tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2012,2013 - ARM Ltd
4 * Author: Marc Zyngier <marc.zyngier@arm.com>
5 */
6
7#ifndef __ARM_KVM_ASM_H__
8#define __ARM_KVM_ASM_H__
9
10#include <asm/hyp_image.h>
11#include <asm/insn.h>
12#include <asm/virt.h>
13
14#define ARM_EXIT_WITH_SERROR_BIT 31
15#define ARM_EXCEPTION_CODE(x) ((x) & ~(1U << ARM_EXIT_WITH_SERROR_BIT))
16#define ARM_EXCEPTION_IS_TRAP(x) (ARM_EXCEPTION_CODE((x)) == ARM_EXCEPTION_TRAP)
17#define ARM_SERROR_PENDING(x) !!((x) & (1U << ARM_EXIT_WITH_SERROR_BIT))
18
19#define ARM_EXCEPTION_IRQ 0
20#define ARM_EXCEPTION_EL1_SERROR 1
21#define ARM_EXCEPTION_TRAP 2
22#define ARM_EXCEPTION_IL 3
23/* The hyp-stub will return this for any kvm_call_hyp() call */
24#define ARM_EXCEPTION_HYP_GONE HVC_STUB_ERR
25
26#define kvm_arm_exception_type \
27 {ARM_EXCEPTION_IRQ, "IRQ" }, \
28 {ARM_EXCEPTION_EL1_SERROR, "SERROR" }, \
29 {ARM_EXCEPTION_TRAP, "TRAP" }, \
30 {ARM_EXCEPTION_HYP_GONE, "HYP_GONE" }
31
32/*
33 * Size of the HYP vectors preamble. kvm_patch_vector_branch() generates code
34 * that jumps over this.
35 */
36#define KVM_VECTOR_PREAMBLE (2 * AARCH64_INSN_SIZE)
37
38#define KVM_HOST_SMCCC_ID(id) \
39 ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
40 ARM_SMCCC_SMC_64, \
41 ARM_SMCCC_OWNER_VENDOR_HYP, \
42 (id))
43
44#define KVM_HOST_SMCCC_FUNC(name) KVM_HOST_SMCCC_ID(__KVM_HOST_SMCCC_FUNC_##name)
45
46#define __KVM_HOST_SMCCC_FUNC___kvm_hyp_init 0
47
48#ifndef __ASSEMBLY__
49
50#include <linux/mm.h>
51
52enum __kvm_host_smccc_func {
53 /* Hypercalls available only prior to pKVM finalisation */
54 /* __KVM_HOST_SMCCC_FUNC___kvm_hyp_init */
55 __KVM_HOST_SMCCC_FUNC___kvm_get_mdcr_el2 = __KVM_HOST_SMCCC_FUNC___kvm_hyp_init + 1,
56 __KVM_HOST_SMCCC_FUNC___pkvm_init,
57 __KVM_HOST_SMCCC_FUNC___pkvm_create_private_mapping,
58 __KVM_HOST_SMCCC_FUNC___pkvm_cpu_set_vector,
59 __KVM_HOST_SMCCC_FUNC___kvm_enable_ssbs,
60 __KVM_HOST_SMCCC_FUNC___vgic_v3_init_lrs,
61 __KVM_HOST_SMCCC_FUNC___vgic_v3_get_gic_config,
62 __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize,
63
64 /* Hypercalls available after pKVM finalisation */
65 __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp,
66 __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp,
67 __KVM_HOST_SMCCC_FUNC___kvm_adjust_pc,
68 __KVM_HOST_SMCCC_FUNC___kvm_vcpu_run,
69 __KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,
70 __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa,
71 __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid,
72 __KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context,
73 __KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff,
74 __KVM_HOST_SMCCC_FUNC___vgic_v3_read_vmcr,
75 __KVM_HOST_SMCCC_FUNC___vgic_v3_write_vmcr,
76 __KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs,
77 __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_aprs,
78 __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_init_traps,
79 __KVM_HOST_SMCCC_FUNC___pkvm_init_vm,
80 __KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu,
81 __KVM_HOST_SMCCC_FUNC___pkvm_teardown_vm,
82};
83
84#define DECLARE_KVM_VHE_SYM(sym) extern char sym[]
85#define DECLARE_KVM_NVHE_SYM(sym) extern char kvm_nvhe_sym(sym)[]
86
87/*
88 * Define a pair of symbols sharing the same name but one defined in
89 * VHE and the other in nVHE hyp implementations.
90 */
91#define DECLARE_KVM_HYP_SYM(sym) \
92 DECLARE_KVM_VHE_SYM(sym); \
93 DECLARE_KVM_NVHE_SYM(sym)
94
95#define DECLARE_KVM_VHE_PER_CPU(type, sym) \
96 DECLARE_PER_CPU(type, sym)
97#define DECLARE_KVM_NVHE_PER_CPU(type, sym) \
98 DECLARE_PER_CPU(type, kvm_nvhe_sym(sym))
99
100#define DECLARE_KVM_HYP_PER_CPU(type, sym) \
101 DECLARE_KVM_VHE_PER_CPU(type, sym); \
102 DECLARE_KVM_NVHE_PER_CPU(type, sym)
103
104/*
105 * Compute pointer to a symbol defined in nVHE percpu region.
