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Diffstat (limited to 'arch/arm64/include/asm/kvm_asm.h')
| -rw-r--r-- | arch/arm64/include/asm/kvm_asm.h | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h new file mode 100644 index 000000000..ada24a20a --- /dev/null +++ b/arch/arm64/include/asm/kvm_asm.h @@ -0,0 +1,337 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2012,2013 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + */ + +#ifndef __ARM_KVM_ASM_H__ +#define __ARM_KVM_ASM_H__ + +#include <asm/hyp_image.h> +#include <asm/virt.h> + +#define ARM_EXIT_WITH_SERROR_BIT 31 +#define ARM_EXCEPTION_CODE(x) ((x) & ~(1U << ARM_EXIT_WITH_SERROR_BIT)) +#define ARM_EXCEPTION_IS_TRAP(x) (ARM_EXCEPTION_CODE((x)) == ARM_EXCEPTION_TRAP) +#define ARM_SERROR_PENDING(x) !!((x) & (1U << ARM_EXIT_WITH_SERROR_BIT)) + +#define ARM_EXCEPTION_IRQ 0 +#define ARM_EXCEPTION_EL1_SERROR 1 +#define ARM_EXCEPTION_TRAP 2 +#define ARM_EXCEPTION_IL 3 +/* The hyp-stub will return this for any kvm_call_hyp() call */ +#define ARM_EXCEPTION_HYP_GONE HVC_STUB_ERR + +#define kvm_arm_exception_type \ + {ARM_EXCEPTION_IRQ, "IRQ" }, \ + {ARM_EXCEPTION_EL1_SERROR, "SERROR" }, \ + {ARM_EXCEPTION_TRAP, "TRAP" }, \ + {ARM_EXCEPTION_HYP_GONE, "HYP_GONE" } + +/* + * Size of the HYP vectors preamble. kvm_patch_vector_branch() generates code + * that jumps over this. + */ +#define KVM_VECTOR_PREAMBLE (2 * AARCH64_INSN_SIZE) + +#define __SMCCC_WORKAROUND_1_SMC_SZ 36 +#define __SMCCC_WORKAROUND_3_SMC_SZ 36 +#define __SPECTRE_BHB_LOOP_SZ 44 +#define __SPECTRE_BHB_CLEARBHB_SZ 12 + +#define KVM_HOST_SMCCC_ID(id) \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_64, \ + ARM_SMCCC_OWNER_VENDOR_HYP, \ + (id)) + +#define KVM_HOST_SMCCC_FUNC(name) KVM_HOST_SMCCC_ID(__KVM_HOST_SMCCC_FUNC_##name) + +#define __KVM_HOST_SMCCC_FUNC___kvm_hyp_init 0 +#define __KVM_HOST_SMCCC_FUNC___kvm_vcpu_run 1 +#define __KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context 2 +#define __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid_ipa 3 +#define __KVM_HOST_SMCCC_FUNC___kvm_tlb_flush_vmid 4 +#define __KVM_HOST_SMCCC_FUNC___kvm_flush_cpu_context 5 +#define __KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff 6 +#define __KVM_HOST_SMCCC_FUNC___kvm_enable_ssbs 7 +#define __KVM_HOST_SMCCC_FUNC___vgic_v3_get_ich_vtr_el2 8 +#define __KVM_HOST_SMCCC_FUNC___vgic_v3_read_vmcr 9 +#define __KVM_HOST_SMCCC_FUNC___vgic_v3_write_vmcr 10 +#define __KVM_HOST_SMCCC_FUNC___vgic_v3_init_lrs 11 +#define __KVM_HOST_SMCCC_FUNC___kvm_get_mdcr_el2 12 +#define __KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs 13 +#define __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_aprs 14 + +#ifndef __ASSEMBLY__ + +#include <linux/mm.h> + +#define DECLARE_KVM_VHE_SYM(sym) extern char sym[] +#define DECLARE_KVM_NVHE_SYM(sym) extern char kvm_nvhe_sym(sym)[] + +/* + * Define a pair of symbols sharing the same name but one defined in + * VHE and the other in nVHE hyp implementations. + */ +#define DECLARE_KVM_HYP_SYM(sym) \ + DECLARE_KVM_VHE_SYM(sym); \ + DECLARE_KVM_NVHE_SYM(sym) + +#define DECLARE_KVM_VHE_PER_CPU(type, sym) \ + DECLARE_PER_CPU(type, sym) +#define DECLARE_KVM_NVHE_PER_CPU(type, sym) \ + DECLARE_PER_CPU(type, kvm_nvhe_sym(sym)) + +#define DECLARE_KVM_HYP_PER_CPU(type, sym) \ + DECLARE_KVM_VHE_PER_CPU(type, sym); \ + DECLARE_KVM_NVHE_PER_CPU(type, sym) + +/* + * Compute pointer to a symbol defined in nVHE percpu region. + * Returns NULL if percpu memory has not been allocated yet. + */ +#define this_cpu_ptr_nvhe_sym(sym) per_cpu_ptr_nvhe_sym(sym, smp_processor_id()) +#define per_cpu_ptr_nvhe_sym(sym, cpu) \ + ({ \ + unsigned long base, off; \ + base = kvm_arm_hyp_percpu_base[cpu]; \ + off = (unsigned long)&CHOOSE_NVHE_SYM(sym) - \ + (unsigned long)&CHOOSE_NVHE_SYM(__per_cpu_start); \ + base ? (typeof(CHOOSE_NVHE_SYM(sym))*)(base + off) : NULL; \ + }) + +#if defined(__KVM_NVHE_HYPERVISOR__) + +#define CHOOSE_NVHE_SYM(sym) sym +#define CHOOSE_HYP_SYM(sym) CHOOSE_NVHE_SYM(sym) + +/* The nVHE hypervisor shouldn't even try to access VHE symbols */ +extern void *__nvhe_undefined_symbol; +#define CHOOSE_VHE_SYM(sym) __nvhe_undefined_symbol +#define this_cpu_ptr_hyp_sym(sym) (&__nvhe_undefined_symbol) +#define per_cpu_ptr_hyp_sym(sym, cpu) (&__nvhe_undefined_symbol) + +#elif defined(__KVM_VHE_HYPERVISOR__) + +#define CHOOSE_VHE_SYM(sym) sym +#define CHOOSE_HYP_SYM(sym) CHOOSE_VHE_SYM(sym) + +/* The VHE hypervisor shouldn't even try to access nVHE symbols */ +extern void *__vhe_undefined_symbol; +#define CHOOSE_NVHE_SYM(sym) __vhe_undefined_symbol +#define this_cpu_ptr_hyp_sym(sym) (&__vhe_undefined_symbol) +#define per_cpu_ptr_hyp_sym(sym, cpu) (&__vhe_undefined_symbol) + +#else + +/* + * BIG FAT WARNINGS: + * + * - Don't be tempted to change the following is_kernel_in_hyp_mode() + * to has_vhe(). has_vhe() is implemented as a *final* capability, + * while this is used early at boot time, when the capabilities are + * not final yet.... + * + * - Don't let the nVHE hypervisor have access to this, as it will + * pick the *wrong* symbol (yes, it runs at EL2...). + */ +#define CHOOSE_HYP_SYM(sym) (is_kernel_in_hyp_mode() \ + ? CHOOSE_VHE_SYM(sym) \ + : CHOOSE_NVHE_SYM(sym)) + +#define this_cpu_ptr_hyp_sym(sym) (is_kernel_in_hyp_mode() \ + ? this_cpu_ptr(&sym) \ + : this_cpu_ptr_nvhe_sym(sym)) + +#define per_cpu_ptr_hyp_sym(sym, cpu) (is_kernel_in_hyp_mode() \ + ? per_cpu_ptr(&sym, cpu) \ + : per_cpu_ptr_nvhe_sym(sym, cpu)) + +#define CHOOSE_VHE_SYM(sym) sym +#define CHOOSE_NVHE_SYM(sym) kvm_nvhe_sym(sym) + +#endif + +/* Translate a kernel address @ptr into its equivalent linear mapping */ +#define kvm_ksym_ref(ptr) \ + ({ \ + void *val = (ptr); \ + if (!is_kernel_in_hyp_mode()) \ + val = lm_alias((ptr)); \ + val; \ + }) +#define kvm_ksym_ref_nvhe(sym) kvm_ksym_ref(kvm_nvhe_sym(sym)) + +struct kvm; +struct kvm_vcpu; +struct kvm_s2_mmu; + +DECLARE_KVM_NVHE_SYM(__kvm_hyp_init); +DECLARE_KVM_NVHE_SYM(__kvm_hyp_host_vector); +DECLARE_KVM_HYP_SYM(__kvm_hyp_vector); +#define __kvm_hyp_init CHOOSE_NVHE_SYM(__kvm_hyp_init) +#define __kvm_hyp_host_vector CHOOSE_NVHE_SYM(__kvm_hyp_host_vector) +#define __kvm_hyp_vector CHOOSE_HYP_SYM(__kvm_hyp_vector) + +extern unsigned long kvm_arm_hyp_percpu_base[NR_CPUS]; +DECLARE_KVM_NVHE_SYM(__per_cpu_start); +DECLARE_KVM_NVHE_SYM(__per_cpu_end); + +extern atomic_t arm64_el2_vector_last_slot; +DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs); +#define __bp_harden_hyp_vecs CHOOSE_HYP_SYM(__bp_harden_hyp_vecs) + +extern void __kvm_flush_vm_context(void); +extern void __kvm_flush_cpu_context(struct kvm_s2_mmu *mmu); +extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa, + int level); +extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu); + +extern void __kvm_timer_set_cntvoff(u64 cntvoff); + +extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu); + +extern void __kvm_enable_ssbs(void); + +extern u64 __vgic_v3_get_ich_vtr_el2(void); +extern u64 __vgic_v3_read_vmcr(void); +extern void __vgic_v3_write_vmcr(u32 vmcr); +extern void __vgic_v3_init_lrs(void); + +extern u32 __kvm_get_mdcr_el2(void); + +extern char __smccc_workaround_1_smc[__SMCCC_WORKAROUND_1_SMC_SZ]; +extern char __smccc_workaround_3_smc[__SMCCC_WORKAROUND_3_SMC_SZ]; +extern char __spectre_bhb_loop_k8[__SPECTRE_BHB_LOOP_SZ]; +extern char __spectre_bhb_loop_k24[__SPECTRE_BHB_LOOP_SZ]; +extern char __spectre_bhb_loop_k32[__SPECTRE_BHB_LOOP_SZ]; +extern