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
17static 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
42static 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
54static 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
73static 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
82void __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(&vcpu->arch.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(&vcpu->arch.host_debug_state.trfcr_el1);
90}
91
92void __debug_switch_to_guest(struct kvm_vcpu *vcpu)
93{
94	__debug_switch_to_guest_common(vcpu);
95}
96
97void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu)
98{
99	if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE))
100		__debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1);
101	if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE))
102		__debug_restore_trace(vcpu->arch.host_debug_state.trfcr_el1);
103}
104
105void __debug_switch_to_host(struct kvm_vcpu *vcpu)
106{
107	__debug_switch_to_host_common(vcpu);
108}
109
110u64 __kvm_get_mdcr_el2(void)
111{
112	return read_sysreg(mdcr_el2);
113}
114