Fix and rewrite arm64 spectre mitigations

index c332d49780dc..88966496806a 100644
@@ -234,14 +234,17 @@ static int detect_harden_bp_fw(void)
 		smccc_end = NULL;
 		break;
 
-#if IS_ENABLED(CONFIG_KVM)
 	case SMCCC_CONDUIT_SMC:
 		cb = call_smc_arch_workaround_1;
+#if IS_ENABLED(CONFIG_KVM)
 		smccc_start = __smccc_workaround_1_smc;
 		smccc_end = __smccc_workaround_1_smc +
 			__SMCCC_WORKAROUND_1_SMC_SZ;
-		break;
+#else
+		smccc_start = NULL;
+		smccc_end = NULL;
 #endif
+		break;
 
 	default:
 		return -1;

index 88966496806a..3fe64bf5a58d 100644
@@ -599,6 +599,12 @@ check_branch_predictor(const struct arm64_cpu_capabilities *entry, int scope)
 	return (need_wa > 0);
 }
 
+static void
+cpu_enable_branch_predictor_hardening(const struct arm64_cpu_capabilities *cap)
+{
+	cap->matches(cap, SCOPE_LOCAL_CPU);
+}
+
 static const __maybe_unused struct midr_range tx2_family_cpus[] = {
 	MIDR_ALL_VERSIONS(MIDR_BRCM_VULCAN),
 	MIDR_ALL_VERSIONS(MIDR_CAVIUM_THUNDERX2),

@@ -890,9 +896,11 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 	},
 #endif
 	{
+		.desc = "Branch predictor hardening",
 		.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
 		.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
 		.matches = check_branch_predictor,
+		.cpu_enable = cpu_enable_branch_predictor_hardening,
 	},
 #ifdef CONFIG_RANDOMIZE_BASE
 	{

index 3fe64bf5a58d..abfef5f3b5fd 100644
@@ -457,6 +457,12 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
 	return required;
 }
 
+static void cpu_enable_ssbd_mitigation(const struct arm64_cpu_capabilities *cap)
+{
+	if (ssbd_state != ARM64_SSBD_FORCE_DISABLE)
+		cap->matches(cap, SCOPE_LOCAL_CPU);
+}
+
 /* known invulnerable cores */
 static const struct midr_range arm64_ssb_cpus[] = {
 	MIDR_ALL_VERSIONS(MIDR_CORTEX_A35),

@@ -914,6 +920,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 		.capability = ARM64_SSBD,
 		.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
 		.matches = has_ssbd_mitigation,
+		.cpu_enable = cpu_enable_ssbd_mitigation,
 		.midr_range_list = arm64_ssb_cpus,
 	},
 #ifdef CONFIG_ARM64_ERRATUM_1418040

index 89b4f0142c28..851d144527ed 100644
@@ -712,12 +712,8 @@ int get_spectre_v2_workaround_state(void);
 
 static inline int arm64_get_ssbd_state(void)
 {
-#ifdef CONFIG_ARM64_SSBD
 	extern int ssbd_state;
 	return ssbd_state;
-#else
-	return ARM64_SSBD_UNKNOWN;
-#endif
 }
 
 void arm64_set_ssbd_mitigation(bool state);

index 189839c3706a..1df85a3ddb9b 100644
@@ -527,7 +527,6 @@ static inline int kvm_map_vectors(void)
 }
 #endif
 
-#ifdef CONFIG_ARM64_SSBD
 DECLARE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);
 
 static inline int hyp_map_aux_data(void)

@@ -544,12 +543,6 @@ static inline int hyp_map_aux_data(void)
 	}
 	return 0;
 }
-#else
-static inline int hyp_map_aux_data(void)
-{
-	return 0;
-}
-#endif
 
 #define kvm_phys_to_vttbr(addr)		phys_to_ttbr(addr)
 

index a7a5ecaa2e83..f5e3efeb5b97 100644
@@ -45,7 +45,6 @@ struct bp_hardening_data {
 	bp_hardening_cb_t	fn;
 };
 
-#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
 DECLARE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);
 
 static inline struct bp_hardening_data *arm64_get_bp_hardening_data(void)

@@ -64,14 +63,6 @@ static inline void arm64_apply_bp_hardening(void)
 	if (d->fn)
 		d->fn();
 }
-#else
-static inline struct bp_hardening_data *arm64_get_bp_hardening_data(void)
-{
-	return NULL;
-}
-
-static inline void arm64_apply_bp_hardening(void)	{ }
-#endif	/* CONFIG_HARDEN_BRANCH_PREDICTOR */
 
 extern void arm64_memblock_init(void);
 extern void paging_init(void);

index abfef5f3b5fd..dd9103915f1e 100644
@@ -254,9 +254,7 @@ static int detect_harden_bp_fw(void)
 	    ((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR_V1))
 		cb = qcom_link_stack_sanitization;
 
-	if (IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR))
-		install_bp_hardening_cb(cb, smccc_start, smccc_end);
-
+	install_bp_hardening_cb(cb, smccc_start, smccc_end);
 	return 1;
 }
 

@@ -335,11 +333,6 @@ void arm64_set_ssbd_mitigation(bool state)
 {
 	int conduit;
 
-	if (!IS_ENABLED(CONFIG_ARM64_SSBD)) {
-		pr_info_once("SSBD disabled by kernel configuration\n");
-		return;
-	}
-
 	if (this_cpu_has_cap(ARM64_SSBS)) {
 		if (state)
 			asm volatile(SET_PSTATE_SSBS(0));

@@ -584,12 +577,6 @@ check_branch_predictor(const struct arm64_cpu_capabilities *entry, int scope)
 
 	__spectrev2_safe = false;
 
-	if (!IS_ENABLED(CONFIG_HARDEN_BRANCH_PREDICTOR)) {
-		pr_warn_once("spectrev2 mitigation disabled by kernel configuration\n");
-		__hardenbp_enab = false;
-		return false;
-	}
-
 	/* forced off */
 	if (__nospectre_v2 || cpu_mitigations_off()) {
 		pr_info_once("spectrev2 mitigation disabled by command line option\n");

