[PATCH V1 libibverbs 0/2] RoCE V2 support for UD traffic

[PATCH V1 libibverbs 0/2] RoCE V2 support for UD traffic

[Yishai Hadas]

Hi Doug,

This patch-set from Noa enables user application to work
properly with RoCE V2 when UD traffic is used.

Sending V1 to address the symbol table note that Jason pointed
on, no other changes from V0, details below.

The series was tested successfully with mlx5 driver (lib, kernel)
and can be accessed also from my openfabrics GIT at:
git://openfabrics.org/~yishaih/libibverbs.git branch: rocev2_v1

It's sent over your master branch, to take it on top of RSS series
you can take it from the 'for-upstream' branch in above GIT.
(solves a conflict in src/libibverbs.map)

No change is required in the application side, all is done transparently
to the application.

Yishai

In General:
Currently, UD traffic is not supported over RoCE V2 in libibverbs,
since libibverbs can't differ between V1 and V2 GIDs and can't
select GID index properly.

This series contains two patches targeted to solve this:
- The first one introduces an internal helper function,
  ibv_query_gid_type, to be used by libibverbs and its vendors libs
  in order to select the correct GID index.
 
- The second patch changes init_ah_from_wc to use the first patch and
  set the GID index according to the RoCE version used.

Changes from V0:
patch #1: Use IBVERBS_1.3 as the symbol label.

Noa Osherovich (2):
  Add ibv_query_gid_type to support RoCE v2 UD traffic
  Add support for UD traffic on RoCE v2

 include/infiniband/driver.h |   7 ++
 src/libibverbs.map          |   5 +
 src/verbs.c                 | 243 ++++++++++++++++++++++++++++++++++++++++----
 3 files changed, 236 insertions(+), 19 deletions(-)

-- 
1.8.3.1

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[PATCH V1 libibverbs 1/2] Add ibv_query_gid_type to support RoCE v2 UD traffic

[Yishai Hadas]

From: Noa Osherovich <noaos-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

Currently, libibverbs does not support UD traffic for RoCE v2 since
it can't differ between v1 and v2 GIDs (both have the same GID, only
the version is different). This means that GID index can't be
selected correctly.

This patch introduces ibv_query_gid_type helper function to be used
by libibverbs and its vendors to return GID type based on its GID
index by using the relevant sysfs.

Signed-off-by: Noa Osherovich <noaos-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Reviewed-by: Yishai Hadas <yishaih-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
 include/infiniband/driver.h |  7 +++++
 src/libibverbs.map          |  5 ++++
 src/verbs.c                 | 65 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 77 insertions(+)

diff --git a/include/infiniband/driver.h b/include/infiniband/driver.h
index 65fa44f..d4b6f58 100644
--- a/include/infiniband/driver.h
+++ b/include/infiniband/driver.h
@@ -86,6 +86,11 @@ enum verbs_qp_mask {
 	VERBS_QP_RESERVED	= 1 << 1
 };
 
+enum ibv_gid_type {
+	IBV_GID_TYPE_IB_ROCE_V1,
+	IBV_GID_TYPE_ROCE_V2,
+};
+
 struct verbs_qp {
 	struct ibv_qp		qp;
 	uint32_t		comp_mask;
@@ -258,4 +263,6 @@ static inline int verbs_get_srq_num(struct ibv_srq *srq, uint32_t *srq_num)
 	return ENOSYS;
 }
 
+int ibv_query_gid_type(struct ibv_context *context, uint8_t port_num,
+		       unsigned int index, enum ibv_gid_type *type);
 #endif /* INFINIBAND_DRIVER_H */
diff --git a/src/libibverbs.map b/src/libibverbs.map
index 5134bd9..b88b471 100644
--- a/src/libibverbs.map
+++ b/src/libibverbs.map
@@ -118,5 +118,10 @@ IBVERBS_1.1 {
 		ibv_cmd_create_qp_ex2;
 		ibv_cmd_open_qp;
 		ibv_cmd_rereg_mr;
+};
+
+IBVERBS_1.3 {
+        global:
+		ibv_query_gid_type;
 
