xref: /openbmc/linux/arch/arm64/kvm/vgic-sys-reg-v3.c (revision fb574682)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * VGIC system registers handling functions for AArch64 mode
4  */
5 
6 #include <linux/irqchip/arm-gic-v3.h>
7 #include <linux/kvm.h>
8 #include <linux/kvm_host.h>
9 #include <asm/kvm_emulate.h>
10 #include "vgic/vgic.h"
11 #include "sys_regs.h"
12 
13 static bool access_gic_ctlr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
14 			    const struct sys_reg_desc *r)
15 {
16 	u32 host_pri_bits, host_id_bits, host_seis, host_a3v, seis, a3v;
17 	struct vgic_cpu *vgic_v3_cpu = &vcpu->arch.vgic_cpu;
18 	struct vgic_vmcr vmcr;
19 	u64 val;
20 
21 	vgic_get_vmcr(vcpu, &vmcr);
22 	if (p->is_write) {
23 		val = p->regval;
24 
25 		/*
26 		 * Disallow restoring VM state if not supported by this
27 		 * hardware.
28 		 */
29 		host_pri_bits = ((val & ICC_CTLR_EL1_PRI_BITS_MASK) >>
30 				 ICC_CTLR_EL1_PRI_BITS_SHIFT) + 1;
31 		if (host_pri_bits > vgic_v3_cpu->num_pri_bits)
32 			return false;
33 
34 		vgic_v3_cpu->num_pri_bits = host_pri_bits;
35 
36 		host_id_bits = (val & ICC_CTLR_EL1_ID_BITS_MASK) >>
37 				ICC_CTLR_EL1_ID_BITS_SHIFT;
38 		if (host_id_bits > vgic_v3_cpu->num_id_bits)
39 			return false;
40 
41 		vgic_v3_cpu->num_id_bits = host_id_bits;
42 
43 		host_seis = ((kvm_vgic_global_state.ich_vtr_el2 &
44 			     ICH_VTR_SEIS_MASK) >> ICH_VTR_SEIS_SHIFT);
45 		seis = (val & ICC_CTLR_EL1_SEIS_MASK) >>
46 			ICC_CTLR_EL1_SEIS_SHIFT;
47 		if (host_seis != seis)
48 			return false;
49 
50 		host_a3v = ((kvm_vgic_global_state.ich_vtr_el2 &
51 			    ICH_VTR_A3V_MASK) >> ICH_VTR_A3V_SHIFT);
52 		a3v = (val & ICC_CTLR_EL1_A3V_MASK) >> ICC_CTLR_EL1_A3V_SHIFT;
53 		if (host_a3v != a3v)
54 			return false;
55 
56 		/*
57 		 * Here set VMCR.CTLR in ICC_CTLR_EL1 layout.
58 		 * The vgic_set_vmcr() will convert to ICH_VMCR layout.
59 		 */
60 		vmcr.cbpr = (val & ICC_CTLR_EL1_CBPR_MASK) >> ICC_CTLR_EL1_CBPR_SHIFT;
61 		vmcr.eoim = (val & ICC_CTLR_EL1_EOImode_MASK) >> ICC_CTLR_EL1_EOImode_SHIFT;
62 		vgic_set_vmcr(vcpu, &vmcr);
63 	} else {
64 		val = 0;
65 		val |= (vgic_v3_cpu->num_pri_bits - 1) <<
66 			ICC_CTLR_EL1_PRI_BITS_SHIFT;
67 		val |= vgic_v3_cpu->num_id_bits << ICC_CTLR_EL1_ID_BITS_SHIFT;
68 		val |= ((kvm_vgic_global_state.ich_vtr_el2 &
69 			ICH_VTR_SEIS_MASK) >> ICH_VTR_SEIS_SHIFT) <<
70 			ICC_CTLR_EL1_SEIS_SHIFT;
71 		val |= ((kvm_vgic_global_state.ich_vtr_el2 &
72 			ICH_VTR_A3V_MASK) >> ICH_VTR_A3V_SHIFT) <<
73 			ICC_CTLR_EL1_A3V_SHIFT;
74 		/*
75 		 * The VMCR.CTLR value is in ICC_CTLR_EL1 layout.
76 		 * Extract it directly using ICC_CTLR_EL1 reg definitions.
