10 files changed, 1880 insertions, 0 deletions

diff --git a/tools/perf/arch/s390/Makefile b/tools/perf/arch/s390/Makefile
new file mode 100644
index 000000000000..15130b50dfe3
--- /dev/null
+++ b/tools/perf/arch/s390/Makefile
@@ -0,0 +1,4 @@
+ifndef NO_DWARF
+PERF_HAVE_DWARF_REGS := 1
+LIB_OBJS += $(OUTPUT)arch/$(ARCH)/util/dwarf-regs.o
+endif
diff --git a/tools/perf/arch/s390/util/dwarf-regs.c b/tools/perf/arch/s390/util/dwarf-regs.c
new file mode 100644
index 000000000000..e19653e025fa
--- /dev/null
+++ b/tools/perf/arch/s390/util/dwarf-regs.c
@@ -0,0 +1,22 @@
+/*
+ * Mapping of DWARF debug register numbers into register names.
+ *
+ *    Copyright IBM Corp. 2010
+ *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
+ *
+ */
+
+#include <libio.h>
+#include <dwarf-regs.h>
+
+#define NUM_GPRS 16
+
+static const char *gpr_names[NUM_GPRS] = {
+	"%r0", "%r1",  "%r2",  "%r3",  "%r4",  "%r5",  "%r6",  "%r7",
+	"%r8", "%r9", "%r10", "%r11", "%r12", "%r13", "%r14", "%r15",
+};
+
+const char *get_arch_regstr(unsigned int n)
+{
+	return (n >= NUM_GPRS) ? NULL : gpr_names[n];
+}
diff --git a/tools/slub/slabinfo.c b/tools/slub/slabinfo.c
new file mode 100644
index 000000000000..516551c9f172
--- /dev/null
+++ b/tools/slub/slabinfo.c
@@ -0,0 +1,1364 @@
+/*
+ * Slabinfo: Tool to get reports about slabs
+ *
+ * (C) 2007 sgi, Christoph Lameter
+ *
+ * Compile by:
+ *
+ * gcc -o slabinfo slabinfo.c
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <strings.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdarg.h>
+#include <getopt.h>
+#include <regex.h>
+#include <errno.h>
+
+#define MAX_SLABS 500
+#define MAX_ALIASES 500
+#define MAX_NODES 1024
+
+struct slabinfo {
+	char *name;
+	int alias;
+	int refs;
+	int aliases, align, cache_dma, cpu_slabs, destroy_by_rcu;
+	int hwcache_align, object_size, objs_per_slab;
+	int sanity_checks, slab_size, store_user, trace;
+	int order, poison, reclaim_account, red_zone;
+	unsigned long partial, objects, slabs, objects_partial, objects_total;
+	unsigned long alloc_fastpath, alloc_slowpath;
+	unsigned long free_fastpath, free_slowpath;
+	unsigned long free_frozen, free_add_partial, free_remove_partial;
+	unsigned long alloc_from_partial, alloc_slab, free_slab, alloc_refill;
+	unsigned long cpuslab_flush, deactivate_full, deactivate_empty;
+	unsigned long deactivate_to_head, deactivate_to_tail;
+	unsigned long deactivate_remote_frees, order_fallback;
+	int numa[MAX_NODES];
+	int numa_partial[MAX_NODES];
+} slabinfo[MAX_SLABS];
+
+struct aliasinfo {
+	char *name;
+	char *ref;
+	struct slabinfo *slab;
+} aliasinfo[MAX_ALIASES];
+
+int slabs = 0;
+int actual_slabs = 0;
+int aliases = 0;
+int alias_targets = 0;
+int highest_node = 0;
+
+char buffer[4096];
+
+int show_empty = 0;
+int show_report = 0;
+int show_alias = 0;
+int show_slab = 0;
+int skip_zero = 1;
+int show_numa = 0;
+int show_track = 0;
+int show_first_alias = 0;
+int validate = 0;
+int shrink = 0;
+int show_inverted = 0;
+int show_single_ref = 0;
+int show_totals = 0;
+int sort_size = 0;
+int sort_active = 0;
+int set_debug = 0;
+int show_ops = 0;
+int show_activity = 0;
+
+/* Debug options */
+int sanity = 0;
+int redzone = 0;
+int poison = 0;
+int tracking = 0;
+int tracing = 0;
+
+int page_size;
+
+regex_t pattern;
+
+static void fatal(const char *x, ...)
