KVM: s390: Intercept SCK instruction

Interception of the SET CLOCK instruction is mandatory, so this patch
provides a simple handler for this instruction (by setting up the
"epoch" field in the sie_block).

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 6f95994..2440602 100644 (file)
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -30,6 +30,38 @@
 #include "kvm-s390.h"
 #include "trace.h"
 
+/* Handle SCK (SET CLOCK) interception */
+static int handle_set_clock(struct kvm_vcpu *vcpu)
+{
+       struct kvm_vcpu *cpup;
+       s64 hostclk, val;
+       u64 op2;
+       int i;
+
+       if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
+               return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
+
+       op2 = kvm_s390_get_base_disp_s(vcpu);
+       if (op2 & 7)    /* Operand must be on a doubleword boundary */
+               return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+       if (get_guest(vcpu, val, (u64 __user *) op2))
+               return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+
+       if (store_tod_clock(&hostclk)) {
+               kvm_s390_set_psw_cc(vcpu, 3);
+               return 0;
+       }
+       val = (val - hostclk) & ~0x3fUL;
+
+       mutex_lock(&vcpu->kvm->lock);
+       kvm_for_each_vcpu(i, cpup, vcpu->kvm)
+               cpup->arch.sie_block->epoch = val;
+       mutex_unlock(&vcpu->kvm->lock);
+
+       kvm_s390_set_psw_cc(vcpu, 0);
+       return 0;
+}
+
 static int handle_set_prefix(struct kvm_vcpu *vcpu)
 {
        u64 operand2;
@@ -465,6 +497,7 @@ out_exception:
 
 static const intercept_handler_t b2_handlers[256] = {
        [0x02] = handle_stidp,
+       [0x04] = handle_set_clock,
        [0x10] = handle_set_prefix,
        [0x11] = handle_store_prefix,
        [0x12] = handle_store_cpu_address,