1 /*
2  * diag.c - handling diagnose instructions
3  *
4  * Copyright IBM Corp. 2008
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License (version 2 only)
8  * as published by the Free Software Foundation.
9  *
10  *    Author(s): Carsten Otte <cotte@de.ibm.com>
11  *               Christian Borntraeger <borntraeger@de.ibm.com>
12  */
13 
14 #include <linux/kvm.h>
15 #include <linux/kvm_host.h>
16 #include "kvm-s390.h"
17 
__diag_time_slice_end(struct kvm_vcpu * vcpu)18 static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
19 {
20 	VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
21 	vcpu->stat.diagnose_44++;
22 	vcpu_put(vcpu);
23 	yield();
24 	vcpu_load(vcpu);
25 	return 0;
26 }
27 
__diag_ipl_functions(struct kvm_vcpu * vcpu)28 static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
29 {
30 	unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
31 	unsigned long subcode = vcpu->arch.guest_gprs[reg] & 0xffff;
32 
33 	VCPU_EVENT(vcpu, 5, "diag ipl functions, subcode %lx", subcode);
34 	switch (subcode) {
35 	case 3:
36 		vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
37 		break;
38 	case 4:
39 		vcpu->run->s390_reset_flags = 0;
40 		break;
41 	default:
42 		return -EOPNOTSUPP;
43 	}
44 
45 	atomic_clear_mask(CPUSTAT_RUNNING, &vcpu->arch.sie_block->cpuflags);
46 	vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
47 	vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
48 	vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
49 	vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
50 	VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
51 	  vcpu->run->s390_reset_flags);
52 	return -EREMOTE;
53 }
54 
kvm_s390_handle_diag(struct kvm_vcpu * vcpu)55 int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
56 {
57 	int code = (vcpu->arch.sie_block->ipb & 0xfff0000) >> 16;
58 
59 	switch (code) {
60 	case 0x44:
61 		return __diag_time_slice_end(vcpu);
62 	case 0x308:
63 		return __diag_ipl_functions(vcpu);
64 	default:
65 		return -EOPNOTSUPP;
66 	}
67 }
68