+{
+	va_list ap;
+
+	va_start(ap, x);
+	vfprintf(stderr, x, ap);
+	va_end(ap);
+	exit(EXIT_FAILURE);
+}
+
+static void usage(void)
+{
+	printf("slabinfo 5/7/2007. (c) 2007 sgi.\n\n"
+		"slabinfo [-ahnpvtsz] [-d debugopts] [slab-regexp]\n"
+		"-a|--aliases           Show aliases\n"
+		"-A|--activity          Most active slabs first\n"
+		"-d<options>|--debug=<options> Set/Clear Debug options\n"
+		"-D|--display-active    Switch line format to activity\n"
+		"-e|--empty             Show empty slabs\n"
+		"-f|--first-alias       Show first alias\n"
+		"-h|--help              Show usage information\n"
+		"-i|--inverted          Inverted list\n"
+		"-l|--slabs             Show slabs\n"
+		"-n|--numa              Show NUMA information\n"
+		"-o|--ops		Show kmem_cache_ops\n"
+		"-s|--shrink            Shrink slabs\n"
+		"-r|--report		Detailed report on single slabs\n"
+		"-S|--Size              Sort by size\n"
+		"-t|--tracking          Show alloc/free information\n"
+		"-T|--Totals            Show summary information\n"
+		"-v|--validate          Validate slabs\n"
+		"-z|--zero              Include empty slabs\n"
+		"-1|--1ref              Single reference\n"
+		"\nValid debug options (FZPUT may be combined)\n"
+		"a / A          Switch on all debug options (=FZUP)\n"
+		"-              Switch off all debug options\n"
+		"f / F          Sanity Checks (SLAB_DEBUG_FREE)\n"
+		"z / Z          Redzoning\n"
+		"p / P          Poisoning\n"
+		"u / U          Tracking\n"
+		"t / T          Tracing\n"
+	);
+}
+
+static unsigned long read_obj(const char *name)
+{
+	FILE *f = fopen(name, "r");
+
+	if (!f)
+		buffer[0] = 0;
+	else {
+		if (!fgets(buffer, sizeof(buffer), f))
+			buffer[0] = 0;
+		fclose(f);
+		if (buffer[strlen(buffer)] == '\n')
+			buffer[strlen(buffer)] = 0;
+	}
+	return strlen(buffer);
+}
+
+
+/*
+ * Get the contents of an attribute
+ */
+static unsigned long get_obj(const char *name)
+{
+	if (!read_obj(name))
+		return 0;
+
+	return atol(buffer);
+}
+
+static unsigned long get_obj_and_str(const char *name, char **x)
+{
+	unsigned long result = 0;
+	char *p;
+
+	*x = NULL;
+
+	if (!read_obj(name)) {
+		x = NULL;
+		return 0;
+	}
+	result = strtoul(buffer, &p, 10);
+	while (*p == ' ')
+		p++;
+	if (*p)
+		*x = strdup(p);
+	return result;
+}
+
+static void set_obj(struct slabinfo *s, const char *name, int n)
+{
+	char x[100];
+	FILE *f;
+
+	snprintf(x, 100, "%s/%s", s->name, name);
+	f = fopen(x, "w");
+	if (!f)
+		fatal("Cannot write to %s\n", x);
+
+	fprintf(f, "%d\n", n);
+	fclose(f);
+}
+
+static unsigned long read_slab_obj(struct slabinfo *s, const char *name)
+{
+	char x[100];
+	FILE *f;
+	size_t l;
+
+	snprintf(x, 100, "%s/%s", s->name, name);
+	f = fopen(x, "r");
+	if (!f) {
+		buffer[0] = 0;
+		l = 0;
+	} else {
+		l = fread(buffer, 1, sizeof(buffer), f);
+		buffer[l] = 0;
