The unwinding code doesn't really belong to the exit handling
code. Instead, move it to a file (conveniently named stacktrace.c
to confuse the reviewer), and move all the stacktrace-related
stuff there.
It will be joined by more code very soon.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
arch/arm64/include/asm/stacktrace/nvhe.h | 2 +
arch/arm64/kvm/Makefile | 2 +-
arch/arm64/kvm/handle_exit.c | 98 ------------------
arch/arm64/kvm/stacktrace.c | 120 +++++++++++++++++++++++
4 files changed, 123 insertions(+), 99 deletions(-)
create mode 100644 arch/arm64/kvm/stacktrace.c
diff --git a/arch/arm64/include/asm/stacktrace/nvhe.h b/arch/arm64/include/asm/stacktrace/nvhe.h
index 600dbc2220b6..8a5cb96d7143 100644
--- a/arch/arm64/include/asm/stacktrace/nvhe.h
+++ b/arch/arm64/include/asm/stacktrace/nvhe.h
@@ -172,5 +172,7 @@ static inline int notrace unwind_next(struct unwind_state *state)
}
NOKPROBE_SYMBOL(unwind_next);
+void kvm_nvhe_dump_backtrace(unsigned long hyp_offset);
+
#endif /* __KVM_NVHE_HYPERVISOR__ */
#endif /* __ASM_STACKTRACE_NVHE_H */
diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index aa127ae9f675..5e33c2d4645a 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -12,7 +12,7 @@ obj-$(CONFIG_KVM) += hyp/
kvm-y += arm.o mmu.o mmio.o psci.o hypercalls.o pvtime.o \
inject_fault.o va_layout.o handle_exit.o \
- guest.o debug.o reset.o sys_regs.o \
+ guest.o debug.o reset.o sys_regs.o stacktrace.o \
vgic-sys-reg-v3.o fpsimd.o pkvm.o \
arch_timer.o trng.o vmid.o \
vgic/vgic.o vgic/vgic-init.o \
diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index c14fc4ba4422..ef8b57953aa2 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -319,104 +319,6 @@ 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();
-}
-
-#ifdef CONFIG_PROTECTED_NVHE_STACKTRACE
-DECLARE_KVM_NVHE_PER_CPU(unsigned long [NVHE_STACKTRACE_SIZE/sizeof(long)],
- pkvm_stacktrace);
-
-/*
- * pkvm_dump_backtrace - Dump the protected nVHE HYP backtrace.
- *
- * @hyp_offset: hypervisor offset, used for address translation.
- *
- * Dumping of the pKVM HYP backtrace is done by reading the
- * stack addresses from the shared stacktrace buffer, since the
- * host cannot directly access hypervisor memory in protected
- * mode.
- */
-static void pkvm_dump_backtrace(unsigned long hyp_offset)
-{
- unsigned long *stacktrace
- = (unsigned long *) this_cpu_ptr_nvhe_sym(pkvm_stacktrace);
- int i, size = NVHE_STACKTRACE_SIZE / sizeof(long);
-
- kvm_nvhe_dump_backtrace_start();
- /* The saved stacktrace is terminated by a null entry */
- for (i = 0; i < size && stacktrace[i]; i++)
- kvm_nvhe_dump_backtrace_entry((void *)hyp_offset, stacktrace[i]);
- kvm_nvhe_dump_backtrace_end();
-}
-#else /* !CONFIG_PROTECTED_NVHE_STACKTRACE */
-static void pkvm_dump_backtrace(unsigned long hyp_offset)
-{
- kvm_err("Cannot dump pKVM nVHE stacktrace: !CONFIG_PROTECTED_NVHE_STACKTRACE\n");
-}
-#endif /* CONFIG_PROTECTED_NVHE_STACKTRACE */
-
-/*
- * 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())
- pkvm_dump_backtrace(hyp_offset);
- 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,
diff --git a/arch/arm64/kvm/stacktrace.c b/arch/arm64/kvm/stacktrace.c
new file mode 100644
index 000000000000..9812aefdcfb4
--- /dev/null
+++ b/arch/arm64/kvm/stacktrace.c
@@ -0,0 +1,120 @@
+/* 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.
+ *
+ * 2) pKVM (protected nVHE) mode - the host cannot directly access
+ * the HYP memory. The stack is unwinded in EL2 and dumped to a shared
+ * buffer where the host can read and print the stacktrace.
+ *
+ * Copyright (C) 2022 Google LLC
+ */
+
+#include <linux/kvm.h>
+#include <linux/kvm_host.h>
+
+#include <asm/stacktrace/nvhe.h>
+
+/*
+ * 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 void kvm_nvhe_dump_backtrace_start(void)
+{
+ kvm_err("nVHE call trace:\n");
+}
+
+static 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();
+}
+
+#ifdef CONFIG_PROTECTED_NVHE_STACKTRACE
+DECLARE_KVM_NVHE_PER_CPU(unsigned long [NVHE_STACKTRACE_SIZE/sizeof(long)],
+ pkvm_stacktrace);
+
+/*
+ * pkvm_dump_backtrace - Dump the protected nVHE HYP backtrace.
+ *
+ * @hyp_offset: hypervisor offset, used for address translation.
+ *
+ * Dumping of the pKVM HYP backtrace is done by reading the
+ * stack addresses from the shared stacktrace buffer, since the
+ * host cannot directly access hypervisor memory in protected
+ * mode.
+ */
+static void pkvm_dump_backtrace(unsigned long hyp_offset)
+{
+ unsigned long *stacktrace
+ = (unsigned long *) this_cpu_ptr_nvhe_sym(pkvm_stacktrace);
+ int i, size = NVHE_STACKTRACE_SIZE / sizeof(long);
+
+ kvm_nvhe_dump_backtrace_start();
+ /* The saved stacktrace is terminated by a null entry */
+ for (i = 0; i < size && stacktrace[i]; i++)
+ kvm_nvhe_dump_backtrace_entry((void *)hyp_offset, stacktrace[i]);
+ kvm_nvhe_dump_backtrace_end();
+}
+#else /* !CONFIG_PROTECTED_NVHE_STACKTRACE */
+static void pkvm_dump_backtrace(unsigned long hyp_offset)
+{
+ kvm_err("Cannot dump pKVM nVHE stacktrace: !CONFIG_PROTECTED_NVHE_STACKTRACE\n");
+}
+#endif /* CONFIG_PROTECTED_NVHE_STACKTRACE */
+
+/*
+ * kvm_nvhe_dump_backtrace - Dump KVM nVHE hypervisor backtrace.
+ *
+ * @hyp_offset: hypervisor offset, used for address translation.
+ */
+void kvm_nvhe_dump_backtrace(unsigned long hyp_offset)
+{
+ if (is_protected_kvm_enabled())
+ pkvm_dump_backtrace(hyp_offset);
+ else
+ hyp_dump_backtrace(hyp_offset);
+}
--
2.34.1
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