tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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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};
80
81#define DECLARE_KVM_VHE_SYM(sym) extern char sym[]
82#define DECLARE_KVM_NVHE_SYM(sym) extern char kvm_nvhe_sym(sym)[]
83
84/*
85 * Define a pair of symbols sharing the same name but one defined in
86 * VHE and the other in nVHE hyp implementations.
87 */
88#define DECLARE_KVM_HYP_SYM(sym) \
89 DECLARE_KVM_VHE_SYM(sym); \
90 DECLARE_KVM_NVHE_SYM(sym)
91
92#define DECLARE_KVM_VHE_PER_CPU(type, sym) \
93 DECLARE_PER_CPU(type, sym)
94#define DECLARE_KVM_NVHE_PER_CPU(type, sym) \
95 DECLARE_PER_CPU(type, kvm_nvhe_sym(sym))
96
97#define DECLARE_KVM_HYP_PER_CPU(type, sym) \
98 DECLARE_KVM_VHE_PER_CPU(type, sym); \
99 DECLARE_KVM_NVHE_PER_CPU(type, sym)
100
101/*
102 * Compute pointer to a symbol defined in nVHE percpu region.
103 * Returns NULL if percpu memory has not been allocated yet.
104 */
105#define this_cpu_ptr_nvhe_sym(sym) per_cpu_ptr_nvhe_sym(sym, smp_processor_id())
106#define per_cpu_ptr_nvhe_sym(sym, cpu) \
107 ({ \
108 unsigned long base, off; \
109 base = kvm_arm_hyp_percpu_base[cpu]; \
110 off = (unsigned long)&CHOOSE_NVHE_SYM(sym) - \
111 (unsigned long)&CHOOSE_NVHE_SYM(__per_cpu_start); \
112 base ? (typeof(CHOOSE_NVHE_SYM(sym))*)(base + off) : NULL; \
113 })
114
115#if defined(__KVM_NVHE_HYPERVISOR__)
116
117#define CHOOSE_NVHE_SYM(sym) sym
118#define CHOOSE_HYP_SYM(sym) CHOOSE_NVHE_SYM(sym)
119
120/* The nVHE hypervisor shouldn't even try to access VHE symbols */
121extern void *__nvhe_undefined_symbol;
122#define CHOOSE_VHE_SYM(sym) __nvhe_undefined_symbol
123#define this_cpu_ptr_hyp_sym(sym) (&__nvhe_undefined_symbol)
124#define per_cpu_ptr_hyp_sym(sym, cpu) (&__nvhe_undefined_symbol)
125
126#elif defined(__KVM_VHE_HYPERVISOR__)
127
128#define CHOOSE_VHE_SYM(sym) sym
129#define CHOOSE_HYP_SYM(sym) CHOOSE_VHE_SYM(sym)
130
131/* The VHE hypervisor shouldn't even try to access nVHE symbols */
132extern void *__vhe_undefined_symbol;
133#define CHOOSE_NVHE_SYM(sym) __vhe_undefined_symbol
134#define this_cpu_ptr_hyp_sym(sym) (&__vhe_undefined_symbol)
135#define per_cpu_ptr_hyp_sym(sym, cpu) (&__vhe_undefined_symbol)
136
137#else
138
139/*
140 * BIG FAT WARNINGS:
141 *
142 * - Don't be tempted to change the following is_kernel_in_hyp_mode()
143 * to has_vhe(). has_vhe() is implemented as a *final* capability,
144 * while this is used early at boot time, when the capabilities are
145 * not final yet....
146 *
147 * - Don't let the nVHE hypervisor have access to this, as it will
148 * pick the *wrong* symbol (yes, it runs at EL2...).
149 */
150#define CHOOSE_HYP_SYM(sym) (is_kernel_in_hyp_mode() \
151 ? CHOOSE_VHE_SYM(sym) \
152 : CHOOSE_NVHE_SYM(sym))
153
154#define this_cpu_ptr_hyp_sym(sym) (is_kernel_in_hyp_mode() \
155 ? this_cpu_ptr(&sym) \
156 : this_cpu_ptr_nvhe_sym(sym))
157
158#define per_cpu_ptr_hyp_sym(sym, cpu) (is_kernel_in_hyp_mode() \
159 ? per_cpu_ptr(&sym, cpu) \
160 : per_cpu_ptr_nvhe_sym(sym, cpu))
161
162#define CHOOSE_VHE_SYM(sym) sym
163#define CHOOSE_NVHE_SYM(sym) kvm_nvhe_sym(sym)
164
165#endif
166
167struct kvm_nvhe_init_params {
168 unsigned long mair_el2;
169 unsigned long tcr_el2;
170 unsigned long tpidr_el2;
171 unsigned long stack_hyp_va;
172 unsigned long stack_pa;
173 phys_addr_t pgd_pa;
174 unsigned long hcr_el2;
175 unsigned long vttbr;
176 unsigned long vtcr;
177};
178
179/*
180 * Used by the host in EL1 to dump the nVHE hypervisor backtrace on
181 * hyp_panic() in non-protected mode.
182 *
183 * @stack_base: hyp VA of the hyp_stack base.
184 * @overflow_stack_base: hyp VA of the hyp_overflow_stack base.
185 * @fp: hyp FP where the backtrace begins.
186 * @pc: hyp PC where the backtrace begins.
