KVM: arm64: nv: Load guest hyp's ZCR into EL1 state

Load the guest hypervisor's ZCR_EL2 into the corresponding EL1 register
when restoring SVE state, as ZCR_EL2 affects the VL in the hypervisor
context.

Reviewed-by: Marc Zyngier <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Oliver Upton <[email protected]>

Author: oupton

arch/arm64/include/asm/kvm_host.h

@@ -868,6 +868,9 @@ struct kvm_vcpu_arch {
 
 #define vcpu_sve_max_vq(vcpu)	sve_vq_from_vl((vcpu)->arch.sve_max_vl)
 
+#define vcpu_sve_zcr_elx(vcpu)						\
+	(unlikely(is_hyp_ctxt(vcpu)) ? ZCR_EL2 : ZCR_EL1)
+
 #define vcpu_sve_state_size(vcpu) ({					\
 	size_t __size_ret;						\
 	unsigned int __vcpu_vq;						\

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

@@ -318,7 +318,8 @@ static inline void __hyp_sve_restore_guest(struct kvm_vcpu *vcpu)
 	__sve_restore_state(vcpu_sve_pffr(vcpu),
 			    &vcpu->arch.ctxt.fp_regs.fpsr,
 			    true);
-	write_sysreg_el1(__vcpu_sys_reg(vcpu, ZCR_EL1), SYS_ZCR);
+
+	write_sysreg_el1(__vcpu_sys_reg(vcpu, vcpu_sve_zcr_elx(vcpu)), SYS_ZCR);
 }
 
 static inline void __hyp_sve_save_host(void)