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