77 		 */
78 		val |= (vmcr.cbpr << ICC_CTLR_EL1_CBPR_SHIFT) & ICC_CTLR_EL1_CBPR_MASK;
79 		val |= (vmcr.eoim << ICC_CTLR_EL1_EOImode_SHIFT) & ICC_CTLR_EL1_EOImode_MASK;
80 
81 		p->regval = val;
82 	}
83 
84 	return true;
85 }
86 
87 static bool access_gic_pmr(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
88 			   const struct sys_reg_desc *r)
89 {
90 	struct vgic_vmcr vmcr;
91 
92 	vgic_get_vmcr(vcpu, &vmcr);
93 	if (p->is_write) {
94 		vmcr.pmr = (p->regval & ICC_PMR_EL1_MASK) >> ICC_PMR_EL1_SHIFT;
95 		vgic_set_vmcr(vcpu, &vmcr);
96 	} else {
97 		p->regval = (vmcr.pmr << ICC_PMR_EL1_SHIFT) & ICC_PMR_EL1_MASK;
98 	}
99 
100 	return true;
101 }
102 
103 static bool access_gic_bpr0(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
104 			    const struct sys_reg_desc *r)
105 {
106 	struct vgic_vmcr vmcr;
107 
108 	vgic_get_vmcr(vcpu, &vmcr);
109 	if (p->is_write) {
110 		vmcr.bpr = (p->regval & ICC_BPR0_EL1_MASK) >>
111 			    ICC_BPR0_EL1_SHIFT;
112 		vgic_set_vmcr(vcpu, &vmcr);
113 	} else {
114 		p->regval = (vmcr.bpr << ICC_BPR0_EL1_SHIFT) &
115 			     ICC_BPR0_EL1_MASK;
116 	}
117 
118 	return true;
119 }
120 
121 static bool access_gic_bpr1(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
122 			    const struct sys_reg_desc *r)
123 {
124 	struct vgic_vmcr vmcr;
125 
126 	if (!p->is_write)
127 		p->regval = 0;
128 
129 	vgic_get_vmcr(vcpu, &vmcr);
130 	if (!vmcr.cbpr) {
131 		if (p->is_write) {
132 			vmcr.abpr = (p->regval & ICC_BPR1_EL1_MASK) >>
133 				     ICC_BPR1_EL1_SHIFT;
134 			vgic_set_vmcr(vcpu, &vmcr);
135 		} else {
136 			p->regval = (vmcr.abpr << ICC_BPR1_EL1_SHIFT) &
137 				     ICC_BPR1_EL1_MASK;
138 		}
139 	} else {
140 		if (!p->is_write)
141 			p->regval = min((vmcr.bpr + 1), 7U);
142 	}
143 
144 	return true;
145 }
146 
147 static bool access_gic_grpen0(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
148 			      const struct sys_reg_desc *r)
149 {
150 	struct vgic_vmcr vmcr;
151 
152 	vgic_get_vmcr(vcpu, &vmcr);
153 	if (p->is_write) {
154 		vmcr.grpen0 = (p->regval & ICC_IGRPEN0_EL1_MASK) >>
155 			       ICC_IGRPEN0_EL1_SHIFT;
156 		vgic_set_vmcr(vcpu, &vmcr);
157 	} else {
158 		p->regval = (vmcr.grpen0 << ICC_IGRPEN0_EL1_SHIFT) &
159 			     ICC_IGRPEN0_EL1_MASK;
160 	}
161 
162 	return true;
163 }
164 
165 static bool access_gic_grpen1(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
166 			      const struct sys_reg_desc *r)
167 {
168 	struct vgic_vmcr vmcr;
169 
170 	vgic_get_vmcr(vcpu, &vmcr);
171 	if (p->is_write) {
172 		vmcr.grpen1 = (p->regval & ICC_IGRPEN1_EL1_MASK) >>
173 			       ICC_IGRPEN1_EL1_SHIFT;
174 		vgic_set_vmcr(vcpu, &vmcr);
175 	} else {
176 		p->regval = (vmcr.grpen1 << ICC_IGRPEN1_EL1_SHIFT) &
177 			     ICC_IGRPEN1_EL1_MASK;
178 	}
179 
180 	return true;
181 }
182 
183 static void vgic_v3_access_apr_reg(struct kvm_vcpu *vcpu,
184 				   struct sys_reg_params *p, u8 apr, u8 idx)
185 {
186 	struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;
187 	uint32_t *ap_reg;
188 
189 	if (apr)
190 		ap_reg = &vgicv3->vgic_ap1r[idx];
191 	else
192 		ap_reg = &vgicv3->vgic_ap0r[idx];
193 
194 	if (p->is_write)
195 		*ap_reg = p->regval;
196 	else
197 		p->regval = *ap_reg;
198 }
199 
