vdpa: handle irq bypass register failure case

LKP considered variable 'ret' in vhost_vdpa_setup_vq_irq() as
a unused variable, so suggest we remove it. Actually it stores
return value of irq_bypass_register_producer(), but we did not
check it, we should handle the failure case.

This commit will print a message if irq bypass register producer
fail, in this case, vqs still remain functional.

Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/r/20201023104046.404794-1-lingshan.zhu@intel.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>

diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index ec223da..2754f30 100644 (file)
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -104,6 +104,9 @@ static void vhost_vdpa_setup_vq_irq(struct vhost_vdpa *v, u16 qid)
        vq->call_ctx.producer.token = vq->call_ctx.ctx;
        vq->call_ctx.producer.irq = irq;
        ret = irq_bypass_register_producer(&vq->call_ctx.producer);
+       if (unlikely(ret))
+               dev_info(&v->dev, "vq %u, irq bypass producer (token %p) registration fails, ret =  %d\n",
+                        qid, vq->call_ctx.producer.token, ret);
 }
 
 static void vhost_vdpa_unsetup_vq_irq(struct vhost_vdpa *v, u16 qid)