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-rw-r--r--arch/arm64/kvm/fpsimd.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c
index 0815ff0347f5..c53e5b14038d 100644
--- a/arch/arm64/kvm/fpsimd.c
+++ b/arch/arm64/kvm/fpsimd.c
@@ -195,11 +195,14 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu)
* Note that this means that at guest exit ZCR_EL1 is
* not necessarily the same as on guest entry.
*
- * Restoring the VL isn't needed in VHE mode since
- * ZCR_EL2 (accessed via ZCR_EL1) would fulfill the same
- * role when doing the save from EL2.
+ * ZCR_EL2 holds the guest hypervisor's VL when running
+ * a nested guest, which could be smaller than the
+ * max for the vCPU. Similar to above, we first need to
+ * switch to a VL consistent with the layout of the
+ * vCPU's SVE state. KVM support for NV implies VHE, so
+ * using the ZCR_EL1 alias is safe.
*/
- if (!has_vhe())
+ if (!has_vhe() || (vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu)))
sve_cond_update_zcr_vq(vcpu_sve_max_vq(vcpu) - 1,
SYS_ZCR_EL1);
}