arch/arm64/include/asm/kvm_hyp.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Copyright (C) 2015 - ARM Ltd
   4  * Author: Marc Zyngier <marc.zyngier@arm.com>
   5  */
   6
   7 #ifndef __ARM64_KVM_HYP_H__
   8 #define __ARM64_KVM_HYP_H__
   9
  10 #include <linux/compiler.h>
  11 #include <linux/kvm_host.h>
  12 #include <asm/alternative.h>
  13 #include <asm/kvm_mmu.h>
  14 #include <asm/sysreg.h>
  15
  16 #define __hyp_text __section(.hyp.text) notrace
  17
  18 #define read_sysreg_elx(r,nvh,vh)                                       \
  19         ({                                                              \
  20                 u64 reg;                                                \
  21                 asm volatile(ALTERNATIVE(__mrs_s("%0", r##nvh), \
  22                                          __mrs_s("%0", r##vh),          \
  23                                          ARM64_HAS_VIRT_HOST_EXTN)      \
  24                              : "=r" (reg));                             \
  25                 reg;                                                    \
  26         })
  27
  28 #define write_sysreg_elx(v,r,nvh,vh)                                    \
  29         do {                                                            \
  30                 u64 __val = (u64)(v);                                   \
  31                 asm volatile(ALTERNATIVE(__msr_s(r##nvh, "%x0"),        \
  32                                          __msr_s(r##vh, "%x0"),         \
  33                                          ARM64_HAS_VIRT_HOST_EXTN)      \
  34                                          : : "rZ" (__val));             \
  35         } while (0)
  36
  37 /*
  38  * Unified accessors for registers that have a different encoding
  39  * between VHE and non-VHE. They must be specified without their "ELx"
  40  * encoding, but with the SYS_ prefix, as defined in asm/sysreg.h.
  41  */
  42
  43 #define read_sysreg_el0(r)      read_sysreg_elx(r, _EL0, _EL02)
  44 #define write_sysreg_el0(v,r)   write_sysreg_elx(v, r, _EL0, _EL02)
  45 #define read_sysreg_el1(r)      read_sysreg_elx(r, _EL1, _EL12)
  46 #define write_sysreg_el1(v,r)   write_sysreg_elx(v, r, _EL1, _EL12)
  47 #define read_sysreg_el2(r)      read_sysreg_elx(r, _EL2, _EL1)
  48 #define write_sysreg_el2(v,r)   write_sysreg_elx(v, r, _EL2, _EL1)
  49
  50 /**
  51  * hyp_alternate_select - Generates patchable code sequences that are
  52  * used to switch between two implementations of a function, depending
  53  * on the availability of a feature.
  54  *
  55  * @fname: a symbol name that will be defined as a function returning a
  56  * function pointer whose type will match @orig and @alt
  57  * @orig: A pointer to the default function, as returned by @fname when
  58  * @cond doesn't hold
  59  * @alt: A pointer to the alternate function, as returned by @fname
  60  * when @cond holds
  61  * @cond: a CPU feature (as described in asm/cpufeature.h)
  62  */
  63 #define hyp_alternate_select(fname, orig, alt, cond)                    \
  64 typeof(orig) * __hyp_text fname(void)                                   \
  65 {                                                                       \
  66         typeof(alt) *val = orig;                                        \
  67         asm volatile(ALTERNATIVE("nop           \n",                    \
  68                                  "mov   %0, %1  \n",                    \
  69                                  cond)                                  \
  70                      : "+r" (val) : "r" (alt));                         \
  71         return val;                                                     \
  72 }
  73
  74 int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu);
  75
  76 void __vgic_v3_save_state(struct kvm_vcpu *vcpu);
  77 void __vgic_v3_restore_state(struct kvm_vcpu *vcpu);
  78 void __vgic_v3_activate_traps(struct kvm_vcpu *vcpu);
  79 void __vgic_v3_deactivate_traps(struct kvm_vcpu *vcpu);
  80 void __vgic_v3_save_aprs(struct kvm_vcpu *vcpu);
  81 void __vgic_v3_restore_aprs(struct kvm_vcpu *vcpu);
  82 int __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu);
  83
  84 void __timer_enable_traps(struct kvm_vcpu *vcpu);
  85 void __timer_disable_traps(struct kvm_vcpu *vcpu);
  86
  87 void __sysreg_save_state_nvhe(struct kvm_cpu_context *ctxt);
  88 void __sysreg_restore_state_nvhe(struct kvm_cpu_context *ctxt);
  89 void sysreg_save_host_state_vhe(struct kvm_cpu_context *ctxt);
  90 void sysreg_restore_host_state_vhe(struct kvm_cpu_context *ctxt);
  91 void sysreg_save_guest_state_vhe(struct kvm_cpu_context *ctxt);
  92 void sysreg_restore_guest_state_vhe(struct kvm_cpu_context *ctxt);
  93 void __sysreg32_save_state(struct kvm_vcpu *vcpu);
  94 void __sysreg32_restore_state(struct kvm_vcpu *vcpu);
  95
  96 void __debug_switch_to_guest(struct kvm_vcpu *vcpu);
  97 void __debug_switch_to_host(struct kvm_vcpu *vcpu);
  98
  99 void __fpsimd_save_state(struct user_fpsimd_state *fp_regs);
 100 void __fpsimd_restore_state(struct user_fpsimd_state *fp_regs);
 101
 102 void activate_traps_vhe_load(struct kvm_vcpu *vcpu);
 103 void deactivate_traps_vhe_put(void);
 104
 105 u64 __guest_enter(struct kvm_vcpu *vcpu, struct kvm_cpu_context *host_ctxt);
 106 void __noreturn __hyp_do_panic(unsigned long, ...);
 107
 108 /*
 109  * Must be called from hyp code running at EL2 with an updated VTTBR
 110  * and interrupts disabled.
 111  */
 112 static __always_inline void __hyp_text __load_guest_stage2(struct kvm *kvm)
 113 {
 114         write_sysreg(kvm->arch.vtcr, vtcr_el2);
 115         write_sysreg(kvm_get_vttbr(kvm), vttbr_el2);
 116
 117         /*
 118          * ARM erratum 1165522 requires the actual execution of the above
 119          * before we can switch to the EL1/EL0 translation regime used by
 120          * the guest.
 121          */
 122         asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_1165522));
 123 }
 124
 125 #endif /* __ARM64_KVM_HYP_H__ */
 126