xref: /openbmc/linux/arch/s390/kvm/diag.c (revision 2223cbec)
1 /*
2  * 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 #include "trace.h"
18 #include "trace-s390.h"
19 
20 static int diag_release_pages(struct kvm_vcpu *vcpu)
21 {
22 	unsigned long start, end;
23 	unsigned long prefix  = vcpu->arch.sie_block->prefix;
24 
25 	start = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
26 	end = vcpu->run->s.regs.gprs[vcpu->arch.sie_block->ipa & 0xf] + 4096;
27 
28 	if (start & ~PAGE_MASK || end & ~PAGE_MASK || start > end
29 	    || start < 2 * PAGE_SIZE)
30 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
31 
32 	VCPU_EVENT(vcpu, 5, "diag release pages %lX %lX", start, end);
33 	vcpu->stat.diagnose_10++;
34 
35 	/* we checked for start > end above */
36 	if (end < prefix || start >= prefix + 2 * PAGE_SIZE) {
37 		gmap_discard(start, end, vcpu->arch.gmap);
38 	} else {
39 		if (start < prefix)
40 			gmap_discard(start, prefix, vcpu->arch.gmap);
41 		if (end >= prefix)
42 			gmap_discard(prefix + 2 * PAGE_SIZE,
43 				     end, vcpu->arch.gmap);
44 	}
45 	return 0;
46 }
47 
48 static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
49 {
50 	VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
51 	vcpu->stat.diagnose_44++;
52 	kvm_vcpu_on_spin(vcpu);
53 	return 0;
54 }
55 
56 static int __diag_time_slice_end_directed(struct kvm_vcpu *vcpu)
57 {
58 	struct kvm *kvm = vcpu->kvm;
59 	struct kvm_vcpu *tcpu;
60 	int tid;
61 	int i;
62 
63 	tid = vcpu->run->s.regs.gprs[(vcpu->arch.sie_block->ipa & 0xf0) >> 4];
64 	vcpu->stat.diagnose_9c++;
65 	VCPU_EVENT(vcpu, 5, "diag time slice end directed to %d", tid);
66 
67 	if (tid == vcpu->vcpu_id)
68 		return 0;
69 
70 	kvm_for_each_vcpu(i, tcpu, kvm)
71 		if (tcpu->vcpu_id == tid) {
72 			kvm_vcpu_yield_to(tcpu);
73 			break;
74 		}
75 
76 	return 0;
77 }
78 
79 static int __diag_ipl_functions(struct kvm_vcpu *vcpu)
80 {
81 	unsigned int reg = vcpu->arch.sie_block->ipa & 0xf;
82 	unsigned long subcode = vcpu->run->s.regs.gprs[reg] & 0xffff;
83 
84 	VCPU_EVENT(vcpu, 5, "diag ipl functions, subcode %lx", subcode);
85 	switch (subcode) {
86 	case 3:
87 		vcpu->run->s390_reset_flags = KVM_S390_RESET_CLEAR;
88 		break;
89 	case 4:
90 		vcpu->run->s390_reset_flags = 0;
91 		break;
92 	default:
93 		return -EOPNOTSUPP;
94 	}
95 
96 	atomic_set_mask(CPUSTAT_STOPPED, &vcpu->arch.sie_block->cpuflags);
97 	vcpu->run->s390_reset_flags |= KVM_S390_RESET_SUBSYSTEM;
98 	vcpu->run->s390_reset_flags |= KVM_S390_RESET_IPL;
99 	vcpu->run->s390_reset_flags |= KVM_S390_RESET_CPU_INIT;
100 	vcpu->run->exit_reason = KVM_EXIT_S390_RESET;
101 	VCPU_EVENT(vcpu, 3, "requesting userspace resets %llx",
102 	  vcpu->run->s390_reset_flags);
103 	trace_kvm_s390_request_resets(vcpu->run->s390_reset_flags);
104 	return -EREMOTE;
105 }
106 
107 int kvm_s390_handle_diag(struct kvm_vcpu *vcpu)
108 {
109 	int code = (vcpu->arch.sie_block->ipb & 0xfff0000) >> 16;
110 
111 	trace_kvm_s390_handle_diag(vcpu, code);
112 	switch (code) {
113 	case 0x10:
114 		return diag_release_pages(vcpu);
115 	case 0x44:
116 		return __diag_time_slice_end(vcpu);
117 	case 0x9c:
118 		return __diag_time_slice_end_directed(vcpu);
119 	case 0x308:
120 		return __diag_ipl_functions(vcpu);
121 	default:
122 		return -EOPNOTSUPP;
123 	}
124 }
125