xref: /linux/arch/powerpc/kvm/book3s_hv_tm.c (revision b8d312aa075f33282565467662c4628dae0a2aff)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2017 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
4  */
5 
6 #include <linux/kvm_host.h>
7 
8 #include <asm/kvm_ppc.h>
9 #include <asm/kvm_book3s.h>
10 #include <asm/kvm_book3s_64.h>
11 #include <asm/reg.h>
12 #include <asm/ppc-opcode.h>
13 
14 static void emulate_tx_failure(struct kvm_vcpu *vcpu, u64 failure_cause)
15 {
16 	u64 texasr, tfiar;
17 	u64 msr = vcpu->arch.shregs.msr;
18 
19 	tfiar = vcpu->arch.regs.nip & ~0x3ull;
20 	texasr = (failure_cause << 56) | TEXASR_ABORT | TEXASR_FS | TEXASR_EXACT;
21 	if (MSR_TM_SUSPENDED(vcpu->arch.shregs.msr))
22 		texasr |= TEXASR_SUSP;
23 	if (msr & MSR_PR) {
24 		texasr |= TEXASR_PR;
25 		tfiar |= 1;
26 	}
27 	vcpu->arch.tfiar = tfiar;
28 	/* Preserve ROT and TL fields of existing TEXASR */
29 	vcpu->arch.texasr = (vcpu->arch.texasr & 0x3ffffff) | texasr;
30 }
31 
32 /*
33  * This gets called on a softpatch interrupt on POWER9 DD2.2 processors.
34  * We expect to find a TM-related instruction to be emulated.  The
35  * instruction image is in vcpu->arch.emul_inst.  If the guest was in
36  * TM suspended or transactional state, the checkpointed state has been
37  * reclaimed and is in the vcpu struct.  The CPU is in virtual mode in
38  * host context.
39  */
40 int kvmhv_p9_tm_emulation(struct kvm_vcpu *vcpu)
41 {
42 	u32 instr = vcpu->arch.emul_inst;
43 	u64 msr = vcpu->arch.shregs.msr;
44 	u64 newmsr, bescr;
45 	int ra, rs;
46 
47 	switch (instr & 0xfc0007ff) {
48 	case PPC_INST_RFID:
49 		/* XXX do we need to check for PR=0 here? */
50 		newmsr = vcpu->arch.shregs.srr1;
51 		/* should only get here for Sx -> T1 transition */
52 		WARN_ON_ONCE(!(MSR_TM_SUSPENDED(msr) &&
53 			       MSR_TM_TRANSACTIONAL(newmsr) &&
54 			       (newmsr & MSR_TM)));
55 		newmsr = sanitize_msr(newmsr);
56 		vcpu->arch.shregs.msr = newmsr;
57 		vcpu->arch.cfar = vcpu->arch.regs.nip - 4;
58 		vcpu->arch.regs.nip = vcpu->arch.shregs.srr0;
59 		return RESUME_GUEST;
60 
61 	case PPC_INST_RFEBB:
62 		if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206)) {
63 			/* generate an illegal instruction interrupt */
64 			kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
65 			return RESUME_GUEST;
66 		}
67 		/* check EBB facility is available */
68 		if (!(vcpu->arch.hfscr & HFSCR_EBB)) {
69 			/* generate an illegal instruction interrupt */
70 			kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
71 			return RESUME_GUEST;
72 		}
73 		if ((msr & MSR_PR) && !(vcpu->arch.fscr & FSCR_EBB)) {
74 			/* generate a facility unavailable interrupt */
75 			vcpu->arch.fscr = (vcpu->arch.fscr & ~(0xffull << 56)) |
76 				((u64)FSCR_EBB_LG << 56);
77 			kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_FAC_UNAVAIL);
78 			return RESUME_GUEST;
79 		}
80 		bescr = vcpu->arch.bescr;
81 		/* expect to see a S->T transition requested */
82 		WARN_ON_ONCE(!(MSR_TM_SUSPENDED(msr) &&
83 			       ((bescr >> 30) & 3) == 2));
84 		bescr &= ~BESCR_GE;
85 		if (instr & (1 << 11))
86 			bescr |= BESCR_GE;
87 		vcpu->arch.bescr = bescr;
88 		msr = (msr & ~MSR_TS_MASK) | MSR_TS_T;
89 		vcpu->arch.shregs.msr = msr;
90 		vcpu->arch.cfar = vcpu->arch.regs.nip - 4;
91 		vcpu->arch.regs.nip = vcpu->arch.ebbrr;
92 		return RESUME_GUEST;
93 
94 	case PPC_INST_MTMSRD:
95 		/* XXX do we need to check for PR=0 here? */
96 		rs = (instr >> 21) & 0x1f;
97 		newmsr = kvmppc_get_gpr(vcpu, rs);
98 		/* check this is a Sx -> T1 transition */
99 		WARN_ON_ONCE(!(MSR_TM_SUSPENDED(msr) &&
100 			       MSR_TM_TRANSACTIONAL(newmsr) &&
101 			       (newmsr & MSR_TM)));
102 		/* mtmsrd doesn't change LE */
103 		newmsr = (newmsr & ~MSR_LE) | (msr & MSR_LE);
104 		newmsr = sanitize_msr(newmsr);
105 		vcpu->arch.shregs.msr = newmsr;
106 		return RESUME_GUEST;
107 
108 	case PPC_INST_TSR:
109 		/* check for PR=1 and arch 2.06 bit set in PCR */
