diff options
author | Marc Zyngier <maz@kernel.org> | 2020-11-27 14:47:08 +0300 |
---|---|---|
committer | Marc Zyngier <maz@kernel.org> | 2020-11-27 14:47:08 +0300 |
commit | dc2286f397e69989c803abfdb0d75ae90b88c98c (patch) | |
tree | f37b2b578b84a7186896ecb4540c7a160a5aff81 /arch | |
parent | 6e5d8c713d1e0d1e3efb327dd61fdf01ffd256db (diff) | |
parent | 4f6a36fed71dfe51df0ae9a282dc87c76d629bff (diff) | |
download | linux-dc2286f397e69989c803abfdb0d75ae90b88c98c.tar.xz |
Merge branch 'kvm-arm64/vector-rework' into kvmarm-master/next
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/arm64/include/asm/cpucaps.h | 2 | ||||
-rw-r--r-- | arch/arm64/include/asm/kvm_asm.h | 5 | ||||
-rw-r--r-- | arch/arm64/include/asm/kvm_mmu.h | 46 | ||||
-rw-r--r-- | arch/arm64/include/asm/mmu.h | 29 | ||||
-rw-r--r-- | arch/arm64/include/asm/spectre.h | 63 | ||||
-rw-r--r-- | arch/arm64/kernel/cpu_errata.c | 19 | ||||
-rw-r--r-- | arch/arm64/kernel/proton-pack.c | 84 | ||||
-rw-r--r-- | arch/arm64/kvm/arm.c | 102 | ||||
-rw-r--r-- | arch/arm64/kvm/hyp/Makefile | 2 | ||||
-rw-r--r-- | arch/arm64/kvm/hyp/hyp-entry.S | 71 | ||||
-rw-r--r-- | arch/arm64/kvm/hyp/smccc_wa.S | 32 | ||||
-rw-r--r-- | arch/arm64/kvm/va_layout.c | 18 |
12 files changed, 214 insertions, 259 deletions
diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index e7d98997c09c..162539d4c8cd 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -21,7 +21,7 @@ #define ARM64_HAS_VIRT_HOST_EXTN 11 #define ARM64_WORKAROUND_CAVIUM_27456 12 #define ARM64_HAS_32BIT_EL0 13 -#define ARM64_HARDEN_EL2_VECTORS 14 +#define ARM64_SPECTRE_V3A 14 #define ARM64_HAS_CNP 15 #define ARM64_HAS_NO_FPSIMD 16 #define ARM64_WORKAROUND_REPEAT_TLBI 17 diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index a542c422a036..4a6a77d8d13e 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -34,8 +34,6 @@ */ #define KVM_VECTOR_PREAMBLE (2 * AARCH64_INSN_SIZE) -#define __SMCCC_WORKAROUND_1_SMC_SZ 36 - #define KVM_HOST_SMCCC_ID(id) \ ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ ARM_SMCCC_SMC_64, \ @@ -175,7 +173,6 @@ 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) @@ -196,8 +193,6 @@ 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]; - /* * Obtain the PC-relative address of a kernel symbol * s: symbol diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 5633c5a27aad..e298191a854d 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -248,52 +248,6 @@ static inline int kvm_write_guest_lock(struct kvm *kvm, gpa_t gpa, return ret; } -/* - * EL2 vectors can be mapped and rerouted in a number of ways, - * depending on the kernel configuration and CPU present: - * - * - If the CPU is affected by Spectre-v2, the hardening sequence is - * placed in one of the vector slots, which is executed before jumping - * to the real vectors. - * - * - If the CPU also has the ARM64_HARDEN_EL2_VECTORS cap, the slot - * containing the hardening sequence is mapped next to the idmap page, - * and executed before jumping to the real vectors. - * - * - If the CPU only has the ARM64_HARDEN_EL2_VECTORS cap, then an - * empty slot is selected, mapped next to the idmap page, and - * executed before jumping to the real vectors. - * - * Note