1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright 2017 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
4 */
5
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8 #include <linux/kvm_host.h>
9
10 #include <asm/kvm_ppc.h>
11 #include <asm/kvm_book3s.h>
12 #include <asm/kvm_book3s_64.h>
13 #include <asm/reg.h>
14 #include <asm/ppc-opcode.h>
15
16 static void emulate_tx_failure(struct kvm_vcpu *vcpu, u64 failure_cause)
17 {
18 u64 texasr, tfiar;
19 u64 msr = vcpu->arch.shregs.msr;
20
21 tfiar = vcpu->arch.regs.nip & ~0x3ull;
22 texasr = (failure_cause << 56) | TEXASR_ABORT | TEXASR_FS | TEXASR_EXACT;
23 if (MSR_TM_SUSPENDED(vcpu->arch.shregs.msr))
24 texasr |= TEXASR_SUSP;
25 if (msr & MSR_PR) {
26 texasr |= TEXASR_PR;
27 tfiar |= 1;
28 }
29 vcpu->arch.tfiar = tfiar;
30 /* Preserve ROT and TL fields of existing TEXASR */
31 vcpu->arch.texasr = (vcpu->arch.texasr & 0x3ffffff) | texasr;
32 }
33
34 /*
35 * This gets called on a softpatch interrupt on POWER9 DD2.2 processors.
36 * We expect to find a TM-related instruction to be emulated. The
37 * instruction image is in vcpu->arch.emul_inst. If the guest was in
38 * TM suspended or transactional state, the checkpointed state has been
39 * reclaimed and is in the vcpu struct. The CPU is in virtual mode in
40 * host context.
41 */
42 int kvmhv_p9_tm_emulation(struct kvm_vcpu *vcpu)
43 {
44 u32 instr = vcpu->arch.emul_inst;
45 u64 msr = vcpu->arch.shregs.msr;
46 u64 newmsr, bescr;
47 int ra, rs;
48
49 /*
50 * The TM softpatch interrupt sets NIP to the instruction following
51 * the faulting instruction, which is not executed. Rewind nip to the
52 * faulting instruction so it looks like a normal synchronous
53 * interrupt, then update nip in the places where the instruction is
54 * emulated.
55 */
56 vcpu->arch.regs.nip -= 4;
57
58 /*
59 * rfid, rfebb, and mtmsrd encode bit 31 = 0 since it's a reserved bit
60 * in these instructions, so masking bit 31 out doesn't change these
61 * instructions. For treclaim., tsr., and trechkpt. instructions if bit
62 * 31 = 0 then they are per ISA invalid forms, however P9 UM, in section
63 * 4.6.10 Book II Invalid Forms, informs specifically that ignoring bit
64 * 31 is an acceptable way to handle these invalid forms that have
65 * bit 31 = 0. Moreover, for emulation purposes both forms (w/ and wo/
66 * bit 31 set) can generate a softpatch interrupt. Hence both forms
67 * are handled below for these instructions so they behave the same way.
