[PATCH v3 08/11] KVM: arm64: Add an isb before restoring guest sve state

[Fuad Tabba]

Since sve_cond_update_zcr_vq() does not have a barrier, add an
instruction synchronization barrier after updating ZCR before
restoring the guest sve state.

Signed-off-by: Fuad Tabba <tabba at google.com>
---
 arch/arm64/kvm/hyp/include/hyp/switch.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 89c52b59d2a9..24b43f1f3d51 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -315,6 +315,7 @@ static bool kvm_hyp_handle_mops(struct kvm_vcpu *vcpu, u64 *exit_code)
 static inline void __hyp_sve_restore_guest(struct kvm_vcpu *vcpu)
 {
 	sve_cond_update_zcr_vq(vcpu_sve_max_vq(vcpu) - 1, SYS_ZCR_EL2);
+	isb();
 	__sve_restore_state(vcpu_sve_pffr(vcpu),
 			    &vcpu->arch.ctxt.fp_regs.fpsr);
 	write_sysreg_el1(__vcpu_sys_reg(vcpu, ZCR_EL1), SYS_ZCR);
-- 
2.45.1.288.g0e0cd299f1-goog