 } IBVERBS_1.0;
diff --git a/src/verbs.c b/src/verbs.c
index 68888c3..08f03e3 100644
--- a/src/verbs.c
+++ b/src/verbs.c
@@ -41,6 +41,7 @@
 #include <stdlib.h>
 #include <errno.h>
 #include <string.h>
+#include <dirent.h>
 
 #include "ibverbs.h"
 #ifndef NRESOLVE_NEIGH
@@ -585,6 +586,70 @@ struct ibv_ah *__ibv_create_ah(struct ibv_pd *pd, struct ibv_ah_attr *attr)
 }
 default_symver(__ibv_create_ah, ibv_create_ah);
 
+/* GID types as appear in sysfs, no change is expected as of ABI
+ * compatibility.
+ */
+#define V1_TYPE "IB/RoCE v1"
+#define V2_TYPE "RoCE v2"
+int ibv_query_gid_type(struct ibv_context *context, uint8_t port_num,
+		       unsigned int index, enum ibv_gid_type *type)
+{
+	char name[32];
+	char buff[11];
+
+	snprintf(name, sizeof(name), "ports/%d/gid_attrs/types/%d", port_num,
+		 index);
+
+	/* Reset errno so that we can rely on its value upon any error flow in
+	 * ibv_read_sysfs_file.
+	 */
+	errno = 0;
+	if (ibv_read_sysfs_file(context->device->ibdev_path, name, buff,
+				sizeof(buff)) <= 0) {
+		char *dir_path;
+		DIR *dir;
+
+		if (errno == EINVAL) {
+			/* In IB, this file doesn't exist and the kernel sets
+			 * errno to -EINVAL.
+			 */
+			*type = IBV_GID_TYPE_IB_ROCE_V1;
+			return 0;
+		}
+		if (asprintf(&dir_path, "%s/%s/%d/%s/",
+			     context->device->ibdev_path, "ports", port_num,
+			     "gid_attrs") < 0)
+			return -1;
+		dir = opendir(dir_path);
+		free(dir_path);
+		if (!dir) {
+			if (errno == ENOENT)
+				/* Assuming that if gid_attrs doesn't exist,
+				 * we have an old kernel and all GIDs are
+				 * IB/RoCE v1
+				 */
+				*type = IBV_GID_TYPE_IB_ROCE_V1;
+			else
+				return -1;
+		} else {
+			closedir(dir);
+			errno = EFAULT;
+			return -1;
+		}
+	} else {
+		if (!strcmp(buff, V1_TYPE)) {
+			*type = IBV_GID_TYPE_IB_ROCE_V1;
+		} else if (!strcmp(buff, V2_TYPE)) {
+			*type = IBV_GID_TYPE_ROCE_V2;
+		} else {
+			errno = ENOTSUP;
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
 static int ibv_find_gid_index(struct ibv_context *context, uint8_t port_num,
 			      union ibv_gid *gid)
 {
-- 
1.8.3.1

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[PATCH V1 libibverbs 2/2] Add support for UD traffic on RoCE v2

[Yishai Hadas]

From: Noa Osherovich <noaos-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>

When creating an Address Handle from a Work Completion, source GID index must
be set. To enable RoCE v2, libibverbs should select the right GID index for
it.

RoCE v2 is using UDP/IP layers so a WC's GRH could be either an IB GRH, IPv4
header or an IPv6 header. Libibverbs should be able to differ between them in a
driver-agnostic way to avoid API changes.

This patch is using the fact that for RoCE v2, the GRH is either an IPv6 header
or 20 garbled bytes followed by an IPv4 header, as defined in RoCE v2 annex.
The annex also specifies that for packets with IPv4 header, the version number
is 4, for packets with IPv6 header it's 6 or the packet is silently dropped.
This fact is also taken into account when parsing the GRH.