@@ -1004,9 +991,7 @@ ssize_t cpu_show_spec_store_bypass(struct device *dev,
 	switch (ssbd_state) {
 	case ARM64_SSBD_KERNEL:
 	case ARM64_SSBD_FORCE_ENABLE:
-		if (IS_ENABLED(CONFIG_ARM64_SSBD))
-			return sprintf(buf,
-			    "Mitigation: Speculative Store Bypass disabled via prctl\n");
+		return sprintf(buf, "Mitigation: Speculative Store Bypass disabled via prctl\n");
 	}
 
 	return sprintf(buf, "Vulnerable\n");

index 6424584be01e..4bb45b1d4ae4 100644
@@ -1583,7 +1583,6 @@ static void cpu_has_fwb(const struct arm64_cpu_capabilities *__unused)
 	WARN_ON(val & (7 << 27 | 7 << 21));
 }
 
-#ifdef CONFIG_ARM64_SSBD
 static int ssbs_emulation_handler(struct pt_regs *regs, u32 instr)
 {
 	if (user_mode(regs))

@@ -1623,7 +1622,6 @@ static void cpu_enable_ssbs(const struct arm64_cpu_capabilities *__unused)
 		arm64_set_ssbd_mitigation(true);
 	}
 }
-#endif /* CONFIG_ARM64_SSBD */
 
 #ifdef CONFIG_ARM64_PAN
 static void cpu_enable_pan(const struct arm64_cpu_capabilities *__unused)

@@ -1976,7 +1974,6 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 		.field_pos = ID_AA64ISAR0_CRC32_SHIFT,
 		.min_field_value = 1,
 	},
-#ifdef CONFIG_ARM64_SSBD
 	{
 		.desc = "Speculative Store Bypassing Safe (SSBS)",
 		.capability = ARM64_SSBS,

@@ -1988,7 +1985,6 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 		.min_field_value = ID_AA64PFR1_SSBS_PSTATE_ONLY,
 		.cpu_enable = cpu_enable_ssbs,
 	},
-#endif
 #ifdef CONFIG_ARM64_CNP
 	{
 		.desc = "Common not Private translations",

index 5b6b8fa00f0a..b503f19c37c5 100644
@@ -489,7 +489,6 @@ static inline bool __needs_ssbd_off(struct kvm_vcpu *vcpu)
 
 static inline void __set_guest_arch_workaround_state(struct kvm_vcpu *vcpu)
 {
-#ifdef CONFIG_ARM64_SSBD
 	/*
 	 * The host runs with the workaround always present. If the
 	 * guest wants it disabled, so be it...

@@ -497,19 +496,16 @@ static inline void __set_guest_arch_workaround_state(struct kvm_vcpu *vcpu)
 	if (__needs_ssbd_off(vcpu) &&
 	    __hyp_this_cpu_read(arm64_ssbd_callback_required))
 		arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_2, 0, NULL);
-#endif
 }
 
 static inline void __set_host_arch_workaround_state(struct kvm_vcpu *vcpu)
 {
-#ifdef CONFIG_ARM64_SSBD
 	/*
 	 * If the guest has disabled the workaround, bring it back on.
 	 */
 	if (__needs_ssbd_off(vcpu) &&
 	    __hyp_this_cpu_read(arm64_ssbd_callback_required))
 		arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_2, 1, NULL);
-#endif
 }
 
 static inline void __kvm_unexpected_el2_exception(void)

index 6f98fbd0ac81..e9378cc8049d 100644
@@ -102,7 +102,7 @@ DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
 #define __kvm_hyp_init		CHOOSE_NVHE_SYM(__kvm_hyp_init)
 #define __kvm_hyp_vector	CHOOSE_HYP_SYM(__kvm_hyp_vector)
 
-#ifdef CONFIG_KVM_INDIRECT_VECTORS
+#ifdef CONFIG_RANDOMIZE_BASE
 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)

index 1df85a3ddb9b..dfd176b0642e 100644
@@ -430,7 +430,7 @@ static inline int kvm_write_guest_lock(struct kvm *kvm, gpa_t gpa,
 	return ret;
 }
 
-#ifdef CONFIG_KVM_INDIRECT_VECTORS
+#ifdef CONFIG_RANDOMIZE_BASE
 /*
  * EL2 vectors can be mapped and rerouted in a number of ways,
  * depending on the kernel configuration and CPU present:

index dd9103915f1e..135bf7f92d4a 100644
@@ -113,7 +113,7 @@ atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1);
 
 DEFINE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);
 
-#ifdef CONFIG_KVM_INDIRECT_VECTORS
+#ifdef CONFIG_RANDOMIZE_BASE
 static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start,
 				const char *hyp_vecs_end)
 {

@@ -167,7 +167,7 @@ static void install_bp_hardening_cb(bp_hardening_cb_t fn,
 {
 	__this_cpu_write(bp_hardening_data.fn, fn);
 }
-#endif	/* CONFIG_KVM_INDIRECT_VECTORS */
+#endif	/* CONFIG_RANDOMIZE_BASE */
 
 #include <linux/arm-smccc.h>
 

index 135bf7f92d4a..a72ca57f5630 100644
@@ -126,18 +126,19 @@ static void __copy_hyp_vect_bpi(int slot, const char *hyp_vecs_start,
 	__flush_icache_range((uintptr_t)dst, (uintptr_t)dst + SZ_2K);
 }
 
-static void install_bp_hardening_cb(bp_hardening_cb_t fn,
-				    const char *hyp_vecs_start,
-				    const char *hyp_vecs_end)
+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;
 
 	/*
 	 * detect_harden_bp_fw() passes NULL for the hyp_vecs start/end if
 	 * we're a guest. Skip the hyp-vectors work.
 	 */
-	if (!hyp_vecs_start) {
+	if (!is_hyp_mode_available()) {
 		__this_cpu_write(bp_hardening_data.fn, fn);
 		return;
 	}

