summaryrefslogtreecommitdiffstats
path: root/arch/arm64/kvm/hyp/debug-sr.c
blob: f4363d40e2cd7fd62d40d826d5296c95f15cde9f (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
/*
 * Copyright (C) 2015 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/compiler.h>
#include <linux/kvm_host.h>

#include <asm/debug-monitors.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_hyp.h>

#define read_debug(r,n)		read_sysreg(r##n##_el1)
#define write_debug(v,r,n)	write_sysreg(v, r##n##_el1)

#define save_debug(ptr,reg,nr)						\
	switch (nr) {							\
	case 15:	ptr[15] = read_debug(reg, 15);			\
	case 14:	ptr[14] = read_debug(reg, 14);			\
	case 13:	ptr[13] = read_debug(reg, 13);			\
	case 12:	ptr[12] = read_debug(reg, 12);			\
	case 11:	ptr[11] = read_debug(reg, 11);			\
	case 10:	ptr[10] = read_debug(reg, 10);			\
	case 9:		ptr[9] = read_debug(reg, 9);			\
	case 8:		ptr[8] = read_debug(reg, 8);			\
	case 7:		ptr[7] = read_debug(reg, 7);			\
	case 6:		ptr[6] = read_debug(reg, 6);			\
	case 5:		ptr[5] = read_debug(reg, 5);			\
	case 4:		ptr[4] = read_debug(reg, 4);			\
	case 3:		ptr[3] = read_debug(reg, 3);			\
	case 2:		ptr[2] = read_debug(reg, 2);			\
	case 1:		ptr[1] = read_debug(reg, 1);			\
	default:	ptr[0] = read_debug(reg, 0);			\
	}

#define restore_debug(ptr,reg,nr)					\
	switch (nr) {							\
	case 15:	write_debug(ptr[15], reg, 15);			\
	case 14:	write_debug(ptr[14], reg, 14);			\
	case 13:	write_debug(ptr[13], reg, 13);			\
	case 12:	write_debug(ptr[12], reg, 12);			\
	case 11:	write_debug(ptr[11], reg, 11);			\
	case 10:	write_debug(ptr[10], reg, 10);			\
	case 9:		write_debug(ptr[9], reg, 9);			\
	case 8:		write_debug(ptr[8], reg, 8);			\
	case 7:		write_debug(ptr[7], reg, 7);			\
	case 6:		write_debug(ptr[6], reg, 6);			\
	case 5:		write_debug(ptr[5], reg, 5);			\
	case 4:		write_debug(ptr[4], reg, 4);			\
	case 3:		write_debug(ptr[3], reg, 3);			\
	case 2:		write_debug(ptr[2], reg, 2);			\
	case 1:		write_debug(ptr[1], reg, 1);			\
	default:	write_debug(ptr[0], reg, 0);			\
	}

static void __hyp_text __debug_save_spe_vhe(u64 *pmscr_el1)
{
	/* The vcpu can run. but it can't hide. */
}

static void __hyp_text __debug_save_spe_nvhe(u64 *pmscr_el1)
{
	u64 reg;

	/* Clear pmscr in case of early return */
	*pmscr_el1 = 0;

	/* SPE present on this CPU? */
	if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
						  ID_AA64DFR0_PMSVER_SHIFT))
		return;

	/* Yes; is it owned by EL3? */
	reg = read_sysreg_s(SYS_PMBIDR_EL1);
	if (reg & BIT(SYS_PMBIDR_EL1_P_SHIFT))
		return;

	/* No; is the host actually using the thing? */
	reg = read_sysreg_s(SYS_PMBLIMITR_EL1);
	if (!(reg & BIT(SYS_PMBLIMITR_EL1_E_SHIFT)))
		return;

	/* Yes; save the control register and disable data generation */
	*pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1);
	write_sysreg_s(0, SYS_PMSCR_EL1);
	isb();

	/* Now drain all buffered data to memory */
	psb_csync();
	dsb(nsh);
}

static hyp_alternate_select(__debug_save_spe,
			    __debug_save_spe_nvhe, __debug_save_spe_vhe,
			    ARM64_HAS_VIRT_HOST_EXTN);

static void __hyp_text __debug_restore_spe(u64 pmscr_el1)
{
	if (!pmscr_el1)
		return;

	/* The host page table is installed, but not yet synchronised */
	isb();

	/* Re-enable data generation */
	write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1);
}

void __hyp_text __debug_save_state(struct kvm_vcpu *vcpu,
				   struct kvm_guest_debug_arch *dbg,
				   struct kvm_cpu_context *ctxt)
{
	u64 aa64dfr0;
	int brps, wrps;

	if (!(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY))
		return;

	aa64dfr0 = read_sysreg(id_aa64dfr0_el1);
	brps = (aa64dfr0 >> 12) & 0xf;
	wrps = (aa64dfr0 >> 20) & 0xf;

	save_debug(dbg->dbg_bcr, dbgbcr, brps);
	save_debug(dbg->dbg_bvr, dbgbvr, brps);
	save_debug(dbg->dbg_wcr, dbgwcr, wrps);
	save_debug(dbg->dbg_wvr, dbgwvr, wrps);

	ctxt->sys_regs[MDCCINT_EL1] = read_sysreg(mdccint_el1);
}

void __hyp_text __debug_restore_state(struct kvm_vcpu *vcpu,
				      struct kvm_guest_debug_arch *dbg,
				      struct kvm_cpu_context *ctxt)
{
	u64 aa64dfr0;
	int brps, wrps;

	if (!(vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY))
		return;

	aa64dfr0 = read_sysreg(id_aa64dfr0_el1);

	brps = (aa64dfr0 >> 12) & 0xf;
	wrps = (aa64dfr0 >> 20) & 0xf;

	restore_debug(dbg->dbg_bcr, dbgbcr, brps);
	restore_debug(dbg->dbg_bvr, dbgbvr, brps);
	restore_debug(dbg->dbg_wcr, dbgwcr, wrps);
	restore_debug(dbg->dbg_wvr, dbgwvr, wrps);

	write_sysreg(ctxt->sys_regs[MDCCINT_EL1], mdccint_el1);
}

void __hyp_text __debug_cond_save_host_state(struct kvm_vcpu *vcpu)
{
	/* If any of KDE, MDE or KVM_ARM64_DEBUG_DIRTY is set, perform
	 * a full save/restore cycle. */
	if ((vcpu->arch.ctxt.sys_regs[MDSCR_EL1] & DBG_MDSCR_KDE) ||
	    (vcpu->arch.ctxt.sys_regs[MDSCR_EL1] & DBG_MDSCR_MDE))
		vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;

	__debug_save_state(vcpu, &vcpu->arch.host_debug_state.regs,
			   kern_hyp_va(vcpu->arch.host_cpu_context));
	__debug_save_spe()(&vcpu->arch.host_debug_state.pmscr_el1);
}

void __hyp_text __debug_cond_restore_host_state(struct kvm_vcpu *vcpu)
{
	__debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1);
	__debug_restore_state(vcpu, &vcpu->arch.host_debug_state.regs,
			      kern_hyp_va(vcpu->arch.host_cpu_context));

	if (vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY)
		vcpu->arch.debug_flags &= ~KVM_ARM64_DEBUG_DIRTY;
}

u32 __hyp_text __kvm_get_mdcr_el2(void)
{
	return read_sysreg(mdcr_el2);
}