Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2015 - ARM Ltd
4 * Author: Marc Zyngier <marc.zyngier@arm.com>
5 */
6
7#include <linux/compiler.h>
8#include <linux/kvm_host.h>
9
10#include <asm/debug-monitors.h>
11#include <asm/kvm_asm.h>
12#include <asm/kvm_hyp.h>
13#include <asm/kvm_mmu.h>
14
15#define read_debug(r,n) read_sysreg(r##n##_el1)
16#define write_debug(v,r,n) write_sysreg(v, r##n##_el1)
17
18#define save_debug(ptr,reg,nr) \
19 switch (nr) { \
20 case 15: ptr[15] = read_debug(reg, 15); \
21 case 14: ptr[14] = read_debug(reg, 14); \
22 case 13: ptr[13] = read_debug(reg, 13); \
23 case 12: ptr[12] = read_debug(reg, 12); \
24 case 11: ptr[11] = read_debug(reg, 11); \
25 case 10: ptr[10] = read_debug(reg, 10); \
26 case 9: ptr[9] = read_debug(reg, 9); \
27 case 8: ptr[8] = read_debug(reg, 8); \
28 case 7: ptr[7] = read_debug(reg, 7); \
29 case 6: ptr[6] = read_debug(reg, 6); \
30 case 5: ptr[5] = read_debug(reg, 5); \
31 case 4: ptr[4] = read_debug(reg, 4); \
32 case 3: ptr[3] = read_debug(reg, 3); \
33 case 2: ptr[2] = read_debug(reg, 2); \
34 case 1: ptr[1] = read_debug(reg, 1); \
35 default: ptr[0] = read_debug(reg, 0); \
36 }
37
38#define restore_debug(ptr,reg,nr) \
39 switch (nr) { \
40 case 15: write_debug(ptr[15], reg, 15); \
41 case 14: write_debug(ptr[14], reg, 14); \
42 case 13: write_debug(ptr[13], reg, 13); \
43 case 12: write_debug(ptr[12], reg, 12); \
44 case 11: write_debug(ptr[11], reg, 11); \
45 case 10: write_debug(ptr[10], reg, 10); \
46 case 9: write_debug(ptr[9], reg, 9); \
47 case 8: write_debug(ptr[8], reg, 8); \
48 case 7: write_debug(ptr[7], reg, 7); \
49 case 6: write_debug(ptr[6], reg, 6); \
50 case 5: write_debug(ptr[5], reg, 5); \
51 case 4: write_debug(ptr[4], reg, 4); \
52 case 3: write_debug(ptr[3], reg, 3); \
53 case 2: write_debug(ptr[2], reg, 2); \
54 case 1: write_debug(ptr[1], reg, 1); \
55 default: write_debug(ptr[0], reg, 0); \
56 }
57
58static void __hyp_text __debug_save_spe_nvhe(u64 *pmscr_el1)
59{
60 u64 reg;
61
62 /* Clear pmscr in case of early return */
63 *pmscr_el1 = 0;
64
65 /* SPE present on this CPU? */
66 if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
67 ID_AA64DFR0_PMSVER_SHIFT))
68 return;
69
70 /* Yes; is it owned by EL3? */
71 reg = read_sysreg_s(SYS_PMBIDR_EL1);
72 if (reg & BIT(SYS_PMBIDR_EL1_P_SHIFT))
73 return;
74
75 /* No; is the host actually using the thing? */
76 reg = read_sysreg_s(SYS_PMBLIMITR_EL1);
77 if (!(reg & BIT(SYS_PMBLIMITR_EL1_E_SHIFT)))
78 return;
79
80 /* Yes; save the control register and disable data generation */
81 *pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1);
82 write_sysreg_s(0, SYS_PMSCR_EL1);
83 isb();
84
85 /* Now drain all buffered data to memory */
86 psb_csync();
87 dsb(nsh);
88}
89
90static void __hyp_text __debug_restore_spe_nvhe(u64 pmscr_el1)
91{
92 if (!pmscr_el1)
93 return;
94
95 /* The host page table is installed, but not yet synchronised */
96 isb();
97
98 /* Re-enable data generation */