200 static bool access_gic_aprn(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
201 			    const struct sys_reg_desc *r, u8 apr)
202 {
203 	u8 idx = r->Op2 & 3;
204 
205 	if (idx > vgic_v3_max_apr_idx(vcpu))
206 		goto err;
207 
208 	vgic_v3_access_apr_reg(vcpu, p, apr, idx);
209 	return true;
210 err:
211 	if (!p->is_write)
212 		p->regval = 0;
213 
214 	return false;
215 }
216 
217 static bool access_gic_ap0r(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
218 			    const struct sys_reg_desc *r)
219 
220 {
221 	return access_gic_aprn(vcpu, p, r, 0);
222 }
223 
224 static bool access_gic_ap1r(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
225 			    const struct sys_reg_desc *r)
226 {
227 	return access_gic_aprn(vcpu, p, r, 1);
228 }
229 
230 static bool access_gic_sre(struct kvm_vcpu *vcpu, struct sys_reg_params *p,
231 			   const struct sys_reg_desc *r)
232 {
233 	struct vgic_v3_cpu_if *vgicv3 = &vcpu->arch.vgic_cpu.vgic_v3;
234 
235 	/* Validate SRE bit */
236 	if (p->is_write) {
237 		if (!(p->regval & ICC_SRE_EL1_SRE))
238 			return false;
239 	} else {
240 		p->regval = vgicv3->vgic_sre;
241 	}
242 
243 	return true;
244 }
245 static const struct sys_reg_desc gic_v3_icc_reg_descs[] = {
246 	{ SYS_DESC(SYS_ICC_PMR_EL1), access_gic_pmr },
247 	{ SYS_DESC(SYS_ICC_BPR0_EL1), access_gic_bpr0 },
248 	{ SYS_DESC(SYS_ICC_AP0R0_EL1), access_gic_ap0r },
249 	{ SYS_DESC(SYS_ICC_AP0R1_EL1), access_gic_ap0r },
250 	{ SYS_DESC(SYS_ICC_AP0R2_EL1), access_gic_ap0r },
251 	{ SYS_DESC(SYS_ICC_AP0R3_EL1), access_gic_ap0r },
252 	{ SYS_DESC(SYS_ICC_AP1R0_EL1), access_gic_ap1r },
253 	{ SYS_DESC(SYS_ICC_AP1R1_EL1), access_gic_ap1r },
254 	{ SYS_DESC(SYS_ICC_AP1R2_EL1), access_gic_ap1r },
255 	{ SYS_DESC(SYS_ICC_AP1R3_EL1), access_gic_ap1r },
256 	{ SYS_DESC(SYS_ICC_BPR1_EL1), access_gic_bpr1 },
257 	{ SYS_DESC(SYS_ICC_CTLR_EL1), access_gic_ctlr },
258 	{ SYS_DESC(SYS_ICC_SRE_EL1), access_gic_sre },
259 	{ SYS_DESC(SYS_ICC_IGRPEN0_EL1), access_gic_grpen0 },
260 	{ SYS_DESC(SYS_ICC_IGRPEN1_EL1), access_gic_grpen1 },
261 };
262 
263 int vgic_v3_has_cpu_sysregs_attr(struct kvm_vcpu *vcpu, bool is_write, u64 id,
264 				u64 *reg)
265 {
266 	struct sys_reg_params params;
267 	u64 sysreg = (id & KVM_DEV_ARM_VGIC_SYSREG_MASK) | KVM_REG_SIZE_U64;
268 
269 	params.regval = *reg;
270 	params.is_write = is_write;
271 	params.is_aarch32 = false;
272 	params.is_32bit = false;
273 
274 	if (find_reg_by_id(sysreg, &params, gic_v3_icc_reg_descs,
275 			      ARRAY_SIZE(gic_v3_icc_reg_descs)))
276 		return 0;
277 
278 	return -ENXIO;
279 }
280 
281 int vgic_v3_cpu_sysregs_uaccess(struct kvm_vcpu *vcpu, bool is_write, u64 id,
282 				u64 *reg)
283 {
284 	struct sys_reg_params params;
285 	const struct sys_reg_desc *r;
286 	u64 sysreg = (id & KVM_DEV_ARM_VGIC_SYSREG_MASK) | KVM_REG_SIZE_U64;
287 
288 	if (is_write)
289 		params.regval = *reg;
290 	params.is_write = is_write;
291 	params.is_aarch32 = false;
292 	params.is_32bit = false;
293 
294 	r = find_reg_by_id(sysreg, &params, gic_v3_icc_reg_descs,
295 			   ARRAY_SIZE(gic_v3_icc_reg_descs));
296 	if (!r)
297 		return -ENXIO;
298 
299 	if (!r->access(vcpu, &params, r))
300 		return -EINVAL;
301 
302 	if (!is_write)
303 		*reg = params.regval;
304 
305 	return 0;
306 }
307