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 */
30 static 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
48 DECLARE_KVM_NVHE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack);
49 DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_stacktrace_info, kvm_stacktrace_info);
50 DECLARE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
51
52 void kvm_nvhe_dump_backtrace(unsigned long hyp_offset);
53
54 #endif /* __KVM_NVHE_HYPERVISOR__ */
55 #endif /* __ASM_STACKTRACE_NVHE_H */
56
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