kvm_asm.h

  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#include <asm/sysreg.h>
 14
 15#define ARM_EXIT_WITH_SERROR_BIT  31
 16#define ARM_EXCEPTION_CODE(x)	  ((x) & ~(1U << ARM_EXIT_WITH_SERROR_BIT))
 17#define ARM_EXCEPTION_IS_TRAP(x)  (ARM_EXCEPTION_CODE((x)) == ARM_EXCEPTION_TRAP)
 18#define ARM_SERROR_PENDING(x)	  !!((x) & (1U << ARM_EXIT_WITH_SERROR_BIT))
 19
 20#define ARM_EXCEPTION_IRQ	  0
 21#define ARM_EXCEPTION_EL1_SERROR  1
 22#define ARM_EXCEPTION_TRAP	  2
 23#define ARM_EXCEPTION_IL	  3
 24/* The hyp-stub will return this for any kvm_call_hyp() call */
 25#define ARM_EXCEPTION_HYP_GONE	  HVC_STUB_ERR
 26
 27#define kvm_arm_exception_type					\
 28	{ARM_EXCEPTION_IRQ,		"IRQ"		},	\
 29	{ARM_EXCEPTION_EL1_SERROR, 	"SERROR"	},	\
 30	{ARM_EXCEPTION_TRAP, 		"TRAP"		},	\
 31	{ARM_EXCEPTION_HYP_GONE,	"HYP_GONE"	}
 32
 33/*
 34 * Size of the HYP vectors preamble. kvm_patch_vector_branch() generates code
 35 * that jumps over this.
 36 */
 37#define KVM_VECTOR_PREAMBLE	(2 * AARCH64_INSN_SIZE)
 38
 39#define KVM_HOST_SMCCC_ID(id)						\
 40	ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL,				\
 41			   ARM_SMCCC_SMC_64,				\
 42			   ARM_SMCCC_OWNER_VENDOR_HYP,			\
 43			   (id))
 44
 45#define KVM_HOST_SMCCC_FUNC(name) KVM_HOST_SMCCC_ID(__KVM_HOST_SMCCC_FUNC_##name)
 46
 47#define __KVM_HOST_SMCCC_FUNC___kvm_hyp_init			0
 48
 49#ifndef __ASSEMBLER__
 50
 51#include <linux/mm.h>
 52
 53enum __kvm_host_smccc_func {
 54	/* Hypercalls available only prior to pKVM finalisation */
 55	/* __KVM_HOST_SMCCC_FUNC___kvm_hyp_init */
 56	__KVM_HOST_SMCCC_FUNC___pkvm_init = __KVM_HOST_SMCCC_FUNC___kvm_hyp_init + 1,
 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___pkvm_host_share_guest,
 68	__KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_guest,
 69	__KVM_HOST_SMCCC_FUNC___pkvm_host_relax_perms_guest,
 70	__KVM_HOST_SMCCC_FUNC___pkvm_host_wrprotect_guest,
 71	__KVM_HOST_SMCCC_FUNC___pkvm_host_test_clear_young_guest,
 72	__KVM_HOST_SMCCC_FUNC___pkvm_host_mkyoung_guest,
 73	__KVM_HOST_SMCCC_FUNC___kvm_adjust_pc,
 74	__KVM_HOST_SMCCC_FUNC___kvm_vcpu_run,
 75	__KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,
 76	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa,
 77	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa_nsh,
 78	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid,
 79	__KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_range,
 80	__KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context,
 81	__KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff,
 82	__KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs,
 83	__KVM_HOST_SMCCC_FUNC___vgic_v3_restore_vmcr_aprs,
 84	__KVM_HOST_SMCCC_FUNC___pkvm_reserve_vm,
 85	__KVM_HOST_SMCCC_FUNC___pkvm_unreserve_vm,
 86	__KVM_HOST_SMCCC_FUNC___pkvm_init_vm,
 87	__KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu,
 88	__KVM_HOST_SMCCC_FUNC___pkvm_teardown_vm,
 89	__KVM_HOST_SMCCC_FUNC___pkvm_vcpu_load,
 90	__KVM_HOST_SMCCC_FUNC___pkvm_vcpu_put,
 91	__KVM_HOST_SMCCC_FUNC___pkvm_tlb_flush_vmid,
 92};
 93
 94#define DECLARE_KVM_VHE_SYM(sym)	extern char sym[]
 95#define DECLARE_KVM_NVHE_SYM(sym)	extern char kvm_nvhe_sym(sym)[]
 96
 97/*
 98 * Define a pair of symbols sharing the same name but one defined in
 99 * VHE and the other in nVHE hyp implementations.