@@ -161,9 +162,7 @@ static void install_bp_hardening_cb(bp_hardening_cb_t fn,
 	raw_spin_unlock(&bp_lock);
 }
 #else
-static void install_bp_hardening_cb(bp_hardening_cb_t fn,
-				      const char *hyp_vecs_start,
-				      const char *hyp_vecs_end)
+static void install_bp_hardening_cb(bp_hardening_cb_t fn)
 {
 	__this_cpu_write(bp_hardening_data.fn, fn);
 }

@@ -209,7 +208,6 @@ early_param("nospectre_v2", parse_nospectre_v2);
 static int detect_harden_bp_fw(void)
 {
 	bp_hardening_cb_t cb;
-	void *smccc_start, *smccc_end;
 	struct arm_smccc_res res;
 	u32 midr = read_cpuid_id();
 

@@ -229,21 +227,10 @@ static int detect_harden_bp_fw(void)
 	switch (arm_smccc_1_1_get_conduit()) {
 	case SMCCC_CONDUIT_HVC:
 		cb = call_hvc_arch_workaround_1;
-		/* This is a guest, no need to patch KVM vectors */
-		smccc_start = NULL;
-		smccc_end = NULL;
 		break;
 
 	case SMCCC_CONDUIT_SMC:
 		cb = call_smc_arch_workaround_1;
-#if IS_ENABLED(CONFIG_KVM)
-		smccc_start = __smccc_workaround_1_smc;
-		smccc_end = __smccc_workaround_1_smc +
-			__SMCCC_WORKAROUND_1_SMC_SZ;
-#else
-		smccc_start = NULL;
-		smccc_end = NULL;
-#endif
 		break;
 
 	default:

@@ -254,7 +241,7 @@ static int detect_harden_bp_fw(void)
 	    ((midr & MIDR_CPU_MODEL_MASK) == MIDR_QCOM_FALKOR_V1))
 		cb = qcom_link_stack_sanitization;
 
-	install_bp_hardening_cb(cb, smccc_start, smccc_end);
+	install_bp_hardening_cb(cb);
 	return 1;
 }
 

index 07b643a70710..348bfcf6c818 100644
@@ -31,7 +31,7 @@
 #define ARM64_HAS_DCPOP				21
 #define ARM64_SVE				22
 #define ARM64_UNMAP_KERNEL_AT_EL0		23
-#define ARM64_HARDEN_BRANCH_PREDICTOR		24
+#define ARM64_SPECTRE_V2			24
 #define ARM64_HAS_RAS_EXTN			25
 #define ARM64_WORKAROUND_843419			26
 #define ARM64_HAS_CACHE_IDC			27

index dfd176b0642e..873e12430ac7 100644
@@ -435,14 +435,13 @@ static inline int kvm_write_guest_lock(struct kvm *kvm, gpa_t gpa,
  * EL2 vectors can be mapped and rerouted in a number of ways,
  * depending on the kernel configuration and CPU present:
  *
- * - If the CPU has the ARM64_HARDEN_BRANCH_PREDICTOR cap, the
- *   hardening sequence is placed in one of the vector slots, which is
- *   executed before jumping to the real vectors.
+ * - 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 has both the ARM64_HARDEN_EL2_VECTORS cap and the
- *   ARM64_HARDEN_BRANCH_PREDICTOR 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 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

@@ -464,7 +463,7 @@ static inline void *kvm_get_hyp_vector(void)
 	void *vect = kern_hyp_va(kvm_ksym_ref(__kvm_hyp_vector));
 	int slot = -1;
 
-	if (cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR) && data->fn) {
+	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;
 	}

@@ -485,15 +484,15 @@ static inline void *kvm_get_hyp_vector(void)
 static inline int kvm_map_vectors(void)
 {
 	/*
-	 * HBP  = ARM64_HARDEN_BRANCH_PREDICTOR
+	 * SV2  = ARM64_SPECTRE_V2
 	 * HEL2 = ARM64_HARDEN_EL2_VECTORS
 	 *
-	 * !HBP + !HEL2 -> use direct vectors
-	 *  HBP + !HEL2 -> use hardened vectors in place
-	 * !HBP +  HEL2 -> allocate one vector slot and use exec mapping
-	 *  HBP +  HEL2 -> use hardened vertors and use exec mapping
+	 * !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 vertors and use exec mapping
 	 */
-	if (cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR)) {
+	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);
 	}

index f5e3efeb5b97..cbff2d42c1d8 100644
@@ -56,7 +56,7 @@ static inline void arm64_apply_bp_hardening(void)
 {
 	struct bp_hardening_data *d;
 
-	if (!cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR))
+	if (!cpus_have_const_cap(ARM64_SPECTRE_V2))
 		return;
 
 	d = arm64_get_bp_hardening_data();

index a72ca57f5630..b275f2d5e7a3 100644
@@ -877,7 +877,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 #endif
 	{
 		.desc = "Branch predictor hardening",
-		.capability = ARM64_HARDEN_BRANCH_PREDICTOR,
+		.capability = ARM64_SPECTRE_V2,
 		.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
 		.matches = check_branch_predictor,
 		.cpu_enable = cpu_enable_branch_predictor_hardening,

index b275f2d5e7a3..5eb9a9126dc4 100644
@@ -949,12 +949,6 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 	}
 };
 
-ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr,
-			    char *buf)
-{
-	return sprintf(buf, "Mitigation: __user pointer sanitization\n");
-}
-
 ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr,
 		char *buf)
 {

new file mode 100644
index 000000000000..c37bf468e4a4
@@ -0,0 +1,32 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Handle detection, reporting and mitigation of Spectre v1, v2 and v4, as
+ * detailed at:
+ *
+ *   https://developer.arm.com/support/arm-security-updates/speculative-processor-vulnerability
+ *
+ * This code was originally written hastily under an awful lot of stress and so
+ * aspects of it are somewhat hacky. Unfortunately, changing anything in here
+ * instantly makes me feel ill. Thanks, Jann. Thann.
+ *
+ * Copyright (C) 2018 ARM Ltd, All Rights Reserved.
+ * Copyright (C) 2020 Google LLC
+ *
+ * "If there's something strange in your neighbourhood, who you gonna call?"
+ *
+ * Authors: Will Deacon <[email protected]> and Marc Zyngier <[email protected]>
+ */
+
+#include <linux/device.h>
+
+/*
+ * Spectre v1.
+ *
+ * The kernel can't protect userspace for this one: it's each person for
+ * themselves. Advertise what we're doing and be done with it.
+ */
+ssize_t cpu_show_spectre_v1(struct device *dev, struct device_attribute *attr,
+			    char *buf)
+{
+	return sprintf(buf, "Mitigation: __user pointer sanitization\n");
+}

index 851d144527ed..3b48aa121cee 100644
@@ -698,12 +698,6 @@ static inline bool system_supports_tlb_range(void)
 		cpus_have_const_cap(ARM64_HAS_TLB_RANGE);
 }
 
-#define ARM64_BP_HARDEN_UNKNOWN		-1
-#define ARM64_BP_HARDEN_WA_NEEDED	0
-#define ARM64_BP_HARDEN_NOT_REQUIRED	1
-
-int get_spectre_v2_workaround_state(void);
-
 #define ARM64_SSBD_UNKNOWN		-1
 #define ARM64_SSBD_FORCE_DISABLE	0
 #define ARM64_SSBD_KERNEL		1

index 905c2b87e05a..9edce004d7c7 100644
@@ -631,23 +631,6 @@ static inline void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr) {}
 static inline void kvm_clr_pmu_events(u32 clr) {}
 #endif
 
-#define KVM_BP_HARDEN_UNKNOWN		-1
-#define KVM_BP_HARDEN_WA_NEEDED		0
-#define KVM_BP_HARDEN_NOT_REQUIRED	1
-
-static inline int kvm_arm_harden_branch_predictor(void)
-{
-	switch (get_spectre_v2_workaround_state()) {
-	case ARM64_BP_HARDEN_WA_NEEDED:
-		return KVM_BP_HARDEN_WA_NEEDED;
-	case ARM64_BP_HARDEN_NOT_REQUIRED:
-		return KVM_BP_HARDEN_NOT_REQUIRED;
-	case ARM64_BP_HARDEN_UNKNOWN:
-	default:
-		return KVM_BP_HARDEN_UNKNOWN;
-	}
-}
-
 #define KVM_SSBD_UNKNOWN		-1
 #define KVM_SSBD_FORCE_DISABLE		0
 #define KVM_SSBD_KERNEL		1

index 240fe5e5b720..436ab1549ec6 100644
@@ -38,6 +38,7 @@
 #include <asm/pgtable-hwdef.h>
 #include <asm/pointer_auth.h>
 #include <asm/ptrace.h>
+#include <asm/spectre.h>
 #include <asm/types.h>
 
 /*

new file mode 100644
index 000000000000..b776abe28dff
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Interface for managing mitigations for Spectre vulnerabilities.
+ *
+ * Copyright (C) 2020 Google LLC
+ * Author: Will Deacon <[email protected]>
+ */
+
+#ifndef __ASM_SPECTRE_H
+#define __ASM_SPECTRE_H
+
+#include <asm/cpufeature.h>
+
+/* Watch out, ordering is important here. */
+enum mitigation_state {
+	SPECTRE_UNAFFECTED,
+	SPECTRE_MITIGATED,
+	SPECTRE_VULNERABLE,
+};
+
+struct task_struct;
+
+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);
+
+#endif	/* __ASM_SPECTRE_H */

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index 550dfa3e53cd..413d46b9bc07 100644
@@ -24,13 +24,13 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
 		feature = smccc_get_arg1(vcpu);
 		switch (feature) {
 		case ARM_SMCCC_ARCH_WORKAROUND_1:
-			switch (kvm_arm_harden_branch_predictor()) {
-			case KVM_BP_HARDEN_UNKNOWN:
+			switch (arm64_get_spectre_v2_state()) {
+			case SPECTRE_VULNERABLE:
 				break;
-			case KVM_BP_HARDEN_WA_NEEDED:
+			case SPECTRE_MITIGATED:
 				val = SMCCC_RET_SUCCESS;
 				break;
-			case KVM_BP_HARDEN_NOT_REQUIRED:
+			case SPECTRE_UNAFFECTED:
 				val = SMCCC_RET_NOT_REQUIRED;
 				break;
 			}

index 83415e96b589..fbdd6f3bea7f 100644
@@ -425,12 +425,12 @@ static int get_kernel_wa_level(u64 regid)
 {
 	switch (regid) {
 	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1:
-		switch (kvm_arm_harden_branch_predictor()) {
-		case KVM_BP_HARDEN_UNKNOWN:
+		switch (arm64_get_spectre_v2_state()) {
+		case SPECTRE_VULNERABLE:
 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL;
-		case KVM_BP_HARDEN_WA_NEEDED:
+		case SPECTRE_MITIGATED:
 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_AVAIL;
-		case KVM_BP_HARDEN_NOT_REQUIRED:
+		case SPECTRE_UNAFFECTED:
 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_REQUIRED;
 		}
 		return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL;

index 077293b5115f..7b8a8f6169d0 100644
@@ -1131,6 +1131,9 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
 		if (!vcpu_has_sve(vcpu))
 			val &= ~(0xfUL << ID_AA64PFR0_SVE_SHIFT);
 		val &= ~(0xfUL << ID_AA64PFR0_AMU_SHIFT);
+		if (!(val & (0xfUL << ID_AA64PFR0_CSV2_SHIFT)) &&
+		    arm64_get_spectre_v2_state() == SPECTRE_UNAFFECTED)
+			val |= (1UL << ID_AA64PFR0_CSV2_SHIFT);
 	} else if (id == SYS_ID_AA64ISAR1_EL1 && !vcpu_has_ptrauth(vcpu)) {
 		val &= ~((0xfUL << ID_AA64ISAR1_APA_SHIFT) |
 			 (0xfUL << ID_AA64ISAR1_API_SHIFT) |

index 436ab1549ec6..d636c3eb9cf6 100644
@@ -220,18 +220,6 @@ static inline void start_thread(struct pt_regs *regs, unsigned long pc,
 	regs->sp = sp;
 }
 