Signed-off-by: Noa Osherovich <noaos-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Reviewed-by: Yishai Hadas <yishaih-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
 src/verbs.c | 178 +++++++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 159 insertions(+), 19 deletions(-)

diff --git a/src/verbs.c b/src/verbs.c
index 08f03e3..fc8b9f6 100644
--- a/src/verbs.c
+++ b/src/verbs.c
@@ -41,6 +41,7 @@
 #include <stdlib.h>
 #include <errno.h>
 #include <string.h>
+#include <linux/ip.h>
 #include <dirent.h>
 
 #include "ibverbs.h"
@@ -651,48 +652,187 @@ int ibv_query_gid_type(struct ibv_context *context, uint8_t port_num,
 }
 
 static int ibv_find_gid_index(struct ibv_context *context, uint8_t port_num,
-			      union ibv_gid *gid)
+			      union ibv_gid *gid, enum ibv_gid_type gid_type)
 {
+	enum ibv_gid_type sgid_type = 0;
 	union ibv_gid sgid;
 	int i = 0, ret;
 
 	do {
-		ret = ibv_query_gid(context, port_num, i++, &sgid);
-	} while (!ret && memcmp(&sgid, gid, sizeof *gid));
+		ret = ibv_query_gid(context, port_num, i, &sgid);
+		if (!ret) {
+			ret = ibv_query_gid_type(context, port_num, i,
+						 &sgid_type);
+		}
+		i++;
+	} while (!ret && (memcmp(&sgid, gid, sizeof(*gid)) ||
+		 (gid_type != sgid_type)));
 
 	return ret ? ret : i - 1;
 }
 
-int ibv_init_ah_from_wc(struct ibv_context *context, uint8_t port_num,
-			struct ibv_wc *wc, struct ibv_grh *grh,
-			struct ibv_ah_attr *ah_attr)
+static inline void map_ipv4_addr_to_ipv6(__be32 ipv4, struct in6_addr *ipv6)
+{
+	ipv6->s6_addr32[0] = 0;
+	ipv6->s6_addr32[1] = 0;
+	ipv6->s6_addr32[2] = htonl(0x0000FFFF);
+	ipv6->s6_addr32[3] = ipv4;
+}
+
+static inline uint16_t ipv4_calc_hdr_csum(uint16_t *data, unsigned int num_hwords)
+{
+	unsigned int i = 0;
+	uint32_t sum = 0;
+
+	for (i = 0; i < num_hwords; i++)
+		sum += *(data++);
+
+	sum = (sum & 0xffff) + (sum >> 16);
+
+	return ~sum;
+}
+
+static inline int get_grh_header_version(struct ibv_grh *grh)
+{
+	int ip6h_version = (ntohl(grh->version_tclass_flow) >> 28) & 0xf;
+	struct iphdr *ip4h = (struct iphdr *)((void *)grh + 20);
+	struct iphdr ip4h_checked;
+
+	if (ip6h_version != 6) {
+		if (ip4h->version == 4)
+			return 4;
+		errno = EPROTONOSUPPORT;
+		return -1;
+	}
+	/* version may be 6 or 4 */
+	if (ip4h->ihl != 5) /* IPv4 header length must be 5 for RoCE v2. */
+		return 6;
+	/*
+	* Verify checksum.
+	* We can't write on scattered buffers so we have to copy to temp
+	* buffer.
+	*/
+	memcpy(&ip4h_checked, ip4h, sizeof(ip4h_checked));
+	/* Need to set the checksum field (check) to 0 before re-calculating
+	 * the checksum.
+	 */
+	ip4h_checked.check = 0;
+	ip4h_checked.check = ipv4_calc_hdr_csum((uint16_t *)&ip4h_checked, 10);
+	/* if IPv4 header checksum is OK, believe it */
+	if (ip4h->check == ip4h_checked.check)
+		return 4;
+	return 6;
+}
+
+static inline void set_ah_attr_generic_fields(struct ibv_ah_attr *ah_attr,
+					      struct ibv_wc *wc,
+					      struct ibv_grh *grh,
+					      uint8_t port_num)
 {
 	uint32_t flow_class;
-	int ret;
 
-	memset(ah_attr, 0, sizeof *ah_attr);
+	flow_class = ntohl(grh->version_tclass_flow);
+	ah_attr->grh.flow_label = flow_class & 0xFFFFF;
 	ah_attr->dlid = wc->slid;
 	ah_attr->sl = wc->sl;
 	ah_attr->src_path_bits = wc->dlid_path_bits;
 	ah_attr->port_num = port_num;
+}
 
