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Using XRC between kernel and user space.

DISCUSSION Shlomo Pongratz 1 participant 2 messages Apr 4, 2013 – Apr 5, 2013 1 message not in the archive InfiniBand

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Hi,

I wonder how a kernel "program" and a user space one can communicate using XRC.
A example for such an application is iSER kernel initiator connected to tgtd target that runs in user space.
The XRC domain in the kernel is created with "struct ib_xrcd *ib_alloc_xrcd(struct ib_device *device)" while in the user space it is created with "static inline struct ibv_xrcd * ibv_open_xrcd(struct ibv_context *context, struct ibv_xrcd_init_attr *xrcd_init_attr)". When looking in "xrc_pingpong.c" example we can see that the attribute has some file descriptor of some file ("/tmp/xrc_domain").
So how a kernel "program" on one machine can communicate with a user space program on another one?
The XRC annex (page 9) sates that all QP should belong to the same XRC domain.

S.P.

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A message that is not in the archive (sent off-list or not yet received): 515DBC10.1080009-VPRAkNaXOzVWk0Htik3J/[email protected]

#2 lore raw
Quoted 11 lines · Shlomo Pongratz

Hi,

I wonder how a kernel "program" and a user space one can communicate using XRC.
A example for such an application is iSER kernel initiator connected to tgtd target that runs in user space.
The XRC domain in the kernel is created with "struct ib_xrcd *ib_alloc_xrcd(struct ib_device *device)" while in the user space it is created with "static inline struct ibv_xrcd * ibv_open_xrcd(struct ibv_context *context, struct ibv_xrcd_init_attr *xrcd_init_attr)". When looking in "xrc_pingpong.c" example we can see that the attribute has some file descriptor of some file ("/tmp/xrc_domain").
So how a kernel "program" on one machine can communicate with a user space program on another one?
The XRC annex (page 9) sates that all QP should belong to the same XRC domain.

S.P.

Sorry, I misinterpreted the annex.
I thank Roland for clarifying this to me.

S.P.

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