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 70 alternative_if_not ARM64_HAS_ADDRESS_AUTH 71 b .L__skip_switch\@ 72 alternative_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 82 alternative_if_not ARM64_HAS_ADDRESS_AUTH 83 b .L__skip_switch\@ 84 alternative_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 */ 102 103 #else /* !__ASSEMBLY */ 104 105 #define __ptrauth_save_key(ctxt, key) \ 106 do { \ 107 u64 __val; \ 108 __val = read_sysreg_s(SYS_ ## key ## KEYLO_EL1); \ 109 ctxt_sys_reg(ctxt, key ## KEYLO_EL1) = __val; \ 110 __val = read_sysreg_s(SYS_ ## key ## KEYHI_EL1); \ 111 ctxt_sys_reg(ctxt, key ## KEYHI_EL1) = __val; \ 112 } while(0) 113 114 #define ptrauth_save_keys(ctxt) \ 115 do { \ 116 __ptrauth_save_key(ctxt, APIA); \ 117 __ptrauth_save_key(ctxt, APIB); \ 118 __ptrauth_save_key(ctxt, APDA); \ 119 __ptrauth_save_key(ctxt, APDB); \ 120 __ptrauth_save_key(ctxt, APGA); \ 121 } while(0) 122 123 #endif /* __ASSEMBLY__ */ 124 #endif /* __ASM_KVM_PTRAUTH_H */ 125