Merge tag 'kvmarm-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for 5.20:

- Unwinder implementations for both nVHE modes (classic and
  protected), complete with an overflow stack

- Rework of the sysreg access from userspace, with a complete
  rewrite of the vgic-v3 view to allign with the rest of the
  infrastructure

- Disagregation of the vcpu flags in separate sets to better track
  their use model.

- A fix for the GICv2-on-v3 selftest

- A small set of cosmetic fixes

arch/arm64/include/asm/kvm_asm.h

@@ -176,6 +176,22 @@ struct kvm_nvhe_init_params {
 	unsigned long vtcr;
 };
 
+/*
+ * Used by the host in EL1 to dump the nVHE hypervisor backtrace on
+ * hyp_panic() in non-protected mode.
+ *
+ * @stack_base:                 hyp VA of the hyp_stack base.
+ * @overflow_stack_base:        hyp VA of the hyp_overflow_stack base.
+ * @fp:                         hyp FP where the backtrace begins.
+ * @pc:                         hyp PC where the backtrace begins.
+ */
+struct kvm_nvhe_stacktrace_info {
+	unsigned long stack_base;
+	unsigned long overflow_stack_base;
+	unsigned long fp;
+	unsigned long pc;
+};
+
 /* Translate a kernel address @ptr into its equivalent linear mapping */
 #define kvm_ksym_ref(ptr)						\
 	({								\

arch/arm64/include/asm/kvm_emulate.h

@@ -473,9 +473,18 @@ static inline unsigned long vcpu_data_host_to_guest(struct kvm_vcpu *vcpu,
 
 static __always_inline void kvm_incr_pc(struct kvm_vcpu *vcpu)
 {
-	vcpu->arch.flags |= KVM_ARM64_INCREMENT_PC;
+	WARN_ON(vcpu_get_flag(vcpu, PENDING_EXCEPTION));
+	vcpu_set_flag(vcpu, INCREMENT_PC);
 }
 
+#define kvm_pend_exception(v, e)					\
+	do {								\
+		WARN_ON(vcpu_get_flag((v), INCREMENT_PC));		\
+		vcpu_set_flag((v), PENDING_EXCEPTION);			\
+		vcpu_set_flag((v), e);					\
+	} while (0)
+
+
 static inline bool vcpu_has_feature(struct kvm_vcpu *vcpu, int feature)
 {
 	return test_bit(feature, vcpu->arch.features);

arch/arm64/include/asm/kvm_host.h

@@ -325,8 +325,30 @@ struct kvm_vcpu_arch {
 	/* Exception Information */
 	struct kvm_vcpu_fault_info fault;
 
-	/* Miscellaneous vcpu state flags */
-	u64 flags;
+	/* Ownership of the FP regs */
+	enum {
+		FP_STATE_FREE,
+		FP_STATE_HOST_OWNED,
+		FP_STATE_GUEST_OWNED,
+	} fp_state;
+
+	/* Configuration flags, set once and for all before the vcpu can run */
+	u8 cflags;
+
+	/* Input flags to the hypervisor code, potentially cleared after use */
+	u8 iflags;
+
+	/* State flags for kernel bookkeeping, unused by the hypervisor code */
+	u8 sflags;
+
+	/*
+	 * Don't run the guest (internal implementation need).
+	 *
+	 * Contrary to the flags above, this is set/cleared outside of
+	 * a vcpu context, and thus cannot be mixed with the flags
+	 * themselves (or the flag accesses need to be made atomic).
+	 */
+	bool pause;
 
 	/*
 	 * We maintain more than a single set of debug registers to support
@@ -376,9 +398,6 @@ struct kvm_vcpu_arch {
 	/* vcpu power state */
 	struct kvm_mp_state mp_state;
 
-	/* Don't run the guest (internal implementation need) */
-	bool pause;
-
 	/* Cache some mmu pages needed inside spinlock regions */
 	struct kvm_mmu_memory_cache mmu_page_cache;
 
@@ -392,10 +411,6 @@ struct kvm_vcpu_arch {
 	/* Additional reset state */
 	struct vcpu_reset_state	reset_state;
 
-	/* True when deferrable sysregs are loaded on the physical CPU,
-	 * see kvm_vcpu_load_sysregs_vhe and kvm_vcpu_put_sysregs_vhe. */
-	bool sysregs_loaded_on_cpu;
-
 	/* Guest PV state */
 	struct {
 		u64 last_steal;
@@ -403,6 +418,124 @@ struct kvm_vcpu_arch {
 	} steal;
 };
 
+/*
+ * Each 'flag' is composed of a comma-separated triplet:
+ *
+ * - the flag-set it belongs to in the vcpu->arch structure
+ * - the value for that flag
+ * - the mask for that flag
+ *
+ *  __vcpu_single_flag() builds such a triplet for a single-bit flag.
+ * unpack_vcpu_flag() extract the flag value from the triplet for
+ * direct use outside of the flag accessors.
+ */
+#define __vcpu_single_flag(_set, _f)	_set, (_f), (_f)
+
+#define __unpack_flag(_set, _f, _m)	_f
+#define unpack_vcpu_flag(...)		__unpack_flag(__VA_ARGS__)
+
+#define __build_check_flag(v, flagset, f, m)			\
+	do {							\
+		typeof(v->arch.flagset) *_fset;			\
+								\
+		/* Check that the flags fit in the mask */	\
+		BUILD_BUG_ON(HWEIGHT(m) != HWEIGHT((f) | (m)));	\
+		/* Check that the flags fit in the type */	\
+		BUILD_BUG_ON((sizeof(*_fset) * 8) <= __fls(m));	\
+	} while (0)
+
+#define __vcpu_get_flag(v, flagset, f, m)			\
+	({							\
+		__build_check_flag(v, flagset, f, m);		\
+								\
+		v->arch.flagset & (m);				\
+	})
+
+#define __vcpu_set_flag(v, flagset, f, m)			\
+	do {							\
+		typeof(v->arch.flagset) *fset;			\
+								\
+		__build_check_flag(v, flagset, f, m);		\
+								\
+		fset = &v->arch.flagset;			\
+		if (HWEIGHT(m) > 1)				\
+			*fset &= ~(m);				\
+		*fset |= (f);					\
+	} while (0)
+
+#define __vcpu_clear_flag(v, flagset, f, m)			\
+	do {							\
+		typeof(v->arch.flagset) *fset;			\
+								\
+		__build_check_flag(v, flagset, f, m);		\
+								\
+		fset = &v->arch.flagset;			\
+		*fset &= ~(m);					\
+	} while (0)
+
+#define vcpu_get_flag(v, ...)	__vcpu_get_flag((v), __VA_ARGS__)
+#define vcpu_set_flag(v, ...)	__vcpu_set_flag((v), __VA_ARGS__)
+#define vcpu_clear_flag(v, ...)	__vcpu_clear_flag((v), __VA_ARGS__)
+
+/* SVE exposed to guest */
+#define GUEST_HAS_SVE		__vcpu_single_flag(cflags, BIT(0))
+/* SVE config completed */
+#define VCPU_SVE_FINALIZED	__vcpu_single_flag(cflags, BIT(1))
+/* PTRAUTH exposed to guest */
+#define GUEST_HAS_PTRAUTH	__vcpu_single_flag(cflags, BIT(2))
+
+/* Exception pending */
+#define PENDING_EXCEPTION	__vcpu_single_flag(iflags, BIT(0))
+/*
+ * PC increment. Overlaps with EXCEPT_MASK on purpose so that it can't
+ * be set together with an exception...
+ */
+#define INCREMENT_PC		__vcpu_single_flag(iflags, BIT(1))
+/* Target EL/MODE (not a single flag, but let's abuse the macro) */
+#define EXCEPT_MASK		__vcpu_single_flag(iflags, GENMASK(3, 1))
+
+/* Helpers to encode exceptions with minimum fuss */
+#define __EXCEPT_MASK_VAL	unpack_vcpu_flag(EXCEPT_MASK)
+#define __EXCEPT_SHIFT		__builtin_ctzl(__EXCEPT_MASK_VAL)
+#define __vcpu_except_flags(_f)	iflags, (_f << __EXCEPT_SHIFT), __EXCEPT_MASK_VAL
+
+/*
+ * When PENDING_EXCEPTION is set, EXCEPT_MASK can take the following
+ * values:
+ *
+ * For AArch32 EL1:
+ */
+#define EXCEPT_AA32_UND		__vcpu_except_flags(0)
+#define EXCEPT_AA32_IABT	__vcpu_except_flags(1)
+#define EXCEPT_AA32_DABT	__vcpu_except_flags(2)
+/* For AArch64: */
+#define EXCEPT_AA64_EL1_SYNC	__vcpu_except_flags(0)
+#define EXCEPT_AA64_EL1_IRQ	__vcpu_except_flags(1)
+#define EXCEPT_AA64_EL1_FIQ	__vcpu_except_flags(2)
+#define EXCEPT_AA64_EL1_SERR	__vcpu_except_flags(3)
+/* For AArch64 with NV (one day): */
+#define EXCEPT_AA64_EL2_SYNC	__vcpu_except_flags(4)
+#define EXCEPT_AA64_EL2_IRQ	__vcpu_except_flags(5)
+#define EXCEPT_AA64_EL2_FIQ	__vcpu_except_flags(6)
+#define EXCEPT_AA64_EL2_SERR	__vcpu_except_flags(7)
+/* Guest debug is live */
+#define DEBUG_DIRTY		__vcpu_single_flag(iflags, BIT(4))
+/* Save SPE context if active  */
+#define DEBUG_STATE_SAVE_SPE	__vcpu_single_flag(iflags, BIT(5))
+/* Save TRBE context if active  */
+#define DEBUG_STATE_SAVE_TRBE	__vcpu_single_flag(iflags, BIT(6))
+
+/* SVE enabled for host EL0 */
+#define HOST_SVE_ENABLED	__vcpu_single_flag(sflags, BIT(0))
+/* SME enabled for EL0 */
+#define HOST_SME_ENABLED	__vcpu_single_flag(sflags, BIT(1))
+/* Physical CPU not in supported_cpus */
+#define ON_UNSUPPORTED_CPU	__vcpu_single_flag(sflags, BIT(2))
+/* WFIT instruction trapped */
+#define IN_WFIT			__vcpu_single_flag(sflags, BIT(3))
+/* vcpu system registers loaded on physical CPU */
+#define SYSREGS_ON_CPU		__vcpu_single_flag(sflags, BIT(4))
+
 /* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */
 #define vcpu_sve_pffr(vcpu) (kern_hyp_va((vcpu)->arch.sve_state) +	\
 			     sve_ffr_offset((vcpu)->arch.sve_max_vl))
@@ -423,70 +556,31 @@ struct kvm_vcpu_arch {
 	__size_ret;							\
 })
 
