[PATCH RFC v3 20/27] KVM: arm64: Provide assembly for SME state restore

[Mark Brown]

Provide a __sme_restore_state() for the hypervisor to allow it to restore
ZA and ZT for guests.

Signed-off-by: Mark Brown <broonie at kernel.org>
---
 arch/arm64/include/asm/kvm_hyp.h |  2 ++
 arch/arm64/kvm/hyp/fpsimd.S      | 16 ++++++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index 21943cb98542750a1b626a8de6bbc095d7770ccf..5a1f8e4be18624efa6b887f09c36f0e8ad318c40 100644
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -113,6 +113,8 @@ 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, int save_ffr);
 void __sve_restore_state(void *sve_pffr, u32 *fpsr, int restore_ffr);
+int __sve_get_vl(void);
+void __sme_restore_state(void const *state, bool restore_zt);
 
 u64 __guest_enter(struct kvm_vcpu *vcpu);
 
diff --git a/arch/arm64/kvm/hyp/fpsimd.S b/arch/arm64/kvm/hyp/fpsimd.S
index e950875e31cee4df58d041519b7584356463c91b..9e4bce86ef2e632a6071480c06a0b7d69bf48f3d 100644
--- a/arch/arm64/kvm/hyp/fpsimd.S
+++ b/arch/arm64/kvm/hyp/fpsimd.S
@@ -31,3 +31,19 @@ SYM_FUNC_START(__sve_save_state)
 	sve_save 0, x1, x2, 3
 	ret
 SYM_FUNC_END(__sve_save_state)
+
+SYM_FUNC_START(__sve_get_vl)
+	_sve_rdvl	0, 1
+	ret
+SYM_FUNC_END(__sve_get_vl)
+
+SYM_FUNC_START(__sme_restore_state)
+	_sme_rdsvl	2, 1		// x2 = VL/8
+	sme_load_za	0, x2, 12	// Leaves x0 pointing to end of ZA
+
+	cbz	x1, 1f
+	_ldr_zt 0
+
+1:
+	ret
+SYM_FUNC_END(__sme_restore_state)

-- 
2.39.5