that ARM64_HARDEN_EL2_VECTORS is somewhat incompatible with - * VHE, as we don't have hypervisor-specific mappings. If the system - * is VHE and yet selects this capability, it will be ignored. - */ -extern void *__kvm_bp_vect_base; -extern int __kvm_harden_el2_vector_slot; - -static inline void *kvm_get_hyp_vector(void) -{ - struct bp_hardening_data *data = arm64_get_bp_hardening_data(); - void *vect = kern_hyp_va(kvm_ksym_ref(__kvm_hyp_vector)); - int slot = -1; - - if (cpus_have_const_cap(ARM64_SPECTRE_V2) && data->fn) { - vect = kern_hyp_va(kvm_ksym_ref(__bp_harden_hyp_vecs)); - slot = data->hyp_vectors_slot; - } - - if (this_cpu_has_cap(ARM64_HARDEN_EL2_VECTORS) && !has_vhe()) { - vect = __kvm_bp_vect_base; - if (slot == -1) - slot = __kvm_harden_el2_vector_slot; - } - - if (slot != -1) - vect += slot * SZ_2K; - - return vect; -} - #define kvm_phys_to_vttbr(addr) phys_to_ttbr(addr) static __always_inline u64 kvm_get_vttbr(struct kvm_s2_mmu *mmu) diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h index b2e91c187e2a..75beffe2ee8a 100644 --- a/arch/arm64/include/asm/mmu.h +++ b/arch/arm64/include/asm/mmu.h @@ -12,9 +12,6 @@ #define USER_ASID_FLAG (UL(1) << USER_ASID_BIT) #define TTBR_ASID_MASK (UL(0xffff) << 48) -#define BP_HARDEN_EL2_SLOTS 4 -#define __BP_HARDEN_HYP_VECS_SZ (BP_HARDEN_EL2_SLOTS * SZ_2K) - #ifndef __ASSEMBLY__ #include <linux/refcount.h> @@ -41,32 +38,6 @@ static inline bool arm64_kernel_unmapped_at_el0(void) return cpus_have_const_cap(ARM64_UNMAP_KERNEL_AT_EL0); } -typedef void (*bp_hardening_cb_t)(void); - -struct bp_hardening_data { - int hyp_vectors_slot; - bp_hardening_cb_t fn; -}; - -DECLARE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data); - -static inline struct bp_hardening_data *arm64_get_bp_hardening_data(void) -{ - return this_cpu_ptr(&bp_hardening_data); -} - -static inline void arm64_apply_bp_hardening(void) -{ - struct bp_hardening_data *d; - - if (!cpus_have_const_cap(ARM64_SPECTRE_V2)) - return; - - d = arm64_get_bp_hardening_data(); - if (d->fn) - d->fn(); -} - extern void arm64_memblock_init(void); extern void paging_init(void); extern void bootmem_init(void); diff --git a/arch/arm64/include/asm/spectre.h b/arch/arm64/include/asm/spectre.h index fcdfbce302bd..4e6d90a4fbe0 100644 --- a/arch/arm64/include/asm/spectre.h +++ b/arch/arm64/include/asm/spectre.h @@ -9,7 +9,15 @@ #ifndef __ASM_SPECTRE_H #define __ASM_SPECTRE_H +#define BP_HARDEN_EL2_SLOTS 4 +#define __BP_HARDEN_HYP_VECS_SZ ((BP_HARDEN_EL2_SLOTS - 1) * SZ_2K) + +#ifndef __ASSEMBLY__ + +#include <linux/percpu.h> + #include <asm/cpufeature.h> +#include <asm/virt.h> /* Watch out, ordering is important here. */ enum mitigation_state { @@ -20,13 +28,68 @@ enum mitigation_state { struct task_struct; +/* + * Note: the order of this enum corresponds to __bp_harden_hyp_vecs and + * we rely on having the direct vectors first. + */ +enum arm64_hyp_spectre_vector { + /* + * Take exceptions directly to __kvm_hyp_vector. This must be + * 0 so that it used by default when mitigations are not needed. + */ + HYP_VECTOR_DIRECT, + + /* + * Bounce via a slot in the hypervisor text mapping of + * __bp_harden_hyp_vecs, which contains an SMC call. + */ + HYP_VECTOR_SPECTRE_DIRECT, + + /* + * Bounce via a slot in a special mapping of __bp_harden_hyp_vecs + * next to the idmap page. + */ + HYP_VECTOR_INDIRECT, + + /* + * Bounce via a slot in a special mapping of __bp_harden_hyp_vecs + * next to the idmap page, which contains an SMC call. + */ + HYP_VECTOR_SPECTRE_INDIRECT, +}; + +typedef void (*bp_hardening_cb_t)(void); + +struct bp_hardening_data { + enum arm64_hyp_spectre_vector slot; + bp_hardening_cb_t fn; +}; + +DECLARE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data); + +static inline void arm64_apply_bp_hardening(void) +{ + struct bp_hardening_data *d; + + if (!cpus_have_const_cap(ARM64_SPECTRE_V2)) + return; + + d = this_cpu_ptr(&bp_hardening_data); + if (d->fn) + d->fn(); +} + enum mitigation_state arm64_get_spectre_v2_state(void); bool has_spectre_v2(const struct arm64_cpu_capabilities *cap, int scope); void spectre_v2_enable_mitigation(const struct arm64_cpu_capabilities *__unused); +bool has_spectre_v3a(const struct arm64_cpu_capabilities *cap, int scope); +void spectre_v3a_enable_mitigation(const struct arm64_cpu_capabilities *__unused); + enum mitigation_state arm64_get_spectre_v4_state(void); bool has_spectre_v4(const struct arm64_cpu_capabilities *cap, int scope); void spectre_v4_enable_mitigation(const struct arm64_cpu_capabilities *__unused); void spectre_v4_enable_task_mitigation(struct task_struct *tsk); +#endif /* __ASSEMBLY__ */ #endif /* __ASM_SPECTRE_H */ diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index cafaf0da05b7..a63428301f42 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -196,16 +196,6 @@ has_neoverse_n1_erratum_1542419(const struct arm64_cpu_capabilities *entry, return is_midr_in_range(midr, &range) && has_dic; } -#ifdef CONFIG_RANDOMIZE_BASE - -static const struct midr_range ca57_a72[] = { - MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), - MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), - {}, -}; - -#endif - #ifdef CONFIG_ARM64_WORKAROUND_REPEAT_TLBI static const struct arm64_cpu_capabilities arm64_repeat_tlbi_list[] = { #ifdef CONFIG_QCOM_FALKOR_ERRATUM_1009 @@ -461,9 +451,12 @@ const struct arm64_cpu_capabilities arm64_errata[] = { }, #ifdef CONFIG_RANDOMIZE_BASE { - .desc = "EL2 vector hardening", - .capability = ARM64_HARDEN_EL2_VECTORS, - ERRATA_MIDR_RANGE_LIST(ca57_a72), + /* Must come after the Spectre-v2 entry */ + .desc = "Spectre-v3a", + .capability = ARM64_SPECTRE_V3A, + .type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM, + .matches = has_spectre_v3a, + .cpu_enable = spectre_v3a_enable_mitigation, }, #endif { diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c index f6e4e3737405..fca03648e270 100644 --- a/arch/arm64/kernel/proton-pack.c +++ b/arch/arm64/kernel/proton-pack.c @@ -1,6 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-only /* - * Handle detection, reporting and mitigation of Spectre v1, v2 and v4, as + * Handle detection, reporting and mitigation of Spectre v1, v2, v3a and v4, as * detailed at: * * https://developer.arm.com/support/arm-security-updates/speculative-processor-vulnerability @@ -26,6 +26,7 @@ #include <asm/spectre.h> #include <asm/traps.h> +#include <asm/virt.h> /* * We try to ensure