & 0x200ul)
- return 1;
- return 0;
+ case KVM_S390_INT_PFAULT_INIT:
+ case KVM_S390_INT_PFAULT_DONE:
case KVM_S390_INT_VIRTIO:
if (psw_extint_disabled(vcpu))
return 0;
@@ -150,6 +147,8 @@
case KVM_S390_INT_EXTERNAL_CALL:
case KVM_S390_INT_EMERGENCY:
case KVM_S390_INT_SERVICE:
+ case KVM_S390_INT_PFAULT_INIT:
+ case KVM_S390_INT_PFAULT_DONE:
case KVM_S390_INT_VIRTIO:
if (psw_extint_disabled(vcpu))
__set_cpuflag(vcpu, CPUSTAT_EXT_INT);
@@ -223,6 +222,30 @@
rc |= put_guest(vcpu, inti->ext.ext_params,
(u32 __user *)__LC_EXT_PARAMS);
break;
+ case KVM_S390_INT_PFAULT_INIT:
+ trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id, inti->type, 0,
+ inti->ext.ext_params2);
+ rc = put_guest(vcpu, 0x2603, (u16 __user *) __LC_EXT_INT_CODE);
+ rc |= put_guest(vcpu, 0x0600, (u16 __user *) __LC_EXT_CPU_ADDR);
+ rc |= copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
+ &vcpu->arch.sie_block->gpsw, sizeof(psw_t));
+ rc |= copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
+ __LC_EXT_NEW_PSW, sizeof(psw_t));
+ rc |= put_guest(vcpu, inti->ext.ext_params2,
+ (u64 __user *) __LC_EXT_PARAMS2);
+ break;
+ case KVM_S390_INT_PFAULT_DONE:
+ trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id, inti->type, 0,
+ inti->ext.ext_params2);
+ rc = put_guest(vcpu, 0x2603, (u16 __user *) __LC_EXT_INT_CODE);
+ rc |= put_guest(vcpu, 0x0680, (u16 __user *) __LC_EXT_CPU_ADDR);
+ rc |= copy_to_guest(vcpu, __LC_EXT_OLD_PSW,
+ &vcpu->arch.sie_block->gpsw, sizeof(psw_t));
+ rc |= copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
+ __LC_EXT_NEW_PSW, sizeof(psw_t));
+ rc |= put_guest(vcpu, inti->ext.ext_params2,
+ (u64 __user *) __LC_EXT_PARAMS2);
+ break;
case KVM_S390_INT_VIRTIO:
VCPU_EVENT(vcpu, 4, "interrupt: virtio parm:%x,parm64:%llx",
inti->ext.ext_params, inti->ext.ext_params2);
@@ -357,7 +380,7 @@
return 1;
}
-static int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu)
+int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu)
{
struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
struct kvm_s390_float_interrupt *fi = vcpu->arch.local_int.float_int;
@@ -737,6 +760,10 @@
VM_EVENT(kvm, 5, "inject: sclp parm:%x", s390int->parm);
inti->ext.ext_params = s390int->parm;
break;
+ case KVM_S390_INT_PFAULT_DONE:
+ inti->type = s390int->type;
+ inti->ext.ext_params2 = s390int->parm64;
+ break;
case KVM_S390_MCHK:
VM_EVENT(kvm, 5, "inject: machine check parm64:%llx",
s390int->parm64);
@@ -823,6 +850,10 @@
inti->type = s390int->type;
inti->mchk.mcic = s390int->parm64;
break;
+ case KVM_S390_INT_PFAULT_INIT:
+ inti->type = s390int->type;
+ inti->ext.ext_params2 = s390int->parm64;
+ break;
case KVM_S390_INT_VIRTIO:
case KVM_S390_INT_SERVICE:
case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:
@@ -877,6 +908,8 @@
irq.type = inti->type;
switch (inti->type) {
+ case KVM_S390_INT_PFAULT_INIT:
+ case KVM_S390_INT_PFAULT_DONE:
case KVM_S390_INT_VIRTIO:
case KVM_S390_INT_SERVICE:
irq.u.ext = inti->ext;
@@ -956,6 +989,8 @@
return -EFAULT;
switch (inti->type) {
+ case KVM_S390_INT_PFAULT_INIT:
+ case KVM_S390_INT_PFAULT_DONE:
case KVM_S390_INT_VIRTIO:
case KVM_S390_INT_SERVICE:
target = (void *) &inti->ext;
@@ -1019,6 +1054,8 @@
static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr)
{
int r = 0;
+ unsigned int i;
+ struct kvm_vcpu *vcpu;
switch (attr->group) {
case KVM_DEV_FLIC_ENQUEUE:
@@ -1028,6 +1065,20 @@
r = 0;
clear_floating_interrupts(dev->kvm);
break;
+ case KVM_DEV_FLIC_APF_ENABLE:
+ dev->kvm->arch.gmap->pfault_enabled = 1;
+ break;
+ case KVM_DEV_FLIC_APF_DISABLE_WAIT:
+ dev->kvm->arch.gmap->pfault_enabled = 0;
+ /*
+ * Make sure no async faults are in transition when
+ * clearing the queues. So we don't need to worry
+ * about late coming workers.
+ */
+ synchronize_srcu(&dev->kvm->srcu);
+ kvm_for_each_vcpu(i, vcpu, dev->kvm)
+ kvm_clear_async_pf_completion_queue(vcpu);
+ break;
default:
r = -EINVAL;
}