1 /*
2 * Copyright (C) 2015 - ARM Ltd
3 * Author: Marc Zyngier <marc.zyngier@arm.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
16 */
17
18 #include <linux/compiler.h>
19 #include <linux/kvm_host.h>
20
21 #include <asm/debug-monitors.h>
22 #include <asm/kvm_asm.h>
23 #include <asm/kvm_hyp.h>
24 #include <asm/kvm_mmu.h>
25
26 #define read_debug(r,n) read_sysreg(r##n##_el1)
27 #define write_debug(v,r,n) write_sysreg(v, r##n##_el1)
28
29 #define save_debug(ptr,reg,nr) \
30 switch (nr) { \
31 case 15: ptr[15] = read_debug(reg, 15); \
32 case 14: ptr[14] = read_debug(reg, 14); \
33 case 13: ptr[13] = read_debug(reg, 13); \
34 case 12: ptr[12] = read_debug(reg, 12); \
35 case 11: ptr[11] = read_debug(reg, 11); \
36 case 10: ptr[10] = read_debug(reg, 10); \
37 case 9: ptr[9] = read_debug(reg, 9); \
38 case 8: ptr[8] = read_debug(reg, 8); \
39 case 7: ptr[7] = read_debug(reg, 7); \
40 case 6: ptr[6] = read_debug(reg, 6); \
41 case 5: ptr[5] = read_debug(reg, 5); \
42 case 4: ptr[4] = read_debug(reg, 4); \
43 case 3: ptr[3] = read_debug(reg, 3); \
44 case 2: ptr[2] = read_debug(reg, 2); \
45 case 1: ptr[1] = read_debug(reg, 1); \
46 default: ptr[0] = read_debug(reg, 0); \
47 }
48
49 #define restore_debug(ptr,reg,nr) \
50 switch (nr) { \
51 case 15: write_debug(ptr[15], reg, 15); \
52 case 14: write_debug(ptr[14], reg, 14); \
53 case 13: write_debug(ptr[13], reg, 13); \
54 case 12: write_debug(ptr[12], reg, 12); \
55 case 11: write_debug(ptr[11], reg, 11); \
56 case 10: write_debug(ptr[10], reg, 10); \
57 case 9: write_debug(ptr[9], reg, 9); \
58 case 8: write_debug(ptr[8], reg, 8); \
59 case 7: write_debug(ptr[7], reg, 7); \
60 case 6: write_debug(ptr[6], reg, 6); \
61 case 5: write_debug(ptr[5], reg, 5); \
62 case 4: write_debug(ptr[4], reg, 4); \
63 case 3: write_debug(ptr[3], reg, 3); \
64 case 2: write_debug(ptr[2], reg, 2); \
65 case 1: write_debug(ptr[1], reg, 1); \
66 default: write_debug(ptr[0], reg, 0); \
67 }
68
__debug_save_spe_nvhe(u64 * pmscr_el1)69 static void __hyp_text __debug_save_spe_nvhe(u64 *pmscr_el1)
70 {
71 u64 reg;
72
73 /* Clear pmscr in case of early return */
74 *pmscr_el1 = 0;
75
76 /* SPE present on this CPU? */
77 if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
78 ID_AA64DFR0_PMSVER_SHIFT))
79 return;
80
81 /* Yes; is it owned by EL3? */
82 reg = read_sysreg_s(SYS_PMBIDR_EL1);
83 if (reg & BIT(SYS_PMBIDR_EL1_P_SHIFT))
84 return;
85
86 /* No; is the host actually using the thing? */
87 reg = read_sysreg_s(SYS_PMBLIMITR_EL1);
88 if (!(reg & BIT(SYS_PMBLIMITR_EL1_E_SHIFT)))
89 return;
90
91 /* Yes; save the control register and disable data generation */
92 *pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1);
93 write_sysreg_s(0, SYS_PMSCR_EL1);
94 isb();
95
96 /* Now drain all buffered data to memory */
97 psb_csync();
98 dsb(nsh);
99 }
100
__debug_restore_spe_nvhe(u64 pmscr_el1)101 static void __hyp_text __debug_restore_spe_nvhe(u64 pmscr_el1)
102 {
103 if (!pmscr_el1)
104 return;
105
106 /* The host page table is installed, but not yet synchronised */
107 isb();
108
109 /* Re-enable data generation */
110 write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1);
111 }
112