-/* vcpu_arch flags field values: */
-#define KVM_ARM64_DEBUG_DIRTY		(1 << 0)
-#define KVM_ARM64_FP_ENABLED		(1 << 1) /* guest FP regs loaded */
-#define KVM_ARM64_FP_HOST		(1 << 2) /* host FP regs loaded */
-#define KVM_ARM64_HOST_SVE_ENABLED	(1 << 4) /* SVE enabled for EL0 */
-#define KVM_ARM64_GUEST_HAS_SVE		(1 << 5) /* SVE exposed to guest */
-#define KVM_ARM64_VCPU_SVE_FINALIZED	(1 << 6) /* SVE config completed */
-#define KVM_ARM64_GUEST_HAS_PTRAUTH	(1 << 7) /* PTRAUTH exposed to guest */
-#define KVM_ARM64_PENDING_EXCEPTION	(1 << 8) /* Exception pending */
-/*
- * Overlaps with KVM_ARM64_EXCEPT_MASK on purpose so that it can't be
- * set together with an exception...
- */
-#define KVM_ARM64_INCREMENT_PC		(1 << 9) /* Increment PC */
-#define KVM_ARM64_EXCEPT_MASK		(7 << 9) /* Target EL/MODE */
-/*
- * When KVM_ARM64_PENDING_EXCEPTION is set, KVM_ARM64_EXCEPT_MASK can
- * take the following values:
- *
- * For AArch32 EL1:
- */
-#define KVM_ARM64_EXCEPT_AA32_UND	(0 << 9)
-#define KVM_ARM64_EXCEPT_AA32_IABT	(1 << 9)
-#define KVM_ARM64_EXCEPT_AA32_DABT	(2 << 9)
-/* For AArch64: */
-#define KVM_ARM64_EXCEPT_AA64_ELx_SYNC	(0 << 9)
-#define KVM_ARM64_EXCEPT_AA64_ELx_IRQ	(1 << 9)
-#define KVM_ARM64_EXCEPT_AA64_ELx_FIQ	(2 << 9)
-#define KVM_ARM64_EXCEPT_AA64_ELx_SERR	(3 << 9)
-#define KVM_ARM64_EXCEPT_AA64_EL1	(0 << 11)
-#define KVM_ARM64_EXCEPT_AA64_EL2	(1 << 11)
-
-#define KVM_ARM64_DEBUG_STATE_SAVE_SPE	(1 << 12) /* Save SPE context if active  */
-#define KVM_ARM64_DEBUG_STATE_SAVE_TRBE	(1 << 13) /* Save TRBE context if active  */
-#define KVM_ARM64_FP_FOREIGN_FPSTATE	(1 << 14)
-#define KVM_ARM64_ON_UNSUPPORTED_CPU	(1 << 15) /* Physical CPU not in supported_cpus */
-#define KVM_ARM64_HOST_SME_ENABLED	(1 << 16) /* SME enabled for EL0 */
-#define KVM_ARM64_WFIT			(1 << 17) /* WFIT instruction trapped */
-
 #define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE | \
 				 KVM_GUESTDBG_USE_SW_BP | \
 				 KVM_GUESTDBG_USE_HW | \
 				 KVM_GUESTDBG_SINGLESTEP)
 
 #define vcpu_has_sve(vcpu) (system_supports_sve() &&			\
-			    ((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_SVE))
+			    vcpu_get_flag(vcpu, GUEST_HAS_SVE))
 
 #ifdef CONFIG_ARM64_PTR_AUTH
 #define vcpu_has_ptrauth(vcpu)						\
 	((cpus_have_final_cap(ARM64_HAS_ADDRESS_AUTH) ||		\
 	  cpus_have_final_cap(ARM64_HAS_GENERIC_AUTH)) &&		\
-	 (vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_PTRAUTH)
+	  vcpu_get_flag(vcpu, GUEST_HAS_PTRAUTH))
 #else
 #define vcpu_has_ptrauth(vcpu)		false
 #endif
 
 #define vcpu_on_unsupported_cpu(vcpu)					\
-	((vcpu)->arch.flags & KVM_ARM64_ON_UNSUPPORTED_CPU)
+	vcpu_get_flag(vcpu, ON_UNSUPPORTED_CPU)
 
 #define vcpu_set_on_unsupported_cpu(vcpu)				\
-	((vcpu)->arch.flags |= KVM_ARM64_ON_UNSUPPORTED_CPU)
+	vcpu_set_flag(vcpu, ON_UNSUPPORTED_CPU)
 
 #define vcpu_clear_on_unsupported_cpu(vcpu)				\
-	((vcpu)->arch.flags &= ~KVM_ARM64_ON_UNSUPPORTED_CPU)
+	vcpu_clear_flag(vcpu, ON_UNSUPPORTED_CPU)
 
 #define vcpu_gp_regs(v)		(&(v)->arch.ctxt.regs)
 
@@ -620,8 +714,6 @@ int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
 
 unsigned long kvm_arm_num_sys_reg_descs(struct kvm_vcpu *vcpu);
 int kvm_arm_copy_sys_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices);
-int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *);
-int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *);
 
 int __kvm_arm_vcpu_get_events(struct kvm_vcpu *vcpu,
 			      struct kvm_vcpu_events *events);
@@ -831,8 +923,7 @@ void kvm_init_protected_traps(struct kvm_vcpu *vcpu);
 int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu, int feature);
 bool kvm_arm_vcpu_is_finalized(struct kvm_vcpu *vcpu);
 
-#define kvm_arm_vcpu_sve_finalized(vcpu) \
-	((vcpu)->arch.flags & KVM_ARM64_VCPU_SVE_FINALIZED)
+#define kvm_arm_vcpu_sve_finalized(vcpu) vcpu_get_flag(vcpu, VCPU_SVE_FINALIZED)
 
 #define kvm_has_mte(kvm)					\
 	(system_supports_mte() &&				\

arch/arm64/include/asm/memory.h

@@ -113,6 +113,14 @@
 
 #define OVERFLOW_STACK_SIZE	SZ_4K
 
+/*
+ * With the minimum frame size of [x29, x30], exactly half the combined
+ * sizes of the hyp and overflow stacks is the maximum size needed to
+ * save the unwinded stacktrace; plus an additional entry to delimit the
+ * end.
+ */
+#define NVHE_STACKTRACE_SIZE	((OVERFLOW_STACK_SIZE + PAGE_SIZE) / 2 + sizeof(long))
+
 /*
  * Alignment of kernel segments (e.g. .text, .data).
  *

arch/arm64/include/asm/stacktrace.h

@@ -8,52 +8,20 @@
 #include <linux/percpu.h>
 #include <linux/sched.h>
 #include <linux/sched/task_stack.h>
-#include <linux/types.h>
 #include <linux/llist.h>
 
 #include <asm/memory.h>
+#include <asm/pointer_auth.h>
 #include <asm/ptrace.h>
 #include <asm/sdei.h>
 
-enum stack_type {
-	STACK_TYPE_UNKNOWN,
-	STACK_TYPE_TASK,
-	STACK_TYPE_IRQ,
-	STACK_TYPE_OVERFLOW,
-	STACK_TYPE_SDEI_NORMAL,
-	STACK_TYPE_SDEI_CRITICAL,
-	__NR_STACK_TYPES
-};
-
-struct stack_info {
-	unsigned long low;
-	unsigned long high;
-	enum stack_type type;
-};
+#include <asm/stacktrace/common.h>
 
 extern void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk,
 			   const char *loglvl);
 
 DECLARE_PER_CPU(unsigned long *, irq_stack_ptr);
 
-static inline bool on_stack(unsigned long sp, unsigned long size,
-			    unsigned long low, unsigned long high,
-			    enum stack_type type, struct stack_info *info)
-{
-	if (!low)
-		return false;
-
-	if (sp < low || sp + size < sp || sp + size > high)
-		return false;
-
-	if (info) {
-		info->low = low;
-		info->high = high;
-		info->type = type;
-	}
-	return true;
-}
-
 static inline bool on_irq_stack(unsigned long sp, unsigned long size,
 				struct stack_info *info)
 {
@@ -89,30 +57,4 @@ static inline bool on_overflow_stack(unsigned long sp, unsigned long size,
 			struct stack_info *info) { return false; }
 #endif
 
-
-/*
- * We can only safely access per-cpu stacks from current in a non-preemptible
- * context.
- */
-static inline bool on_accessible_stack(const struct task_struct *tsk,
-				       unsigned long sp, unsigned long size,
-				       struct stack_info *info)
-{
-	if (info)
-		info->type = STACK_TYPE_UNKNOWN;
-
-	if (on_task_stack(tsk, sp, size, info))
-		return true;
-	if (tsk != current || preemptible())
-		return false;
-	if (on_irq_stack(sp, size, info))
-		return true;
-	if (on_overflow_stack(sp, size, info))
-		return true;
-	if (on_sdei_stack(sp, size, info))
-		return true;
-
-	return false;
-}
-
 #endif	/* __ASM_STACKTRACE_H */