that the mitigation state can never change as the result of @@ -170,72 +171,26 @@ bool has_spectre_v2(const struct arm64_cpu_capabilities *entry, int scope) return true; } -DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data); - enum mitigation_state arm64_get_spectre_v2_state(void) { return spectre_v2_state; } -#ifdef CONFIG_KVM -#include <asm/cacheflush.h> -#include <asm/kvm_asm.h> - -atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1); - -static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start, - const char *hyp_vecs_end) -{ - void *dst = lm_alias(__bp_harden_hyp_vecs + slot * SZ_2K); - int i; - - for (i = 0; i < SZ_2K; i += 0x80) - memcpy(dst + i, hyp_vecs_start, hyp_vecs_end - hyp_vecs_start); - - __flush_icache_range((uintptr_t)dst, (uintptr_t)dst + SZ_2K); -} +DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data); static void install_bp_hardening_cb(bp_hardening_cb_t fn) { - static DEFINE_RAW_SPINLOCK(bp_lock); - int cpu, slot = -1; - const char *hyp_vecs_start = __smccc_workaround_1_smc; - const char *hyp_vecs_end = __smccc_workaround_1_smc + - __SMCCC_WORKAROUND_1_SMC_SZ; + __this_cpu_write(bp_hardening_data.fn, fn); /* * Vinz Clortho takes the hyp_vecs start/end "keys" at * the door when we're a guest. Skip the hyp-vectors work. */ - if (!is_hyp_mode_available()) { - __this_cpu_write(bp_hardening_data.fn, fn); + if (!is_hyp_mode_available()) return; - } - - raw_spin_lock(&bp_lock); - for_each_possible_cpu(cpu) { - if (per_cpu(bp_hardening_data.fn, cpu) == fn) { - slot = per_cpu(bp_hardening_data.hyp_vectors_slot, cpu); - break; - } - } - - if (slot == -1) { - slot = atomic_inc_return(&arm64_el2_vector_last_slot); - BUG_ON(slot >= BP_HARDEN_EL2_SLOTS); - __copy_hyp_vect_bpi(slot, hyp_vecs_start, hyp_vecs_end); - } - __this_cpu_write(bp_hardening_data.hyp_vectors_slot, slot); - __this_cpu_write(bp_hardening_data.fn, fn); - raw_spin_unlock(&bp_lock); -} -#else -static void install_bp_hardening_cb(bp_hardening_cb_t fn) -{ - __this_cpu_write(bp_hardening_data.fn, fn); + __this_cpu_write(bp_hardening_data.slot, HYP_VECTOR_SPECTRE_DIRECT); } -#endif /* CONFIG_KVM */ static void call_smc_arch_workaround_1(void) { @@ -317,6 +272,33 @@ void spectre_v2_enable_mitigation(const struct arm64_cpu_capabilities *__unused) } /* + * Spectre-v3a. + * + * Phew, there's not an awful lot to do here! We just instruct EL2 to use + * an indirect trampoline for the hyp vectors so that guests can't read + * VBAR_EL2 to defeat randomisation of the hypervisor VA layout. + */ +bool has_spectre_v3a(const struct arm64_cpu_capabilities *entry, int scope) +{ + static const struct midr_range spectre_v3a_unsafe_list[] = { + MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), + {}, + }; + + WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible()); + return is_midr_in_range_list(read_cpuid_id(), spectre_v3a_unsafe_list); +} + +void spectre_v3a_enable_mitigation(const struct arm64_cpu_capabilities *__unused) +{ + struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data); + + if (this_cpu_has_cap(ARM64_SPECTRE_V3A)) + data->slot += HYP_VECTOR_INDIRECT; +} + +/* * Spectre v4. * * If you thought Spectre v2 was nasty, wait until you see this