kvm_ptrauth.h (3543B)
1/* SPDX-License-Identifier: GPL-2.0 */ 2/* arch/arm64/include/asm/kvm_ptrauth.h: Guest/host ptrauth save/restore 3 * Copyright 2019 Arm Limited 4 * Authors: Mark Rutland <mark.rutland@arm.com> 5 * Amit Daniel Kachhap <amit.kachhap@arm.com> 6 */ 7 8#ifndef __ASM_KVM_PTRAUTH_H 9#define __ASM_KVM_PTRAUTH_H 10 11#ifdef __ASSEMBLY__ 12 13#include <asm/sysreg.h> 14 15#ifdef CONFIG_ARM64_PTR_AUTH 16 17#define PTRAUTH_REG_OFFSET(x) (x - CPU_APIAKEYLO_EL1) 18 19/* 20 * CPU_AP*_EL1 values exceed immediate offset range (512) for stp 21 * instruction so below macros takes CPU_APIAKEYLO_EL1 as base and 22 * calculates the offset of the keys from this base to avoid an extra add 23 * instruction. These macros assumes the keys offsets follow the order of 24 * the sysreg enum in kvm_host.h. 25 */ 26.macro ptrauth_save_state base, reg1, reg2 27 mrs_s \reg1, SYS_APIAKEYLO_EL1 28 mrs_s \reg2, SYS_APIAKEYHI_EL1 29 stp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APIAKEYLO_EL1)] 30 mrs_s \reg1, SYS_APIBKEYLO_EL1 31 mrs_s \reg2, SYS_APIBKEYHI_EL1 32 stp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APIBKEYLO_EL1)] 33 mrs_s \reg1, SYS_APDAKEYLO_EL1 34 mrs_s \reg2, SYS_APDAKEYHI_EL1 35 stp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APDAKEYLO_EL1)] 36 mrs_s \reg1, SYS_APDBKEYLO_EL1 37 mrs_s \reg2, SYS_APDBKEYHI_EL1 38 stp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APDBKEYLO_EL1)] 39 mrs_s \reg1, SYS_APGAKEYLO_EL1 40 mrs_s \reg2, SYS_APGAKEYHI_EL1 41 stp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APGAKEYLO_EL1)] 42.endm 43 44.macro ptrauth_restore_state base, reg1, reg2 45 ldp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APIAKEYLO_EL1)] 46 msr_s SYS_APIAKEYLO_EL1, \reg1 47 msr_s SYS_APIAKEYHI_EL1, \reg2 48 ldp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APIBKEYLO_EL1)] 49 msr_s SYS_APIBKEYLO_EL1, \reg1 50 msr_s SYS_APIBKEYHI_EL1, \reg2 51 ldp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APDAKEYLO_EL1)] 52 msr_s SYS_APDAKEYLO_EL1, \reg1 53 msr_s SYS_APDAKEYHI_EL1, \reg2 54 ldp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APDBKEYLO_EL1)] 55 msr_s SYS_APDBKEYLO_EL1, \reg1 56 msr_s SYS_APDBKEYHI_EL1, \reg2 57 ldp \reg1, \reg2, [\base, #PTRAUTH_REG_OFFSET(CPU_APGAKEYLO_EL1)] 58 msr_s SYS_APGAKEYLO_EL1, \reg1 59 msr_s SYS_APGAKEYHI_EL1, \reg2 60.endm 61 62/* 63 * Both ptrauth_switch_to_guest and ptrauth_switch_to_hyp macros will 64 * check for the presence ARM64_HAS_ADDRESS_AUTH, which is defined as 65 * (ARM64_HAS_ADDRESS_AUTH_ARCH || ARM64_HAS_ADDRESS_AUTH_IMP_DEF) and 66 * then proceed ahead with the save/restore of Pointer Authentication 67 * key registers if enabled for the guest. 68 */ 69.macro ptrauth_switch_to_guest g_ctxt, reg1, reg2, reg3 70alternative_if_not ARM64_HAS_ADDRESS_AUTH 71 b .L__skip_switch\@ 72alternative_else_nop_endif 73 mrs \reg1, hcr_el2 74 and \reg1, \reg1, #(HCR_API | HCR_APK) 75 cbz \reg1, .L__skip_switch\@ 76 add \reg1, \g_ctxt, #CPU_APIAKEYLO_EL1 77 ptrauth_restore_state \reg1, \reg2, \reg3 78.L__skip_switch\@: 79.endm 80 81.macro ptrauth_switch_to_hyp g_ctxt, h_ctxt, reg1, reg2, reg3 82alternative_if_not ARM64_HAS_ADDRESS_AUTH 83 b .L__skip_switch\@ 84alternative_else_nop_endif 85 mrs \reg1, hcr_el2 86 and \reg1, \reg1, #(HCR_API | HCR_APK) 87 cbz \reg1, .L__skip_switch\@ 88 add \reg1, \g_ctxt, #CPU_APIAKEYLO_EL1 89 ptrauth_save_state \reg1, \reg2, \reg3 90 add \reg1, \h_ctxt, #CPU_APIAKEYLO_EL1 91 ptrauth_restore_state \reg1, \reg2, \reg3 92 isb 93.L__skip_switch\@: 94.endm 95 96#else /* !CONFIG_ARM64_PTR_AUTH */ 97.macro ptrauth_switch_to_guest g_ctxt, reg1, reg2, reg3 98.endm 99.macro ptrauth_switch_to_hyp g_ctxt, h_ctxt, reg1, reg2, reg3 100.endm 101#endif /* CONFIG_ARM64_PTR_AUTH */ 102#endif /* __ASSEMBLY__ */ 103#endif /* __ASM_KVM_PTRAUTH_H */