100 */
101#define DECLARE_KVM_HYP_SYM(sym)		\
102	DECLARE_KVM_VHE_SYM(sym);		\
103	DECLARE_KVM_NVHE_SYM(sym)
104
105#define DECLARE_KVM_VHE_PER_CPU(type, sym)	\
106	DECLARE_PER_CPU(type, sym)
107#define DECLARE_KVM_NVHE_PER_CPU(type, sym)	\
108	DECLARE_PER_CPU(type, kvm_nvhe_sym(sym))
109
110#define DECLARE_KVM_HYP_PER_CPU(type, sym)	\
111	DECLARE_KVM_VHE_PER_CPU(type, sym);	\
112	DECLARE_KVM_NVHE_PER_CPU(type, sym)
113
114/*
115 * Compute pointer to a symbol defined in nVHE percpu region.
116 * Returns NULL if percpu memory has not been allocated yet.
117 */
118#define this_cpu_ptr_nvhe_sym(sym)	per_cpu_ptr_nvhe_sym(sym, smp_processor_id())
119#define per_cpu_ptr_nvhe_sym(sym, cpu)						\
120	({									\
121		unsigned long base, off;					\
122		base = kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[cpu];		\
123		off = (unsigned long)&CHOOSE_NVHE_SYM(sym) -			\
124		      (unsigned long)&CHOOSE_NVHE_SYM(__per_cpu_start);		\
125		base ? (typeof(CHOOSE_NVHE_SYM(sym))*)(base + off) : NULL;	\
126	})
127
128#if defined(__KVM_NVHE_HYPERVISOR__)
129
130#define CHOOSE_NVHE_SYM(sym)	sym
131#define CHOOSE_HYP_SYM(sym)	CHOOSE_NVHE_SYM(sym)
132
133/* The nVHE hypervisor shouldn't even try to access VHE symbols */
134extern void *__nvhe_undefined_symbol;
135#define CHOOSE_VHE_SYM(sym)		__nvhe_undefined_symbol
136#define this_cpu_ptr_hyp_sym(sym)	(&__nvhe_undefined_symbol)
137#define per_cpu_ptr_hyp_sym(sym, cpu)	(&__nvhe_undefined_symbol)
138
139#elif defined(__KVM_VHE_HYPERVISOR__)
140
141#define CHOOSE_VHE_SYM(sym)	sym
142#define CHOOSE_HYP_SYM(sym)	CHOOSE_VHE_SYM(sym)
143
144/* The VHE hypervisor shouldn't even try to access nVHE symbols */
145extern void *__vhe_undefined_symbol;
146#define CHOOSE_NVHE_SYM(sym)		__vhe_undefined_symbol
147#define this_cpu_ptr_hyp_sym(sym)	(&__vhe_undefined_symbol)
148#define per_cpu_ptr_hyp_sym(sym, cpu)	(&__vhe_undefined_symbol)
149
150#else
151
152/*
153 * BIG FAT WARNINGS:
154 *
155 * - Don't be tempted to change the following is_kernel_in_hyp_mode()
156 *   to has_vhe(). has_vhe() is implemented as a *final* capability,
157 *   while this is used early at boot time, when the capabilities are
158 *   not final yet....
159 *
160 * - Don't let the nVHE hypervisor have access to this, as it will
161 *   pick the *wrong* symbol (yes, it runs at EL2...).
162 */
163#define CHOOSE_HYP_SYM(sym)		(is_kernel_in_hyp_mode()	\
164					   ? CHOOSE_VHE_SYM(sym)	\
165					   : CHOOSE_NVHE_SYM(sym))
166
167#define this_cpu_ptr_hyp_sym(sym)	(is_kernel_in_hyp_mode()	\
168					   ? this_cpu_ptr(&sym)		\
169					   : this_cpu_ptr_nvhe_sym(sym))
170
171#define per_cpu_ptr_hyp_sym(sym, cpu)	(is_kernel_in_hyp_mode()	\
172					   ? per_cpu_ptr(&sym, cpu)	\
173					   : per_cpu_ptr_nvhe_sym(sym, cpu))
174
175#define CHOOSE_VHE_SYM(sym)	sym
176#define CHOOSE_NVHE_SYM(sym)	kvm_nvhe_sym(sym)
177
178#endif
179
180struct kvm_nvhe_init_params {
181	unsigned long mair_el2;
182	unsigned long tcr_el2;
183	unsigned long tpidr_el2;
184	unsigned long stack_hyp_va;
185	unsigned long stack_pa;
186	phys_addr_t pgd_pa;
187	unsigned long hcr_el2;
188	unsigned long vttbr;
189	unsigned long vtcr;
190	unsigned long tmp;
191};
192
193/*
194 * Used by the host in EL1 to dump the nVHE hypervisor backtrace on
195 * hyp_panic() in non-protected mode.