-	if (wc->wc_flags & IBV_WC_GRH) {
-		ah_attr->is_global = 1;
-		ah_attr->grh.dgid = grh->sgid;
+static inline int set_ah_attr_by_ipv4(struct ibv_context *context,
+				      struct ibv_ah_attr *ah_attr,
+				      struct iphdr *ip4h, uint8_t port_num)
+{
+	union ibv_gid sgid;
+	int ret;
+
+	/* No point searching multicast GIDs in GID table */
+	if (IN_CLASSD(ntohl(ip4h->daddr))) {
+		errno = EINVAL;
+		return -1;
+	}
 
-		ret = ibv_find_gid_index(context, port_num, &grh->dgid);
-		if (ret < 0)
-			return ret;
+	map_ipv4_addr_to_ipv6(ip4h->daddr, (struct in6_addr *)&sgid);
+	ret = ibv_find_gid_index(context, port_num, &sgid,
+				 IBV_GID_TYPE_ROCE_V2);
+	if (ret < 0)
+		return ret;
 
-		ah_attr->grh.sgid_index = (uint8_t) ret;
-		flow_class = ntohl(grh->version_tclass_flow);
-		ah_attr->grh.flow_label = flow_class & 0xFFFFF;
-		ah_attr->grh.hop_limit = grh->hop_limit;
-		ah_attr->grh.traffic_class = (flow_class >> 20) & 0xFF;
+	map_ipv4_addr_to_ipv6(ip4h->saddr,
+			      (struct in6_addr *)&ah_attr->grh.dgid);
+	ah_attr->grh.sgid_index = (uint8_t) ret;
+	ah_attr->grh.hop_limit = ip4h->ttl;
+	ah_attr->grh.traffic_class = ip4h->tos;
+
+	return 0;
+}
+
+#define IB_NEXT_HDR    0x1b
+static inline int set_ah_attr_by_ipv6(struct ibv_context *context,
+				  struct ibv_ah_attr *ah_attr,
+				  struct ibv_grh *grh, uint8_t port_num)
+{
+	uint32_t flow_class;
+	uint32_t sgid_type;
+	int ret;
+
+	/* No point searching multicast GIDs in GID table */
+	if (grh->dgid.raw[0] == 0xFF) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	ah_attr->grh.dgid = grh->sgid;
+	if (grh->next_hdr == IPPROTO_UDP) {
+		sgid_type = IBV_GID_TYPE_ROCE_V2;
+	} else if (grh->next_hdr == IB_NEXT_HDR) {
+		sgid_type = IBV_GID_TYPE_IB_ROCE_V1;
+	} else {
+		errno = EPROTONOSUPPORT;
+		return -1;
 	}
+
+	ret = ibv_find_gid_index(context, port_num, &grh->dgid,
+				 sgid_type);
+	if (ret < 0)
+		return ret;
+
+	ah_attr->grh.sgid_index = (uint8_t) ret;
+	flow_class = ntohl(grh->version_tclass_flow);
+	ah_attr->grh.hop_limit = grh->hop_limit;
+	ah_attr->grh.traffic_class = (flow_class >> 20) & 0xFF;
+
 	return 0;
 }
 
+int ibv_init_ah_from_wc(struct ibv_context *context, uint8_t port_num,
+			struct ibv_wc *wc, struct ibv_grh *grh,
+			struct ibv_ah_attr *ah_attr)
+{
+	int version;
+	int ret = 0;
+
+	memset(ah_attr, 0, sizeof *ah_attr);
+	set_ah_attr_generic_fields(ah_attr, wc, grh, port_num);
+
+	if (wc->wc_flags & IBV_WC_GRH) {
+		ah_attr->is_global = 1;
+		version = get_grh_header_version(grh);
+
+		if (version == 4)
+			ret = set_ah_attr_by_ipv4(context, ah_attr,
+						  (struct iphdr *)((void *)grh + 20),
+						  port_num);
+		else if (version == 6)
+			ret = set_ah_attr_by_ipv6(context, ah_attr, grh,
+						  port_num);
+		else
+			ret = -1;
+	}
+
+	return ret;
+}
+
 struct ibv_ah *ibv_create_ah_from_wc(struct ibv_pd *pd, struct ibv_wc *wc,
 				     struct ibv_grh *grh, uint8_t port_num)
 {
-- 
1.8.3.1

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