68 */
69 switch (instr & PO_XOP_OPCODE_MASK) {
70 case PPC_INST_RFID:
71 /* XXX do we need to check for PR=0 here? */
72 newmsr = vcpu->arch.shregs.srr1;
73 /* should only get here for Sx -> T1 transition */
74 WARN_ON_ONCE(!(MSR_TM_SUSPENDED(msr) &&
75 MSR_TM_TRANSACTIONAL(newmsr) &&
76 (newmsr & MSR_TM)));
77 newmsr = sanitize_msr(newmsr);
78 vcpu->arch.shregs.msr = newmsr;
79 vcpu->arch.cfar = vcpu->arch.regs.nip;
80 vcpu->arch.regs.nip = vcpu->arch.shregs.srr0;
81 return RESUME_GUEST;
82
83 case PPC_INST_RFEBB:
84 if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206)) {
85 /* generate an illegal instruction interrupt */
86 kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
87 return RESUME_GUEST;
88 }
89 /* check EBB facility is available */
90 if (!(vcpu->arch.hfscr & HFSCR_EBB)) {
91 vcpu->arch.hfscr &= ~HFSCR_INTR_CAUSE;
92 vcpu->arch.hfscr |= (u64)FSCR_EBB_LG << 56;
93 vcpu->arch.trap = BOOK3S_INTERRUPT_H_FAC_UNAVAIL;
94 return -1; /* rerun host interrupt handler */
95 }
96 if ((msr & MSR_PR) && !(vcpu->arch.fscr & FSCR_EBB)) {
97 /* generate a facility unavailable interrupt */
98 vcpu->arch.fscr &= ~FSCR_INTR_CAUSE;
99 vcpu->arch.fscr |= (u64)FSCR_EBB_LG << 56;
100 kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_FAC_UNAVAIL);
101 return RESUME_GUEST;
102 }
103 bescr = vcpu->arch.bescr;
104 /* expect to see a S->T transition requested */
105 WARN_ON_ONCE(!(MSR_TM_SUSPENDED(msr) &&
106 ((bescr >> 30) & 3) == 2));
107 bescr &= ~BESCR_GE;
108 if (instr & (1 << 11))
109 bescr |= BESCR_GE;
110 vcpu->arch.bescr = bescr;
111 msr = (msr & ~MSR_TS_MASK) | MSR_TS_T;
112 vcpu->arch.shregs.msr = msr;
113 vcpu->arch.cfar = vcpu->arch.regs.nip;
114 vcpu->arch.regs.nip = vcpu->arch.ebbrr;
115 return RESUME_GUEST;
116
117 case PPC_INST_MTMSRD:
118 /* XXX do we need to check for PR=0 here? */
119 rs = (instr >> 21) & 0x1f;
120 newmsr = kvmppc_get_gpr(vcpu, rs);
121 /* check this is a Sx -> T1 transition */
122 WARN_ON_ONCE(!(MSR_TM_SUSPENDED(msr) &&
123 MSR_TM_TRANSACTIONAL(newmsr) &&
124 (newmsr & MSR_TM)));
125 /* mtmsrd doesn't change LE */
126 newmsr = (newmsr & ~MSR_LE) | (msr & MSR_LE);
127 newmsr = sanitize_msr(newmsr);
128 vcpu->arch.shregs.msr = newmsr;
129 vcpu->arch.regs.nip += 4;
130 return RESUME_GUEST;
131
132 /* ignore bit 31, see comment above */
133 case (PPC_INST_TSR & PO_XOP_OPCODE_MASK):
134 /* check for PR=1 and arch 2.06 bit set in PCR */
135 if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206)) {
136 /* generate an illegal instruction interrupt */
137 kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
138 return RESUME_GUEST;
139 }
140 /* check for TM disabled in the HFSCR or MSR */
141 if (!(vcpu->arch.hfscr & HFSCR_TM)) {
142 vcpu->arch.hfscr &= ~HFSCR_INTR_CAUSE;
143 vcpu->arch.hfscr |= (u64)FSCR_TM_LG << 56;
144 vcpu->arch.trap = BOOK3S_INTERRUPT_H_FAC_UNAVAIL;
145 return -1; /* rerun host interrupt handler */
146 }
147 if (!(msr & MSR_TM)) {
148 /* generate a facility unavailable interrupt */
149 vcpu->arch.fscr &= ~FSCR_INTR_CAUSE;
150 vcpu->arch.fscr |= (u64)FSCR_TM_LG << 56;
151 kvmppc_book3s_queue_irqprio(vcpu,
152 BOOK3S_INTERRUPT_FAC_UNAVAIL);
153 return RESUME_GUEST;
154 }
155 /* Set CR0 to indicate previous transactional state */
156 vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) |
