prov/util: Integrate kdreg2 into libfabric

kdreg2 is a Linux kernel module used to enabled the libfabric MR cache
for FI_HMEM_SYSTEM.

Signed-off-by: Mike Uttormark <mike.uttormark@hpe.com>
Signed-off-by: Ian Ziemba <ian.ziemba@hpe.com>

Makefile.am

@@ -100,7 +100,8 @@ common_srcs =				\
 	prov/coll/src/coll_eq.c		\
 	prov/coll/src/coll_fabric.c	\
 	prov/coll/src/coll_init.c	\
-	prov/coll/src/coll.h
+	prov/coll/src/coll.h		\
+	prov/util/src/kdreg2_mem_monitor.c
 
 if MACOS
 common_srcs += src/osx/osd.c

configure.ac

@@ -598,6 +598,53 @@ AC_ARG_ENABLE([restricted_dl],
 AC_DEFINE_UNQUOTED([HAVE_RESTRICTED_DL], [$restricted_dl],
   [Define to 1 to only look for dl providers under default location if FI_PROVIDER_PATH is not set])
 
+dnl Check kdreg2 support
+kdreg2_enabled=1
+have_kdreg2=0
+have_kdreg2_include_path=0
+
+AC_ARG_ENABLE([kdreg2],
+              [AC_HELP_STRING([--disable-kdreg2],
+                              [Determine whether kdreg2 memory monitor is disabled.])],
+              [AS_IF([test "$enable_kdreg2" = "no"], [kdreg2_enabled=0])],
+              [])
+
+AS_IF([test $kdreg2_enabled -ne 0 ],
+      [AC_CHECK_HEADER([linux/kdreg2.h], [have_kdreg2=1], [], [])
+
+       AC_ARG_WITH([kdreg2],
+		   [AS_HELP_STRING([--with-kdreg2=DIR],
+				   [Enable KDREG2 memory monitor.
+				    Optional=<Path to kdreg2.h header file>.])],
+		   [AS_CASE(["$with_kdreg2"],
+			    ["no"], [kdreg2_enabled=0],
+			    ["yes"], [],
+			    [""], [],
+			    [CPPFLAGS="$CPPFLAGS -I$with_kdreg2"
+			     AC_CHECK_HEADER([kdreg2.h],
+					     [have_kdreg2=1
+					      have_kdreg2_include_path=1],
+					     [have_kdreg2=0],
+					     [])])
+		    	     AS_IF([test $have_kdreg2 -eq 0 ],
+			           [AC_MSG_ERROR([KDREG2 header not found in $with_kdreg2.  Cannot enable KDREG2 memory monitor.])])
+		   ])
+       ])
+
+AS_IF([test $kdreg2_enabled -eq 0],
+      [AC_MSG_NOTICE([kdreg2 monitor disabled])],
+      [AS_IF([test $have_kdreg2 -ne 0],
+             [AC_MSG_NOTICE([kdreg2 present and enabled])])])
+
+AC_DEFINE_UNQUOTED(HAVE_KDREG2, [$have_kdreg2],
+	[Define to 1 if kdreg2.h is available.])
+
+AC_DEFINE_UNQUOTED(HAVE_KDREG2_INCLUDE_PATH, [$have_kdreg2_include_path],
+	[Define to 1 if kdreg2.h path is not <linux/kdreg2.h>.])
+
+AC_DEFINE_UNQUOTED(HAVE_KDREG2_MONITOR, [$have_kdreg2],
+	[Define to 1 to enable kdreg2 memory monitor])
+
 dnl Check support to intercept syscalls
 AC_CHECK_HEADERS_ONCE(elf.h sys/auxv.h)
 
