KVM: s390: Fixed priority of execution in STSI

Added some missing validity checks for the operands and fixed the
priority of exceptions for some function codes according to the
"Principles of Operation" document.

Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@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 c7603f5b4c28957b6a474dc122ff7d20fe3ead3b..0da3e6eb6be6cec4d55780b838492e52d093f08d 100644 (file)
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -385,16 +385,27 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
        if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
                return kvm_s390_inject_program_int(vcpu, PGM_PRIVILEGED_OP);
 
-       operand2 = kvm_s390_get_base_disp_s(vcpu);
+       if (fc > 3) {
+               vcpu->arch.sie_block->gpsw.mask |= 3ul << 44;     /* cc 3 */
+               return 0;
+       }
 
-       if (operand2 & 0xfff && fc > 0)
+       if (vcpu->run->s.regs.gprs[0] & 0x0fffff00
+           || vcpu->run->s.regs.gprs[1] & 0xffff0000)
                return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 
-       switch (fc) {
-       case 0:
+       if (fc == 0) {
                vcpu->run->s.regs.gprs[0] = 3 << 28;
-               vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);
+               vcpu->arch.sie_block->gpsw.mask &= ~(3ul << 44);  /* cc 0 */
                return 0;
+       }
+
+       operand2 = kvm_s390_get_base_disp_s(vcpu);
+
+       if (operand2 & 0xfff)
+               return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+
+       switch (fc) {
        case 1: /* same handling for 1 and 2 */
        case 2:
                mem = get_zeroed_page(GFP_KERNEL);
@@ -411,8 +422,6 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
                        goto out_no_data;
                handle_stsi_3_2_2(vcpu, (void *) mem);
                break;
-       default:
-               goto out_no_data;
        }
 
        if (copy_to_guest_absolute(vcpu, operand2, (void *) mem, PAGE_SIZE)) {