187 */
188struct kvm_nvhe_stacktrace_info {
189 unsigned long stack_base;
190 unsigned long overflow_stack_base;
191 unsigned long fp;
192 unsigned long pc;
193};
194
195/* Translate a kernel address @ptr into its equivalent linear mapping */
196#define kvm_ksym_ref(ptr) \
197 ({ \
198 void *val = (ptr); \
199 if (!is_kernel_in_hyp_mode()) \
200 val = lm_alias((ptr)); \
201 val; \
202 })
203#define kvm_ksym_ref_nvhe(sym) kvm_ksym_ref(kvm_nvhe_sym(sym))
204
205struct kvm;
206struct kvm_vcpu;
207struct kvm_s2_mmu;
208
209DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
210DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
211#define __kvm_hyp_init CHOOSE_NVHE_SYM(__kvm_hyp_init)
212#define __kvm_hyp_vector CHOOSE_HYP_SYM(__kvm_hyp_vector)
213
214extern unsigned long kvm_arm_hyp_percpu_base[NR_CPUS];
215DECLARE_KVM_NVHE_SYM(__per_cpu_start);
216DECLARE_KVM_NVHE_SYM(__per_cpu_end);
217
218DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs);
219#define __bp_harden_hyp_vecs CHOOSE_HYP_SYM(__bp_harden_hyp_vecs)
220
221extern void __kvm_flush_vm_context(void);
222extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu);
223extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
224 int level);
225extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
226
227extern void __kvm_timer_set_cntvoff(u64 cntvoff);
228
229extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
230
231extern void __kvm_adjust_pc(struct kvm_vcpu *vcpu);
232
233extern u64 __vgic_v3_get_gic_config(void);
234extern u64 __vgic_v3_read_vmcr(void);
235extern void __vgic_v3_write_vmcr(u32 vmcr);
236extern void __vgic_v3_init_lrs(void);
237
238extern u64 __kvm_get_mdcr_el2(void);
239
240#define __KVM_EXTABLE(from, to) \
241 " .pushsection __kvm_ex_table, \"a\"\n" \
242 " .align 3\n" \
243 " .long (" #from " - .), (" #to " - .)\n" \
244 " .popsection\n"
245
246
247#define __kvm_at(at_op, addr) \
248( { \
249 int __kvm_at_err = 0; \
250 u64 spsr, elr; \
251 asm volatile( \
252 " mrs %1, spsr_el2\n" \
253 " mrs %2, elr_el2\n" \
254 "1: at "at_op", %3\n" \
255 " isb\n" \
256 " b 9f\n" \
257 "2: msr spsr_el2, %1\n" \
258 " msr elr_el2, %2\n" \
259 " mov %w0, %4\n" \
260 "9:\n" \
261 __KVM_EXTABLE(1b, 2b) \
262 : "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr) \
263 : "r" (addr), "i" (-EFAULT)); \
264 __kvm_at_err; \
265} )
266
267
268#else /* __ASSEMBLY__ */
269
270.macro get_host_ctxt reg, tmp
271 adr_this_cpu \reg, kvm_host_data, \tmp
272 add \reg, \reg, #HOST_DATA_CONTEXT
273.endm
274
275.macro get_vcpu_ptr vcpu, ctxt
276 get_host_ctxt \ctxt, \vcpu
277 ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
278.endm
279
280.macro get_loaded_vcpu vcpu, ctxt
281 adr_this_cpu \ctxt, kvm_hyp_ctxt, \vcpu
282 ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
283.endm
284
285.macro set_loaded_vcpu vcpu, ctxt, tmp
286 adr_this_cpu \ctxt, kvm_hyp_ctxt, \tmp
287 str \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
288.endm
289
290/*
291 * KVM extable for unexpected exceptions.
292 * Create a struct kvm_exception_table_entry output to a section that can be
293 * mapped by EL2. The table is not sorted.
294 *
295 * The caller must ensure:
296 * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
297 * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
298 */
299.macro _kvm_extable, from, to
300 .pushsection __kvm_ex_table, "a"
301 .align 3
302 .long (\from - .), (\to - .)
303 .popsection
304.endm
305
306#define CPU_XREG_OFFSET(x) (CPU_USER_PT_REGS + 8*x)
307#define CPU_LR_OFFSET CPU_XREG_OFFSET(30)
308#define CPU_SP_EL0_OFFSET (CPU_LR_OFFSET + 8)
309
310/*
311 * We treat x18 as callee-saved as the host may use it as a platform
312 * register (e.g. for shadow call stack).
313 */
314.macro save_callee_saved_regs ctxt
315 str x18, [\ctxt, #CPU_XREG_OFFSET(18)]
316 stp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
317 stp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
318 stp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
319 stp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
320 stp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
321 stp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)]
322.endm
323
324.macro restore_callee_saved_regs ctxt
325 // We require \ctxt is not x18-x28
326 ldr x18, [\ctxt, #CPU_XREG_OFFSET(18)]
327 ldp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
328 ldp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
329 ldp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
330 ldp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
331 ldp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
332 ldp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)]
333.endm
334
335.macro save_sp_el0 ctxt, tmp
336 mrs \tmp, sp_el0
337 str \tmp, [\ctxt, #CPU_SP_EL0_OFFSET]
338.endm
339
340.macro restore_sp_el0 ctxt, tmp
341 ldr \tmp, [\ctxt, #CPU_SP_EL0_OFFSET]
342 msr sp_el0, \tmp
343.endm
344
345#endif
346
347#endif /* __ARM_KVM_ASM_H__ */