1 files changed, 63 insertions, 0 deletions

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 */