[PATCH] vdpa/ifc: fix argument compatibility check

[Andy Pei <andy.pei@intel.com>]

"sw_fallback_lm=0" means driver does not provide live migration assistance.
so hardware assistance is needed to support live migration.
However registers for live migration in BAR4 are not implemented.
In the case, we just return error after display some logs.

Fixes: 4c3f55cc23ea ("net/ifc: add LM mode parameter")
Cc: stable@dpdk.org

Signed-off-by: Andy Pei <andy.pei@intel.com>
---
 drivers/vdpa/ifc/ifcvf_vdpa.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/vdpa/ifc/ifcvf_vdpa.c b/drivers/vdpa/ifc/ifcvf_vdpa.c
index 49d68ad..9468f66 100644
--- a/drivers/vdpa/ifc/ifcvf_vdpa.c
+++ b/drivers/vdpa/ifc/ifcvf_vdpa.c
@@ -1746,6 +1746,11 @@ struct rte_vdpa_dev_info dev_info[] = {
 			goto error;
 	}
 	internal->sw_lm = sw_fallback_lm;
+	if (!internal->sw_lm && !internal->hw.lm_cfg) {
+		DRV_LOG(ERR, "Device %s does not support HW assist live migration, please enable sw-live-migration!",
+			pci_dev->name);
+		goto error;
+	}
 
 	pthread_mutex_lock(&internal_list_lock);
 	TAILQ_INSERT_TAIL(&internal_list, list, next);
-- 
1.8.3.1