@@ -888,16 +935,18 @@ AC_DEFINE_UNQUOTED(ENABLE_UFFD_MONITOR, [$enable_uffd],
 default_monitor=""
 bad_default="0"
 AC_ARG_WITH([default-monitor],
-	[AS_HELP_STRING([--with-default-monitor=<memhooks|uffd|disabled>],
+	[AS_HELP_STRING([--with-default-monitor=<memhooks|uffd|kdreg2|disabled>],
 			[Select the default memory monitor.])],
 	[AS_CASE([$with_default_monitor],
 		[memhooks],[default_monitor=memhooks],
 		[uffd],[default_monitor=uffd],
+		[kdreg2],[default_monitor=kdreg2]
 		[disabled], [default_monitor=disabled],
 		[AC_MSG_ERROR([Unknown monitor specified: $with_default_monitor.  Choices are memhooks, uffd, or disabled.])])
 	 AS_CASE([$default_monitor],
 		[memhooks], [AS_IF([test "$enable_memhooks" != "1"], [bad_default=1])],
 		[uffd], [AS_IF([test "$enable_uffd" != "1"], [bad_default=1])],
+		[kdreg2], [AS_IF([test "$kdreg2_enabled" != "1"], [bad_default=1])],
 		[])
 	 AS_IF([test "$bad_default" != "0"],
 		[AC_MSG_ERROR(["Default memory monitor is not available: $default_monitor."])])

include/ofi_mr.h

@@ -2,7 +2,7 @@
  * Copyright (c) 2017-2019 Intel Corporation, Inc. All rights reserved.
  * Copyright (c) 2019-2021 Amazon.com, Inc. or its affiliates.
  *                         All rights reserved.
- * (C) Copyright 2020 Hewlett Packard Enterprise Development LP
+ * (C) Copyright 2020-2023 Hewlett Packard Enterprise Development LP
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
@@ -40,6 +40,8 @@
 #  include <config.h>
 #endif /* HAVE_CONFIG_H */
 
+struct ofi_mr;
+
 #include <inttypes.h>
 #include <stdbool.h>
 
@@ -48,6 +50,15 @@
 #include <ofi_lock.h>
 #include <ofi_list.h>
 #include <ofi_tree.h>
+#include <ofi_hmem.h>
+
+#if HAVE_KDREG2_MONITOR
+#if HAVE_KDREG2_INCLUDE_PATH
+#include "kdreg2.h"
+#else
+#include "linux/kdreg2.h"
+#endif
+#endif
 
 int ofi_open_mr_cache(uint32_t version, void *attr, size_t attr_len,
 		      uint64_t flags, struct fid **fid, void *context);
@@ -128,6 +139,12 @@ struct ofi_mr_cache;
 union ofi_mr_hmem_info {
 	uint64_t cuda_id;
 	uint64_t ze_id;
+#if HAVE_KDREG2_MONITOR
+	struct {
+		kdreg2_cookie_t cookie;
+		struct kdreg2_monitoring_params monitoring_params;
+	} kdreg2;
+#endif
 };
 
 struct ofi_mr_entry {
@@ -229,6 +246,23 @@ struct ofi_memhooks {
 
 extern struct ofi_mem_monitor *memhooks_monitor;
 
+/*
+ * Kdreg2 monitor
+ */
+
+struct kdreg2_status_data;
+
+struct ofi_kdreg2 {
+	struct ofi_mem_monitor          monitor;
+	pthread_t                       thread;
+	int                             fd;
+	int                             exit_pipe[2];
+	const struct kdreg2_status_data *status_data;
+	ofi_atomic64_t                  next_cookie;
+};
+
+extern struct ofi_mem_monitor *kdreg2_monitor;
+
 extern struct ofi_mem_monitor *cuda_monitor;
 extern struct ofi_mem_monitor *cuda_ipc_monitor;
 extern struct ofi_mem_monitor *rocr_monitor;
@@ -368,7 +402,7 @@ struct ofi_mr_cache {
 	struct ofi_rbmap		tree;
 	struct dlist_entry		lru_list;
 	struct dlist_entry		dead_region_list;
-	pthread_mutex_t 		lock;
+	pthread_mutex_t			lock;
 
 	size_t				cached_cnt;
 	size_t				cached_size;