[PATCH v3 05/15] KVM: arm64: nv: Save guest's ZCR_EL2 when in hyp context

[Oliver Upton <oliver.upton@linux.dev>]

When running a guest hypervisor, ZCR_EL2 is an alias for the counterpart
EL1 state.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
 arch/arm64/kvm/fpsimd.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c
index 1807d3a79a8a..d948f1c684ca 100644
--- a/arch/arm64/kvm/fpsimd.c
+++ b/arch/arm64/kvm/fpsimd.c
@@ -173,7 +173,13 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu)
 
 	if (guest_owns_fp_regs()) {
 		if (vcpu_has_sve(vcpu)) {
-			__vcpu_sys_reg(vcpu, ZCR_EL1) = read_sysreg_el1(SYS_ZCR);
+			u64 zcr = read_sysreg_el1(SYS_ZCR);
+
+			/*
+			 * If the vCPU is in the hyp context then ZCR_EL1 is
+			 * loaded with its vEL2 counterpart.
+			 */
+			__vcpu_sys_reg(vcpu, vcpu_sve_zcr_elx(vcpu)) = zcr;
 
 			/*
 			 * Restore the VL that was saved when bound to the CPU,
-- 
2.45.2.741.gdbec12cfda-goog