arch/arm64/kvm/hyp/hyp-entry.S

Source file repositories/reference/linux-study-clean/arch/arm64/kvm/hyp/hyp-entry.S

File Facts

System
Linux kernel
Corpus path
arch/arm64/kvm/hyp/hyp-entry.S
Extension
.S
Size
6038 bytes
Lines
265
Domain
Architecture Layer
Bucket
arch/arm64
Inferred role
Architecture Layer: arch/arm64
Status
atlas-only

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

#include <linux/arm-smccc.h>
#include <linux/linkage.h>

#include <asm/alternative.h>
#include <asm/assembler.h>
#include <asm/cpufeature.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_asm.h>
#include <asm/mmu.h>
#include <asm/spectre.h>

.macro save_caller_saved_regs_vect
	/* x0 and x1 were saved in the vector entry */
	stp	x2, x3,   [sp, #-16]!
	stp	x4, x5,   [sp, #-16]!
	stp	x6, x7,   [sp, #-16]!
	stp	x8, x9,   [sp, #-16]!
	stp	x10, x11, [sp, #-16]!
	stp	x12, x13, [sp, #-16]!
	stp	x14, x15, [sp, #-16]!
	stp	x16, x17, [sp, #-16]!
.endm

.macro restore_caller_saved_regs_vect
	ldp	x16, x17, [sp], #16
	ldp	x14, x15, [sp], #16
	ldp	x12, x13, [sp], #16
	ldp	x10, x11, [sp], #16
	ldp	x8, x9,   [sp], #16
	ldp	x6, x7,   [sp], #16
	ldp	x4, x5,   [sp], #16
	ldp	x2, x3,   [sp], #16
	ldp	x0, x1,   [sp], #16
.endm

	.text

el1_sync:				// Guest trapped into EL2

	mrs	x0, esr_el2
	ubfx	x0, x0, #ESR_ELx_EC_SHIFT, #ESR_ELx_EC_WIDTH
	cmp	x0, #ESR_ELx_EC_HVC64
	ccmp	x0, #ESR_ELx_EC_HVC32, #4, ne
	b.ne	el1_trap

	/*
	 * Fastest possible path for ARM_SMCCC_ARCH_WORKAROUND_1.
	 * The workaround has already been applied on the host,
	 * so let's quickly get back to the guest. We don't bother
	 * restoring x1, as it can be clobbered anyway.
	 */
	ldr	x1, [sp]				// Guest's x0
	eor	w1, w1, #ARM_SMCCC_ARCH_WORKAROUND_1
	cbz	w1, wa_epilogue

	/* ARM_SMCCC_ARCH_WORKAROUND_2 handling */
	eor	w1, w1, #(ARM_SMCCC_ARCH_WORKAROUND_1 ^ \
			  ARM_SMCCC_ARCH_WORKAROUND_2)
	cbz	w1, wa_epilogue

	eor	w1, w1, #(ARM_SMCCC_ARCH_WORKAROUND_2 ^ \
			  ARM_SMCCC_ARCH_WORKAROUND_3)
	cbnz	w1, el1_trap

wa_epilogue:
	mov	x0, xzr
	add	sp, sp, #16
	eret
	sb

Annotation

Implementation Notes