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openmpi/opal/mca/common/verbs/common_verbs_fake.c
Jeff Squyres e95010b095 common verbs: only install fake usnic driver when relevant
Only install the fake usnic libibverbs driver when there are actually
usnic kernel devices present.  This prevents some run-time weirdness
on the Cray verbs emulation environment, where apparently
ibv_register_driver() either is not implemented or does not work
properly.
2015-05-11 12:57:06 -07:00

126 строки
3.4 KiB
C

/*
* Copyright (c) 2015 Cisco Systems, Inc. All rights reserved.
*
* $COPYRIGHT$
*
* Additional copyrights may follow
*
* $HEADER$
*/
/*
* The code in this file prevents spurious libibverbs warnings on
* stderr about devices that it doesn't recognize.
*
* Specifically, Cisco usNIC devices are exposed through the Linux
* InfiniBand kernel interface (i.e., they show up in
* /sys/class/infiniband). However, the userspace side of these
* drivers is not exposed through libibverbs (i.e., there is no
* libibverbs provider/plugin for usNIC). Therefore, when
* ibv_get_device_list() is invoked, libibverbs cannot find a plugin
* for usnic devices. This causes libibverbs to emit a spurious
* warning message on stderr.
*
* To avoid these extra stderr warnings, we insert a fake usnic verbs
* libibverbs provider that safely squelches these warnings.
*
* More specifically: the userspace side of usNIC is exposed through
* libfabric; we don't need libibverbs warnings about not being able
* to find a usnic driver.
*/
#include "opal_config.h"
#include <sys/types.h>
#include <dirent.h>
#include <string.h>
#include <infiniband/verbs.h>
#ifdef HAVE_INFINIBAND_DRIVER_H
#include <infiniband/driver.h>
#endif
#include "common_verbs.h"
/***********************************************************************/
#define PCI_VENDOR_ID_CISCO (0x1137)
static struct ibv_context *fake_alloc_context(struct ibv_device *ibdev,
int cmd_fd)
{
/* Nothing to do here */
return NULL;
}
static void fake_free_context(struct ibv_context *ibctx)
{
/* Nothing to do here */
}
/* Put just enough in here to convince libibverbs that this is a valid
device, and a little extra just in case someone looks at this
struct in a debugger. */
static struct ibv_device fake_dev = {
.ops = {
.alloc_context = fake_alloc_context,
.free_context = fake_free_context
},
.name = "fake ibv_device inserted by Open MPI for non-verbs devices"
};
static struct ibv_device *fake_driver_init(const char *uverbs_sys_path,
int abi_version)
{
char value[8];
int vendor;
/* This function should only be invoked for
/sys/class/infiniband/usnic_X devices, but double check just to
be absolutely sure: read the vendor ID and ensure that it is
Cisco. */
if (ibv_read_sysfs_file(uverbs_sys_path, "device/vendor",
value, sizeof(value)) < 0) {
return NULL;
}
sscanf(value, "%i", &vendor);
if (vendor == PCI_VENDOR_ID_CISCO) {
return &fake_dev;
}
/* We didn't find a device that we want to support */
return NULL;
}
void opal_common_verbs_register_fake_drivers(void)
{
/* No need to do this more than once */
static bool already_done = false;
if (already_done) {
return;
}
already_done = true;
/* If there are any usnic devices, then register a fake driver */
DIR *class_dir;
class_dir = opendir("/sys/class/infiniband");
if (NULL == class_dir) {
return;
}
bool found = false;
struct dirent *dent;
while ((dent = readdir(class_dir)) != NULL) {
if (strncmp(dent->d_name, "usnic_", 6) == 0) {
found = true;
break;
}
}
closedir(class_dir);
if (found) {
ibv_register_driver("usnic_verbs", fake_driver_init);
}
}