arch/arm64/include/asm/stacktrace/common.h

+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Common arm64 stack unwinder code.
+ *
+ * To implement a new arm64 stack unwinder:
+ *     1) Include this header
+ *
+ *     2) Call into unwind_next_common() from your top level unwind
+ *        function, passing it the validation and translation callbacks
+ *        (though the later can be NULL if no translation is required).
+ *
+ * See: arch/arm64/kernel/stacktrace.c for the reference implementation.
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ */
+#ifndef __ASM_STACKTRACE_COMMON_H
+#define __ASM_STACKTRACE_COMMON_H
+
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/kprobes.h>
+#include <linux/types.h>
+
+enum stack_type {
+	STACK_TYPE_UNKNOWN,
+	STACK_TYPE_TASK,
+	STACK_TYPE_IRQ,
+	STACK_TYPE_OVERFLOW,
+	STACK_TYPE_SDEI_NORMAL,
+	STACK_TYPE_SDEI_CRITICAL,
+	STACK_TYPE_HYP,
+	__NR_STACK_TYPES
+};
+
+struct stack_info {
+	unsigned long low;
+	unsigned long high;
+	enum stack_type type;
+};
+
+/*
+ * A snapshot of a frame record or fp/lr register values, along with some
+ * accounting information necessary for robust unwinding.
+ *
+ * @fp:          The fp value in the frame record (or the real fp)
+ * @pc:          The lr value in the frame record (or the real lr)
+ *
+ * @stacks_done: Stacks which have been entirely unwound, for which it is no
+ *               longer valid to unwind to.
+ *
+ * @prev_fp:     The fp that pointed to this frame record, or a synthetic value
+ *               of 0. This is used to ensure that within a stack, each
+ *               subsequent frame record is at an increasing address.
+ * @prev_type:   The type of stack this frame record was on, or a synthetic
+ *               value of STACK_TYPE_UNKNOWN. This is used to detect a
+ *               transition from one stack to another.
+ *
+ * @kr_cur:      When KRETPROBES is selected, holds the kretprobe instance
+ *               associated with the most recently encountered replacement lr
+ *               value.
+ *
+ * @task:        The task being unwound.
+ */
+struct unwind_state {
+	unsigned long fp;
+	unsigned long pc;
+	DECLARE_BITMAP(stacks_done, __NR_STACK_TYPES);
+	unsigned long prev_fp;
+	enum stack_type prev_type;
+#ifdef CONFIG_KRETPROBES
+	struct llist_node *kr_cur;
+#endif
+	struct task_struct *task;
+};
+
+static inline bool on_stack(unsigned long sp, unsigned long size,
+			    unsigned long low, unsigned long high,
+			    enum stack_type type, struct stack_info *info)
+{
+	if (!low)
+		return false;
+
+	if (sp < low || sp + size < sp || sp + size > high)
+		return false;
+
+	if (info) {
+		info->low = low;
+		info->high = high;
+		info->type = type;
+	}
+	return true;
+}
+
+static inline void unwind_init_common(struct unwind_state *state,
+				      struct task_struct *task)
+{
+	state->task = task;
+#ifdef CONFIG_KRETPROBES
+	state->kr_cur = NULL;
+#endif
+
+	/*
+	 * Prime the first unwind.
+	 *
+	 * In unwind_next() we'll check that the FP points to a valid stack,
+	 * which can't be STACK_TYPE_UNKNOWN, and the first unwind will be
+	 * treated as a transition to whichever stack that happens to be. The
+	 * prev_fp value won't be used, but we set it to 0 such that it is
+	 * definitely not an accessible stack address.
+	 */
+	bitmap_zero(state->stacks_done, __NR_STACK_TYPES);
+	state->prev_fp = 0;
+	state->prev_type = STACK_TYPE_UNKNOWN;
+}
+
+/*
+ * stack_trace_translate_fp_fn() - Translates a non-kernel frame pointer to
+ * a kernel address.
+ *
+ * @fp:   the frame pointer to be updated to its kernel address.
+ * @type: the stack type associated with frame pointer @fp
+ *
+ * Returns true and success and @fp is updated to the corresponding
+ * kernel virtual address; otherwise returns false.
+ */
+typedef bool (*stack_trace_translate_fp_fn)(unsigned long *fp,
+					    enum stack_type type);
+
+/*
+ * on_accessible_stack_fn() - Check whether a stack range is on any
+ * of the possible stacks.
+ *
+ * @tsk:  task whose stack is being unwound
+ * @sp:   stack address being checked
+ * @size: size of the stack range being checked
+ * @info: stack unwinding context
+ */
+typedef bool (*on_accessible_stack_fn)(const struct task_struct *tsk,
+				       unsigned long sp, unsigned long size,
+				       struct stack_info *info);
+
+static inline int unwind_next_common(struct unwind_state *state,
+				     struct stack_info *info,
+				     on_accessible_stack_fn accessible,
+				     stack_trace_translate_fp_fn translate_fp)
+{
+	unsigned long fp = state->fp, kern_fp = fp;
+	struct task_struct *tsk = state->task;
+
+	if (fp & 0x7)
+		return -EINVAL;
+
+	if (!accessible(tsk, fp, 16, info))
+		return -EINVAL;
+
+	if (test_bit(info->type, state->stacks_done))
+		return -EINVAL;
+
+	/*
+	 * If fp is not from the current address space perform the necessary
+	 * translation before dereferencing it to get the next fp.
+	 */
+	if (translate_fp && !translate_fp(&kern_fp, info->type))
+		return -EINVAL;
+
+	/*
+	 * As stacks grow downward, any valid record on the same stack must be
+	 * at a strictly higher address than the prior record.
+	 *
+	 * Stacks can nest in several valid orders, e.g.
+	 *
+	 * TASK -> IRQ -> OVERFLOW -> SDEI_NORMAL
+	 * TASK -> SDEI_NORMAL -> SDEI_CRITICAL -> OVERFLOW
+	 * HYP -> OVERFLOW
+	 *
+	 * ... but the nesting itself is strict. Once we transition from one
+	 * stack to another, it's never valid to unwind back to that first
+	 * stack.
+	 */
+	if (info->type == state->prev_type) {
+		if (fp <= state->prev_fp)
+			return -EINVAL;
+	} else {
+		__set_bit(state->prev_type, state->stacks_done);
+	}
+
+	/*
+	 * Record this frame record's values and location. The prev_fp and
+	 * prev_type are only meaningful to the next unwind_next() invocation.
+	 */
+	state->fp = READ_ONCE(*(unsigned long *)(kern_fp));
+	state->pc = READ_ONCE(*(unsigned long *)(kern_fp + 8));
+	state->prev_fp = fp;
+	state->prev_type = info->type;
+
+	return 0;
+}
+
+#endif	/* __ASM_STACKTRACE_COMMON_H */

arch/arm64/include/asm/stacktrace/nvhe.h

+/* 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
+ */
+#ifndef __ASM_STACKTRACE_NVHE_H
+#define __ASM_STACKTRACE_NVHE_H
+
+#include <asm/stacktrace/common.h>
+
+/*
+ * 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;
+}
+
+#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).
+ */
+
+DECLARE_KVM_NVHE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack);
+DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_stacktrace_info, kvm_stacktrace_info);
+DECLARE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
+
+void kvm_nvhe_dump_backtrace(unsigned long hyp_offset);
+
+#endif	/* __KVM_NVHE_HYPERVISOR__ */
+#endif	/* __ASM_STACKTRACE_NVHE_H */

arch/arm64/kernel/Makefile

@@ -14,6 +14,11 @@ CFLAGS_REMOVE_return_address.o = $(CC_FLAGS_FTRACE)
 CFLAGS_REMOVE_syscall.o	 = -fstack-protector -fstack-protector-strong
 CFLAGS_syscall.o	+= -fno-stack-protector
 
+# When KASAN is enabled, a stack trace is recorded for every alloc/free, which
+# can significantly impact performance. Avoid instrumenting the stack trace
+# collection code to minimize this impact.
+KASAN_SANITIZE_stacktrace.o := n
+
 # It's not safe to invoke KCOV when portions of the kernel environment aren't
 # available or are out-of-sync with HW state. Since `noinstr` doesn't always
 # inhibit KCOV instrumentation, disable it for the entire compilation unit.

arch/arm64/kernel/stacktrace.c

@@ -7,72 +7,90 @@
 #include <linux/kernel.h>
 #include <linux/export.h>
 #include <linux/ftrace.h>
-#include <linux/kprobes.h>
 #include <linux/sched.h>
 #include <linux/sched/debug.h>
 #include <linux/sched/task_stack.h>
 #include <linux/stacktrace.h>
 
 #include <asm/irq.h>
-#include <asm/pointer_auth.h>
 #include <asm/stack_pointer.h>
 #include <asm/stacktrace.h>
 
 /*
- * A snapshot of a frame record or fp/lr register values, along with some
- * accounting information necessary for robust unwinding.
+ * Start an unwind from a pt_regs.
  *
- * @fp:          The fp value in the frame record (or the real fp)
- * @pc:          The lr value in the frame record (or the real lr)
+ * The unwind will begin at the PC within the regs.
  *
- * @stacks_done: Stacks which have been entirely unwound, for which it is no
- *               longer valid to unwind to.
+ * The regs must be on a stack currently owned by the calling task.
+ */
+static inline void unwind_init_from_regs(struct unwind_state *state,
+					 struct pt_regs *regs)
+{
+	unwind_init_common(state, current);
+
+	state->fp = regs->regs[29];
+	state->pc = regs->pc;
+}
+
+/*
+ * Start an unwind from a caller.
  *
- * @prev_fp:     The fp that pointed to this frame record, or a synthetic value
- *               of 0. This is used to ensure that within a stack, each
- *               subsequent frame record is at an increasing address.
- * @prev_type:   The type of stack this frame record was on, or a synthetic
- *               value of STACK_TYPE_UNKNOWN. This is used to detect a
- *               transition from one stack to another.
+ * The unwind will begin at the caller of whichever function this is inlined
+ * into.
  *
- * @kr_cur:      When KRETPROBES is selected, holds the kretprobe instance
- *               associated with the most recently encountered replacement lr
- *               value.
+ * The function which invokes this must be noinline.
  */
-struct unwind_state {
-	unsigned long fp;
-	unsigned long pc;
-	DECLARE_BITMAP(stacks_done, __NR_STACK_TYPES);
-	unsigned long prev_fp;
-	enum stack_type prev_type;
-#ifdef CONFIG_KRETPROBES
-	struct llist_node *kr_cur;
-#endif
-};
+static __always_inline void unwind_init_from_caller(struct unwind_state *state)
+{
+	unwind_init_common(state, current);
+
+	state->fp = (unsigned long)__builtin_frame_address(1);
+	state->pc = (unsigned long)__builtin_return_address(0);
+}
 
-static notrace void unwind_init(struct unwind_state *state, unsigned long fp,
-				unsigned long pc)
+/*
+ * Start an unwind from a blocked task.
+ *
+ * The unwind will begin at the blocked tasks saved PC (i.e. the caller of
+ * cpu_switch_to()).
+ *
+ * The caller should ensure the task is blocked in cpu_switch_to() for the
+ * duration of the unwind, or the unwind will be bogus. It is never valid to
+ * call this for the current task.
+ */
+static inline void unwind_init_from_task(struct unwind_state *state,
+					 struct task_struct *task)
 {
-	state->fp = fp;
-	state->pc = pc;
-#ifdef CONFIG_KRETPROBES
-	state->kr_cur = NULL;
-#endif
+	unwind_init_common(state, task);
+
+	state->fp = thread_saved_fp(task);
+	state->pc = thread_saved_pc(task);
+}
 
-	/*
-	 * Prime the first unwind.
-	 *
-	 * In unwind_next() we'll check that the FP points to a valid stack,
-	 * which can't be STACK_TYPE_UNKNOWN, and the first unwind will be
-	 * treated as a transition to whichever stack that happens to be. The
-	 * prev_fp value won't be used, but we set it to 0 such that it is
-	 * definitely not an accessible stack address.
-	 */
-	bitmap_zero(state->stacks_done, __NR_STACK_TYPES);
-	state->prev_fp = 0;
-	state->prev_type = STACK_TYPE_UNKNOWN;
+/*
+ * We can only safely access per-cpu stacks from current in a non-preemptible
+ * context.
+ */
+static bool on_accessible_stack(const struct task_struct *tsk,
+				unsigned long sp, unsigned long size,
+				struct stack_info *info)
+{
+	if (info)
+		info->type = STACK_TYPE_UNKNOWN;
+
+	if (on_task_stack(tsk, sp, size, info))
+		return true;
+	if (tsk != current || preemptible())
+		return false;
+	if (on_irq_stack(sp, size, info))
+		return true;
+	if (on_overflow_stack(sp, size, info))
+		return true;
+	if (on_sdei_stack(sp, size, info))
+		return true;
+
+	return false;
 }
-NOKPROBE_SYMBOL(unwind_init);
 
 /*
  * Unwind from one frame record (A) to the next frame record (B).
@@ -81,53 +99,20 @@ NOKPROBE_SYMBOL(unwind_init);
  * records (e.g. a cycle), determined based on the location and fp value of A
  * and the location (but not the fp value) of B.
  */
-static int notrace unwind_next(struct task_struct *tsk,
-			       struct unwind_state *state)
+static int notrace unwind_next(struct unwind_state *state)
 {
+	struct task_struct *tsk = state->task;
 	unsigned long fp = state->fp;
 	struct stack_info info;
+	int err;
 