157 (((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 29);
158 /* L=1 => tresume, L=0 => tsuspend */
159 if (instr & (1 << 21)) {
160 if (MSR_TM_SUSPENDED(msr))
161 msr = (msr & ~MSR_TS_MASK) | MSR_TS_T;
162 } else {
163 if (MSR_TM_TRANSACTIONAL(msr))
164 msr = (msr & ~MSR_TS_MASK) | MSR_TS_S;
165 }
166 vcpu->arch.shregs.msr = msr;
167 vcpu->arch.regs.nip += 4;
168 return RESUME_GUEST;
169
170 /* ignore bit 31, see comment above */
171 case (PPC_INST_TRECLAIM & PO_XOP_OPCODE_MASK):
172 /* check for TM disabled in the HFSCR or MSR */
173 if (!(vcpu->arch.hfscr & HFSCR_TM)) {
174 vcpu->arch.hfscr &= ~HFSCR_INTR_CAUSE;
175 vcpu->arch.hfscr |= (u64)FSCR_TM_LG << 56;
176 vcpu->arch.trap = BOOK3S_INTERRUPT_H_FAC_UNAVAIL;
177 return -1; /* rerun host interrupt handler */
178 }
179 if (!(msr & MSR_TM)) {
180 /* generate a facility unavailable interrupt */
181 vcpu->arch.fscr &= ~FSCR_INTR_CAUSE;
182 vcpu->arch.fscr |= (u64)FSCR_TM_LG << 56;
183 kvmppc_book3s_queue_irqprio(vcpu,
184 BOOK3S_INTERRUPT_FAC_UNAVAIL);
185 return RESUME_GUEST;
186 }
187 /* If no transaction active, generate TM bad thing */
188 if (!MSR_TM_ACTIVE(msr)) {
189 kvmppc_core_queue_program(vcpu, SRR1_PROGTM);
190 return RESUME_GUEST;
191 }
192 /* If failure was not previously recorded, recompute TEXASR */
193 if (!(vcpu->arch.orig_texasr & TEXASR_FS)) {
194 ra = (instr >> 16) & 0x1f;
195 if (ra)
196 ra = kvmppc_get_gpr(vcpu, ra) & 0xff;
197 emulate_tx_failure(vcpu, ra);
198 }
199
200 copy_from_checkpoint(vcpu);
201
202 /* Set CR0 to indicate previous transactional state */
203 vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) |
204 (((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 29);
205 vcpu->arch.shregs.msr &= ~MSR_TS_MASK;
206 vcpu->arch.regs.nip += 4;
207 return RESUME_GUEST;
208
209 /* ignore bit 31, see comment above */
210 case (PPC_INST_TRECHKPT & PO_XOP_OPCODE_MASK):
211 /* XXX do we need to check for PR=0 here? */
212 /* check for TM disabled in the HFSCR or MSR */
213 if (!(vcpu->arch.hfscr & HFSCR_TM)) {
214 vcpu->arch.hfscr &= ~HFSCR_INTR_CAUSE;
215 vcpu->arch.hfscr |= (u64)FSCR_TM_LG << 56;
216 vcpu->arch.trap = BOOK3S_INTERRUPT_H_FAC_UNAVAIL;
217 return -1; /* rerun host interrupt handler */
218 }
219 if (!(msr & MSR_TM)) {
220 /* generate a facility unavailable interrupt */
221 vcpu->arch.fscr &= ~FSCR_INTR_CAUSE;
222 vcpu->arch.fscr |= (u64)FSCR_TM_LG << 56;
223 kvmppc_book3s_queue_irqprio(vcpu,
224 BOOK3S_INTERRUPT_FAC_UNAVAIL);
225 return RESUME_GUEST;
226 }
227 /* If transaction active or TEXASR[FS] = 0, bad thing */
228 if (MSR_TM_ACTIVE(msr) || !(vcpu->arch.texasr & TEXASR_FS)) {
229 kvmppc_core_queue_program(vcpu, SRR1_PROGTM);
230 return RESUME_GUEST;
231 }
232
233 copy_to_checkpoint(vcpu);
234
235 /* Set CR0 to indicate previous transactional state */
236 vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) |
237 (((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 29);
238 vcpu->arch.shregs.msr = msr | MSR_TS_S;
239 vcpu->arch.regs.nip += 4;
240 return RESUME_GUEST;
241 }
242
243 /* What should we do here? We didn't recognize the instruction */
244 kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
245 pr_warn_ratelimited("Unrecognized TM-related instruction %#x for emulation", instr);
246
247 return RESUME_GUEST;
248 }
249
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.