__debug_save_state(struct kvm_vcpu * vcpu,struct kvm_guest_debug_arch * dbg,struct kvm_cpu_context * ctxt)113 static void __hyp_text __debug_save_state(struct kvm_vcpu *vcpu,
114 struct kvm_guest_debug_arch *dbg,
115 struct kvm_cpu_context *ctxt)
116 {
117 u64 aa64dfr0;
118 int brps, wrps;
119
120 aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
121 brps = (aa64dfr0 >> 12) & 0xf;
122 wrps = (aa64dfr0 >> 20) & 0xf;
123
124 save_debug(dbg->dbg_bcr, dbgbcr, brps);
125 save_debug(dbg->dbg_bvr, dbgbvr, brps);
126 save_debug(dbg->dbg_wcr, dbgwcr, wrps);
127 save_debug(dbg->dbg_wvr, dbgwvr, wrps);
128
129 ctxt->sys_regs[MDCCINT_EL1] = read_sysreg(mdccint_el1);
130 }
131
__debug_restore_state(struct kvm_vcpu * vcpu,struct kvm_guest_debug_arch * dbg,struct kvm_cpu_context * ctxt)132 static void __hyp_text __debug_restore_state(struct kvm_vcpu *vcpu,
133 struct kvm_guest_debug_arch *dbg,
134 struct kvm_cpu_context *ctxt)
135 {
136 u64 aa64dfr0;
137 int brps, wrps;
138
139 aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
140
141 brps = (aa64dfr0 >> 12) & 0xf;
142 wrps = (aa64dfr0 >> 20) & 0xf;
143
144 restore_debug(dbg->dbg_bcr, dbgbcr, brps);
145 restore_debug(dbg->dbg_bvr, dbgbvr, brps);
146 restore_debug(dbg->dbg_wcr, dbgwcr, wrps);
147 restore_debug(dbg->dbg_wvr, dbgwvr, wrps);
148
149 write_sysreg(ctxt->sys_regs[MDCCINT_EL1], mdccint_el1);
150 }
151
__debug_switch_to_guest(struct kvm_vcpu * vcpu)152 void __hyp_text __debug_switch_to_guest(struct kvm_vcpu *vcpu)
153 {
154 struct kvm_cpu_context *host_ctxt;
155 struct kvm_cpu_context *guest_ctxt;
156 struct kvm_guest_debug_arch *host_dbg;
157 struct kvm_guest_debug_arch *guest_dbg;
158
159 /*
160 * Non-VHE: Disable and flush SPE data generation
161 * VHE: The vcpu can run, but it can't hide.
162 */
163 if (!has_vhe())
164 __debug_save_spe_nvhe(&vcpu->arch.host_debug_state.pmscr_el1);
165
166 if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
167 return;
168
169 host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
170 guest_ctxt = &vcpu->arch.ctxt;
171 host_dbg = &vcpu->arch.host_debug_state.regs;
172 guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
173
174 __debug_save_state(vcpu, host_dbg, host_ctxt);
175 __debug_restore_state(vcpu, guest_dbg, guest_ctxt);
176 }
177
__debug_switch_to_host(struct kvm_vcpu * vcpu)178 void __hyp_text __debug_switch_to_host(struct kvm_vcpu *vcpu)
179 {
180 struct kvm_cpu_context *host_ctxt;
181 struct kvm_cpu_context *guest_ctxt;
182 struct kvm_guest_debug_arch *host_dbg;
183 struct kvm_guest_debug_arch *guest_dbg;
184
185 if (!has_vhe())
186 __debug_restore_spe_nvhe(vcpu->arch.host_debug_state.pmscr_el1);
187
188 if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
189 return;
190
191 host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
192 guest_ctxt = &vcpu->arch.ctxt;
193 host_dbg = &vcpu->arch.host_debug_state.regs;
194 guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
195
196 __debug_save_state(vcpu, guest_dbg, guest_ctxt);
197 __debug_restore_state(vcpu, host_dbg, host_ctxt);
198
199 vcpu->arch.flags &= ~KVM_ARM64_DEBUG_DIRTY;
200 }
201
__kvm_get_mdcr_el2(void)202 u32 __hyp_text __kvm_get_mdcr_el2(void)
203 {
204 return read_sysreg(mdcr_el2);
205 }
206