-static inline bool is_ttbr0_addr(unsigned long addr)
-{
-	/* entry assembly clears tags for TTBR0 addrs */
-	return addr < TASK_SIZE;
-}
-
-static inline bool is_ttbr1_addr(unsigned long addr)
-{
-	/* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
-	return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
-}
-
 #ifdef CONFIG_COMPAT
 static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
 				       unsigned long sp)

@@ -252,6 +240,18 @@ static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
 }
 #endif
 
+static inline bool is_ttbr0_addr(unsigned long addr)
+{
+	/* entry assembly clears tags for TTBR0 addrs */
+	return addr < TASK_SIZE;
+}
+
+static inline bool is_ttbr1_addr(unsigned long addr)
+{
+	/* TTBR1 addresses may have a tag if KASAN_SW_TAGS is in use */
+	return arch_kasan_reset_tag(addr) >= PAGE_OFFSET;
+}
+
 /* Forward declaration, a strange C thing */
 struct task_struct;
 

index 4bb45b1d4ae4..033e6c952705 100644
@@ -227,7 +227,7 @@ static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
 static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = {
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_MPAMFRAC_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_RASFRAC_SHIFT, 4, 0),
-	ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI),
+	ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI),
 	ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_BTI),
 				    FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_BT_SHIFT, 4, 0),
 	ARM64_FTR_END,

@@ -487,7 +487,7 @@ static const struct arm64_ftr_bits ftr_id_pfr1[] = {
 };
 
 static const struct arm64_ftr_bits ftr_id_pfr2[] = {
-	ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_PFR2_SSBS_SHIFT, 4, 0),
+	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_SSBS_SHIFT, 4, 0),
 	ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_PFR2_CSV3_SHIFT, 4, 0),
 	ARM64_FTR_END,
 };

@@ -1977,7 +1977,7 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
 	{
 		.desc = "Speculative Store Bypassing Safe (SSBS)",
 		.capability = ARM64_SSBS,
-		.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
+		.type = ARM64_CPUCAP_SYSTEM_FEATURE,
 		.matches = has_cpuid_feature,
 		.sys_reg = SYS_ID_AA64PFR1_EL1,
 		.field_pos = ID_AA64PFR1_SSBS_SHIFT,

index 348bfcf6c818..c4ac9a13ad5f 100644
@@ -37,7 +37,7 @@
 #define ARM64_HAS_CACHE_IDC			27
 #define ARM64_HAS_CACHE_DIC			28
 #define ARM64_HW_DBM				29
-#define ARM64_SSBD				30
+#define ARM64_SPECTRE_V4			30
 #define ARM64_MISMATCHED_CACHE_TYPE		31
 #define ARM64_HAS_STAGE2_FWB			32
 #define ARM64_HAS_CRC32				33

index 4103391f51b5..6a48957d44fc 100644
@@ -675,7 +675,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 #endif
 	{
 		.desc = "Speculative Store Bypass Disable",
-		.capability = ARM64_SSBD,
+		.capability = ARM64_SPECTRE_V4,
 		.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
 		.matches = has_ssbd_mitigation,
 		.cpu_enable = cpu_enable_ssbd_mitigation,

index b503f19c37c5..5dec5589625d 100644
@@ -481,7 +481,7 @@ static inline bool fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code)
 
 static inline bool __needs_ssbd_off(struct kvm_vcpu *vcpu)
 {
-	if (!cpus_have_final_cap(ARM64_SSBD))
+	if (!cpus_have_final_cap(ARM64_SPECTRE_V4))
 		return false;
 
 	return !(vcpu->arch.workaround_flags & VCPU_WORKAROUND_2_FLAG);

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index d636c3eb9cf6..7d90ea2e2063 100644
@@ -198,25 +198,12 @@ static inline void start_thread_common(struct pt_regs *regs, unsigned long pc)
 		regs->pmr_save = GIC_PRIO_IRQON;
 }
 
-static inline void set_ssbs_bit(struct pt_regs *regs)
-{
-	regs->pstate |= PSR_SSBS_BIT;
-}
-
-static inline void set_compat_ssbs_bit(struct pt_regs *regs)
-{
-	regs->pstate |= PSR_AA32_SSBS_BIT;
-}
-
 static inline void start_thread(struct pt_regs *regs, unsigned long pc,
 				unsigned long sp)
 {
 	start_thread_common(regs, pc);
 	regs->pstate = PSR_MODE_EL0t;
-
-	if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE)
-		set_ssbs_bit(regs);
-
+	spectre_v4_enable_task_mitigation(current);
 	regs->sp = sp;
 }
 

@@ -233,9 +220,7 @@ static inline void compat_start_thread(struct pt_regs *regs, unsigned long pc,
 	regs->pstate |= PSR_AA32_E_BIT;
 #endif
 
-	if (arm64_get_ssbd_state() != ARM64_SSBD_FORCE_ENABLE)
-		set_compat_ssbs_bit(regs);
-
+	spectre_v4_enable_task_mitigation(current);
 	regs->compat_sp = sp;
 }
 #endif

index b776abe28dff..fcdfbce302bd 100644
@@ -24,4 +24,9 @@ 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);
 