char __spectre_bhb_clearbhb[__SPECTRE_BHB_LOOP_SZ]; + +/* + * Obtain the PC-relative address of a kernel symbol + * s: symbol + * + * The goal of this macro is to return a symbol's address based on a + * PC-relative computation, as opposed to a loading the VA from a + * constant pool or something similar. This works well for HYP, as an + * absolute VA is guaranteed to be wrong. Only use this if trying to + * obtain the address of a symbol (i.e. not something you obtained by + * following a pointer). + */ +#define hyp_symbol_addr(s) \ + ({ \ + typeof(s) *addr; \ + asm("adrp %0, %1\n" \ + "add %0, %0, :lo12:%1\n" \ + : "=r" (addr) : "S" (&s)); \ + addr; \ + }) + +#define __KVM_EXTABLE(from, to) \ + " .pushsection __kvm_ex_table, \"a\"\n" \ + " .align 3\n" \ + " .long (" #from " - .), (" #to " - .)\n" \ + " .popsection\n" + + +#define __kvm_at(at_op, addr) \ +( { \ + int __kvm_at_err = 0; \ + u64 spsr, elr; \ + asm volatile( \ + " mrs %1, spsr_el2\n" \ + " mrs %2, elr_el2\n" \ + "1: at "at_op", %3\n" \ + " isb\n" \ + " b 9f\n" \ + "2: msr spsr_el2, %1\n" \ + " msr elr_el2, %2\n" \ + " mov %w0, %4\n" \ + "9:\n" \ + __KVM_EXTABLE(1b, 2b) \ + : "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr) \ + : "r" (addr), "i" (-EFAULT)); \ + __kvm_at_err; \ +} ) + + +#else /* __ASSEMBLY__ */ + +.macro get_host_ctxt reg, tmp + adr_this_cpu \reg, kvm_host_data, \tmp + add \reg, \reg, #HOST_DATA_CONTEXT +.endm + +.macro get_vcpu_ptr vcpu, ctxt + get_host_ctxt \ctxt, \vcpu + ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU] +.endm + +.macro get_loaded_vcpu vcpu, ctxt + adr_this_cpu \ctxt, kvm_hyp_ctxt, \vcpu + ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU] +.endm + +.macro set_loaded_vcpu vcpu, ctxt, tmp + adr_this_cpu \ctxt, kvm_hyp_ctxt, \tmp + str \vcpu, [\ctxt, #HOST_CONTEXT_VCPU] +.endm + +/* + * KVM extable for unexpected exceptions. + * In the same format _asm_extable, but output to a different section so that + * it can be mapped to EL2. The KVM version is not sorted. The caller must + * ensure: + * x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented + * code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup. + */ +.macro _kvm_extable, from, to + .pushsection __kvm_ex_table, "a" + .align 3 + .long (\from - .), (\to - .) + .popsection +.endm + +#define CPU_XREG_OFFSET(x) (CPU_USER_PT_REGS + 8*x) +#define CPU_LR_OFFSET CPU_XREG_OFFSET(30) +#define CPU_SP_EL0_OFFSET (CPU_LR_OFFSET + 8) + +/* + * We treat x18 as callee-saved as the host may use it as a platform + * register (e.g. for shadow call stack). + */ +.macro save_callee_saved_regs ctxt + str x18, [\ctxt, #CPU_XREG_OFFSET(18)] + stp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)] + stp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)] + stp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)] + stp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)] + stp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)] + stp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)] +.endm + +.macro restore_callee_saved_regs ctxt + // We require \ctxt is not x18-x28 + ldr x18, [\ctxt, #CPU_XREG_OFFSET(18)] + ldp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)] + ldp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)] + ldp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)] + ldp x25, x26, [\ctxt, #CPU_XREG_OFFSET(25)] + ldp x27, x28, [\ctxt, #CPU_XREG_OFFSET(27)] + ldp x29, lr, [\ctxt, #CPU_XREG_OFFSET(29)] +.endm + +.macro save_sp_el0 ctxt, tmp + mrs \tmp, sp_el0 + str \tmp, [\ctxt, #CPU_SP_EL0_OFFSET] +.endm + +.macro restore_sp_el0 ctxt, tmp + ldr \tmp, [\ctxt, #CPU_SP_EL0_OFFSET] + msr sp_el0, \tmp +.endm + +#endif + +#endif /* __ARM_KVM_ASM_H__ */ |