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/* SPDX-License-Identifier: GPL-2.0 */
/* arch/arm64/include/asm/kvm_ptrauth.h: Guest/host ptrauth save/restore
* Copyright 2019 Arm Limited
* Authors: Mark Rutland <mark.rutland@arm.com>
* Amit Daniel Kachhap <amit.kachhap@arm.com>
*/
#ifndef __ASM_KVM_PTRAUTH_H
#define __ASM_KVM_PTRAUTH_H
#ifdef __ASSEMBLY__
#include <asm/sysreg.h>
#ifdef CONFIG_ARM64_PTR_AUTH
#define PTRAUTH_REG_OFFSET(x) (x - CPU_APIAKEYLO_EL1)
/*
* CPU_AP*_EL1 values exceed immediate offset range (512) for stp
* instruction so below macros takes CPU_APIAKEYLO_EL1 as base and
* calculates the offset of the keys from this base to avoid an extra add
* instruction. These macros assumes the keys offsets follow the order of
* the sysreg enum in kvm_host.h.
*/
.macro ptrauth_save_state base, reg1, reg2
mrs_s \reg1, SYS_APIAKEYLO_EL1
mrs_s \reg2, SYS_APIAKEYHI_EL1
stp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APIAKEYLO_EL1)]
mrs_s \reg1, SYS_APIBKEYLO_EL1
mrs_s \reg2, SYS_APIBKEYHI_EL1
stp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APIBKEYLO_EL1)]
mrs_s \reg1, SYS_APDAKEYLO_EL1
mrs_s \reg2, SYS_APDAKEYHI_EL1
stp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APDAKEYLO_EL1)]
mrs_s \reg1, SYS_APDBKEYLO_EL1
mrs_s \reg2, SYS_APDBKEYHI_EL1
stp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APDBKEYLO_EL1)]
mrs_s \reg1, SYS_APGAKEYLO_EL1
mrs_s \reg2, SYS_APGAKEYHI_EL1
stp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APGAKEYLO_EL1)]
.endm
.macro ptrauth_restore_state base, reg1, reg2
ldp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APIAKEYLO_EL1)]
msr_s SYS_APIAKEYLO_EL1, \reg1
msr_s SYS_APIAKEYHI_EL1, \reg2
ldp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APIBKEYLO_EL1)]
msr_s SYS_APIBKEYLO_EL1, \reg1
msr_s SYS_APIBKEYHI_EL1, \reg2
ldp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APDAKEYLO_EL1)]
msr_s SYS_APDAKEYLO_EL1, \reg1
msr_s SYS_APDAKEYHI_EL1, \reg2
ldp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APDBKEYLO_EL1)]
msr_s SYS_APDBKEYLO_EL1, \reg1
msr_s SYS_APDBKEYHI_EL1, \reg2
ldp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APGAKEYLO_EL1)]
msr_s SYS_APGAKEYLO_EL1, \reg1
msr_s SYS_APGAKEYHI_EL1, \reg2
.endm
/*
* Both ptrauth_switch_to_guest and ptrauth_switch_to_host macros will
* check for the presence ARM64_HAS_ADDRESS_AUTH, which is defined as
* (ARM64_HAS_ADDRESS_AUTH_ARCH || ARM64_HAS_ADDRESS_AUTH_IMP_DEF) and
* then proceed ahead with the save/restore of Pointer Authentication
* key registers if enabled for the guest.
*/
.macro ptrauth_switch_to_guest g_ctxt, reg1, reg2, reg3
alternative_if_not ARM64_HAS_ADDRESS_AUTH
b .L__skip_switch\@
alternative_else_nop_endif
mrs \reg1, hcr_el2
and \reg1, \reg1, #(HCR_API | HCR_APK)
cbz \reg1, .L__skip_switch\@
add \reg1, \g_ctxt, #CPU_APIAKEYLO_EL1
ptrauth_restore_state \reg1, \reg2, \reg3
.L__skip_switch\@:
.endm
.macro ptrauth_switch_to_host g_ctxt, h_ctxt, reg1, reg2, reg3
alternative_if_not ARM64_HAS_ADDRESS_AUTH
b .L__skip_switch\@
alternative_else_nop_endif
mrs \reg1, hcr_el2
and \reg1, \reg1, #(HCR_API | HCR_APK)
cbz \reg1, .L__skip_switch\@
add \reg1, \g_ctxt, #CPU_APIAKEYLO_EL1
ptrauth_save_state \reg1, \reg2, \reg3
add \reg1, \h_ctxt, #CPU_APIAKEYLO_EL1
ptrauth_restore_state \reg1, \reg2, \reg3
isb
.L__skip_switch\@:
.endm
#else /* !CONFIG_ARM64_PTR_AUTH */
.macro ptrauth_switch_to_guest g_ctxt, reg1, reg2, reg3
.endm
.macro ptrauth_switch_to_host g_ctxt, h_ctxt, reg1, reg2, reg3
.endm
#endif /* CONFIG_ARM64_PTR_AUTH */
#endif /* __ASSEMBLY__ */
#endif /* __ASM_KVM_PTRAUTH_H */
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