mess. A CPU is diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index b66d7b4234b1..2d0a37c75cda 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1310,37 +1310,44 @@ static unsigned long nvhe_percpu_order(void) return size ? get_order(size) : 0; } -static int kvm_map_vectors(void) +/* A lookup table holding the hypervisor VA for each vector slot */ +static void *hyp_spectre_vector_selector[BP_HARDEN_EL2_SLOTS]; + +static int __kvm_vector_slot2idx(enum arm64_hyp_spectre_vector slot) { - /* - * SV2 = ARM64_SPECTRE_V2 - * HEL2 = ARM64_HARDEN_EL2_VECTORS - * - * !SV2 + !HEL2 -> use direct vectors - * SV2 + !HEL2 -> use hardened vectors in place - * !SV2 + HEL2 -> allocate one vector slot and use exec mapping - * SV2 + HEL2 -> use hardened vectors and use exec mapping - */ - if (cpus_have_const_cap(ARM64_SPECTRE_V2)) { - __kvm_bp_vect_base = kvm_ksym_ref(__bp_harden_hyp_vecs); - __kvm_bp_vect_base = kern_hyp_va(__kvm_bp_vect_base); - } + return slot - (slot != HYP_VECTOR_DIRECT); +} - if (cpus_have_const_cap(ARM64_HARDEN_EL2_VECTORS)) { - phys_addr_t vect_pa = __pa_symbol(__bp_harden_hyp_vecs); - unsigned long size = __BP_HARDEN_HYP_VECS_SZ; +static void kvm_init_vector_slot(void *base, enum arm64_hyp_spectre_vector slot) +{ + int idx = __kvm_vector_slot2idx(slot); - /* - * Always allocate a spare vector slot, as we don't - * know yet which CPUs have a BP hardening slot that - * we can reuse. - */ - __kvm_harden_el2_vector_slot = atomic_inc_return(&arm64_el2_vector_last_slot); - BUG_ON(__kvm_harden_el2_vector_slot >= BP_HARDEN_EL2_SLOTS); - return create_hyp_exec_mappings(vect_pa, size, - &__kvm_bp_vect_base); + hyp_spectre_vector_selector[slot] = base + (idx * SZ_2K); +} + +static int kvm_init_vector_slots(void) +{ + int err; + void *base; + + base = kern_hyp_va(kvm_ksym_ref(__kvm_hyp_vector)); + kvm_init_vector_slot(base, HYP_VECTOR_DIRECT); + + base = kern_hyp_va(kvm_ksym_ref(__bp_harden_hyp_vecs)); + kvm_init_vector_slot(base, HYP_VECTOR_SPECTRE_DIRECT); + + if (!cpus_have_const_cap(ARM64_SPECTRE_V3A)) + return 0; + + if (!has_vhe()) { + err = create_hyp_exec_mappings(__pa_symbol(__bp_harden_hyp_vecs), + __BP_HARDEN_HYP_VECS_SZ, &base); + if (err) + return err; } + kvm_init_vector_slot(base, HYP_VECTOR_INDIRECT); + kvm_init_vector_slot(base, HYP_VECTOR_SPECTRE_INDIRECT); return 0; } @@ -1395,13 +1402,40 @@ static void cpu_hyp_reset(void) __hyp_reset_vectors(); } +/* + * EL2 vectors can be mapped and rerouted in a number of ways, + * depending on the kernel configuration and CPU present: + * + * - If the CPU is affected by Spectre-v2, the hardening sequence is + * placed in one of the vector slots, which is executed before jumping + * to the real vectors. + * + * - If the CPU also has the ARM64_SPECTRE_V3A cap, the slot + * containing the hardening sequence is mapped next to the idmap page, + * and executed before jumping to the real vectors. + * + * - If the CPU only has the ARM64_SPECTRE_V3A cap, then an + * empty slot is selected, mapped next to the idmap page, and + * executed before jumping to the real vectors. + * + * Note that ARM64_SPECTRE_V3A is somewhat incompatible with + * VHE, as we don't have hypervisor-specific mappings. If the