[dpdk-dev] [PATCH v3 2/6] vhost: skip access lock when vDPA is configured

From: Matan Azrad <matan@mellanox.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: dev@dpdk.org, Xiao Wang <xiao.w.wang@intel.com>
Subject: [dpdk-dev] [PATCH v3 2/6] vhost: skip access lock when vDPA is configured
Date: Mon, 29 Jun 2020 14:08:17 +0000	[thread overview]
Message-ID: <1593439701-136089-3-git-send-email-matan@mellanox.com> (raw)
In-Reply-To: <1593439701-136089-1-git-send-email-matan@mellanox.com>

No need to take access lock in the vhost-user message handler when
vDPA driver controls all the data-path of the vhost device.

It allows the vDPA set_vring_state operation callback to configure
guest notifications.

Signed-off-by: Matan Azrad <matan@mellanox.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>
---
 lib/librte_vhost/vhost_user.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
index 4e1af91..8d8050b 100644
--- a/lib/librte_vhost/vhost_user.c
+++ b/lib/librte_vhost/vhost_user.c
@@ -2690,8 +2690,10 @@ typedef int (*vhost_message_handler_t)(struct virtio_net **pdev,
 	case VHOST_USER_SEND_RARP:
 	case VHOST_USER_NET_SET_MTU:
 	case VHOST_USER_SET_SLAVE_REQ_FD:
-		vhost_user_lock_all_queue_pairs(dev);
-		unlock_required = 1;
+		if (!(dev->flags & VIRTIO_DEV_VDPA_CONFIGURED)) {
+			vhost_user_lock_all_queue_pairs(dev);
+			unlock_required = 1;
+		}
 		break;
 	default:
 		break;
-- 
1.8.3.1

