[iproute2-next v2 4/4] vdpa: Enable user to set mtu of the vdpa device

[Parav Pandit <parav@nvidia.com>]

Implement mtu setting for vdpa device.

$ vdpa mgmtdev show
vdpasim_net:
  supported_classes net

Add the device with mac address and mtu:
$ vdpa dev add name bar mgmtdev vdpasim_net mac 00:11:22:33:44:55 mtu 9000

In above command only mac address or only mtu can also be set.

View the config after setting:
$ vdpa dev config show
bar: mac 00:11:22:33:44:55 link up link_announce false mtu 9000

Signed-off-by: Parav Pandit <parav@nvidia.com>
---
changelog:
v1->v2:
 - use get_u16
 - use strcmp() instead of matches()
 - added man page
---
 man/man8/vdpa-dev.8 | 10 ++++++++++
 vdpa/vdpa.c         | 28 ++++++++++++++++++++++++++--
 2 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/man/man8/vdpa-dev.8 b/man/man8/vdpa-dev.8
index 5c5ac469..aa21ae3a 100644
--- a/man/man8/vdpa-dev.8
+++ b/man/man8/vdpa-dev.8
@@ -32,6 +32,7 @@ vdpa-dev \- vdpa device configuration
 .B mgmtdev
 .I MGMTDEV
 .RI "[ mac " MACADDR " ]"
+.RI "[ mtu " MTU " ]"
 
 .ti -8
 .B vdpa dev del
@@ -69,6 +70,10 @@ Name of the management device to use for device addition.
 - specifies the mac address for the new vdpa device.
 This is applicable only for the network type of vdpa device. This is optional.
 
+.BI mtu " MTU"
+- specifies the mtu for the new vdpa device.
+This is applicable only for the network type of vdpa device. This is optional.
+
 .SS vdpa dev del - Delete the vdpa device.
 
 .PP
@@ -109,6 +114,11 @@ vdpa dev add name foo mgmtdev vdpa_sim_net mac 00:11:22:33:44:55
 Add the vdpa device named foo on the management device vdpa_sim_net with mac address of 00:11:22:33:44:55.
 .RE
 .PP
+vdpa dev add name foo mgmtdev vdpa_sim_net mac 00:11:22:33:44:55 mtu 9000
+.RS 4
+Add the vdpa device named foo on the management device vdpa_sim_net with mac address of 00:11:22:33:44:55 and mtu of 9000 bytes.
+.RE
+.PP
 vdpa dev del foo
 .RS 4
 Delete the vdpa device named foo which was previously created.
diff --git a/vdpa/vdpa.c b/vdpa/vdpa.c
index 63d464d1..f048e470 100644
--- a/vdpa/vdpa.c
+++ b/vdpa/vdpa.c
@@ -22,6 +22,7 @@
 #define VDPA_OPT_VDEV_NAME		BIT(2)
 #define VDPA_OPT_VDEV_HANDLE		BIT(3)
 #define VDPA_OPT_VDEV_MAC		BIT(4)
+#define VDPA_OPT_VDEV_MTU		BIT(5)
 
 struct vdpa_opts {
 	uint64_t present; /* flags of present items */
@@ -30,6 +31,7 @@ struct vdpa_opts {
 	const char *vdev_name;
 	unsigned int device_id;
 	char mac[ETH_ALEN];
+	uint16_t mtu;
 };
 
 struct vdpa {
@@ -154,6 +156,17 @@ static int vdpa_argv_mac(struct vdpa *vdpa, int argc, char **argv, char *mac)
 	return 0;
 }
 
+static int vdpa_argv_u16(struct vdpa *vdpa, int argc, char **argv,
+			 uint16_t *result)
+{
+	if (argc <= 0 || *argv == NULL) {
+		fprintf(stderr, "number expected\n");
+		return -EINVAL;
+	}
+
+	return get_u16(result, *argv, 10);
+}
+
 struct vdpa_args_metadata {
 	uint64_t o_flag;
 	const char *err_msg;
@@ -204,6 +217,8 @@ static void vdpa_opts_put(struct nlmsghdr *nlh, struct vdpa *vdpa)
 	if (opts->present & VDPA_OPT_VDEV_MAC)
 		mnl_attr_put(nlh, VDPA_ATTR_DEV_NET_CFG_MACADDR,
 			     sizeof(opts->mac), opts->mac);
+	if (opts->present & VDPA_OPT_VDEV_MTU)
+		mnl_attr_put_u16(nlh, VDPA_ATTR_DEV_NET_CFG_MTU, opts->mtu);
 }
 
 static int vdpa_argv_parse(struct vdpa *vdpa, int argc, char **argv,
@@ -263,6 +278,15 @@ static int vdpa_argv_parse(struct vdpa *vdpa, int argc, char **argv,
 
 			NEXT_ARG_FWD();
 			o_found |= VDPA_OPT_VDEV_MAC;
+		} else if ((strcmp(*argv, "mtu") == 0) &&
+			   (o_all & VDPA_OPT_VDEV_MTU)) {
+			NEXT_ARG_FWD();
+			err = vdpa_argv_u16(vdpa, argc, argv, &opts->mtu);
+			if (err)
+				return err;
+
+			NEXT_ARG_FWD();
+			o_found |= VDPA_OPT_VDEV_MTU;
 		} else {
 			fprintf(stderr, "Unknown option \"%s\"\n", *argv);
 			return -EINVAL;
@@ -443,7 +467,7 @@ static int cmd_mgmtdev(struct vdpa *vdpa, int argc, char **argv)
 static void cmd_dev_help(void)
 {
 	fprintf(stderr, "Usage: vdpa dev show [ DEV ]\n");
-	fprintf(stderr, "       vdpa dev add name NAME mgmtdev MANAGEMENTDEV [ mac MACADDR ]\n");
+	fprintf(stderr, "       vdpa dev add name NAME mgmtdev MANAGEMENTDEV [ mac MACADDR ] [ mtu MTU ]\n");
 	fprintf(stderr, "       vdpa dev del DEV\n");
 	fprintf(stderr, "Usage: vdpa dev config COMMAND [ OPTIONS ]\n");
 }
@@ -533,7 +557,7 @@ static int cmd_dev_add(struct vdpa *vdpa, int argc, char **argv)
 					  NLM_F_REQUEST | NLM_F_ACK);
 	err = vdpa_argv_parse_put(nlh, vdpa, argc, argv,
 				  VDPA_OPT_VDEV_MGMTDEV_HANDLE | VDPA_OPT_VDEV_NAME,
-				  VDPA_OPT_VDEV_MAC);
+				  VDPA_OPT_VDEV_MAC | VDPA_OPT_VDEV_MTU);
 	if (err)
 		return err;
 
-- 
2.26.2