1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * KVM nVHE hypervisor stack tracing support.
4 *
5 * The unwinder implementation depends on the nVHE mode:
6 *
7 *   1) Non-protected nVHE mode - the host can directly access the
8 *      HYP stack pages and unwind the HYP stack in EL1. This saves having
9 *      to allocate shared buffers for the host to read the unwinded
10 *      stacktrace.
11 *
12 *   2) pKVM (protected nVHE) mode - the host cannot directly access
13 *      the HYP memory. The stack is unwinded in EL2 and dumped to a shared
14 *      buffer where the host can read and print the stacktrace.
15 *
16 * Copyright (C) 2022 Google LLC
17 */
18#ifndef __ASM_STACKTRACE_NVHE_H
19#define __ASM_STACKTRACE_NVHE_H
20
21#include <asm/stacktrace/common.h>
22
23/**
24 * kvm_nvhe_unwind_init() - Start an unwind from the given nVHE HYP fp and pc
25 *
26 * @state : unwind_state to initialize
27 * @fp    : frame pointer at which to start the unwinding.
28 * @pc    : program counter at which to start the unwinding.
29 */
30static inline void kvm_nvhe_unwind_init(struct unwind_state *state,
31					unsigned long fp,
32					unsigned long pc)
33{
34	unwind_init_common(state);
35
36	state->fp = fp;
37	state->pc = pc;
38}
39
40#ifndef __KVM_NVHE_HYPERVISOR__
41/*
42 * Conventional (non-protected) nVHE HYP stack unwinder
43 *
44 * In non-protected mode, the unwinding is done from kernel proper context
45 * (by the host in EL1).
46 */
47
48DECLARE_KVM_NVHE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack);
49DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_stacktrace_info, kvm_stacktrace_info);
50DECLARE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
51
52void kvm_nvhe_dump_backtrace(unsigned long hyp_offset);
53
54#endif	/* __KVM_NVHE_HYPERVISOR__ */
55#endif	/* __ASM_STACKTRACE_NVHE_H */
56