KVM: arm64: Provide KVM's own save/restore SVE primitives

as we are about to change the way KVM deals with SVE, provide
KVM with its own save/restore SVE primitives.

No functional change intended.
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>

arch/arm64/include/asm/fpsimdmacros.h

@@ -6,6 +6,8 @@
  * Author: Catalin Marinas <catalin.marinas@arm.com>
  */
 
+#include <asm/assembler.h>
+
 .macro fpsimd_save state, tmpnr
 	stp	q0, q1, [\state, #16 * 0]
 	stp	q2, q3, [\state, #16 * 2]

arch/arm64/include/asm/kvm_hyp.h

@@ -85,6 +85,8 @@ void __debug_switch_to_host(struct kvm_vcpu *vcpu);
 
 void __fpsimd_save_state(struct user_fpsimd_state *fp_regs);
 void __fpsimd_restore_state(struct user_fpsimd_state *fp_regs);
+void __sve_save_state(void *sve_pffr, u32 *fpsr);
+void __sve_restore_state(void *sve_pffr, u32 *fpsr, unsigned int vqminus1);
 
 #ifndef __KVM_NVHE_HYPERVISOR__
 void activate_traps_vhe_load(struct kvm_vcpu *vcpu);

arch/arm64/kvm/hyp/fpsimd.S

@@ -19,3 +19,13 @@ SYM_FUNC_START(__fpsimd_restore_state)
 	fpsimd_restore	x0, 1
 	ret
 SYM_FUNC_END(__fpsimd_restore_state)
+
+SYM_FUNC_START(__sve_restore_state)
+	sve_load 0, x1, x2, 3, x4
+	ret
+SYM_FUNC_END(__sve_restore_state)
+
+SYM_FUNC_START(__sve_save_state)
+	sve_save 0, x1, 2
+	ret
+SYM_FUNC_END(__sve_save_state)

arch/arm64/kvm/hyp/include/hyp/switch.h

@@ -256,8 +256,8 @@ static inline bool __hyp_handle_fpsimd(struct kvm_vcpu *vcpu)
 				vcpu->arch.host_fpsimd_state,
 				struct thread_struct, uw.fpsimd_state);
 
-			sve_save_state(sve_pffr(thread),
-				       &vcpu->arch.host_fpsimd_state->fpsr);
+			__sve_save_state(sve_pffr(thread),
+					 &vcpu->arch.host_fpsimd_state->fpsr);
 		} else {
 			__fpsimd_save_state(vcpu->arch.host_fpsimd_state);
 		}
@@ -266,9 +266,9 @@ static inline bool __hyp_handle_fpsimd(struct kvm_vcpu *vcpu)
 	}
 
 	if (sve_guest) {
-		sve_load_state(vcpu_sve_pffr(vcpu),
-			       &vcpu->arch.ctxt.fp_regs.fpsr,
-			       sve_vq_from_vl(vcpu->arch.sve_max_vl) - 1);
+		__sve_restore_state(vcpu_sve_pffr(vcpu),
+				    &vcpu->arch.ctxt.fp_regs.fpsr,
+				    sve_vq_from_vl(vcpu->arch.sve_max_vl) - 1);
 		write_sysreg_s(__vcpu_sys_reg(vcpu, ZCR_EL1), SYS_ZCR_EL12);
 	} else {
 		__fpsimd_restore_state(&vcpu->arch.ctxt.fp_regs);