 	/* Final frame; nothing to unwind */
 	if (fp == (unsigned long)task_pt_regs(tsk)->stackframe)
 		return -ENOENT;
 
-	if (fp & 0x7)
-		return -EINVAL;
-
-	if (!on_accessible_stack(tsk, fp, 16, &info))
-		return -EINVAL;
-
-	if (test_bit(info.type, state->stacks_done))
-		return -EINVAL;
-
-	/*
-	 * As stacks grow downward, any valid record on the same stack must be
-	 * at a strictly higher address than the prior record.
-	 *
-	 * Stacks can nest in several valid orders, e.g.
-	 *
-	 * TASK -> IRQ -> OVERFLOW -> SDEI_NORMAL
-	 * TASK -> SDEI_NORMAL -> SDEI_CRITICAL -> OVERFLOW
-	 *
-	 * ... but the nesting itself is strict. Once we transition from one
-	 * stack to another, it's never valid to unwind back to that first
-	 * stack.
-	 */
-	if (info.type == state->prev_type) {
-		if (fp <= state->prev_fp)
-			return -EINVAL;
-	} else {
-		set_bit(state->prev_type, state->stacks_done);
-	}
-
-	/*
-	 * Record this frame record's values and location. The prev_fp and
-	 * prev_type are only meaningful to the next unwind_next() invocation.
-	 */
-	state->fp = READ_ONCE_NOCHECK(*(unsigned long *)(fp));
-	state->pc = READ_ONCE_NOCHECK(*(unsigned long *)(fp + 8));
-	state->prev_fp = fp;
-	state->prev_type = info.type;
+	err = unwind_next_common(state, &info, on_accessible_stack, NULL);
+	if (err)
+		return err;
 
 	state->pc = ptrauth_strip_insn_pac(state->pc);
 
@@ -157,8 +142,7 @@ static int notrace unwind_next(struct task_struct *tsk,
 }
 NOKPROBE_SYMBOL(unwind_next);
 
-static void notrace unwind(struct task_struct *tsk,
-			   struct unwind_state *state,
+static void notrace unwind(struct unwind_state *state,
 			   stack_trace_consume_fn consume_entry, void *cookie)
 {
 	while (1) {
@@ -166,7 +150,7 @@ static void notrace unwind(struct task_struct *tsk,
 
 		if (!consume_entry(cookie, state->pc))
 			break;
-		ret = unwind_next(tsk, state);
+		ret = unwind_next(state);
 		if (ret < 0)
 			break;
 	}
@@ -212,15 +196,15 @@ noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry,
 {
 	struct unwind_state state;
 
-	if (regs)
-		unwind_init(&state, regs->regs[29], regs->pc);
-	else if (task == current)
-		unwind_init(&state,
-				(unsigned long)__builtin_frame_address(1),
-				(unsigned long)__builtin_return_address(0));
-	else
-		unwind_init(&state, thread_saved_fp(task),
-				thread_saved_pc(task));
-
-	unwind(task, &state, consume_entry, cookie);
+	if (regs) {
+		if (task != current)
+			return;
+		unwind_init_from_regs(&state, regs);
+	} else if (task == current) {
+		unwind_init_from_caller(&state);
+	} else {
+		unwind_init_from_task(&state, task);
+	}
+
+	unwind(&state, consume_entry, cookie);
 }

arch/arm64/kvm/Kconfig

@@ -56,4 +56,17 @@ config NVHE_EL2_DEBUG
 
 	  If unsure, say N.
 
+config PROTECTED_NVHE_STACKTRACE
+	bool "Protected KVM hypervisor stacktraces"
+	depends on NVHE_EL2_DEBUG
+	default n
+	help
+	  Say Y here to enable pKVM hypervisor stacktraces on hyp_panic()
+
+	  If using protected nVHE mode, but cannot afford the associated
+	  memory cost (less than 0.75 page per CPU) of pKVM stacktraces,
+	  say N.
+
+	  If unsure, or not using protected nVHE (pKVM), say N.
+
 endif # VIRTUALIZATION

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 \

arch/arm64/kvm/arch_timer.c

@@ -242,7 +242,7 @@ static bool kvm_timer_irq_can_fire(struct arch_timer_context *timer_ctx)
 static bool vcpu_has_wfit_active(struct kvm_vcpu *vcpu)
 {
 	return (cpus_have_final_cap(ARM64_HAS_WFXT) &&
-		(vcpu->arch.flags & KVM_ARM64_WFIT));
+		vcpu_get_flag(vcpu, IN_WFIT));
 }
 
 static u64 wfit_delay_ns(struct kvm_vcpu *vcpu)

arch/arm64/kvm/arm.c

@@ -49,7 +49,7 @@ DEFINE_STATIC_KEY_FALSE(kvm_protected_mode_initialized);
 
 DECLARE_KVM_HYP_PER_CPU(unsigned long, kvm_hyp_vector);
 
-static DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
+DEFINE_PER_CPU(unsigned long, kvm_arm_hyp_stack_page);
 unsigned long kvm_arm_hyp_percpu_base[NR_CPUS];
 DECLARE_KVM_NVHE_PER_CPU(struct kvm_nvhe_init_params, kvm_init_params);
 
@@ -330,6 +330,12 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 
 	vcpu->arch.mmu_page_cache.gfp_zero = __GFP_ZERO;
 
+	/*
+	 * Default value for the FP state, will be overloaded at load
+	 * time if we support FP (pretty likely)
+	 */
+	vcpu->arch.fp_state = FP_STATE_FREE;
+
 	/* Set up the timer */
 	kvm_timer_vcpu_init(vcpu);
 
@@ -659,7 +665,7 @@ void kvm_vcpu_wfi(struct kvm_vcpu *vcpu)
 	preempt_enable();
 
 	kvm_vcpu_halt(vcpu);
-	vcpu->arch.flags &= ~KVM_ARM64_WFIT;
+	vcpu_clear_flag(vcpu, IN_WFIT);
 	kvm_clear_request(KVM_REQ_UNHALT, vcpu);
 
 	preempt_disable();
@@ -1015,8 +1021,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
 	 * the vcpu state. Note that this relies on __kvm_adjust_pc()
 	 * being preempt-safe on VHE.
 	 */
-	if (unlikely(vcpu->arch.flags & (KVM_ARM64_PENDING_EXCEPTION |
-					 KVM_ARM64_INCREMENT_PC)))
+	if (unlikely(vcpu_get_flag(vcpu, PENDING_EXCEPTION) ||
+		     vcpu_get_flag(vcpu, INCREMENT_PC)))
 		kvm_call_hyp(__kvm_adjust_pc, vcpu);
 
 	vcpu_put(vcpu);
@@ -1414,18 +1420,11 @@ void kvm_arch_flush_remote_tlbs_memslot(struct kvm *kvm,
 static int kvm_vm_ioctl_set_device_addr(struct kvm *kvm,
 					struct kvm_arm_device_addr *dev_addr)
 {
-	unsigned long dev_id, type;
-
-	dev_id = (dev_addr->id & KVM_ARM_DEVICE_ID_MASK) >>
-		KVM_ARM_DEVICE_ID_SHIFT;
-	type = (dev_addr->id & KVM_ARM_DEVICE_TYPE_MASK) >>
-		KVM_ARM_DEVICE_TYPE_SHIFT;
-
-	switch (dev_id) {
+	switch (FIELD_GET(KVM_ARM_DEVICE_ID_MASK, dev_addr->id)) {
 	case KVM_ARM_DEVICE_VGIC_V2:
 		if (!vgic_present)
 			return -ENXIO;
-		return kvm_vgic_addr(kvm, type, &dev_addr->addr, true);
+		return kvm_set_legacy_vgic_v2_addr(kvm, dev_addr);
 	default:
 		return -ENODEV;
 	}

arch/arm64/kvm/debug.c

@@ -104,11 +104,11 @@ static void kvm_arm_setup_mdcr_el2(struct kvm_vcpu *vcpu)
 	 * Trap debug register access when one of the following is true:
 	 *  - Userspace is using the hardware to debug the guest
 	 *  (KVM_GUESTDBG_USE_HW is set).
-	 *  - The guest is not using debug (KVM_ARM64_DEBUG_DIRTY is clear).
+	 *  - The guest is not using debug (DEBUG_DIRTY clear).
 	 *  - The guest has enabled the OS Lock (debug exceptions are blocked).
 	 */
 	if ((vcpu->guest_debug & KVM_GUESTDBG_USE_HW) ||
-	    !(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY) ||
+	    !vcpu_get_flag(vcpu, DEBUG_DIRTY) ||
 	    kvm_vcpu_os_lock_enabled(vcpu))
 		vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA;
 
@@ -147,8 +147,8 @@ void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu)
  * debug related registers.
  *
  * Additionally, KVM only traps guest accesses to the debug registers if
- * the guest is not actively using them (see the KVM_ARM64_DEBUG_DIRTY
- * flag on vcpu->arch.flags).  Since the guest must not interfere
+ * the guest is not actively using them (see the DEBUG_DIRTY
+ * flag on vcpu->arch.iflags).  Since the guest must not interfere
  * with the hardware state when debugging the guest, we must ensure that
  * trapping is enabled whenever we are debugging the guest using the
  * debug registers.
@@ -205,9 +205,8 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
 		 *
 		 * We simply switch the debug_ptr to point to our new
 		 * external_debug_state which has been populated by the
-		 * debug ioctl. The existing KVM_ARM64_DEBUG_DIRTY
-		 * mechanism ensures the registers are updated on the
-		 * world switch.
+		 * debug ioctl. The existing DEBUG_DIRTY mechanism ensures
+		 * the registers are updated on the world switch.
 		 */
 		if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW) {
 			/* Enable breakpoints/watchpoints */
@@ -216,7 +215,7 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
 			vcpu_write_sys_reg(vcpu, mdscr, MDSCR_EL1);
 
 			vcpu->arch.debug_ptr = &vcpu->arch.external_debug_state;
-			vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;
+			vcpu_set_flag(vcpu, DEBUG_DIRTY);
 
 			trace_kvm_arm_set_regset("BKPTS", get_num_brps(),
 						&vcpu->arch.debug_ptr->dbg_bcr[0],
@@ -246,7 +245,7 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu)
 
 	/* If KDE or MDE are set, perform a full save/restore cycle. */
 	if (vcpu_read_sys_reg(vcpu, MDSCR_EL1) & (DBG_MDSCR_KDE | DBG_MDSCR_MDE))
-		vcpu->arch.flags |= KVM_ARM64_DEBUG_DIRTY;
+		vcpu_set_flag(vcpu, DEBUG_DIRTY);
 
 	/* Write mdcr_el2 changes since vcpu_load on VHE systems */
 	if (has_vhe() && orig_mdcr_el2 != vcpu->arch.mdcr_el2)
@@ -298,16 +297,16 @@ void kvm_arch_vcpu_load_debug_state_flags(struct kvm_vcpu *vcpu)
 	 */
 	if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_PMSVER_SHIFT) &&
 	    !(read_sysreg_s(SYS_PMBIDR_EL1) & BIT(SYS_PMBIDR_EL1_P_SHIFT)))
-		vcpu->arch.flags |= KVM_ARM64_DEBUG_STATE_SAVE_SPE;
+		vcpu_set_flag(vcpu, DEBUG_STATE_SAVE_SPE);
 
