diff --git a/arch/arm64/include/asm/stacktrace/nvhe.h b/arch/arm64/include/asm/stacktrace/nvhe.h index 21082fd4a0b7..170fe7459f7c 100644 --- a/arch/arm64/include/asm/stacktrace/nvhe.h +++ b/arch/arm64/include/asm/stacktrace/nvhe.h @@ -16,6 +16,23 @@ #include +/* + * kvm_nvhe_unwind_init - Start an unwind from the given nVHE HYP fp and pc + * + * @state : unwind_state to initialize + * @fp : frame pointer at which to start the unwinding. + * @pc : program counter at which to start the unwinding. + */ +static inline void kvm_nvhe_unwind_init(struct unwind_state *state, + unsigned long fp, + unsigned long pc) +{ + unwind_init_common(state, NULL); + + state->fp = fp; + state->pc = pc; +} + static inline bool on_hyp_stack(unsigned long sp, unsigned long size, struct stack_info *info); diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index f66c0142b335..e83e6f735100 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include @@ -318,6 +319,71 @@ void handle_exit_early(struct kvm_vcpu *vcpu, int exception_index) kvm_handle_guest_serror(vcpu, kvm_vcpu_get_esr(vcpu)); } +/* + * kvm_nvhe_dump_backtrace_entry - Symbolize and print an nVHE backtrace entry + * + * @arg : the hypervisor offset, used for address translation + * @where : the program counter corresponding to the stack frame + */ +static bool kvm_nvhe_dump_backtrace_entry(void *arg, unsigned long where) +{ + unsigned long va_mask = GENMASK_ULL(vabits_actual - 1, 0); + unsigned long hyp_offset = (unsigned long)arg; + + /* Mask tags and convert to kern addr */ + where = (where & va_mask) + hyp_offset; + kvm_err(" [<%016lx>] %pB\n", where, (void *)(where + kaslr_offset())); + + return true; +} + +static inline void kvm_nvhe_dump_backtrace_start(void) +{ + kvm_err("nVHE call trace:\n"); +} + +static inline void kvm_nvhe_dump_backtrace_end(void) +{ + kvm_err("---[ end nVHE call trace ]---\n"); +} + +/* + * hyp_dump_backtrace - Dump the non-protected nVHE backtrace. + * + * @hyp_offset: hypervisor offset, used for address translation. + * + * The host can directly access HYP stack pages in non-protected + * mode, so the unwinding is done directly from EL1. This removes + * the need for shared buffers between host and hypervisor for + * the stacktrace. + */ +static void hyp_dump_backtrace(unsigned long hyp_offset) +{ + struct kvm_nvhe_stacktrace_info *stacktrace_info; + struct unwind_state state; + + stacktrace_info = this_cpu_ptr_nvhe_sym(kvm_stacktrace_info); + + kvm_nvhe_unwind_init(&state, stacktrace_info->fp, stacktrace_info->pc); + + kvm_nvhe_dump_backtrace_start(); + unwind(&state, kvm_nvhe_dump_backtrace_entry, (void *)hyp_offset); + kvm_nvhe_dump_backtrace_end(); +} + +/* + * kvm_nvhe_dump_backtrace - Dump KVM nVHE hypervisor backtrace. + * + * @hyp_offset: hypervisor offset, used for address translation. + */ +static void kvm_nvhe_dump_backtrace(unsigned long hyp_offset) +{ + if (is_protected_kvm_enabled()) + return; + else + hyp_dump_backtrace(hyp_offset); +} + void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr, u64 elr_virt, u64 elr_phys, u64 par, uintptr_t vcpu, @@ -353,6 +419,9 @@ void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr, (void *)panic_addr); } + /* Dump the nVHE hypervisor backtrace */ + kvm_nvhe_dump_backtrace(hyp_offset); + /* * Hyp has panicked and we're going to handle that by panicking the * kernel. The kernel offset will be revealed in the panic so we're