From 573e1e8275f7167ddd533c6e4e0f500f8be4d974 Mon Sep 17 00:00:00 2001 From: Kalesh Singh Date: Tue, 26 Jul 2022 00:37:41 -0700 Subject: KVM: arm64: Stub implementation of non-protected nVHE HYP stack unwinder Add stub implementations of non-protected nVHE stack unwinder, for building. These are implemented later in this series. Signed-off-by: Kalesh Singh Reviewed-by: Fuad Tabba Tested-by: Fuad Tabba Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220726073750.3219117-9-kaleshsingh@google.com --- arch/arm64/include/asm/stacktrace/nvhe.h | 47 ++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) create mode 100644 arch/arm64/include/asm/stacktrace/nvhe.h (limited to 'arch/arm64/include/asm/stacktrace') diff --git a/arch/arm64/include/asm/stacktrace/nvhe.h b/arch/arm64/include/asm/stacktrace/nvhe.h new file mode 100644 index 000000000000..1192ae0f80c1 --- /dev/null +++ b/arch/arm64/include/asm/stacktrace/nvhe.h @@ -0,0 +1,47 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * KVM nVHE hypervisor stack tracing support. + * + * The unwinder implementation depends on the nVHE mode: + * + * 1) Non-protected nVHE mode - the host can directly access the + * HYP stack pages and unwind the HYP stack in EL1. This saves having + * to allocate shared buffers for the host to read the unwinded + * stacktrace. + * + * Copyright (C) 2022 Google LLC + */ +#ifndef __ASM_STACKTRACE_NVHE_H +#define __ASM_STACKTRACE_NVHE_H + +#include + +static inline bool on_accessible_stack(const struct task_struct *tsk, + unsigned long sp, unsigned long size, + struct stack_info *info) +{ + return false; +} + +#ifndef __KVM_NVHE_HYPERVISOR__ +/* + * Conventional (non-protected) nVHE HYP stack unwinder + * + * In non-protected mode, the unwinding is done from kernel proper context + * (by the host in EL1). + */ + +static inline bool on_overflow_stack(unsigned long sp, unsigned long size, + struct stack_info *info) +{ + return false; +} + +static inline int notrace unwind_next(struct unwind_state *state) +{ + return 0; +} +NOKPROBE_SYMBOL(unwind_next); + +#endif /* !__KVM_NVHE_HYPERVISOR__ */ +#endif /* __ASM_STACKTRACE_NVHE_H */ -- cgit