system + * is VHE and yet selects this capability, it will be ignored. + */ +static void cpu_set_hyp_vector(void) +{ + struct bp_hardening_data *data = this_cpu_ptr(&bp_hardening_data); + void *vector = hyp_spectre_vector_selector[data->slot]; + + *this_cpu_ptr_hyp_sym(kvm_hyp_vector) = (unsigned long)vector; +} + static void cpu_hyp_reinit(void) { kvm_init_host_cpu_context(&this_cpu_ptr_hyp_sym(kvm_host_data)->host_ctxt); cpu_hyp_reset(); - - *this_cpu_ptr_hyp_sym(kvm_hyp_vector) = (unsigned long)kvm_get_hyp_vector(); + cpu_set_hyp_vector(); if (is_kernel_in_hyp_mode()) kvm_timer_init_vhe(); @@ -1631,12 +1665,6 @@ static int init_hyp_mode(void) goto out_err; } - err = kvm_map_vectors(); - if (err) { - kvm_err("Cannot map vectors\n"); - goto out_err; - } - /* * Map the Hyp stack pages */ @@ -1780,6 +1808,12 @@ int kvm_arch_init(void *opaque) goto out_err; } + err = kvm_init_vector_slots(); + if (err) { + kvm_err("Cannot initialise vector slots\n"); + goto out_err; + } + err = init_subsystems(); if (err) goto out_hyp; diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile index 4a81eddabcd8..687598e41b21 100644 --- a/arch/arm64/kvm/hyp/Makefile +++ b/arch/arm64/kvm/hyp/Makefile @@ -10,4 +10,4 @@ subdir-ccflags-y := -I$(incdir) \ -DDISABLE_BRANCH_PROFILING \ $(DISABLE_STACKLEAK_PLUGIN) -obj-$(CONFIG_KVM) += vhe/ nvhe/ pgtable.o smccc_wa.o +obj-$(CONFIG_KVM) += vhe/ nvhe/ pgtable.o diff --git a/arch/arm64/kvm/hyp/hyp-entry.S b/arch/arm64/kvm/hyp/hyp-entry.S index 0a5b36eb54b3..d179056e1af8 100644 --- a/arch/arm64/kvm/hyp/hyp-entry.S +++ b/arch/arm64/kvm/hyp/hyp-entry.S @@ -13,6 +13,7 @@ #include <asm/kvm_arm.h> #include <asm/kvm_asm.h> #include <asm/mmu.h> +#include <asm/spectre.h> .macro save_caller_saved_regs_vect /* x0 and x1 were saved in the vector entry */ @@ -187,52 +188,60 @@ SYM_CODE_START(__kvm_hyp_vector) valid_vect el1_error // Error 32-bit EL1 SYM_CODE_END(__kvm_hyp_vector) -.macro hyp_ventry - .align 7 +.macro spectrev2_smccc_wa1_smc + sub sp, sp, #(8 * 4) + stp x2, x3, [sp, #(8 * 0)] + stp x0, x1, [sp, #(8 * 2)] + mov w0, #ARM_SMCCC_ARCH_WORKAROUND_1 + smc #0 + ldp x2, x3, [sp, #(8 * 0)] + add sp, sp, #(8 * 2) +.endm + +.macro hyp_ventry indirect, spectrev2 + .align 7 1: esb - .rept 26 - nop - .endr -/* - * The default sequence is to directly branch to the KVM vectors, - * using the computed offset. This applies for VHE as well as - * !ARM64_HARDEN_EL2_VECTORS. The first vector must always run the preamble. - * - * For ARM64_HARDEN_EL2_VECTORS configurations, this gets replaced - * with: - * - * stp x0, x1, [sp, #-16]! - * movz x0, #(addr & 0xffff) - * movk x0, #((addr >> 16) & 0xffff), lsl #16 - * movk x0, #((addr >> 32) & 0xffff), lsl #32 - * br x0 - * - * Where: - * addr = kern_hyp_va(__kvm_hyp_vector) + vector-offset + KVM_VECTOR_PREAMBLE. - * See kvm_patch_vector_branch for details. - */ -alternative_cb kvm_patch_vector_branch + .if \spectrev2 != 0 + spectrev2_smccc_wa1_smc + .else stp x0, x1, [sp, #-16]! - b __kvm_hyp_vector + (1b - 0b + KVM_VECTOR_PREAMBLE) + .endif + .if \indirect != 0 + alternative_cb kvm_patch_vector_branch + /* + * For ARM64_SPECTRE_V3A configurations, these NOPs get replaced with: + * + * movz x0, #(addr & 0xffff) + * movk x0, #((addr >> 16) & 0xffff), lsl #16 + * movk x0, #((addr >> 32) & 0xffff), lsl #32 + * br x0 + * + * Where: + * addr = kern_hyp_va(__kvm_hyp_vector) + vector-offset + KVM_VECTOR_PREAMBLE. + * See kvm_patch_vector_branch for details. + */ nop nop nop -alternative_cb_end + nop + alternative_cb_end + .endif + b __kvm_hyp_vector + (1b - 0b + KVM_VECTOR_PREAMBLE) .endm -.macro generate_vectors +.macro generate_vectors indirect, spectrev2 0: .rept 16 - hyp_ventry + hyp_ventry \indirect, \spectrev2 .endr .org 0b + SZ_2K // Safety measure .endm .align 11 SYM_CODE_START(__bp_harden_hyp_vecs) - .rept BP_HARDEN_EL2_SLOTS - generate_vectors - .endr + generate_vectors indirect = 0, spectrev2 = 1 // HYP_VECTOR_SPECTRE_DIRECT + generate_vectors indirect = 1, spectrev2 = 0 // HYP_VECTOR_INDIRECT + generate_vectors indirect = 1, spectrev2 = 1 // HYP_VECTOR_SPECTRE_INDIRECT 1: .org __bp_harden_hyp_vecs + __BP_HARDEN_HYP_VECS_SZ .org 1b SYM_CODE_END(__bp_harden_hyp_vecs) diff --git a/arch/arm64/kvm/hyp/smccc_wa.S b/arch/arm64/kvm/hyp/smccc_wa.S deleted file mode 100644 index b0441dbdf68b..000000000000 --- a/arch/arm64/kvm/hyp/smccc_wa.S +++ /dev/null @@ -1,32 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -/* - * Copyright (C) 2015-2018 - ARM Ltd - * Author: Marc Zyngier <marc.zyngier@arm.com> - */ - -#include <linux/arm-smccc.h> -#include <linux/linkage.h> - -#include <asm/kvm_asm.h> -#include <asm/kvm_mmu.h> - - /* - * This is not executed directly and is instead copied into the vectors - * by install_bp_hardening_cb(). - */ - .data - .pushsection .rodata - .global __smccc_workaround_1_smc -SYM_DATA_START(__smccc_workaround_1_smc) - esb - sub sp, sp, #(8 * 4) - stp x2, x3, [sp, #(8 * 0)] - stp x0, x1, [sp, #(8 * 2)] - mov w0, #ARM_SMCCC_ARCH_WORKAROUND_1 - smc #0 - ldp x2, x3, [sp, #(8 * 0)] - ldp x0, x1, [sp, #(8 * 2)] - add sp, sp, #(8 * 4) -1: .org __smccc_workaround_1_smc + __SMCCC_WORKAROUND_1_SMC_SZ - .org 1b -SYM_DATA_END(__smccc_workaround_1_smc) diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c index d61117805de0..4130b72e6891 100644 --- a/arch/arm64/kvm/va_layout.c +++ b/arch/arm64/kvm/va_layout.c @@ -132,21 +132,16 @@ void __init kvm_update_va_mask(struct alt_instr *alt, } } -void *__kvm_bp_vect_base; -int __kvm_harden_el2_vector_slot; - void kvm_patch_vector_branch(struct alt_instr *alt, __le32 *origptr, __le32 *updptr, int nr_inst) { u64 addr; u32 insn; - BUG_ON(nr_inst != 5); + BUG_ON(nr_inst != 4); - if (has_vhe() || !cpus_have_const_cap(ARM64_HARDEN_EL2_VECTORS)) { - WARN_ON_ONCE(cpus_have_const_cap(ARM64_HARDEN_EL2_VECTORS)); + if (!cpus_have_const_cap(ARM64_SPECTRE_V3A) || WARN_ON_ONCE(has_vhe())) return; - } /* * Compute HYP VA by using the same computation as kern_hyp_va() @@ -164,15 +159,6 @@ void kvm_patch_vector_branch(struct alt_instr *alt, */ addr += KVM_VECTOR_PREAMBLE; - /* stp x0, x1, [sp, #-16]! */ - insn = aarch64_insn_gen_load_store_pair(AARCH64_INSN_REG_0, - AARCH64_INSN_REG_1, - AARCH64_INSN_REG_SP, - -16, - AARCH64_INSN_VARIANT_64BIT, - AARCH64_INSN_LDST_STORE_PAIR_PRE_INDEX); - *updptr++ = cpu_to_le32(insn); - /* movz x0, #(addr & 0xffff) */ insn = aarch64_insn_gen_movewide(AARCH64_INSN_REG_0, (u16)addr, |