KVM: s390: allow user space to handle instr 0x0000
We will use illegal instruction 0x0000 for handling 2 byte sw breakpoints
from user space. As it can be enabled dynamically via a capability,
let's move setting of ICTL_OPEREXC to the post creation step, so we avoid
any races when enabling that capability just while adding new cpus.
Acked-by: Janosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index d42428c..63ac7c1 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -364,6 +364,7 @@
case KVM_CAP_S390_USER_STSI:
case KVM_CAP_S390_SKEYS:
case KVM_CAP_S390_IRQ_STATE:
+ case KVM_CAP_S390_USER_INSTR0:
r = 1;
break;
case KVM_CAP_S390_MEM_OP:
@@ -456,6 +457,16 @@
return r;
}
+static void icpt_operexc_on_all_vcpus(struct kvm *kvm)
+{
+ unsigned int i;
+ struct kvm_vcpu *vcpu;
+
+ kvm_for_each_vcpu(i, vcpu, kvm) {
+ kvm_s390_sync_request(KVM_REQ_ICPT_OPEREXC, vcpu);
+ }
+}
+
static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap)
{
int r;
@@ -507,6 +518,12 @@
kvm->arch.user_stsi = 1;
r = 0;
break;
+ case KVM_CAP_S390_USER_INSTR0:
+ VM_EVENT(kvm, 3, "%s", "ENABLE: CAP_S390_USER_INSTR0");
+ kvm->arch.user_instr0 = 1;
+ icpt_operexc_on_all_vcpus(kvm);
+ r = 0;
+ break;
default:
r = -EINVAL;
break;
@@ -1836,6 +1853,8 @@
vcpu->arch.gmap = vcpu->kvm->arch.gmap;
sca_add_vcpu(vcpu);
}
+ if (test_kvm_facility(vcpu->kvm, 74) || vcpu->kvm->arch.user_instr0)
+ vcpu->arch.sie_block->ictl |= ICTL_OPEREXC;
/* make vcpu_load load the right gmap on the first trigger */
vcpu->arch.enabled_gmap = vcpu->arch.gmap;
}
@@ -1923,8 +1942,6 @@
}
vcpu->arch.sie_block->riccbd = (unsigned long) &vcpu->run->s.regs.riccb;
vcpu->arch.sie_block->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
- if (test_kvm_facility(vcpu->kvm, 74))
- vcpu->arch.sie_block->ictl |= ICTL_OPEREXC;
if (vcpu->kvm->arch.use_cmma) {
rc = kvm_s390_vcpu_setup_cmma(vcpu);
@@ -2369,6 +2386,11 @@
goto retry;
}
+ if (kvm_check_request(KVM_REQ_ICPT_OPEREXC, vcpu)) {
+ vcpu->arch.sie_block->ictl |= ICTL_OPEREXC;
+ goto retry;
+ }
+
/* nothing to do, just clear the request */
clear_bit(KVM_REQ_UNHALT, &vcpu->requests);