+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	/* __ASM_SPECTRE_H */

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index 68e14152d6e9..c7b00120dc3e 100644
@@ -332,11 +332,7 @@ int swsusp_arch_suspend(void)
 		 * mitigation off behind our back, let's set the state
 		 * to what we expect it to be.
 		 */
-		switch (arm64_get_ssbd_state()) {
-		case ARM64_SSBD_FORCE_ENABLE:
-		case ARM64_SSBD_KERNEL:
-			arm64_set_ssbd_mitigation(true);
-		}
+		spectre_v4_enable_mitigation(NULL);
 	}
 
 	local_daif_restore(flags);

index f1804496b935..9dbd35b95253 100644
@@ -421,8 +421,7 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start,
 		    cpus_have_const_cap(ARM64_HAS_UAO))
 			childregs->pstate |= PSR_UAO_BIT;
 
-		if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE)
-			set_ssbs_bit(childregs);
+		spectre_v4_enable_task_mitigation(p);
 
 		if (system_uses_irq_prio_masking())
 			childregs->pmr_save = GIC_PRIO_IRQON;

@@ -472,8 +471,6 @@ void uao_thread_switch(struct task_struct *next)
  */
 static void ssbs_thread_switch(struct task_struct *next)
 {
-	struct pt_regs *regs = task_pt_regs(next);
-
 	/*
 	 * Nothing to do for kernel threads, but 'regs' may be junk
 	 * (e.g. idle task) so check the flags and bail early.

@@ -485,18 +482,10 @@ static void ssbs_thread_switch(struct task_struct *next)
 	 * If all CPUs implement the SSBS extension, then we just need to
 	 * context-switch the PSTATE field.
 	 */
-	if (cpu_have_feature(cpu_feature(SSBS)))
-		return;
-
-	/* If the mitigation is enabled, then we leave SSBS clear. */
-	if ((arm64_get_ssbd_state() == ARM64_SSBD_FORCE_ENABLE) ||
-	    test_tsk_thread_flag(next, TIF_SSBD))
+	if (cpus_have_const_cap(ARM64_SSBS))
 		return;
 
-	if (compat_user_mode(regs))
-		set_compat_ssbs_bit(regs);
-	else if (user_mode(regs))
-		set_ssbs_bit(regs);
+	spectre_v4_enable_task_mitigation(next);
 }
 
 /*

483 lines not on this page · raw message

index c1dee9066ff9..584c14ce3c86 100644
@@ -72,8 +72,7 @@ void notrace __cpu_suspend_exit(void)
 	 * have turned the mitigation on. If the user has forcefully
 	 * disabled it, make sure their wishes are obeyed.
 	 */
-	if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE)
-		arm64_set_ssbd_mitigation(false);
+	spectre_v4_enable_mitigation(NULL);
 }
 
 /*

index e9378cc8049d..abe02cf66880 100644
@@ -9,9 +9,6 @@
 
 #include <asm/virt.h>
 
-#define	VCPU_WORKAROUND_2_FLAG_SHIFT	0
-#define	VCPU_WORKAROUND_2_FLAG		(_AC(1, UL) << VCPU_WORKAROUND_2_FLAG_SHIFT)
-
 #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)

index 49a55be2b9a2..96eccb107ec2 100644
@@ -383,20 +383,6 @@ static inline unsigned long kvm_vcpu_get_mpidr_aff(struct kvm_vcpu *vcpu)
 	return vcpu_read_sys_reg(vcpu, MPIDR_EL1) & MPIDR_HWID_BITMASK;
 }
 
-static inline bool kvm_arm_get_vcpu_workaround_2_flag(struct kvm_vcpu *vcpu)
-{
-	return vcpu->arch.workaround_flags & VCPU_WORKAROUND_2_FLAG;
-}
-
-static inline void kvm_arm_set_vcpu_workaround_2_flag(struct kvm_vcpu *vcpu,
-						      bool flag)
-{
-	if (flag)
-		vcpu->arch.workaround_flags |= VCPU_WORKAROUND_2_FLAG;
-	else
-		vcpu->arch.workaround_flags &= ~VCPU_WORKAROUND_2_FLAG;
-}
-
 static inline void kvm_vcpu_set_be(struct kvm_vcpu *vcpu)
 {
 	if (vcpu_mode_is_32bit(vcpu)) {

index 873e12430ac7..36606ef9e435 100644
@@ -526,23 +526,6 @@ static inline int kvm_map_vectors(void)
 }
 #endif
 
-DECLARE_PER_CPU_READ_MOSTLY(u64, arm64_ssbd_callback_required);
-
-static inline int hyp_map_aux_data(void)
-{
-	int cpu, err;
-
-	for_each_possible_cpu(cpu) {
-		u64 *ptr;
-
-		ptr = per_cpu_ptr(&arm64_ssbd_callback_required, cpu);
-		err = create_hyp_mappings(ptr, ptr + 1, PAGE_HYP);
-		if (err)
-			return err;
-	}
-	return 0;
-}
-
 #define kvm_phys_to_vttbr(addr)		phys_to_ttbr(addr)
 
 /*

index ba85bb23f060..7d804fd0a682 100644
@@ -242,6 +242,15 @@ struct kvm_vcpu_events {
 #define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL		0
 #define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_AVAIL		1
 #define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_REQUIRED	2
+
+/*
+ * Only two states can be presented by the host kernel:
+ * - NOT_REQUIRED: the guest doesn't need to do anything
+ * - NOT_AVAIL: the guest isn't mitigated (it can still use SSBS if available)
+ *
+ * All the other values are deprecated. The host still accepts all
+ * values (they are ABI), but will narrow them to the above two.
+ */
 #define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2	KVM_REG_ARM_FW_REG(2)
 #define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL		0
 #define KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_UNKNOWN		1

index 7fc54c3d4285..7e9caef13db4 100644
@@ -108,20 +108,6 @@ cpu_enable_trap_ctr_access(const struct arm64_cpu_capabilities *cap)
 
 int ssbd_state __read_mostly = ARM64_SSBD_UNKNOWN;
 