 	/* Check if we have TRBE implemented and available at the host */
 	if (cpuid_feature_extract_unsigned_field(dfr0, ID_AA64DFR0_TRBE_SHIFT) &&
 	    !(read_sysreg_s(SYS_TRBIDR_EL1) & TRBIDR_PROG))
-		vcpu->arch.flags |= KVM_ARM64_DEBUG_STATE_SAVE_TRBE;
+		vcpu_set_flag(vcpu, DEBUG_STATE_SAVE_TRBE);
 }
 
 void kvm_arch_vcpu_put_debug_state_flags(struct kvm_vcpu *vcpu)
 {
-	vcpu->arch.flags &= ~(KVM_ARM64_DEBUG_STATE_SAVE_SPE |
-			      KVM_ARM64_DEBUG_STATE_SAVE_TRBE);
+	vcpu_clear_flag(vcpu, DEBUG_STATE_SAVE_SPE);
+	vcpu_clear_flag(vcpu, DEBUG_STATE_SAVE_TRBE);
 }

arch/arm64/kvm/fpsimd.c

@@ -77,12 +77,14 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu)
 	BUG_ON(!current->mm);
 	BUG_ON(test_thread_flag(TIF_SVE));
 
-	vcpu->arch.flags &= ~KVM_ARM64_FP_ENABLED;
-	vcpu->arch.flags |= KVM_ARM64_FP_HOST;
+	if (!system_supports_fpsimd())
+		return;
+
+	vcpu->arch.fp_state = FP_STATE_HOST_OWNED;
 
-	vcpu->arch.flags &= ~KVM_ARM64_HOST_SVE_ENABLED;
+	vcpu_clear_flag(vcpu, HOST_SVE_ENABLED);
 	if (read_sysreg(cpacr_el1) & CPACR_EL1_ZEN_EL0EN)
-		vcpu->arch.flags |= KVM_ARM64_HOST_SVE_ENABLED;
+		vcpu_set_flag(vcpu, HOST_SVE_ENABLED);
 
 	/*
 	 * We don't currently support SME guests but if we leave
@@ -94,29 +96,28 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu)
 	 * operations. Do this for ZA as well for now for simplicity.
 	 */
 	if (system_supports_sme()) {
-		vcpu->arch.flags &= ~KVM_ARM64_HOST_SME_ENABLED;
+		vcpu_clear_flag(vcpu, HOST_SME_ENABLED);
 		if (read_sysreg(cpacr_el1) & CPACR_EL1_SMEN_EL0EN)
-			vcpu->arch.flags |= KVM_ARM64_HOST_SME_ENABLED;
+			vcpu_set_flag(vcpu, HOST_SME_ENABLED);
 
-		if (read_sysreg_s(SYS_SVCR) &
-		    (SVCR_SM_MASK | SVCR_ZA_MASK)) {
-			vcpu->arch.flags &= ~KVM_ARM64_FP_HOST;
+		if (read_sysreg_s(SYS_SVCR) & (SVCR_SM_MASK | SVCR_ZA_MASK)) {
+			vcpu->arch.fp_state = FP_STATE_FREE;
 			fpsimd_save_and_flush_cpu_state();
 		}
 	}
 }
 
 /*
- * Called just before entering the guest once we are no longer
- * preemptable. Syncs the host's TIF_FOREIGN_FPSTATE with the KVM
- * mirror of the flag used by the hypervisor.
+ * Called just before entering the guest once we are no longer preemptable
+ * and interrupts are disabled. If we have managed to run anything using
+ * FP while we were preemptible (such as off the back of an interrupt),
+ * then neither the host nor the guest own the FP hardware (and it was the
+ * responsibility of the code that used FP to save the existing state).
  */
 void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu)
 {
 	if (test_thread_flag(TIF_FOREIGN_FPSTATE))
-		vcpu->arch.flags |= KVM_ARM64_FP_FOREIGN_FPSTATE;
-	else
-		vcpu->arch.flags &= ~KVM_ARM64_FP_FOREIGN_FPSTATE;
+		vcpu->arch.fp_state = FP_STATE_FREE;
 }
 
 /*
@@ -130,7 +131,7 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu)
 {
 	WARN_ON_ONCE(!irqs_disabled());
 
-	if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) {
+	if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED) {
 		/*
 		 * Currently we do not support SME guests so SVCR is
 		 * always 0 and we just need a variable to point to.
@@ -163,7 +164,7 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu)
 	 */
 	if (has_vhe() && system_supports_sme()) {
 		/* Also restore EL0 state seen on entry */
-		if (vcpu->arch.flags & KVM_ARM64_HOST_SME_ENABLED)
+		if (vcpu_get_flag(vcpu, HOST_SME_ENABLED))
 			sysreg_clear_set(CPACR_EL1, 0,
 					 CPACR_EL1_SMEN_EL0EN |
 					 CPACR_EL1_SMEN_EL1EN);
@@ -173,7 +174,7 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu)
 					 CPACR_EL1_SMEN_EL1EN);
 	}
 
-	if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) {
+	if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED) {
 		if (vcpu_has_sve(vcpu)) {
 			__vcpu_sys_reg(vcpu, ZCR_EL1) = read_sysreg_el1(SYS_ZCR);
 
@@ -192,7 +193,7 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu)
 		 * for EL0.  To avoid spurious traps, restore the trap state
 		 * seen by kvm_arch_vcpu_load_fp():
 		 */
-		if (vcpu->arch.flags & KVM_ARM64_HOST_SVE_ENABLED)
+		if (vcpu_get_flag(vcpu, HOST_SVE_ENABLED))
 			sysreg_clear_set(CPACR_EL1, 0, CPACR_EL1_ZEN_EL0EN);
 		else
 			sysreg_clear_set(CPACR_EL1, CPACR_EL1_ZEN_EL0EN, 0);

arch/arm64/kvm/handle_exit.c

@@ -17,6 +17,7 @@
 #include <asm/kvm_emulate.h>
 #include <asm/kvm_mmu.h>
 #include <asm/debug-monitors.h>
+#include <asm/stacktrace/nvhe.h>
 #include <asm/traps.h>
 
 #include <kvm/arm_hypercalls.h>
@@ -120,7 +121,7 @@ static int kvm_handle_wfx(struct kvm_vcpu *vcpu)
 		kvm_vcpu_on_spin(vcpu, vcpu_mode_priv(vcpu));
 	} else {
 		if (esr & ESR_ELx_WFx_ISS_WFxT)
-			vcpu->arch.flags |= KVM_ARM64_WFIT;
+			vcpu_set_flag(vcpu, IN_WFIT);
 
 		kvm_vcpu_wfi(vcpu);
 	}
@@ -347,12 +348,15 @@ void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr,
 			kvm_err("nVHE hyp BUG at: %s:%u!\n", file, line);
 		else
 			kvm_err("nVHE hyp BUG at: [<%016llx>] %pB!\n", panic_addr,
-					(void *)panic_addr);
+					(void *)(panic_addr + kaslr_offset()));
 	} else {
 		kvm_err("nVHE hyp panic at: [<%016llx>] %pB!\n", panic_addr,
-				(void *)panic_addr);
+				(void *)(panic_addr + kaslr_offset()));
 	}
 
+	/* 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

arch/arm64/kvm/hyp/exception.c

@@ -303,14 +303,14 @@ static void enter_exception32(struct kvm_vcpu *vcpu, u32 mode, u32 vect_offset)
 static void kvm_inject_exception(struct kvm_vcpu *vcpu)
 {
 	if (vcpu_el1_is_32bit(vcpu)) {
-		switch (vcpu->arch.flags & KVM_ARM64_EXCEPT_MASK) {
-		case KVM_ARM64_EXCEPT_AA32_UND:
+		switch (vcpu_get_flag(vcpu, EXCEPT_MASK)) {
+		case unpack_vcpu_flag(EXCEPT_AA32_UND):
 			enter_exception32(vcpu, PSR_AA32_MODE_UND, 4);
 			break;
-		case KVM_ARM64_EXCEPT_AA32_IABT:
+		case unpack_vcpu_flag(EXCEPT_AA32_IABT):
 			enter_exception32(vcpu, PSR_AA32_MODE_ABT, 12);
 			break;
-		case KVM_ARM64_EXCEPT_AA32_DABT:
+		case unpack_vcpu_flag(EXCEPT_AA32_DABT):
 			enter_exception32(vcpu, PSR_AA32_MODE_ABT, 16);
 			break;
 		default:
@@ -318,9 +318,8 @@ static void kvm_inject_exception(struct kvm_vcpu *vcpu)
 			break;
 		}
 	} else {
-		switch (vcpu->arch.flags & KVM_ARM64_EXCEPT_MASK) {
-		case (KVM_ARM64_EXCEPT_AA64_ELx_SYNC |
-		      KVM_ARM64_EXCEPT_AA64_EL1):
+		switch (vcpu_get_flag(vcpu, EXCEPT_MASK)) {
+		case unpack_vcpu_flag(EXCEPT_AA64_EL1_SYNC):
 			enter_exception64(vcpu, PSR_MODE_EL1h, except_type_sync);
 			break;
 		default:
@@ -340,12 +339,12 @@ static void kvm_inject_exception(struct kvm_vcpu *vcpu)
  */
 void __kvm_adjust_pc(struct kvm_vcpu *vcpu)
 {
-	if (vcpu->arch.flags & KVM_ARM64_PENDING_EXCEPTION) {
+	if (vcpu_get_flag(vcpu, PENDING_EXCEPTION)) {
 		kvm_inject_exception(vcpu);
-		vcpu->arch.flags &= ~(KVM_ARM64_PENDING_EXCEPTION |
-				      KVM_ARM64_EXCEPT_MASK);
-	} else 	if (vcpu->arch.flags & KVM_ARM64_INCREMENT_PC) {
+		vcpu_clear_flag(vcpu, PENDING_EXCEPTION);
+		vcpu_clear_flag(vcpu, EXCEPT_MASK);
+	} else if (vcpu_get_flag(vcpu, INCREMENT_PC)) {
 		kvm_skip_instr(vcpu);
-		vcpu->arch.flags &= ~KVM_ARM64_INCREMENT_PC;
+		vcpu_clear_flag(vcpu, INCREMENT_PC);
 	}
 }

arch/arm64/kvm/hyp/include/hyp/debug-sr.h

@@ -132,7 +132,7 @@ static inline void __debug_switch_to_guest_common(struct kvm_vcpu *vcpu)
 	struct kvm_guest_debug_arch *host_dbg;
 	struct kvm_guest_debug_arch *guest_dbg;
 
-	if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
+	if (!vcpu_get_flag(vcpu, DEBUG_DIRTY))
 		return;
 
 	host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
@@ -151,7 +151,7 @@ static inline void __debug_switch_to_host_common(struct kvm_vcpu *vcpu)
 	struct kvm_guest_debug_arch *host_dbg;
 	struct kvm_guest_debug_arch *guest_dbg;
 