110 		if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206)) {
111 			/* generate an illegal instruction interrupt */
112 			kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
113 			return RESUME_GUEST;
114 		}
115 		/* check for TM disabled in the HFSCR or MSR */
116 		if (!(vcpu->arch.hfscr & HFSCR_TM)) {
117 			/* generate an illegal instruction interrupt */
118 			kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
119 			return RESUME_GUEST;
120 		}
121 		if (!(msr & MSR_TM)) {
122 			/* generate a facility unavailable interrupt */
123 			vcpu->arch.fscr = (vcpu->arch.fscr & ~(0xffull << 56)) |
124 				((u64)FSCR_TM_LG << 56);
125 			kvmppc_book3s_queue_irqprio(vcpu,
126 						BOOK3S_INTERRUPT_FAC_UNAVAIL);
127 			return RESUME_GUEST;
128 		}
129 		/* Set CR0 to indicate previous transactional state */
130 		vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) |
131 			(((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 29);
132 		/* L=1 => tresume, L=0 => tsuspend */
133 		if (instr & (1 << 21)) {
134 			if (MSR_TM_SUSPENDED(msr))
135 				msr = (msr & ~MSR_TS_MASK) | MSR_TS_T;
136 		} else {
137 			if (MSR_TM_TRANSACTIONAL(msr))
138 				msr = (msr & ~MSR_TS_MASK) | MSR_TS_S;
139 		}
140 		vcpu->arch.shregs.msr = msr;
141 		return RESUME_GUEST;
142 
143 	case PPC_INST_TRECLAIM:
144 		/* check for TM disabled in the HFSCR or MSR */
145 		if (!(vcpu->arch.hfscr & HFSCR_TM)) {
146 			/* generate an illegal instruction interrupt */
147 			kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
148 			return RESUME_GUEST;
149 		}
150 		if (!(msr & MSR_TM)) {
151 			/* generate a facility unavailable interrupt */
152 			vcpu->arch.fscr = (vcpu->arch.fscr & ~(0xffull << 56)) |
153 				((u64)FSCR_TM_LG << 56);
154 			kvmppc_book3s_queue_irqprio(vcpu,
155 						BOOK3S_INTERRUPT_FAC_UNAVAIL);
156 			return RESUME_GUEST;
157 		}
158 		/* If no transaction active, generate TM bad thing */
159 		if (!MSR_TM_ACTIVE(msr)) {
160 			kvmppc_core_queue_program(vcpu, SRR1_PROGTM);
161 			return RESUME_GUEST;
162 		}
163 		/* If failure was not previously recorded, recompute TEXASR */
164 		if (!(vcpu->arch.orig_texasr & TEXASR_FS)) {
165 			ra = (instr >> 16) & 0x1f;
166 			if (ra)
167 				ra = kvmppc_get_gpr(vcpu, ra) & 0xff;
168 			emulate_tx_failure(vcpu, ra);
169 		}
170 
171 		copy_from_checkpoint(vcpu);
172 
173 		/* Set CR0 to indicate previous transactional state */
174 		vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) |
175 			(((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 29);
176 		vcpu->arch.shregs.msr &= ~MSR_TS_MASK;
177 		return RESUME_GUEST;
178 
179 	case PPC_INST_TRECHKPT:
180 		/* XXX do we need to check for PR=0 here? */
181 		/* check for TM disabled in the HFSCR or MSR */
182 		if (!(vcpu->arch.hfscr & HFSCR_TM)) {
183 			/* generate an illegal instruction interrupt */
184 			kvmppc_core_queue_program(vcpu, SRR1_PROGILL);
185 			return RESUME_GUEST;
186 		}
187 		if (!(msr & MSR_TM)) {
188 			/* generate a facility unavailable interrupt */
189 			vcpu->arch.fscr = (vcpu->arch.fscr & ~(0xffull << 56)) |
190 				((u64)FSCR_TM_LG << 56);
191 			kvmppc_book3s_queue_irqprio(vcpu,
192 						BOOK3S_INTERRUPT_FAC_UNAVAIL);
193 			return RESUME_GUEST;
194 		}
195 		/* If transaction active or TEXASR[FS] = 0, bad thing */
196 		if (MSR_TM_ACTIVE(msr) || !(vcpu->arch.texasr & TEXASR_FS)) {
197 			kvmppc_core_queue_program(vcpu, SRR1_PROGTM);
198 			return RESUME_GUEST;
199 		}
200 
201 		copy_to_checkpoint(vcpu);
202 
203 		/* Set CR0 to indicate previous transactional state */
204 		vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) |
205 			(((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 29);
206 		vcpu->arch.shregs.msr = msr | MSR_TS_S;
207 		return RESUME_GUEST;
208 	}
209 
210 	/* What should we do here? We didn't recognize the instruction */
211 	WARN_ON_ONCE(1);
212 	return RESUME_GUEST;
213 }
214