196 *
197 * @stack_base:                 hyp VA of the hyp_stack base.
198 * @overflow_stack_base:        hyp VA of the hyp_overflow_stack base.
199 * @fp:                         hyp FP where the backtrace begins.
200 * @pc:                         hyp PC where the backtrace begins.
201 */
202struct kvm_nvhe_stacktrace_info {
203	unsigned long stack_base;
204	unsigned long overflow_stack_base;
205	unsigned long fp;
206	unsigned long pc;
207};
208
209/* Translate a kernel address @ptr into its equivalent linear mapping */
210#define kvm_ksym_ref(ptr)						\
211	({								\
212		void *val = (ptr);					\
213		if (!is_kernel_in_hyp_mode())				\
214			val = lm_alias((ptr));				\
215		val;							\
216	 })
217#define kvm_ksym_ref_nvhe(sym)	kvm_ksym_ref(kvm_nvhe_sym(sym))
218
219struct kvm;
220struct kvm_vcpu;
221struct kvm_s2_mmu;
222
223DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
224DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
225#define __kvm_hyp_init		CHOOSE_NVHE_SYM(__kvm_hyp_init)
226#define __kvm_hyp_vector	CHOOSE_HYP_SYM(__kvm_hyp_vector)
227
228extern unsigned long kvm_nvhe_sym(kvm_arm_hyp_percpu_base)[];
229DECLARE_KVM_NVHE_SYM(__per_cpu_start);
230DECLARE_KVM_NVHE_SYM(__per_cpu_end);
231
232DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs);
233#define __bp_harden_hyp_vecs	CHOOSE_HYP_SYM(__bp_harden_hyp_vecs)
234
235extern void __kvm_flush_vm_context(void);
236extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu);
237extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
238				     int level);
239extern void __kvm_tlb_flush_vmid_ipa_nsh(struct kvm_s2_mmu *mmu,
240					 phys_addr_t ipa,
241					 int level);
242extern void __kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu,
243					phys_addr_t start, unsigned long pages);
244extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
245
246extern int __kvm_tlbi_s1e2(struct kvm_s2_mmu *mmu, u64 va, u64 sys_encoding);
247
248extern void __kvm_timer_set_cntvoff(u64 cntvoff);
249extern int __kvm_at_s1e01(struct kvm_vcpu *vcpu, u32 op, u64 vaddr);
250extern int __kvm_at_s1e2(struct kvm_vcpu *vcpu, u32 op, u64 vaddr);
251extern int __kvm_at_s12(struct kvm_vcpu *vcpu, u32 op, u64 vaddr);
252
253extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
254
255extern void __kvm_adjust_pc(struct kvm_vcpu *vcpu);
256
257extern u64 __vgic_v3_get_gic_config(void);
258extern void __vgic_v3_init_lrs(void);
259
260#define __KVM_EXTABLE(from, to)						\
261	"	.pushsection	__kvm_ex_table, \"a\"\n"		\
262	"	.align		3\n"					\
263	"	.long		(" #from " - .), (" #to " - .)\n"	\
264	"	.popsection\n"
265
266
267#define __kvm_at(at_op, addr)						\
268( { 									\
269	int __kvm_at_err = 0;						\
270	u64 spsr, elr;							\
271	asm volatile(							\
272	"	mrs	%1, spsr_el2\n"					\
273	"	mrs	%2, elr_el2\n"					\
274	"1:	" __msr_s(at_op, "%3") "\n"				\
275	"	isb\n"							\
276	"	b	9f\n"						\
277	"2:	msr	spsr_el2, %1\n"					\
278	"	msr	elr_el2, %2\n"					\
279	"	mov	%w0, %4\n"					\
280	"9:\n"								\
281	__KVM_EXTABLE(1b, 2b)						\
282	: "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr)		\
283	: "r" (addr), "i" (-EFAULT));					\
284	__kvm_at_err;							\
285} )
286
287void __noreturn hyp_panic(void);
288asmlinkage void kvm_unexpected_el2_exception(void);
289asmlinkage void __noreturn hyp_panic(void);
290asmlinkage void __noreturn hyp_panic_bad_stack(void);
291asmlinkage void kvm_unexpected_el2_exception(void);
292struct kvm_cpu_context;
