xref: /linux/arch/arm64/include/asm/kvm_hyp.h (revision b8d312aa075f33282565467662c4628dae0a2aff)
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 
127