[ofiwg] getting hardware details from libfabric

[Hefty, Sean]

Everyone in the US is starting their 3-day week-end early, which makes this the perfect time to have a conversation with myself.

> The device attributes are per fi_info structure (which includes the
> network address, domain, and ep attributes).  The app does not need
> to open any resources to obtain the data.
> 
> 
> When fi_getinfo() is called with FI_DEVICE_ATTR flag set, each
> fi_info::handle will reference a struct fid_attr, if valid.

We can drop the FI_DEVICE_ATTR flag and make this the default.  This requires that fi_freeinfo() free the handle.


> // Definition of struct fid_attr.  Field types could change.
> struct fid_attr {
> 	struct fid;  /* fclass = FI_TYPE_DEVICE_ATTR */
> 	struct dev_attr {
> 		char *interface;
> 		char *device_id;
> 		char *device_version;
> 		char *vendor_id;
> 		char *firmware;
> 	};
> 	struct bus_attr {
> 		char *domain_id;
> 		char *bus_id;
> 		char *device_id;
> 		char *function_id;
> 	};

I have no idea how to obtain this data outside of Linux, or if it is generic enough to handle anything but PCI.


> 	struct link_attr {
> 		char *address;
> 		size_t mtu;
> 		enum fi_link_state state; /* up, down, unknown */
> 		char *protocol;
> 		size_t speed; /* bits per second */
> 	};
> 	struct prov_attr {
> 		size_t size;
> 		char data[];
> 	};
> };
> 
> 
> The prov_attr structure can be cast to a provider specific structure
> (e.g. usnic_devinfo) if the app knows the structure format.  I would
> add a new public header for all definitions.  Additionally,
> fi_tostr() can be used to display the attributes.  fid_attr allows
> fi_tostr() to route the call to the provider to handle the prov_attr
> portion (done using new fi_control FI_TOSTR option).

The additional attributes would be reported by the fi_info utility automatically - no code changes needed.

- Sean