293void handle_trap(struct kvm_cpu_context *host_ctxt);
294asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on);
295void __noreturn __pkvm_init_finalise(void);
296void kvm_nvhe_prepare_backtrace(unsigned long fp, unsigned long pc);
297void kvm_patch_vector_branch(struct alt_instr *alt,
298	__le32 *origptr, __le32 *updptr, int nr_inst);
299void kvm_get_kimage_voffset(struct alt_instr *alt,
300	__le32 *origptr, __le32 *updptr, int nr_inst);
301void kvm_compute_final_ctr_el0(struct alt_instr *alt,
302	__le32 *origptr, __le32 *updptr, int nr_inst);
303void kvm_pan_patch_el2_entry(struct alt_instr *alt,
304			     __le32 *origptr, __le32 *updptr, int nr_inst);
305void __noreturn __cold nvhe_hyp_panic_handler(u64 esr, u64 spsr, u64 elr_virt,
306	u64 elr_phys, u64 par, uintptr_t vcpu, u64 far, u64 hpfar);
307
308#else /* __ASSEMBLER__ */
309
310.macro get_host_ctxt reg, tmp
311	adr_this_cpu \reg, kvm_host_data, \tmp
312	add	\reg, \reg, #HOST_DATA_CONTEXT
313.endm
314
315.macro get_vcpu_ptr vcpu, ctxt
316	get_host_ctxt \ctxt, \vcpu
317	ldr	\vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
318.endm
319
320.macro get_loaded_vcpu vcpu, ctxt
321	adr_this_cpu \ctxt, kvm_hyp_ctxt, \vcpu
322	ldr	\vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
323.endm
324
325.macro set_loaded_vcpu vcpu, ctxt, tmp
326	adr_this_cpu \ctxt, kvm_hyp_ctxt, \tmp
327	str	\vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
328.endm
329
330/*
331 * KVM extable for unexpected exceptions.
332 * Create a struct kvm_exception_table_entry output to a section that can be
333 * mapped by EL2. The table is not sorted.
334 *
335 * The caller must ensure:
336 * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
337 * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
338 */
339.macro	_kvm_extable, from, to
340	.pushsection	__kvm_ex_table, "a"
341	.align		3
342	.long		(\from - .), (\to - .)
343	.popsection
344.endm
345
346#define CPU_XREG_OFFSET(x)	(CPU_USER_PT_REGS + 8*x)
347#define CPU_LR_OFFSET		CPU_XREG_OFFSET(30)
348#define CPU_SP_EL0_OFFSET	(CPU_LR_OFFSET + 8)
349
350/*
351 * We treat x18 as callee-saved as the host may use it as a platform
352 * register (e.g. for shadow call stack).
353 */
354.macro save_callee_saved_regs ctxt
355	str	x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
356	stp	x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
357	stp	x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
358	stp	x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
359	stp	x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
360	stp	x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
361	stp	x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
362.endm
363
364.macro restore_callee_saved_regs ctxt
365	// We require \ctxt is not x18-x28
366	ldr	x18,      [\ctxt, #CPU_XREG_OFFSET(18)]
367	ldp	x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)]
368	ldp	x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)]
369	ldp	x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)]
370	ldp	x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)]
371	ldp	x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)]
372	ldp	x29, lr,  [\ctxt, #CPU_XREG_OFFSET(29)]
373.endm
374
375.macro save_sp_el0 ctxt, tmp
376	mrs	\tmp,	sp_el0
377	str	\tmp,	[\ctxt, #CPU_SP_EL0_OFFSET]
378.endm
379
380.macro restore_sp_el0 ctxt, tmp
381	ldr	\tmp,	  [\ctxt, #CPU_SP_EL0_OFFSET]
382	msr	sp_el0, \tmp
383.endm
384
385#endif
386
387#endif /* __ARM_KVM_ASM_H__ */