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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Hypervisor stub
+ *
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+
+#include <linux/init.h>
+#include <linux/linkage.h>
+#include <linux/irqchip/arm-gic-v3.h>
+
+#include <asm/assembler.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_asm.h>
+#include <asm/ptrace.h>
+#include <asm/virt.h>
+
+ .text
+ .pushsection .hyp.text, "ax"
+
+ .align 11
+
+SYM_CODE_START(__hyp_stub_vectors)
+ ventry el2_sync_invalid // Synchronous EL2t
+ ventry el2_irq_invalid // IRQ EL2t
+ ventry el2_fiq_invalid // FIQ EL2t
+ ventry el2_error_invalid // Error EL2t
+
+ ventry el2_sync_invalid // Synchronous EL2h
+ ventry el2_irq_invalid // IRQ EL2h
+ ventry el2_fiq_invalid // FIQ EL2h
+ ventry el2_error_invalid // Error EL2h
+
+ ventry el1_sync // Synchronous 64-bit EL1
+ ventry el1_irq_invalid // IRQ 64-bit EL1
+ ventry el1_fiq_invalid // FIQ 64-bit EL1
+ ventry el1_error_invalid // Error 64-bit EL1
+
+ ventry el1_sync_invalid // Synchronous 32-bit EL1
+ ventry el1_irq_invalid // IRQ 32-bit EL1
+ ventry el1_fiq_invalid // FIQ 32-bit EL1
+ ventry el1_error_invalid // Error 32-bit EL1
+SYM_CODE_END(__hyp_stub_vectors)
+
+ .align 11
+
+SYM_CODE_START_LOCAL(el1_sync)
+ cmp x0, #HVC_SET_VECTORS
+ b.ne 2f
+ msr vbar_el2, x1
+ b 9f
+
+2: cmp x0, #HVC_SOFT_RESTART
+ b.ne 3f
+ mov x0, x2
+ mov x2, x4
+ mov x4, x1
+ mov x1, x3
+ br x4 // no return
+
+3: cmp x0, #HVC_RESET_VECTORS
+ beq 9f // Nothing to reset!
+
+ /* Someone called kvm_call_hyp() against the hyp-stub... */
+ mov_q x0, HVC_STUB_ERR
+ eret
+
+9: mov x0, xzr
+ eret
+SYM_CODE_END(el1_sync)
+
+.macro invalid_vector label
+SYM_CODE_START_LOCAL(\label)
+ b \label
+SYM_CODE_END(\label)
+.endm
+
+ invalid_vector el2_sync_invalid
+ invalid_vector el2_irq_invalid
+ invalid_vector el2_fiq_invalid
+ invalid_vector el2_error_invalid
+ invalid_vector el1_sync_invalid
+ invalid_vector el1_irq_invalid
+ invalid_vector el1_fiq_invalid
+ invalid_vector el1_error_invalid
+
+/*
+ * __hyp_set_vectors: Call this after boot to set the initial hypervisor
+ * vectors as part of hypervisor installation. On an SMP system, this should
+ * be called on each CPU.
+ *
+ * x0 must be the physical address of the new vector table, and must be
+ * 2KB aligned.
+ *
+ * Before calling this, you must check that the stub hypervisor is installed
+ * everywhere, by waiting for any secondary CPUs to be brought up and then
+ * checking that is_hyp_mode_available() is true.
+ *
+ * If not, there is a pre-existing hypervisor, some CPUs failed to boot, or
+ * something else went wrong... in such cases, trying to install a new
+ * hypervisor is unlikely to work as desired.
+ *
+ * When you call into your shiny new hypervisor, sp_el2 will contain junk,
+ * so you will need to set that to something sensible at the new hypervisor's
+ * initialisation entry point.
+ */
+
+SYM_FUNC_START(__hyp_set_vectors)
+ mov x1, x0
+ mov x0, #HVC_SET_VECTORS
+ hvc #0
+ ret
+SYM_FUNC_END(__hyp_set_vectors)
+
+SYM_FUNC_START(__hyp_reset_vectors)
+ mov x0, #HVC_RESET_VECTORS
+ hvc #0
+ ret
+SYM_FUNC_END(__hyp_reset_vectors)