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authorDavid Hildenbrand <dahi@linux.vnet.ibm.com>2016-06-21 14:19:51 +0200
committerChristian Borntraeger <borntraeger@de.ibm.com>2016-07-18 14:15:00 +0200
commit6502a34cfd6695929086187f63fe670cc3050e68 (patch)
tree774e386aac358c15baeeba02a38bb8b080e3887d /arch/s390
parentaf1bae5497b98cb99d6b0492e6981f060420a00c (diff)
downloadlinux-6502a34cfd6695929086187f63fe670cc3050e68.tar.bz2
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>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/include/asm/kvm_host.h2
-rw-r--r--arch/s390/kvm/intercept.c3
-rw-r--r--arch/s390/kvm/kvm-s390.c26
3 files changed, 29 insertions, 2 deletions
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 946fc86202fd..183b01727de4 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -43,6 +43,7 @@
/* s390-specific vcpu->requests bit members */
#define KVM_REQ_ENABLE_IBS 8
#define KVM_REQ_DISABLE_IBS 9
+#define KVM_REQ_ICPT_OPEREXC 10
#define SIGP_CTRL_C 0x80
#define SIGP_CTRL_SCN_MASK 0x3f
@@ -666,6 +667,7 @@ struct kvm_arch{
int user_cpu_state_ctrl;
int user_sigp;
int user_stsi;
+ int user_instr0;
struct s390_io_adapter *adapters[MAX_S390_IO_ADAPTERS];
wait_queue_head_t ipte_wq;
int ipte_lock_count;
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index 850be47c4cc9..7a2f1551bc39 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -359,6 +359,9 @@ static int handle_operexc(struct kvm_vcpu *vcpu)
test_kvm_facility(vcpu->kvm, 74))
return handle_sthyi(vcpu);
+ if (vcpu->arch.sie_block->ipa == 0 && vcpu->kvm->arch.user_instr0)
+ return -EOPNOTSUPP;
+
return kvm_s390_inject_program_int(vcpu, PGM_OPERATION);
}
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index d42428c11794..63ac7c1641a7 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -364,6 +364,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
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 @@ out:
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 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap)
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 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
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 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
}
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 @@ retry:
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);