106 * Returns NULL if percpu memory has not been allocated yet.
107 */
108#define this_cpu_ptr_nvhe_sym(sym) per_cpu_ptr_nvhe_sym(sym, smp_processor_id())
109#define per_cpu_ptr_nvhe_sym(sym, cpu) \
110 ({ \
111 unsigned long base, off; \
112 base = kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu]; \
113 off = (unsigned long)&CHOOSE_NVHE_SYM(sym) - \
114 (unsigned long)&CHOOSE_NVHE_SYM(__per_cpu_start); \
115 base ? (typeof(CHOOSE_NVHE_SYM(sym))*)(base + off) : NULL; \
116 })
117
118#if defined(__KVM_NVHE_HYPERVISOR__)
119
120#define CHOOSE_NVHE_SYM(sym) sym
121#define CHOOSE_HYP_SYM(sym) CHOOSE_NVHE_SYM(sym)
122
123/* The nVHE hypervisor shouldn't even try to access VHE symbols */
124extern void *__nvhe_undefined_symbol;
125#define CHOOSE_VHE_SYM(sym) __nvhe_undefined_symbol
126#define this_cpu_ptr_hyp_sym(sym) (&__nvhe_undefined_symbol)
127#define per_cpu_ptr_hyp_sym(sym, cpu) (&__nvhe_undefined_symbol)
128
129#elif defined(__KVM_VHE_HYPERVISOR__)
130
131#define CHOOSE_VHE_SYM(sym) sym
132#define CHOOSE_HYP_SYM(sym) CHOOSE_VHE_SYM(sym)
133
134/* The VHE hypervisor shouldn't even try to access nVHE symbols */
135extern void *__vhe_undefined_symbol;
136#define CHOOSE_NVHE_SYM(sym) __vhe_undefined_symbol
137#define this_cpu_ptr_hyp_sym(sym) (&__vhe_undefined_symbol)
138#define per_cpu_ptr_hyp_sym(sym, cpu) (&__vhe_undefined_symbol)
139
140#else
141
142/*
143 * BIG FAT WARNINGS:
144 *
145 * - Don't be tempted to change the following is_kernel_in_hyp_mode()
146 * to has_vhe(). has_vhe() is implemented as a *final* capability,
147 * while this is used early at boot time, when the capabilities are
148 * not final yet....
149 *
150 * - Don't let the nVHE hypervisor have access to this, as it will
151 * pick the *wrong* symbol (yes, it runs at EL2...).
152 */
153#define CHOOSE_HYP_SYM(sym) (is_kernel_in_hyp_mode() \
154 ? CHOOSE_VHE_SYM(sym) \
155 : CHOOSE_NVHE_SYM(sym))
156
157#define this_cpu_ptr_hyp_sym(sym) (is_kernel_in_hyp_mode() \
158 ? this_cpu_ptr(&sym) \
159 : this_cpu_ptr_nvhe_sym(sym))
160
161#define per_cpu_ptr_hyp_sym(sym, cpu) (is_kernel_in_hyp_mode() \
162 ? per_cpu_ptr(&sym, cpu) \
163 : per_cpu_ptr_nvhe_sym(sym, cpu))
164
165#define CHOOSE_VHE_SYM(sym) sym
166#define CHOOSE_NVHE_SYM(sym) kvm_nvhe_sym(sym)
167
168#endif
169
170struct kvm_nvhe_init_params {
171 unsigned long mair_el2;
172 unsigned long tcr_el2;
173 unsigned long tpidr_el2;
174 unsigned long stack_hyp_va;
175 unsigned long stack_pa;
176 phys_addr_t pgd_pa;
177 unsigned long hcr_el2;
178 unsigned long vttbr;
179 unsigned long vtcr;
180};
181
182/*
183 * Used by the host in EL1 to dump the nVHE hypervisor backtrace on
184 * hyp_panic() in non-protected mode.
185 *
186 * @stack_base: hyp VA of the hyp_stack base.
187 * @overflow_stack_base: hyp VA of the hyp_overflow_stack base.
188 * @fp: hyp FP where the backtrace begins.
189 * @pc: hyp PC where the backtrace begins.