-	if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
+	if (!vcpu_get_flag(vcpu, DEBUG_DIRTY))
 		return;
 
 	host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
@@ -162,7 +162,7 @@ static inline void __debug_switch_to_host_common(struct kvm_vcpu *vcpu)
 	__debug_save_state(guest_dbg, guest_ctxt);
 	__debug_restore_state(host_dbg, host_ctxt);
 
-	vcpu->arch.flags &= ~KVM_ARM64_DEBUG_DIRTY;
+	vcpu_clear_flag(vcpu, DEBUG_DIRTY);
 }
 
 #endif /* __ARM64_KVM_HYP_DEBUG_SR_H__ */

arch/arm64/kvm/hyp/include/hyp/switch.h

@@ -37,22 +37,10 @@ struct kvm_exception_table_entry {
 extern struct kvm_exception_table_entry __start___kvm_ex_table;
 extern struct kvm_exception_table_entry __stop___kvm_ex_table;
 
-/* Check whether the FP regs were dirtied while in the host-side run loop: */
-static inline bool update_fp_enabled(struct kvm_vcpu *vcpu)
+/* Check whether the FP regs are owned by the guest */
+static inline bool guest_owns_fp_regs(struct kvm_vcpu *vcpu)
 {
-	/*
-	 * When the system doesn't support FP/SIMD, we cannot rely on
-	 * the _TIF_FOREIGN_FPSTATE flag. However, we always inject an
-	 * abort on the very first access to FP and thus we should never
-	 * see KVM_ARM64_FP_ENABLED. For added safety, make sure we always
-	 * trap the accesses.
-	 */
-	if (!system_supports_fpsimd() ||
-	    vcpu->arch.flags & KVM_ARM64_FP_FOREIGN_FPSTATE)
-		vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED |
-				      KVM_ARM64_FP_HOST);
-
-	return !!(vcpu->arch.flags & KVM_ARM64_FP_ENABLED);
+	return vcpu->arch.fp_state == FP_STATE_GUEST_OWNED;
 }
 
 /* Save the 32-bit only FPSIMD system register state */
@@ -191,10 +179,8 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
 	isb();
 
 	/* Write out the host state if it's in the registers */
-	if (vcpu->arch.flags & KVM_ARM64_FP_HOST) {
+	if (vcpu->arch.fp_state == FP_STATE_HOST_OWNED)
 		__fpsimd_save_state(vcpu->arch.host_fpsimd_state);
-		vcpu->arch.flags &= ~KVM_ARM64_FP_HOST;
-	}
 
 	/* Restore the guest state */
 	if (sve_guest)
@@ -206,7 +192,7 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
 	if (!(read_sysreg(hcr_el2) & HCR_RW))
 		write_sysreg(__vcpu_sys_reg(vcpu, FPEXC32_EL2), fpexc32_el2);
 
-	vcpu->arch.flags |= KVM_ARM64_FP_ENABLED;
+	vcpu->arch.fp_state = FP_STATE_GUEST_OWNED;
 
 	return true;
 }

arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h

@@ -195,7 +195,7 @@ static inline void __sysreg32_save_state(struct kvm_vcpu *vcpu)
 	__vcpu_sys_reg(vcpu, DACR32_EL2) = read_sysreg(dacr32_el2);
 	__vcpu_sys_reg(vcpu, IFSR32_EL2) = read_sysreg(ifsr32_el2);
 
-	if (has_vhe() || vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)
+	if (has_vhe() || vcpu_get_flag(vcpu, DEBUG_DIRTY))
 		__vcpu_sys_reg(vcpu, DBGVCR32_EL2) = read_sysreg(dbgvcr32_el2);
 }
 
@@ -212,7 +212,7 @@ static inline void __sysreg32_restore_state(struct kvm_vcpu *vcpu)
 	write_sysreg(__vcpu_sys_reg(vcpu, DACR32_EL2), dacr32_el2);
 	write_sysreg(__vcpu_sys_reg(vcpu, IFSR32_EL2), ifsr32_el2);
 
-	if (has_vhe() || vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY)
+	if (has_vhe() || vcpu_get_flag(vcpu, DEBUG_DIRTY))
 		write_sysreg(__vcpu_sys_reg(vcpu, DBGVCR32_EL2), dbgvcr32_el2);
 }
 

arch/arm64/kvm/hyp/nvhe/Makefile

@@ -12,13 +12,13 @@ HOST_EXTRACFLAGS += -I$(objtree)/include
 lib-objs := clear_page.o copy_page.o memcpy.o memset.o
 lib-objs := $(addprefix ../../../lib/, $(lib-objs))
 
-obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o \
+hyp-obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o \
 	 hyp-main.o hyp-smp.o psci-relay.o early_alloc.o page_alloc.o \
-	 cache.o setup.o mm.o mem_protect.o sys_regs.o pkvm.o
-obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
+	 cache.o setup.o mm.o mem_protect.o sys_regs.o pkvm.o stacktrace.o
+hyp-obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \
 	 ../fpsimd.o ../hyp-entry.o ../exception.o ../pgtable.o
-obj-$(CONFIG_DEBUG_LIST) += list_debug.o
-obj-y += $(lib-objs)
+hyp-obj-$(CONFIG_DEBUG_LIST) += list_debug.o
+hyp-obj-y += $(lib-objs)
 
 ##
 ## Build rules for compiling nVHE hyp code
@@ -26,9 +26,9 @@ obj-y += $(lib-objs)
 ## file containing all nVHE hyp code and data.
 ##
 
-hyp-obj := $(patsubst %.o,%.nvhe.o,$(obj-y))
+hyp-obj := $(patsubst %.o,%.nvhe.o,$(hyp-obj-y))
 obj-y := kvm_nvhe.o
-extra-y := $(hyp-obj) kvm_nvhe.tmp.o kvm_nvhe.rel.o hyp.lds hyp-reloc.S hyp-reloc.o
+targets += $(hyp-obj) kvm_nvhe.tmp.o kvm_nvhe.rel.o hyp.lds hyp-reloc.S hyp-reloc.o
 
 # 1) Compile all source files to `.nvhe.o` object files. The file extension
 #    avoids file name clashes for files shared with VHE.

arch/arm64/kvm/hyp/nvhe/debug-sr.c

@@ -84,10 +84,10 @@ static void __debug_restore_trace(u64 trfcr_el1)
 void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu)
 {
 	/* Disable and flush SPE data generation */
-	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_SPE)
+	if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE))
 		__debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1);
 	/* Disable and flush Self-Hosted Trace generation */
-	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_TRBE)
+	if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE))
 		__debug_save_trace(&vcpu->arch.host_debug_state.trfcr_el1);
 }
 
@@ -98,9 +98,9 @@ void __debug_switch_to_guest(struct kvm_vcpu *vcpu)
 
 void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu)
 {
-	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_SPE)
+	if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE))
 		__debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1);
-	if (vcpu->arch.flags & KVM_ARM64_DEBUG_STATE_SAVE_TRBE)
+	if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE))
 		__debug_restore_trace(vcpu->arch.host_debug_state.trfcr_el1);
 }
 

arch/arm64/kvm/hyp/nvhe/host.S

@@ -177,13 +177,8 @@ SYM_FUNC_END(__host_hvc)
 	b	hyp_panic
 
 .L__hyp_sp_overflow\@:
-	/*
-	 * Reset SP to the top of the stack, to allow handling the hyp_panic.
-	 * This corrupts the stack but is ok, since we won't be attempting
-	 * any unwinding here.
-	 */
-	ldr_this_cpu	x0, kvm_init_params + NVHE_INIT_STACK_HYP_VA, x1
-	mov	sp, x0
+	/* Switch to the overflow stack */
+	adr_this_cpu sp, overflow_stack + OVERFLOW_STACK_SIZE, x0
 
 	b	hyp_panic_bad_stack
 	ASM_BUG()

arch/arm64/kvm/hyp/nvhe/stacktrace.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * KVM nVHE hypervisor stack tracing support.
+ *
+ * Copyright (C) 2022 Google LLC
+ */
+#include <asm/kvm_asm.h>
+#include <asm/kvm_hyp.h>
+#include <asm/memory.h>
+#include <asm/percpu.h>
+
+DEFINE_PER_CPU(unsigned long [OVERFLOW_STACK_SIZE/sizeof(long)], overflow_stack)
+	__aligned(16);
+
+DEFINE_PER_CPU(struct kvm_nvhe_stacktrace_info, kvm_stacktrace_info);
+
+/*
+ * hyp_prepare_backtrace - Prepare non-protected nVHE backtrace.
+ *
+ * @fp : frame pointer at which to start the unwinding.
+ * @pc : program counter at which to start the unwinding.
+ *
+ * Save the information needed by the host to unwind the non-protected
+ * nVHE hypervisor stack in EL1.
+ */
+static void hyp_prepare_backtrace(unsigned long fp, unsigned long pc)
+{
+	struct kvm_nvhe_stacktrace_info *stacktrace_info = this_cpu_ptr(&kvm_stacktrace_info);
+	struct kvm_nvhe_init_params *params = this_cpu_ptr(&kvm_init_params);
+
+	stacktrace_info->stack_base = (unsigned long)(params->stack_hyp_va - PAGE_SIZE);
+	stacktrace_info->overflow_stack_base = (unsigned long)this_cpu_ptr(overflow_stack);
+	stacktrace_info->fp = fp;
+	stacktrace_info->pc = pc;
+}
+
+#ifdef CONFIG_PROTECTED_NVHE_STACKTRACE
+#include <asm/stacktrace/nvhe.h>
+
+DEFINE_PER_CPU(unsigned long [NVHE_STACKTRACE_SIZE/sizeof(long)], pkvm_stacktrace);
+
+static bool on_overflow_stack(unsigned long sp, unsigned long size,
+			      struct stack_info *info)
+{
+	unsigned long low = (unsigned long)this_cpu_ptr(overflow_stack);
+	unsigned long high = low + OVERFLOW_STACK_SIZE;
+
+	return on_stack(sp, size, low, high, STACK_TYPE_OVERFLOW, info);
+}
+
+static bool on_hyp_stack(unsigned long sp, unsigned long size,
+			      struct stack_info *info)
+{
+	struct kvm_nvhe_init_params *params = this_cpu_ptr(&kvm_init_params);
+	unsigned long high = params->stack_hyp_va;
+	unsigned long low = high - PAGE_SIZE;
+
+	return on_stack(sp, size, low, high, STACK_TYPE_HYP, info);
+}
+
+static bool on_accessible_stack(const struct task_struct *tsk,
+				unsigned long sp, unsigned long size,
+				struct stack_info *info)
+{
+	if (info)
+		info->type = STACK_TYPE_UNKNOWN;
+
+	return (on_overflow_stack(sp, size, info) ||
+		on_hyp_stack(sp, size, info));
+}
+
+static int unwind_next(struct unwind_state *state)
+{
+	struct stack_info info;
+
+	return unwind_next_common(state, &info, on_accessible_stack, NULL);
+}
+
+static void notrace unwind(struct unwind_state *state,
+			   stack_trace_consume_fn consume_entry,
+			   void *cookie)
+{
+	while (1) {
+		int ret;
+
+		if (!consume_entry(cookie, state->pc))
+			break;
+		ret = unwind_next(state);
+		if (ret < 0)
+			break;
+	}
+}
+
+/*
+ * pkvm_save_backtrace_entry - Saves a protected nVHE HYP stacktrace entry
+ *
+ * @arg    : index of the entry in the stacktrace buffer
+ * @where  : the program counter corresponding to the stack frame
+ *
+ * Save the return address of a stack frame to the shared stacktrace buffer.
+ * The host can access this shared buffer from EL1 to dump the backtrace.
+ */
+static bool pkvm_save_backtrace_entry(void *arg, unsigned long where)
+{
+	unsigned long *stacktrace = this_cpu_ptr(pkvm_stacktrace);
+	int *idx = (int *)arg;
+
+	/*
+	 * Need 2 free slots: 1 for current entry and 1 for the
+	 * delimiter.
+	 */
+	if (*idx > ARRAY_SIZE(pkvm_stacktrace) - 2)
+		return false;
+
+	stacktrace[*idx] = where;
+	stacktrace[++*idx] = 0UL;
+
+	return true;
+}
+
+/*
+ * pkvm_save_backtrace - Saves the protected nVHE HYP stacktrace
+ *
+ * @fp : frame pointer at which to start the unwinding.
+ * @pc : program counter at which to start the unwinding.
+ *
+ * Save the unwinded stack addresses to the shared stacktrace buffer.
+ * The host can access this shared buffer from EL1 to dump the backtrace.
+ */
+static void pkvm_save_backtrace(unsigned long fp, unsigned long pc)
+{
+	struct unwind_state state;
+	int idx = 0;
+
+	kvm_nvhe_unwind_init(&state, fp, pc);
+
+	unwind(&state, pkvm_save_backtrace_entry, &idx);
+}
+#else /* !CONFIG_PROTECTED_NVHE_STACKTRACE */
+static void pkvm_save_backtrace(unsigned long fp, unsigned long pc)
+{
+}
+#endif /* CONFIG_PROTECTED_NVHE_STACKTRACE */
+
+/*
+ * kvm_nvhe_prepare_backtrace - prepare to dump the nVHE backtrace
+ *
+ * @fp : frame pointer at which to start the unwinding.
+ * @pc : program counter at which to start the unwinding.
+ *
+ * Saves the information needed by the host to dump the nVHE hypervisor
+ * backtrace.
+ */
+void kvm_nvhe_prepare_backtrace(unsigned long fp, unsigned long pc)
+{
+	if (is_protected_kvm_enabled())
+		pkvm_save_backtrace(fp, pc);
+	else
+		hyp_prepare_backtrace(fp, pc);
+}

