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 <hyp/debug-sr.h>
8
9 #include <linux/compiler.h>
10 #include <linux/kvm_host.h>
11
12 #include <asm/debug-monitors.h>
13 #include <asm/kvm_asm.h>
14 #include <asm/kvm_hyp.h>
15 #include <asm/kvm_mmu.h>
16
17 static void __debug_save_spe(u64 *pmscr_el1)
18 {
19 u64 reg;
20
21 /* Clear pmscr in case of early return */
22 *pmscr_el1 = 0;
23
24 /*
25 * At this point, we know that this CPU implements
26 * SPE and is available to the host.
27 * Check if the host is actually using it ?
28 */
29 reg = read_sysreg_s(SYS_PMBLIMITR_EL1);
30 if (!(reg & BIT(PMBLIMITR_EL1_E_SHIFT)))
31 return;
32
33 /* Yes; save the control register and disable data generation */
34 *pmscr_el1 = read_sysreg_el1(SYS_PMSCR);
35 write_sysreg_el1(0, SYS_PMSCR);
36 isb();
37
38 /* Now drain all buffered data to memory */
39 psb_csync();
40 }
41
42 static void __debug_restore_spe(u64 pmscr_el1)
43 {
44 if (!pmscr_el1)
45 return;
46
47 /* The host page table is installed, but not yet synchronised */
48 isb();
49
50 /* Re-enable data generation */
51 write_sysreg_el1(pmscr_el1, SYS_PMSCR);
52 }
53
54 static void __debug_save_trace(u64 *trfcr_el1)
55 {
56 *trfcr_el1 = 0;
57
58 /* Check if the TRBE is enabled */
59 if (!(read_sysreg_s(SYS_TRBLIMITR_EL1) & TRBLIMITR_EL1_E))
60 return;
61 /*
62 * Prohibit trace generation while we are in guest.
63 * Since access to TRFCR_EL1 is trapped, the guest can't
64 * modify the filtering set by the host.
65 */
66 *trfcr_el1 = read_sysreg_el1(SYS_TRFCR);
67 write_sysreg_el1(0, SYS_TRFCR);
68 isb();
69 /* Drain the trace buffer to memory */
70 tsb_csync();
71 }
72
73 static void __debug_restore_trace(u64 trfcr_el1)
74 {
75 if (!trfcr_el1)
76 return;
77
78 /* Restore trace filter controls */
79 write_sysreg_el1(trfcr_el1, SYS_TRFCR);
80 }
81
82 void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu)
83 {
84 /* Disable and flush SPE data generation */
85 if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE))
86 __debug_save_spe(host_data_ptr(host_debug_state.pmscr_el1));
87 /* Disable and flush Self-Hosted Trace generation */
88 if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE))
89 __debug_save_trace(host_data_ptr(host_debug_state.trfcr_el1));
90 }
91
92 void __debug_switch_to_guest(struct kvm_vcpu *vcpu)
93 {
94 __debug_switch_to_guest_common(vcpu);
95 }
96
97 void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu)
98 {
99 if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE))
100 __debug_restore_spe(*host_data_ptr(host_debug_state.pmscr_el1));
101 if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE))
102 __debug_restore_trace(*host_data_ptr(host_debug_state.trfcr_el1));
103 }
104
105 void __debug_switch_to_host(struct kvm_vcpu *vcpu)
106 {
107 __debug_switch_to_host_common(vcpu);
108 }
109
110 u64 __kvm_get_mdcr_el2(void)
111 {
112 return read_sysreg(mdcr_el2);
113 }
114
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