190 */
191struct kvm_nvhe_stacktrace_info {
192 unsigned long stack_base;
193 unsigned long overflow_stack_base;
194 unsigned long fp;
195 unsigned long pc;
196};
197
198/* Translate a kernel address @ptr into its equivalent linear mapping */
199#define kvm_ksym_ref(ptr) \
200 ({ \
201 void *val = (ptr); \
202 if (!is_kernel_in_hyp_mode()) \
203 val = lm_alias((ptr)); \
204 val; \
205 })
206#define kvm_ksym_ref_nvhe(sym) kvm_ksym_ref(kvm_nvhe_sym(sym))
207
208struct kvm;
209struct kvm_vcpu;
210struct kvm_s2_mmu;
211
212DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
213DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
214#define __kvm_hyp_init CHOOSE_NVHE_SYM(__kvm_hyp_init)
215#define __kvm_hyp_vector CHOOSE_HYP_SYM(__kvm_hyp_vector)
216
217extern unsigned long kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[];
218DECLARE_KVM_NVHE_SYM(__per_cpu_start);
219DECLARE_KVM_NVHE_SYM(__per_cpu_end);
220
221DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs);
222#define __bp_harden_hyp_vecs CHOOSE_HYP_SYM(__bp_harden_hyp_vecs)
223
224extern void __kvm_flush_vm_context(void);
225extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu);
226extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
227 int level);
228extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
229
230extern void __kvm_timer_set_cntvoff(u64 cntvoff);
231
232extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
233
234extern void __kvm_adjust_pc(struct kvm_vcpu *vcpu);
235
236extern u64 __vgic_v3_get_gic_config(void);
237extern u64 __vgic_v3_read_vmcr(void);
238extern void __vgic_v3_write_vmcr(u32 vmcr);
239extern void __vgic_v3_init_lrs(void);
240
241extern u64 __kvm_get_mdcr_el2(void);
242
243#define __KVM_EXTABLE(from, to) \
244 " .pushsection __kvm_ex_table, \"a\"\n" \
245 " .align 3\n" \
246 " .long (" #from " - .), (" #to " - .)\n" \
247 " .popsection\n"
248
249
250#define __kvm_at(at_op, addr) \
251( { \
252 int __kvm_at_err = 0; \
253 u64 spsr, elr; \
254 asm volatile( \
255 " mrs %1, spsr_el2\n" \
256 " mrs %2, elr_el2\n" \
257 "1: at "at_op", %3\n" \
258 " isb\n" \
259 " b 9f\n" \
260 "2: msr spsr_el2, %1\n" \
261 " msr elr_el2, %2\n" \
262 " mov %w0, %4\n" \
263 "9:\n" \
264 __KVM_EXTABLE(1b, 2b) \
265 : "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr) \
266 : "r" (addr), "i" (-EFAULT)); \
267 __kvm_at_err; \
268} )
269
270
271#else /* __ASSEMBLY__ */
272
273.macro get_host_ctxt reg, tmp
274 adr_this_cpu \reg, kvm_host_data, \tmp
275 add \reg, \reg, #HOST_DATA_CONTEXT
276.endm
277
278.macro get_vcpu_ptr vcpu, ctxt
279 get_host_ctxt \ctxt, \vcpu
280 ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
281.endm
282
283.macro get_loaded_vcpu vcpu, ctxt
284 adr_this_cpu \ctxt, kvm_hyp_ctxt, \vcpu
285 ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
286.endm
287
288.macro set_loaded_vcpu vcpu, ctxt, tmp
289 adr_this_cpu \ctxt, kvm_hyp_ctxt, \tmp
290 str \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
291.endm
292
293/*
294 * KVM extable for unexpected exceptions.
295 * Create a struct kvm_exception_table_entry output to a section that can be
296 * mapped by EL2. The table is not sorted.
297 *
298 * The caller must ensure:
299 * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
300 * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
301 */
302.macro _kvm_extable, from, to
303 .pushsection __kvm_ex_table, "a"
304 .align 3
305 .long (\from - .), (\to - .)
306 .popsection
307.endm
308
309#define CPU_XREG_OFFSET(x) (CPU_USER_PT_REGS + 8*x)
310#define CPU_LR_OFFSET CPU_XREG_OFFSET(30)
311#define CPU_SP_EL0_OFFSET (CPU_LR_OFFSET + 8)
312
313/*
314 * We treat x18 as callee-saved as the host may use it as a platform
315 * register (e.g. for shadow call stack).
316 */
317.macro save_callee_saved_regs ctxt
318 str x18, [\ctxt, #CPU_XREG_OFFSET(18)]
319 stp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
320 stp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
321 stp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
322 stp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
323 stp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
324 stp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)]
325.endm
326
327.macro restore_callee_saved_regs ctxt
328 // We require \ctxt is not x18-x28
329 ldr x18, [\ctxt, #CPU_XREG_OFFSET(18)]
330 ldp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
331 ldp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
332 ldp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
333 ldp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
334 ldp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
335 ldp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)]
336.endm
337
338.macro save_sp_el0 ctxt, tmp
339 mrs \tmp, sp_el0
340 str \tmp, [\ctxt, #CPU_SP_EL0_OFFSET]
341.endm
342
343.macro restore_sp_el0 ctxt, tmp
344 ldr \tmp, [\ctxt, #CPU_SP_EL0_OFFSET]
345 msr sp_el0, \tmp
346.endm
347
348#endif
349
350#endif /* __ARM_KVM_ASM_H__ */