Merge branch 'for-next/sve-state' into for-next/core

* for-next/sve-state:
  arm64/fp: Use a struct to pass data to fpsimd_bind_state_to_cpu()
  arm64/sve: Leave SVE enabled on syscall if we don't context switch
  arm64/fpsimd: SME no longer requires SVE register state
  arm64/fpsimd: Load FP state based on recorded data type
  arm64/fpsimd: Stop using TIF_SVE to manage register saving in KVM
  arm64/fpsimd: Have KVM explicitly say which FP registers to save
  arm64/fpsimd: Track the saved FPSIMD state type separately to TIF_SVE
  KVM: arm64: Discard any SVE state when entering KVM guests

3 files changed, 31 insertions, 5 deletions

diff --git a/arch/arm64/include/asm/fpsimd.h b/arch/arm64/include/asm/fpsimd.h
index 6f86b7ab6c28..e6fa1e2982c8 100644
--- a/arch/arm64/include/asm/fpsimd.h
+++ b/arch/arm64/include/asm/fpsimd.h
@@ -56,11 +56,20 @@ extern void fpsimd_signal_preserve_current_state(void);
 extern void fpsimd_preserve_current_state(void);
 extern void fpsimd_restore_current_state(void);
 extern void fpsimd_update_current_state(struct user_fpsimd_state const *state);
+extern void fpsimd_kvm_prepare(void);
+
+struct cpu_fp_state {
+	struct user_fpsimd_state *st;
+	void *sve_state;
+	void *za_state;
+	u64 *svcr;
+	unsigned int sve_vl;
+	unsigned int sme_vl;
+	enum fp_type *fp_type;
+	enum fp_type to_save;
+};
 
-extern void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *state,
-				     void *sve_state, unsigned int sve_vl,
-				     void *za_state, unsigned int sme_vl,
-				     u64 *svcr);
+extern void fpsimd_bind_state_to_cpu(struct cpu_fp_state *fp_state);
 
 extern void fpsimd_flush_task_state(struct task_struct *target);
 extern void fpsimd_save_and_flush_cpu_state(void);
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 45e2136322ba..fd34ab155d0b 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -306,8 +306,18 @@ struct vcpu_reset_state {
 struct kvm_vcpu_arch {
 	struct kvm_cpu_context ctxt;
 
-	/* Guest floating point state */
+	/*
+	 * Guest floating point state
+	 *
+	 * The architecture has two main floating point extensions,
+	 * the original FPSIMD and SVE.  These have overlapping
+	 * register views, with the FPSIMD V registers occupying the
+	 * low 128 bits of the SVE Z registers.  When the core
+	 * floating point code saves the register state of a task it
+	 * records which view it saved in fp_type.
+	 */
 	void *sve_state;
+	enum fp_type fp_type;
 	unsigned int sve_max_vl;
 	u64 svcr;
 
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
index b15fd6c11294..0dcb1f7f485d 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -122,6 +122,12 @@ enum vec_type {
 	ARM64_VEC_MAX,
 };
 
+enum fp_type {
+	FP_STATE_CURRENT,	/* Save based on current task state. */
+	FP_STATE_FPSIMD,
+	FP_STATE_SVE,
+};
+
 struct cpu_context {
 	unsigned long x19;
 	unsigned long x20;
@@ -152,6 +158,7 @@ struct thread_struct {
 		struct user_fpsimd_state fpsimd_state;
 	} uw;
 
+	enum fp_type		fp_type;	/* registers FPSIMD or SVE? */
 	unsigned int		fpsimd_cpu;
 	void			*sve_state;	/* SVE registers, if any */
 	void			*za_state;	/* ZA register, if any */