aboutsummaryrefslogtreecommitdiff
path: root/arch/powerpc/kvm/book3s_hv_tm.c
blob: 866cadd70094d4c789792e1223af73acb9cde32f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2017 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kvm_host.h>

#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/kvm_book3s_64.h>
#include <asm/reg.h>
#include <asm/ppc-opcode.h>

static void emulate_tx_failure(struct kvm_vcpu *vcpu, u64 failure_cause)
{
	u64 texasr, tfiar;
	u64 msr = vcpu->arch.shregs.msr;

	tfiar = vcpu->arch.regs.nip & ~0x3ull;
	texasr = (failure_cause << 56) | TEXASR_ABORT | TEXASR_FS | TEXASR_EXACT;
	if (MSR_TM_SUSPENDED(vcpu->arch.shregs.msr))
		texasr |= TEXASR_SUSP;
	if (msr & MSR_PR) {
		texasr |= TEXASR_PR;
		tfiar |= 1;
	}
	vcpu->arch.tfiar = tfiar;
	/* Preserve ROT and TL fields of existing TEXASR */
	vcpu->arch.texasr = (vcpu->arch.texasr & 0x3ffffff) | texasr;
}

/*
 * This gets called on a softpatch interrupt on POWER9 DD2.2 processors.
 * We expect to find a TM-related instruction to be emulated.  The
 * instruction image is in vcpu->arch.emul_inst.  If the guest was in
 * TM suspended or transactional state, the checkpointed state has been
 * reclaimed and is in the vcpu struct.  The CPU is in virtual mode in
 * host context.
 */
int kvmhv_p9_tm_emulation(struct kvm_vcpu *vcpu)
{
	u32 instr = vcpu->arch.emul_inst;
	u64 msr = vcpu->arch.shregs.msr;
	u64 newmsr, bescr;
	int ra, rs;

	/*
	 * The TM softpatch interrupt sets NIP to the instruction following
	 * the faulting instruction, which is not executed. Rewind nip to the
	 * faulting instruction so it looks like a normal synchronous
	 * interrupt, then update nip in the places where the instruction is
	 * emulated.
	 */
	vcpu->arch.regs.nip -= 4;

	/*
	 * rfid, rfebb, and mtmsrd encode bit 31 = 0 since it's a reserved bit
	 * in these instructions, so masking bit 31 out doesn't change these
	 * instructions. For treclaim., tsr., and trechkpt. instructions if bit
	 * 31 = 0 then they are per ISA invalid forms, however P9 UM, in section
	 * 4.6.10 Book II Invalid Forms, informs specifically that ignoring bit
	 * 31 is an acceptable way to handle these invalid forms that have
	 * bit 31 = 0. Moreover, for emulation purposes both forms (w/ and wo/
	 * bit 31 set) can generate a softpatch interrupt. Hence both forms
	 * are handled below for these instructions so they behave the same way.
	 */
	switch (instr & PO_XOP_OPCODE_MASK) {
	case PPC_INST_RFID:
		/* XXX do we need to check for PR=0 here? */
		newmsr = vcpu->arch.shregs.srr1;
		/* should only get here for Sx -> T1 transition */
		WARN_ON_ONCE(!(MSR_TM_SUSPENDED(msr) &&
			       MSR_TM_TRANSACTIONAL(newmsr) &&
			       (newmsr & MSR_TM)));
		newmsr = sanitize_msr(newmsr);
		vcpu->arch.shregs.msr = newmsr;
		vcpu->arch.cfar = vcpu->arch.regs.nip;
		vcpu->arch.regs.nip = vcpu->arch.shregs.srr0;
		return RESUME_GUEST;

	case PPC_INST_RFEBB:
		if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206)) {
			/* generate an illegal instruction interrupt */
			kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
			return RESUME_GUEST;
		}
		/* check EBB facility is available */
		if (!(vcpu->arch.hfscr & HFSCR_EBB)) {
			vcpu->arch.hfscr &= ~HFSCR_INTR_CAUSE;
			vcpu->arch.hfscr |= (u64)FSCR_EBB_LG << 56;
			vcpu->arch.trap = BOOK3S_INTERRUPT_H_FAC_UNAVAIL;
			return -1; /* rerun host interrupt handler */
		}
		if ((msr & MSR_PR) && !(vcpu->arch.fscr & FSCR_EBB)) {
			/* generate a facility unavailable interrupt */
			vcpu->arch.fscr &= ~FSCR_INTR_CAUSE;
			vcpu->arch.fscr |= (u64)FSCR_EBB_LG << 56;
			kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_FAC_UNAVAIL);
			return RESUME_GUEST;
		}
		bescr = vcpu->arch.bescr;
		/* expect to see a S->T transition requested */
		WARN_ON_ONCE(!(MSR_TM_SUSPENDED(msr) &&
			       ((bescr >> 30) & 3) == 2));
		bescr &= ~BESCR_GE;
		if (instr & (1 << 11))
			bescr |= BESCR_GE;
		vcpu->arch.bescr = bescr;
		msr = (msr & ~MSR_TS_MASK) | MSR_TS_T;
		vcpu->arch.shregs.msr = msr;
		vcpu->arch.cfar = vcpu->arch.regs.nip;
		vcpu->arch.regs.nip = vcpu->arch.ebbrr;
		return RESUME_GUEST;

	case PPC_INST_MTMSRD:
		/* XXX do we need to check for PR=0 here? */
		rs = (instr >> 21) & 0x1f;
		newmsr = kvmppc_get_gpr(vcpu, rs);
		/* check this is a Sx -> T1 transition */
		WARN_ON_ONCE(!(MSR_TM_SUSPENDED(msr) &&
			       MSR_TM_TRANSACTIONAL(newmsr) &&
			       (newmsr & MSR_TM)));
		/* mtmsrd doesn't change LE */
		newmsr = (newmsr & ~MSR_LE) | (msr & MSR_LE);
		newmsr = sanitize_msr(newmsr);
		vcpu->arch.shregs.msr = newmsr;
		vcpu->arch.regs.nip += 4;
		return RESUME_GUEST;

	/* ignore bit 31, see comment above */
	case (PPC_INST_TSR & PO_XOP_OPCODE_MASK):
		/* check for PR=1 and arch 2.06 bit set in PCR */
		if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206)) {
			/* generate an illegal instruction interrupt */
			kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
			return RESUME_GUEST;
		}
		/* check for TM disabled in the HFSCR or MSR */
		if (!(vcpu->arch.hfscr & HFSCR_TM)) {
			vcpu->arch.hfscr &= ~HFSCR_INTR_CAUSE;
			vcpu->arch.hfscr |= (u64)FSCR_TM_LG << 56;
			vcpu->arch.trap = BOOK3S_INTERRUPT_H_FAC_UNAVAIL;
			return -1; /* rerun host interrupt handler */
		}
		if (!(msr & MSR_TM)) {
			/* generate a facility unavailable interrupt */
			vcpu->arch.fscr &= ~FSCR_INTR_CAUSE;
			vcpu->arch.fscr |= (u64)FSCR_TM_LG << 56;
			kvmppc_book3s_queue_irqprio(vcpu,
						BOOK3S_INTERRUPT_FAC_UNAVAIL);
			return RESUME_GUEST;
		}
		/* Set CR0 to indicate previous transactional state */
		vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) |
			(((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 29);
		/* L=1 => tresume, L=0 => tsuspend */
		if (instr & (1 << 21)) {
			if (MSR_TM_SUSPENDED(msr))
				msr = (msr & ~MSR_TS_MASK) | MSR_TS_T;
		} else {
			if (MSR_TM_TRANSACTIONAL(msr))
				msr = (msr & ~MSR_TS_MASK) | MSR_TS_S;
		}
		vcpu->arch.shregs.msr = msr;
		vcpu->arch.regs.nip += 4;
		return RESUME_GUEST;

	/* ignore bit 31, see comment above */
	case (PPC_INST_TRECLAIM & PO_XOP_OPCODE_MASK):
		/* check for TM disabled in the HFSCR or MSR */
		if (!(vcpu->arch.hfscr & HFSCR_TM)) {
			vcpu->arch.hfscr &= ~HFSCR_INTR_CAUSE;
			vcpu->arch.hfscr |= (u64)FSCR_TM_LG << 56;
			vcpu->arch.trap = BOOK3S_INTERRUPT_H_FAC_UNAVAIL;
			return -1; /* rerun host interrupt handler */
		}
		if (!(msr & MSR_TM)) {
			/* generate a facility unavailable interrupt */
			vcpu->arch.fscr &= ~FSCR_INTR_CAUSE;
			vcpu->arch.fscr |= (u64)FSCR_TM_LG << 56;
			kvmppc_book3s_queue_irqprio(vcpu,
						BOOK3S_INTERRUPT_FAC_UNAVAIL);
			return RESUME_GUEST;
		}
		/* If no transaction active, generate TM bad thing */
		if (!MSR_TM_ACTIVE(msr)) {
			kvmppc_core_queue_program(vcpu, SRR1_PROGTM);
			return RESUME_GUEST;
		}
		/* If failure was not previously recorded, recompute TEXASR */
		if (!(vcpu->arch.orig_texasr & TEXASR_FS)) {
			ra = (instr >> 16) & 0x1f;
			if (ra)
				ra = kvmppc_get_gpr(vcpu, ra) & 0xff;
			emulate_tx_failure(vcpu, ra);
		}

		copy_from_checkpoint(vcpu);

		/* Set CR0 to indicate previous transactional state */
		vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) |
			(((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 29);
		vcpu->arch.shregs.msr &= ~MSR_TS_MASK;
		vcpu->arch.regs.nip += 4;
		return RESUME_GUEST;

	/* ignore bit 31, see comment above */
	case (PPC_INST_TRECHKPT & PO_XOP_OPCODE_MASK):
		/* XXX do we need to check for PR=0 here? */
		/* check for TM disabled in the HFSCR or MSR */
		if (!(vcpu->arch.hfscr & HFSCR_TM)) {
			vcpu->arch.hfscr &= ~HFSCR_INTR_CAUSE;
			vcpu->arch.hfscr |= (u64)FSCR_TM_LG << 56;
			vcpu->arch.trap = BOOK3S_INTERRUPT_H_FAC_UNAVAIL;
			return -1; /* rerun host interrupt handler */
		}
		if (!(msr & MSR_TM)) {
			/* generate a facility unavailable interrupt */
			vcpu->arch.fscr &= ~FSCR_INTR_CAUSE;
			vcpu->arch.fscr |= (u64)FSCR_TM_LG << 56;
			kvmppc_book3s_queue_irqprio(vcpu,
						BOOK3S_INTERRUPT_FAC_UNAVAIL);
			return RESUME_GUEST;
		}
		/* If transaction active or TEXASR[FS] = 0, bad thing */
		if (MSR_TM_ACTIVE(msr) || !(vcpu->arch.texasr & TEXASR_FS)) {
			kvmppc_core_queue_program(vcpu, SRR1_PROGTM);
			return RESUME_GUEST;
		}

		copy_to_checkpoint(vcpu);

		/* Set CR0 to indicate previous transactional state */
		vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) |
			(((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 29);
		vcpu->arch.shregs.msr = msr | MSR_TS_S;
		vcpu->arch.regs.nip += 4;
		return RESUME_GUEST;
	}

	/* What should we do here? We didn't recognize the instruction */
	kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
	pr_warn_ratelimited("Unrecognized TM-related instruction %#x for emulation", instr);

	return RESUME_GUEST;
}