1/*
2 * diag.c - handling diagnose instructions
3 *
4 * Copyright IBM Corp. 2008,2011
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
18static int diag_release_pages(struct kvm_vcpu *vcpu)
19{
20	unsigned long start, end;
21	unsigned long prefix  = vcpu->arch.sie_block->prefix;
22
23	start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
24	end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + 4096;
25
26	if (start & ~PAGE_MASK || end & ~PAGE_MASK || start > end
27	    || start < 2 * PAGE_SIZE)
28		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
29
30	VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end);
31	vcpu->stat.diagnose_10++;
32
33	/* we checked for start > end above */
34	if (end < prefix || start >= prefix + 2 * PAGE_SIZE) {
35		gmap_discard(start, end, vcpu->arch.gmap);
36	} else {
37		if (start < prefix)
38			gmap_discard(start, prefix, vcpu->arch.gmap);
39		if (end >= prefix)
40			gmap_discard(prefix + 2 * PAGE_SIZE,
41				     end, vcpu->arch.gmap);
42	}
43	return 0;
44}
45
46static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
47{
48	VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
49	vcpu->stat.diagnose_44++;
50	vcpu_put(vcpu);
51	yield();
52	vcpu_load(vcpu);
53	return 0;
54}
55
56static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
57{
58	unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
59	unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;
60
61	VCPU_EVENT(vcpu, 5, "diag ipl functions, subcode %lx", subcode);
62	switch (subcode) {
63	case 3:
64		vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
65		break;
66	case 4:
67		vcpu->run->s390_reset_flags = 0;
68		break;
69	default:
70		return -EOPNOTSUPP;
71	}
72
73	atomic_set_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
74	vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
75	vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
76	vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
77	vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
78	VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
79	  vcpu->run->s390_reset_flags);
80	return -EREMOTE;
81}
82
83int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
84{
85	int code = (vcpu->arch.sie_block->ipb & 0xfff0000) >> 16;
86
87	switch (code) {
88	case 0x10:
89		return diag_release_pages(vcpu);
90	case 0x44:
91		return __diag_time_slice_end(vcpu);
92	case 0x308:
93		return __diag_ipl_functions(vcpu);
94	default:
95		return -EOPNOTSUPP;
96	}
97}
98