arch/arm64/kvm/hyp/nvhe/switch.c

@@ -34,6 +34,8 @@ DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data);
 DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);
 DEFINE_PER_CPU(unsigned long, kvm_hyp_vector);
 
+extern void kvm_nvhe_prepare_backtrace(unsigned long fp, unsigned long pc);
+
 static void __activate_traps(struct kvm_vcpu *vcpu)
 {
 	u64 val;
@@ -43,7 +45,7 @@ static void __activate_traps(struct kvm_vcpu *vcpu)
 
 	val = vcpu->arch.cptr_el2;
 	val |= CPTR_EL2_TTA | CPTR_EL2_TAM;
-	if (!update_fp_enabled(vcpu)) {
+	if (!guest_owns_fp_regs(vcpu)) {
 		val |= CPTR_EL2_TFP | CPTR_EL2_TZ;
 		__activate_traps_fpsimd32(vcpu);
 	}
@@ -123,7 +125,7 @@ static void __deactivate_traps(struct kvm_vcpu *vcpu)
 	}
 
 	cptr = CPTR_EL2_DEFAULT;
-	if (vcpu_has_sve(vcpu) && (vcpu->arch.flags & KVM_ARM64_FP_ENABLED))
+	if (vcpu_has_sve(vcpu) && (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED))
 		cptr |= CPTR_EL2_TZ;
 	if (cpus_have_final_cap(ARM64_SME))
 		cptr &= ~CPTR_EL2_TSM;
@@ -335,7 +337,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
 
 	__sysreg_restore_state_nvhe(host_ctxt);
 
-	if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED)
+	if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED)
 		__fpsimd_save_fpexc32(vcpu);
 
 	__debug_switch_to_host(vcpu);
@@ -375,6 +377,10 @@ asmlinkage void __noreturn hyp_panic(void)
 		__sysreg_restore_state_nvhe(host_ctxt);
 	}
 
+	/* Prepare to dump kvm nvhe hyp stacktrace */
+	kvm_nvhe_prepare_backtrace((unsigned long)__builtin_frame_address(0),
+				   _THIS_IP_);
+
 	__hyp_do_panic(host_ctxt, spsr, elr, par);
 	unreachable();
 }
@@ -386,5 +392,5 @@ asmlinkage void __noreturn hyp_panic_bad_stack(void)
 
 asmlinkage void kvm_unexpected_el2_exception(void)
 {
-	return __kvm_unexpected_el2_exception();
+	__kvm_unexpected_el2_exception();
 }

arch/arm64/kvm/hyp/nvhe/sys_regs.c

@@ -38,9 +38,7 @@ static void inject_undef64(struct kvm_vcpu *vcpu)
 	*vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR);
 	*vcpu_cpsr(vcpu) = read_sysreg_el2(SYS_SPSR);
 
-	vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_EL1 |
-			     KVM_ARM64_EXCEPT_AA64_ELx_SYNC |
-			     KVM_ARM64_PENDING_EXCEPTION);
+	kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
 
 	__kvm_adjust_pc(vcpu);
 

arch/arm64/kvm/hyp/vhe/switch.c

@@ -55,7 +55,7 @@ static void __activate_traps(struct kvm_vcpu *vcpu)
 
 	val |= CPTR_EL2_TAM;
 
-	if (update_fp_enabled(vcpu)) {
+	if (guest_owns_fp_regs(vcpu)) {
 		if (vcpu_has_sve(vcpu))
 			val |= CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN;
 	} else {
@@ -175,7 +175,7 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
 
 	sysreg_restore_host_state_vhe(host_ctxt);
 
-	if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED)
+	if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED)
 		__fpsimd_save_fpexc32(vcpu);
 
 	__debug_switch_to_host(vcpu);
@@ -249,5 +249,5 @@ void __noreturn hyp_panic(void)
 
 asmlinkage void kvm_unexpected_el2_exception(void)
 {
-	return __kvm_unexpected_el2_exception();
+	__kvm_unexpected_el2_exception();
 }

arch/arm64/kvm/hyp/vhe/sysreg-sr.c

@@ -79,7 +79,7 @@ void kvm_vcpu_load_sysregs_vhe(struct kvm_vcpu *vcpu)
 	__sysreg_restore_user_state(guest_ctxt);
 	__sysreg_restore_el1_state(guest_ctxt);
 
-	vcpu->arch.sysregs_loaded_on_cpu = true;
+	vcpu_set_flag(vcpu, SYSREGS_ON_CPU);
 
 	activate_traps_vhe_load(vcpu);
 }
@@ -110,5 +110,5 @@ void kvm_vcpu_put_sysregs_vhe(struct kvm_vcpu *vcpu)
 	/* Restore host user state */
 	__sysreg_restore_user_state(host_ctxt);
 
-	vcpu->arch.sysregs_loaded_on_cpu = false;
+	vcpu_clear_flag(vcpu, SYSREGS_ON_CPU);
 }

arch/arm64/kvm/inject_fault.c

@@ -20,9 +20,7 @@ static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr
 	bool is_aarch32 = vcpu_mode_is_32bit(vcpu);
 	u64 esr = 0;
 
-	vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_EL1		|
-			     KVM_ARM64_EXCEPT_AA64_ELx_SYNC	|
-			     KVM_ARM64_PENDING_EXCEPTION);
+	kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
 
 	vcpu_write_sys_reg(vcpu, addr, FAR_EL1);
 
@@ -52,9 +50,7 @@ static void inject_undef64(struct kvm_vcpu *vcpu)
 {
 	u64 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT);
 
-	vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_EL1		|
-			     KVM_ARM64_EXCEPT_AA64_ELx_SYNC	|
-			     KVM_ARM64_PENDING_EXCEPTION);
+	kvm_pend_exception(vcpu, EXCEPT_AA64_EL1_SYNC);
 
 	/*
 	 * Build an unknown exception, depending on the instruction
@@ -73,8 +69,7 @@ static void inject_undef64(struct kvm_vcpu *vcpu)
 
 static void inject_undef32(struct kvm_vcpu *vcpu)
 {
-	vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA32_UND |
-			     KVM_ARM64_PENDING_EXCEPTION);
+	kvm_pend_exception(vcpu, EXCEPT_AA32_UND);
 }
 
 /*
@@ -97,14 +92,12 @@ static void inject_abt32(struct kvm_vcpu *vcpu, bool is_pabt, u32 addr)
 	far = vcpu_read_sys_reg(vcpu, FAR_EL1);
 
 	if (is_pabt) {
-		vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA32_IABT |
-				     KVM_ARM64_PENDING_EXCEPTION);
+		kvm_pend_exception(vcpu, EXCEPT_AA32_IABT);
 		far &= GENMASK(31, 0);
 		far |= (u64)addr << 32;
 		vcpu_write_sys_reg(vcpu, fsr, IFSR32_EL2);
 	} else { /* !iabt */
-		vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA32_DABT |
-				     KVM_ARM64_PENDING_EXCEPTION);
+		kvm_pend_exception(vcpu, EXCEPT_AA32_DABT);
 		far &= GENMASK(63, 32);
 		far |= addr;
 		vcpu_write_sys_reg(vcpu, fsr, ESR_EL1);

arch/arm64/kvm/reset.c

@@ -81,7 +81,7 @@ static int kvm_vcpu_enable_sve(struct kvm_vcpu *vcpu)
 	 * KVM_REG_ARM64_SVE_VLS.  Allocation is deferred until
 	 * kvm_arm_vcpu_finalize(), which freezes the configuration.
 	 */
-	vcpu->arch.flags |= KVM_ARM64_GUEST_HAS_SVE;
+	vcpu_set_flag(vcpu, GUEST_HAS_SVE);
 
 	return 0;
 }
@@ -120,7 +120,7 @@ static int kvm_vcpu_finalize_sve(struct kvm_vcpu *vcpu)
 	}
 	
 	vcpu->arch.sve_state = buf;
-	vcpu->arch.flags |= KVM_ARM64_VCPU_SVE_FINALIZED;
+	vcpu_set_flag(vcpu, VCPU_SVE_FINALIZED);
 	return 0;
 }
 
@@ -177,7 +177,7 @@ static int kvm_vcpu_enable_ptrauth(struct kvm_vcpu *vcpu)
 	    !system_has_full_ptr_auth())
 		return -EINVAL;
 