-void __init arm64_enable_wa2_handling(struct alt_instr *alt,
-				      __le32 *origptr, __le32 *updptr,
-				      int nr_inst)
-{
-	BUG_ON(nr_inst != 1);
-	/*
-	 * Only allow mitigation on EL1 entry/exit and guest
-	 * ARCH_WORKAROUND_2 handling if the SSBD state allows it to
-	 * be flipped.
-	 */
-	if (arm64_get_ssbd_state() == ARM64_SSBD_KERNEL)
-		*updptr = cpu_to_le32(aarch64_insn_gen_nop());
-}
-
 #ifdef CONFIG_ARM64_ERRATUM_1463225
 DEFINE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa);
 

index 8982b68289b7..d0f3f35dd0d7 100644
@@ -64,12 +64,10 @@ __efistub__ctype		= _ctype;
 #define KVM_NVHE_ALIAS(sym) __kvm_nvhe_##sym = sym;
 
 /* Alternative callbacks for init-time patching of nVHE hyp code. */
-KVM_NVHE_ALIAS(arm64_enable_wa2_handling);
 KVM_NVHE_ALIAS(kvm_patch_vector_branch);
 KVM_NVHE_ALIAS(kvm_update_va_mask);
 
 /* Global kernel state accessed by nVHE hyp code. */
-KVM_NVHE_ALIAS(arm64_ssbd_callback_required);
 KVM_NVHE_ALIAS(kvm_host_data);
 KVM_NVHE_ALIAS(kvm_vgic_global_state);
 

index b588c3b5c2f0..0a316dee491f 100644
@@ -1552,10 +1552,6 @@ static int init_hyp_mode(void)
 		}
 	}
 
-	err = hyp_map_aux_data();
-	if (err)
-		kvm_err("Cannot map host auxiliary data: %d\n", err);
-
 	return 0;
 
 out_err:

index 5dec5589625d..a6840823b60e 100644
@@ -479,35 +479,6 @@ static inline bool fixup_guest_exit(struct kvm_vcpu *vcpu, u64 *exit_code)
 	return false;
 }
 
-static inline bool __needs_ssbd_off(struct kvm_vcpu *vcpu)
-{
-	if (!cpus_have_final_cap(ARM64_SPECTRE_V4))
-		return false;
-
-	return !(vcpu->arch.workaround_flags & VCPU_WORKAROUND_2_FLAG);
-}
-
-static inline void __set_guest_arch_workaround_state(struct kvm_vcpu *vcpu)
-{
-	/*
-	 * The host runs with the workaround always present. If the
-	 * guest wants it disabled, so be it...
-	 */
-	if (__needs_ssbd_off(vcpu) &&
-	    __hyp_this_cpu_read(arm64_ssbd_callback_required))
-		arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_2, 0, NULL);
-}
-
-static inline void __set_host_arch_workaround_state(struct kvm_vcpu *vcpu)
-{
-	/*
-	 * If the guest has disabled the workaround, bring it back on.
-	 */
-	if (__needs_ssbd_off(vcpu) &&
-	    __hyp_this_cpu_read(arm64_ssbd_callback_required))
-		arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_2, 1, NULL);
-}
-
 static inline void __kvm_unexpected_el2_exception(void)
 {
 	unsigned long addr, fixup;

index 0970442d2dbc..8d3dd4f47924 100644
@@ -202,8 +202,6 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
 
 	__debug_switch_to_guest(vcpu);
 
-	__set_guest_arch_workaround_state(vcpu);
-
 	do {
 		/* Jump in the fire! */
 		exit_code = __guest_enter(vcpu, host_ctxt);

@@ -211,8 +209,6 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
 		/* And we're baaack! */
 	} while (fixup_guest_exit(vcpu, &exit_code));
 
-	__set_host_arch_workaround_state(vcpu);
-
 	__sysreg_save_state_nvhe(guest_ctxt);
 	__sysreg32_save_state(vcpu);
 	__timer_disable_traps(vcpu);

index c1da4f86ccac..ecf67e678203 100644
@@ -131,8 +131,6 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
 	sysreg_restore_guest_state_vhe(guest_ctxt);
 	__debug_switch_to_guest(vcpu);
 
-	__set_guest_arch_workaround_state(vcpu);
-
 	do {
 		/* Jump in the fire! */
 		exit_code = __guest_enter(vcpu, host_ctxt);

@@ -140,8 +138,6 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
 		/* And we're baaack! */
 	} while (fixup_guest_exit(vcpu, &exit_code));
 
-	__set_host_arch_workaround_state(vcpu);
-
 	sysreg_save_guest_state_vhe(guest_ctxt);
 
 	__deactivate_traps(vcpu);

index 413d46b9bc07..69e023dfafce 100644
@@ -36,15 +36,13 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
 			}
 			break;
 		case ARM_SMCCC_ARCH_WORKAROUND_2:
-			switch (kvm_arm_have_ssbd()) {
-			case KVM_SSBD_FORCE_DISABLE:
-			case KVM_SSBD_UNKNOWN:
+			switch (arm64_get_ssbd_state()) {
+			case ARM64_SSBD_FORCE_DISABLE:
+			case ARM64_SSBD_UNKNOWN:
 				break;
-			case KVM_SSBD_KERNEL:
-				val = SMCCC_RET_SUCCESS;
-				break;
-			case KVM_SSBD_FORCE_ENABLE:
-			case KVM_SSBD_MITIGATED:
+			case ARM64_SSBD_KERNEL:
+			case ARM64_SSBD_FORCE_ENABLE:
+			case ARM64_SSBD_MITIGATED:
 				val = SMCCC_RET_NOT_REQUIRED;
 				break;
 			}

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index ee33875c5c2a..f6e8b4a75cbb 100644
@@ -319,10 +319,6 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
 		vcpu->arch.reset_state.reset = false;
 	}
 
