According to SRP specifications 'srp-r16a' and 'srp2r06',
IOControllerProfile attributes for SRP target port include the maximum
initiator to target IU size.
SRP connection daemons, such as srp_daemon, can get the value from the
subnet manager. The SRP connection daemon can pass this value to kernel.
This patch adds a parse function for it.
Upstream commit [1] enables the kernel parameter, 'use_imm_data', by
default. [1] also use (8 * 1024) as the default value for kernel parameter
'max_imm_data'. With those default values, the maximum initiator to target
IU size will be 8260.
In case the SRPT modules, which include the in-tree 'ib_srpt.ko' module,
do not support SRP-2 'immediate data' feature, the default maximum
initiator to target IU size is significantly smaller than 8260. For
'ib_srpt.ko' module, which built from source before [2], the default
maximum initiator to target IU is 2116.
[1] introduces a regression issue for old srp targets with default kernel
parameters, as the connection will be rejected because of a too large
maximum initiator to target IU size.
[1] commit
882981f4a411 ("RDMA/srp: Add support for immediate data")
[2] commit
5dabcd0456d7 ("RDMA/srpt: Add support for immediate data")
Link: https://lore.kernel.org/r/20190927174352.7800-1-honli@redhat.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Honggang Li <honli@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
initiator is allowed to queue per SCSI host. The default
value for this parameter is 62. The lowest supported value
is 2.
+ * max_it_iu_size, a decimal number specifying the maximum
+ initiator to target information unit length.
What: /sys/class/infiniband_srp/srp-<hca>-<port_number>/ibdev
Date: January 2, 2006
SRP_OPT_IP_SRC = 1 << 15,
SRP_OPT_IP_DEST = 1 << 16,
SRP_OPT_TARGET_CAN_QUEUE= 1 << 17,
+ SRP_OPT_MAX_IT_IU_SIZE = 1 << 18,
};
static unsigned int srp_opt_mandatory[] = {
{ SRP_OPT_QUEUE_SIZE, "queue_size=%d" },
{ SRP_OPT_IP_SRC, "src=%s" },
{ SRP_OPT_IP_DEST, "dest=%s" },
+ { SRP_OPT_MAX_IT_IU_SIZE, "max_it_iu_size=%d" },
{ SRP_OPT_ERR, NULL }
};
target->tl_retry_count = token;
break;
+ case SRP_OPT_MAX_IT_IU_SIZE:
+ if (match_int(args, &token) || token < 0) {
+ pr_warn("bad maximum initiator to target IU size '%s'\n", p);
+ goto out;
+ }
+ target->max_it_iu_size = token;
+ break;
+
default:
pr_warn("unknown parameter or missing value '%s' in target creation request\n",
p);
u32 ch_count;
u32 lkey;
enum srp_target_state state;
+ uint32_t max_it_iu_size;
unsigned int cmd_sg_cnt;
unsigned int indirect_size;
bool allow_ext_sg;