99 write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1);
100}
101
102static void __hyp_text __debug_save_state(struct kvm_vcpu *vcpu,
103 struct kvm_guest_debug_arch *dbg,
104 struct kvm_cpu_context *ctxt)
105{
106 u64 aa64dfr0;
107 int brps, wrps;
108
109 aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
110 brps = (aa64dfr0 >> 12) & 0xf;
111 wrps = (aa64dfr0 >> 20) & 0xf;
112
113 save_debug(dbg->dbg_bcr, dbgbcr, brps);
114 save_debug(dbg->dbg_bvr, dbgbvr, brps);
115 save_debug(dbg->dbg_wcr, dbgwcr, wrps);
116 save_debug(dbg->dbg_wvr, dbgwvr, wrps);
117
118 ctxt->sys_regs[MDCCINT_EL1] = read_sysreg(mdccint_el1);
119}
120
121static void __hyp_text __debug_restore_state(struct kvm_vcpu *vcpu,
122 struct kvm_guest_debug_arch *dbg,
123 struct kvm_cpu_context *ctxt)
124{
125 u64 aa64dfr0;
126 int brps, wrps;
127
128 aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
129
130 brps = (aa64dfr0 >> 12) & 0xf;
131 wrps = (aa64dfr0 >> 20) & 0xf;
132
133 restore_debug(dbg->dbg_bcr, dbgbcr, brps);
134 restore_debug(dbg->dbg_bvr, dbgbvr, brps);
135 restore_debug(dbg->dbg_wcr, dbgwcr, wrps);
136 restore_debug(dbg->dbg_wvr, dbgwvr, wrps);
137
138 write_sysreg(ctxt->sys_regs[MDCCINT_EL1], mdccint_el1);
139}
140
141void __hyp_text __debug_switch_to_guest(struct kvm_vcpu *vcpu)
142{
143 struct kvm_cpu_context *host_ctxt;
144 struct kvm_cpu_context *guest_ctxt;
145 struct kvm_guest_debug_arch *host_dbg;
146 struct kvm_guest_debug_arch *guest_dbg;
147
148 /*
149 * Non-VHE: Disable and flush SPE data generation
150 * VHE: The vcpu can run, but it can't hide.
151 */
152 if (!has_vhe())
153 __debug_save_spe_nvhe(&vcpu->arch.host_debug_state.pmscr_el1);
154
155 if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
156 return;
157
158 host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
159 guest_ctxt = &vcpu->arch.ctxt;
160 host_dbg = &vcpu->arch.host_debug_state.regs;
161 guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
162
163 __debug_save_state(vcpu, host_dbg, host_ctxt);
164 __debug_restore_state(vcpu, guest_dbg, guest_ctxt);
165}
166
167void __hyp_text __debug_switch_to_host(struct kvm_vcpu *vcpu)
168{
169 struct kvm_cpu_context *host_ctxt;
170 struct kvm_cpu_context *guest_ctxt;
171 struct kvm_guest_debug_arch *host_dbg;
172 struct kvm_guest_debug_arch *guest_dbg;
173
174 if (!has_vhe())
175 __debug_restore_spe_nvhe(vcpu->arch.host_debug_state.pmscr_el1);
176
177 if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
178 return;
179
180 host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
181 guest_ctxt = &vcpu->arch.ctxt;
182 host_dbg = &vcpu->arch.host_debug_state.regs;
183 guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
184
185 __debug_save_state(vcpu, guest_dbg, guest_ctxt);
186 __debug_restore_state(vcpu, host_dbg, host_ctxt);
187
188 vcpu->arch.flags &= ~KVM_ARM64_DEBUG_DIRTY;
189}
190
191u32 __hyp_text __kvm_get_mdcr_el2(void)
192{
193 return read_sysreg(mdcr_el2);
194}