-	/* Default workaround setup is enabled (if supported) */
-	if (kvm_arm_have_ssbd() == KVM_SSBD_KERNEL)
-		vcpu->arch.workaround_flags |= VCPU_WORKAROUND_2_FLAG;
-
 	/* Reset timer */
 	ret = kvm_timer_vcpu_reset(vcpu);
 out:

index 9edce004d7c7..bb5e5b88d439 100644
@@ -631,29 +631,6 @@ static inline void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr) {}
 static inline void kvm_clr_pmu_events(u32 clr) {}
 #endif
 
-#define KVM_SSBD_UNKNOWN		-1
-#define KVM_SSBD_FORCE_DISABLE		0
-#define KVM_SSBD_KERNEL		1
-#define KVM_SSBD_FORCE_ENABLE		2
-#define KVM_SSBD_MITIGATED		3
-
-static inline int kvm_arm_have_ssbd(void)
-{
-	switch (arm64_get_ssbd_state()) {
-	case ARM64_SSBD_FORCE_DISABLE:
-		return KVM_SSBD_FORCE_DISABLE;
-	case ARM64_SSBD_KERNEL:
-		return KVM_SSBD_KERNEL;
-	case ARM64_SSBD_FORCE_ENABLE:
-		return KVM_SSBD_FORCE_ENABLE;
-	case ARM64_SSBD_MITIGATED:
-		return KVM_SSBD_MITIGATED;
-	case ARM64_SSBD_UNKNOWN:
-	default:
-		return KVM_SSBD_UNKNOWN;
-	}
-}
-
 void kvm_vcpu_load_sysregs_vhe(struct kvm_vcpu *vcpu);
 void kvm_vcpu_put_sysregs_vhe(struct kvm_vcpu *vcpu);
 

index 0a316dee491f..dd28c325db34 100644
@@ -1295,7 +1295,7 @@ static void cpu_init_hyp_mode(void)
 	 * at EL2.
 	 */
 	if (this_cpu_has_cap(ARM64_SSBS) &&
-	    arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) {
+	    arm64_get_spectre_v4_state() == SPECTRE_VULNERABLE) {
 		kvm_call_hyp_nvhe(__kvm_enable_ssbs);
 	}
 }

index 69e023dfafce..9824025ccc5c 100644
@@ -36,13 +36,24 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu)
 			}
 			break;
 		case ARM_SMCCC_ARCH_WORKAROUND_2:
-			switch (arm64_get_ssbd_state()) {
-			case ARM64_SSBD_FORCE_DISABLE:
-			case ARM64_SSBD_UNKNOWN:
+			switch (arm64_get_spectre_v4_state()) {
+			case SPECTRE_VULNERABLE:
 				break;
-			case ARM64_SSBD_KERNEL:
-			case ARM64_SSBD_FORCE_ENABLE:
-			case ARM64_SSBD_MITIGATED:
+			case SPECTRE_MITIGATED:
+				/*
+				 * SSBS everywhere: Indicate no firmware
+				 * support, as the SSBS support will be
+				 * indicated to the guest and the default is
+				 * safe.
+				 *
+				 * Otherwise, expose a permanent mitigation
+				 * to the guest, and hide SSBS so that the
+				 * guest stays protected.
+				 */
+				if (cpus_have_final_cap(ARM64_SSBS))
+					break;
+				fallthrough;
+			case SPECTRE_UNAFFECTED:
 				val = SMCCC_RET_NOT_REQUIRED;
 				break;
 			}

index 87e6e3818fb5..db4056ecccfd 100644
@@ -435,14 +435,19 @@ static int get_kernel_wa_level(u64 regid)
 		}
 		return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_1_NOT_AVAIL;
 	case KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2:
-		switch (arm64_get_ssbd_state()) {
-		case ARM64_SSBD_FORCE_ENABLE:
-		case ARM64_SSBD_MITIGATED:
-		case ARM64_SSBD_KERNEL:
+		switch (arm64_get_spectre_v4_state()) {
+		case SPECTRE_MITIGATED:
+			/*
+			 * As for the hypercall discovery, we pretend we
+			 * don't have any FW mitigation if SSBS is there at
+			 * all times.
+			 */
+			if (cpus_have_final_cap(ARM64_SSBS))
+				return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
+			fallthrough;
+		case SPECTRE_UNAFFECTED:
 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_REQUIRED;
-		case ARM64_SSBD_UNKNOWN:
-		case ARM64_SSBD_FORCE_DISABLE:
-		default:
+		case SPECTRE_VULNERABLE:
 			return KVM_REG_ARM_SMCCC_ARCH_WORKAROUND_2_NOT_AVAIL;
 		}
 	}

index 3b48aa121cee..fba6700b457b 100644
@@ -698,20 +698,6 @@ static inline bool system_supports_tlb_range(void)
 		cpus_have_const_cap(ARM64_HAS_TLB_RANGE);
 }
 
-#define ARM64_SSBD_UNKNOWN		-1
-#define ARM64_SSBD_FORCE_DISABLE	0
-#define ARM64_SSBD_KERNEL		1
-#define ARM64_SSBD_FORCE_ENABLE		2
-#define ARM64_SSBD_MITIGATED		3
-
-static inline int arm64_get_ssbd_state(void)
-{
-	extern int ssbd_state;
-	return ssbd_state;
-}
-
-void arm64_set_ssbd_mitigation(bool state);
-
 extern int do_emulate_mrs(struct pt_regs *regs, u32 sys_reg, u32 rt);
 
 static inline u32 id_aa64mmfr0_parange_to_phys_shift(int parange)

index 7e9caef13db4..6c8303559beb 100644
@@ -106,8 +106,6 @@ cpu_enable_trap_ctr_access(const struct arm64_cpu_capabilities *cap)
 		sysreg_clear_set(sctlr_el1, SCTLR_EL1_UCT, 0);
 }
 
-int ssbd_state __read_mostly = ARM64_SSBD_UNKNOWN;
-
 #ifdef CONFIG_ARM64_ERRATUM_1463225
 DEFINE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa);