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 
__debug_save_spe(u64 * pmscr_el1)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(SYS_PMBLIMITR_EL1_E_SHIFT)))
31 		return;
32 
33 	/* Yes; save the control register and disable data generation */
34 	*pmscr_el1 = read_sysreg_s(SYS_PMSCR_EL1);
35 	write_sysreg_s(0, SYS_PMSCR_EL1);
36 	isb();
37 
38 	/* Now drain all buffered data to memory */
39 	psb_csync();
40 	dsb(nsh);
41 }
42 
__debug_restore_spe(u64 pmscr_el1)43 static void __debug_restore_spe(u64 pmscr_el1)
44 {
45 	if (!pmscr_el1)
46 		return;
47 
48 	/* The host page table is installed, but not yet synchronised */
49 	isb();
50 
51 	/* Re-enable data generation */
52 	write_sysreg_s(pmscr_el1, SYS_PMSCR_EL1);
53 }
54 
__debug_save_trace(u64 * trfcr_el1)55 static void __debug_save_trace(u64 *trfcr_el1)
56 {
57 	*trfcr_el1 = 0;
58 
59 	/* Check if the TRBE is enabled */
60 	if (!(read_sysreg_s(SYS_TRBLIMITR_EL1) & TRBLIMITR_ENABLE))
61 		return;
62 	/*
63 	 * Prohibit trace generation while we are in guest.
64 	 * Since access to TRFCR_EL1 is trapped, the guest can't
65 	 * modify the filtering set by the host.
66 	 */
67 	*trfcr_el1 = read_sysreg_s(SYS_TRFCR_EL1);
68 	write_sysreg_s(0, SYS_TRFCR_EL1);
69 	isb();
70 	/* Drain the trace buffer to memory */
71 	tsb_csync();
72 	dsb(nsh);
73 }
74 
__debug_restore_trace(u64 trfcr_el1)75 static void __debug_restore_trace(u64 trfcr_el1)
76 {
77 	if (!trfcr_el1)
78 		return;
79 
80 	/* Restore trace filter controls */
81 	write_sysreg_s(trfcr_el1, SYS_TRFCR_EL1);
82 }
83 
__debug_save_host_buffers_nvhe(struct kvm_vcpu * vcpu)84 void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu)
85 {
86 	/* Disable and flush SPE data generation */
87 	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_SPE)
88 		__debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1);
89 	/* Disable and flush Self-Hosted Trace generation */
90 	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_TRBE)
91 		__debug_save_trace(&vcpu->arch.host_debug_state.trfcr_el1);
92 }
93 
__debug_switch_to_guest(struct kvm_vcpu * vcpu)94 void __debug_switch_to_guest(struct kvm_vcpu *vcpu)
95 {
96 	__debug_switch_to_guest_common(vcpu);
97 }
98 
__debug_restore_host_buffers_nvhe(struct kvm_vcpu * vcpu)99 void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu)
100 {
101 	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_SPE)
102 		__debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1);
103 	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_TRBE)
104 		__debug_restore_trace(vcpu->arch.host_debug_state.trfcr_el1);
105 }
106 
__debug_switch_to_host(struct kvm_vcpu * vcpu)107 void __debug_switch_to_host(struct kvm_vcpu *vcpu)
108 {
109 	__debug_switch_to_host_common(vcpu);
110 }
111 
__kvm_get_mdcr_el2(void)112 u64 __kvm_get_mdcr_el2(void)
113 {
114 	return read_sysreg(mdcr_el2);
115 }
116