diff options
Diffstat (limited to 'arch/arm64/include/asm/kvm_ptrauth.h')
| -rw-r--r-- | arch/arm64/include/asm/kvm_ptrauth.h | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_ptrauth.h b/arch/arm64/include/asm/kvm_ptrauth.h new file mode 100644 index 000000000000..6301813dcace --- /dev/null +++ b/arch/arm64/include/asm/kvm_ptrauth.h @@ -0,0 +1,111 @@ +/* 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 of one of the cpufeature flag + * ARM64_HAS_ADDRESS_AUTH_ARCH or ARM64_HAS_ADDRESS_AUTH_IMP_DEF and + * then proceed ahead with the save/restore of Pointer Authentication + * key registers. + */ +.macro ptrauth_switch_to_guest g_ctxt, reg1, reg2, reg3 +alternative_if ARM64_HAS_ADDRESS_AUTH_ARCH + b 1000f +alternative_else_nop_endif +alternative_if_not ARM64_HAS_ADDRESS_AUTH_IMP_DEF + b 1001f +alternative_else_nop_endif +1000: + ldr \reg1, [\g_ctxt, #(VCPU_HCR_EL2 - VCPU_CONTEXT)] + and \reg1, \reg1, #(HCR_API | HCR_APK) + cbz \reg1, 1001f + add \reg1, \g_ctxt, #CPU_APIAKEYLO_EL1 + ptrauth_restore_state \reg1, \reg2, \reg3 +1001: +.endm + +.macro ptrauth_switch_to_host g_ctxt, h_ctxt, reg1, reg2, reg3 +alternative_if ARM64_HAS_ADDRESS_AUTH_ARCH + b 2000f +alternative_else_nop_endif +alternative_if_not ARM64_HAS_ADDRESS_AUTH_IMP_DEF + b 2001f +alternative_else_nop_endif +2000: + ldr \reg1, [\g_ctxt, #(VCPU_HCR_EL2 - VCPU_CONTEXT)] + and \reg1, \reg1, #(HCR_API | HCR_APK) + cbz \reg1, 2001f + 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 +2001: +.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 */ |