-	vcpu->arch.flags |= KVM_ARM64_GUEST_HAS_PTRAUTH;
+	vcpu_set_flag(vcpu, GUEST_HAS_PTRAUTH);
 	return 0;
 }
 

arch/arm64/kvm/stacktrace.c

+/* 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_stack_kern_va - Convert KVM nVHE HYP stack addresses to a kernel VAs
+ *
+ * The nVHE hypervisor stack is mapped in the flexible 'private' VA range, to
+ * allow for guard pages below the stack. Consequently, the fixed offset address
+ * translation macros won't work here.
+ *
+ * The kernel VA is calculated as an offset from the kernel VA of the hypervisor
+ * stack base.
+ *
+ * Returns true on success and updates @addr to its corresponding kernel VA;
+ * otherwise returns false.
+ */
+static bool kvm_nvhe_stack_kern_va(unsigned long *addr,
+				   enum stack_type type)
+{
+	struct kvm_nvhe_stacktrace_info *stacktrace_info;
+	unsigned long hyp_base, kern_base, hyp_offset;
+
+	stacktrace_info = this_cpu_ptr_nvhe_sym(kvm_stacktrace_info);
+
+	switch (type) {
+	case STACK_TYPE_HYP:
+		kern_base = (unsigned long)*this_cpu_ptr(&kvm_arm_hyp_stack_page);
+		hyp_base = (unsigned long)stacktrace_info->stack_base;
+		break;
+	case STACK_TYPE_OVERFLOW:
+		kern_base = (unsigned long)this_cpu_ptr_nvhe_sym(overflow_stack);
+		hyp_base = (unsigned long)stacktrace_info->overflow_stack_base;
+		break;
+	default:
+		return false;
+	}
+
+	hyp_offset = *addr - hyp_base;
+
+	*addr = kern_base + hyp_offset;
+
+	return true;
+}
+
+static bool on_overflow_stack(unsigned long sp, unsigned long size,
+			      struct stack_info *info)
+{
+	struct kvm_nvhe_stacktrace_info *stacktrace_info
+				= this_cpu_ptr_nvhe_sym(kvm_stacktrace_info);
+	unsigned long low = (unsigned long)stacktrace_info->overflow_stack_base;
+	unsigned long high = low + OVERFLOW_STACK_SIZE;
+
+	return on_stack(sp, size, low, high, STACK_TYPE_OVERFLOW, info);
+}
+
+static bool on_hyp_stack(unsigned long sp, unsigned long size,
+			 struct stack_info *info)
+{
+	struct kvm_nvhe_stacktrace_info *stacktrace_info
+				= this_cpu_ptr_nvhe_sym(kvm_stacktrace_info);
+	unsigned long low = (unsigned long)stacktrace_info->stack_base;
+	unsigned long high = low + PAGE_SIZE;
+
+	return on_stack(sp, size, low, high, STACK_TYPE_HYP, info);
+}
+
+static bool on_accessible_stack(const struct task_struct *tsk,
+				unsigned long sp, unsigned long size,
+				struct stack_info *info)
+{
+	if (info)
+		info->type = STACK_TYPE_UNKNOWN;
+
+	return (on_overflow_stack(sp, size, info) ||
+		on_hyp_stack(sp, size, info));
+}
+
+static int unwind_next(struct unwind_state *state)
+{
+	struct stack_info info;
+
+	return unwind_next_common(state, &info, on_accessible_stack,
+				  kvm_nvhe_stack_kern_va);
+}
+
+static void unwind(struct unwind_state *state,
+		   stack_trace_consume_fn consume_entry, void *cookie)
+{
+	while (1) {
+		int ret;
+
+		if (!consume_entry(cookie, state->pc))
+			break;
+		ret = unwind_next(state);
+		if (ret < 0)
+			break;
+	}
+}
+
+/*
+ * 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;
+
+	kvm_nvhe_dump_backtrace_start();
+	/* The saved stacktrace is terminated by a null entry */
+	for (i = 0;
+	     i < ARRAY_SIZE(kvm_nvhe_sym(pkvm_stacktrace)) && 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);
+}

arch/arm64/kvm/sys_regs.h

@@ -75,9 +75,9 @@ struct sys_reg_desc {
 
 	/* Custom get/set_user functions, fallback to generic if NULL */
 	int (*get_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-			const struct kvm_one_reg *reg, void __user *uaddr);
+			u64 *val);
 	int (*set_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
-			const struct kvm_one_reg *reg, void __user *uaddr);
+			u64 val);
 
 	/* Return mask of REG_* runtime visibility overrides */
 	unsigned int (*visibility)(const struct kvm_vcpu *vcpu,
@@ -190,10 +190,16 @@ find_reg(const struct sys_reg_params *params, const struct sys_reg_desc table[],
 	return __inline_bsearch((void *)pval, table, num, sizeof(table[0]), match_sys_reg);
 }
 
-const struct sys_reg_desc *find_reg_by_id(u64 id,
-					  struct sys_reg_params *params,
-					  const struct sys_reg_desc table[],
-					  unsigned int num);
+const struct sys_reg_desc *get_reg_by_id(u64 id,
+					 const struct sys_reg_desc table[],
+					 unsigned int num);
+
+int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *);
+int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *);
+int kvm_sys_reg_get_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg,
+			 const struct sys_reg_desc table[], unsigned int num);
+int kvm_sys_reg_set_user(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg,
+			 const struct sys_reg_desc table[], unsigned int num);
 
 #define AA32(_x)	.aarch32_map = AA32_##_x
 #define Op0(_x) 	.Op0 = _x

arch/arm64/kvm/vgic/vgic-mmio-v3.c

@@ -986,12 +986,8 @@ int vgic_v3_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr)
 		iodev.base_addr = 0;
 		break;
 	}
-	case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS: {
-		u64 reg, id;
-
-		id = (attr->attr & KVM_DEV_ARM_VGIC_SYSREG_INSTR_MASK);
-		return vgic_v3_has_cpu_sysregs_attr(vcpu, 0, id, &reg);
-	}
+	case KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS:
+		return vgic_v3_has_cpu_sysregs_attr(vcpu, attr);
 	default:
 		return -ENXIO;
 	}
@@ -1158,7 +1154,7 @@ int vgic_v3_redist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
 }
 
 int vgic_v3_line_level_info_uaccess(struct kvm_vcpu *vcpu, bool is_write,
-				    u32 intid, u64 *val)
+				    u32 intid, u32 *val)
 {
 	if (intid % 32)
 		return -EINVAL;

arch/arm64/kvm/vgic/vgic-mmio.c

@@ -775,10 +775,10 @@ void vgic_mmio_write_config(struct kvm_vcpu *vcpu,
 	}
 }
 
-u64 vgic_read_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid)
+u32 vgic_read_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid)
 {
 	int i;
-	u64 val = 0;
+	u32 val = 0;
 	int nr_irqs = vcpu->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
 
 	for (i = 0; i < 32; i++) {
@@ -798,7 +798,7 @@ u64 vgic_read_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid)
 }
 
 void vgic_write_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid,
-				    const u64 val)
+				    const u32 val)
 {
 	int i;
 	int nr_irqs = vcpu->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;

arch/arm64/kvm/vgic/vgic-mmio.h

@@ -207,10 +207,10 @@ void vgic_mmio_write_config(struct kvm_vcpu *vcpu,
 int vgic_uaccess(struct kvm_vcpu *vcpu, struct vgic_io_device *dev,
 		 bool is_write, int offset, u32 *val);
 
-u64 vgic_read_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid);
+u32 vgic_read_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid);
 
 void vgic_write_irq_line_level_info(struct kvm_vcpu *vcpu, u32 intid,
-				    const u64 val);
+				    const u32 val);
 
 unsigned int vgic_v2_init_dist_iodev(struct vgic_io_device *dev);
 

arch/arm64/kvm/vgic/vgic.h

@@ -245,12 +245,11 @@ int vgic_v3_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
 			 int offset, u32 *val);
 int vgic_v3_redist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
 			 int offset, u32 *val);
-int vgic_v3_cpu_sysregs_uaccess(struct kvm_vcpu *vcpu, bool is_write,
-			 u64 id, u64 *val);
-int vgic_v3_has_cpu_sysregs_attr(struct kvm_vcpu *vcpu, bool is_write, u64 id,
-				u64 *reg);
+int vgic_v3_cpu_sysregs_uaccess(struct kvm_vcpu *vcpu,
+				struct kvm_device_attr *attr, bool is_write);
+int vgic_v3_has_cpu_sysregs_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr);
 int vgic_v3_line_level_info_uaccess(struct kvm_vcpu *vcpu, bool is_write,
-				    u32 intid, u64 *val);
+				    u32 intid, u32 *val);
 int kvm_register_vgic_device(unsigned long type);
 void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);
 void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr);

include/kvm/arm_vgic.h

@@ -364,7 +364,7 @@ struct vgic_cpu {
 extern struct static_key_false vgic_v2_cpuif_trap;
 extern struct static_key_false vgic_v3_cpuif_trap;
 
-int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr, bool write);
+int kvm_set_legacy_vgic_v2_addr(struct kvm *kvm, struct kvm_arm_device_addr *dev_addr);
 void kvm_vgic_early_init(struct kvm *kvm);
 int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu);
 int kvm_vgic_create(struct kvm *kvm, u32 type);

tools/testing/selftests/kvm/aarch64/vgic_init.c

@@ -663,7 +663,7 @@ int test_kvm_device(uint32_t gic_dev_type)
 
 	if (!__kvm_test_create_device(v.vm, other)) {
 		ret = __kvm_test_create_device(v.vm, other);
-		TEST_ASSERT(ret && errno == EINVAL,
+		TEST_ASSERT(ret && (errno == EINVAL || errno == EEXIST),
 				"create GIC device while other version exists");
 	}
 
@@ -691,6 +691,7 @@ int main(int ac, char **av)
 {
 	int ret;
 	int pa_bits;
+	int cnt_impl = 0;
 
 	pa_bits = vm_guest_mode_params[VM_MODE_DEFAULT].pa_bits;
 	max_phys_size = 1ULL << pa_bits;
@@ -699,13 +700,19 @@ int main(int ac, char **av)
 	if (!ret) {
 		pr_info("Running GIC_v3 tests.\n");
 		run_tests(KVM_DEV_TYPE_ARM_VGIC_V3);
-		return 0;
+		cnt_impl++;
 	}
 
 	ret = test_kvm_device(KVM_DEV_TYPE_ARM_VGIC_V2);
-	__TEST_REQUIRE(!ret, "No GICv2 nor GICv3 support");
+	if (!ret) {
+		pr_info("Running GIC_v2 tests.\n");
+		run_tests(KVM_DEV_TYPE_ARM_VGIC_V2);
+		cnt_impl++;
+	}
 
-	pr_info("Running GIC_v2 tests.\n");
-	run_tests(KVM_DEV_TYPE_ARM_VGIC_V2);
+	if (!cnt_impl) {
+		print_skip("No GICv2 nor GICv3 support");
+		exit(KSFT_SKIP);
+	}
 	return 0;
 }