net/vhost: add parameter to enable IOMMU feature

Introduce a new iommu-support parameter to Vhost PMD that
passes the RTE_VHOST_USER_IOMMU_SUPPORT flag at vhost
device register time.

Default value is 0, meaning that IOMMU support is disabled
if not specified explicitly.

Example to enable IOMMU support for a given device:

--vdev 'net_vhost0,iface=/tmp/vhost-user2,iommu-support=1'

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Yuanhan Liu <yliu@fridaylinux.org>
Tested-by: Mark Kavanagh <mark.b.kavanagh@intel.com>
Acked-by: Mark Kavanagh <mark.b.kavanagh@intel.com>

diff --git a/doc/guides/nics/vhost.rst b/doc/guides/nics/vhost.rst
index e651a16..4f7ae89 100644 (file)
--- a/doc/guides/nics/vhost.rst
+++ b/doc/guides/nics/vhost.rst
@@ -66,6 +66,11 @@ The user can specify below arguments in `--vdev` option.
     It is used to specify the number of queues virtio-net device has.
     (Default: 1)
 
+#.  ``iommu-support``:
+
+    It is used to enable iommu support in vhost library.
+    (Default: 0 (disabled))
+
 Vhost PMD event handling
 ------------------------
 

diff --git a/drivers/net/vhost/rte_eth_vhost.c b/drivers/net/vhost/rte_eth_vhost.c
index f98c980..a28cc3b 100644 (file)
--- a/drivers/net/vhost/rte_eth_vhost.c
+++ b/drivers/net/vhost/rte_eth_vhost.c
@@ -52,6 +52,7 @@ enum {VIRTIO_RXQ, VIRTIO_TXQ, VIRTIO_QNUM};
 #define ETH_VHOST_QUEUES_ARG           "queues"
 #define ETH_VHOST_CLIENT_ARG           "client"
 #define ETH_VHOST_DEQUEUE_ZERO_COPY    "dequeue-zero-copy"
+#define ETH_VHOST_IOMMU_SUPPORT                "iommu-support"
 #define VHOST_MAX_PKT_BURST 32
 
 static const char *valid_arguments[] = {
@@ -59,6 +60,7 @@ static const char *valid_arguments[] = {
        ETH_VHOST_QUEUES_ARG,
        ETH_VHOST_CLIENT_ARG,
        ETH_VHOST_DEQUEUE_ZERO_COPY,
+       ETH_VHOST_IOMMU_SUPPORT,
        NULL
 };
 
@@ -1164,6 +1166,7 @@ rte_pmd_vhost_probe(struct rte_vdev_device *dev)
        uint64_t flags = 0;
        int client_mode = 0;
        int dequeue_zero_copy = 0;
+       int iommu_support = 0;
 
        RTE_LOG(INFO, PMD, "Initializing pmd_vhost for %s\n",
                rte_vdev_device_name(dev));
@@ -1211,6 +1214,16 @@ rte_pmd_vhost_probe(struct rte_vdev_device *dev)
                        flags |= RTE_VHOST_USER_DEQUEUE_ZERO_COPY;
        }
 
+       if (rte_kvargs_count(kvlist, ETH_VHOST_IOMMU_SUPPORT) == 1) {
+               ret = rte_kvargs_process(kvlist, ETH_VHOST_IOMMU_SUPPORT,
+                                        &open_int, &iommu_support);
+               if (ret < 0)
+                       goto out_free;
+
+               if (iommu_support)
+                       flags |= RTE_VHOST_USER_IOMMU_SUPPORT;
+       }
+
        if (dev->device.numa_node == SOCKET_ID_ANY)
                dev->device.numa_node = rte_socket_id();