+		fclose(f);
+	}
+	return l;
+}
+
+
+/*
+ * Put a size string together
+ */
+static int store_size(char *buffer, unsigned long value)
+{
+	unsigned long divisor = 1;
+	char trailer = 0;
+	int n;
+
+	if (value > 1000000000UL) {
+		divisor = 100000000UL;
+		trailer = 'G';
+	} else if (value > 1000000UL) {
+		divisor = 100000UL;
+		trailer = 'M';
+	} else if (value > 1000UL) {
+		divisor = 100;
+		trailer = 'K';
+	}
+
+	value /= divisor;
+	n = sprintf(buffer, "%ld",value);
+	if (trailer) {
+		buffer[n] = trailer;
+		n++;
+		buffer[n] = 0;
+	}
+	if (divisor != 1) {
+		memmove(buffer + n - 2, buffer + n - 3, 4);
+		buffer[n-2] = '.';
+		n++;
+	}
+	return n;
+}
+
+static void decode_numa_list(int *numa, char *t)
+{
+	int node;
+	int nr;
+
+	memset(numa, 0, MAX_NODES * sizeof(int));
+
+	if (!t)
+		return;
+
+	while (*t == 'N') {
+		t++;
+		node = strtoul(t, &t, 10);
+		if (*t == '=') {
+			t++;
+			nr = strtoul(t, &t, 10);
+			numa[node] = nr;
+			if (node > highest_node)
+				highest_node = node;
+		}
+		while (*t == ' ')
+			t++;
+	}
+}
+
+static void slab_validate(struct slabinfo *s)
+{
+	if (strcmp(s->name, "*") == 0)
+		return;
+
+	set_obj(s, "validate", 1);
+}
+
+static void slab_shrink(struct slabinfo *s)
+{
+	if (strcmp(s->name, "*") == 0)
+		return;
+
+	set_obj(s, "shrink", 1);
+}
+
+int line = 0;
+
+static void first_line(void)
+{
+	if (show_activity)
+		printf("Name                   Objects      Alloc       Free   %%Fast Fallb O\n");
+	else
+		printf("Name                   Objects Objsize    Space "
+			"Slabs/Part/Cpu  O/S O %%Fr %%Ef Flg\n");
+}
+
+/*
+ * Find the shortest alias of a slab
+ */
+static struct aliasinfo *find_one_alias(struct slabinfo *find)
+{
+	struct aliasinfo *a;
+	struct aliasinfo *best = NULL;
+
+	for(a = aliasinfo;a < aliasinfo + aliases; a++) {
+		if (a->slab == find &&
+			(!best || strlen(best->name) < strlen(a->name))) {
+				best = a;
+				if (strncmp(a->name,"kmall", 5) == 0)
+					return best;
+			}
+	}
+	return best;
+}
+
+static unsigned long slab_size(struct slabinfo *s)
+{
+	return 	s->slabs * (page_size << s->order);
+}
+
+static unsigned long slab_activity(struct slabinfo *s)
+{
+	return 	s->alloc_fastpath + s->free_fastpath +
+		s->alloc_slowpath + s->free_slowpath;
+}
+
+static void slab_numa(struct slabinfo *s, int mode)
+{
+	int node;
+
+	if (strcmp(s->name, "*") == 0)
+		return;
+
+	if (!highest_node) {
+		printf("\n%s: No NUMA information available.\n", s->name);
+		return;
+	}
+
+	if (skip_zero && !s->slabs)
+		return;
+
+	if (!line) {
+		printf("\n%-21s:", mode ? "NUMA nodes" : "Slab");
+		for(node = 0; node <= highest_node; node++)
+			printf(" %4d", node);
+		printf("\n----------------------");
+		for(node = 0; node <= highest_node; node++)
+			printf("-----");
+		printf("\n");
+	}
+	printf("%-21s ", mode ? "All slabs" : s->name);
+	for(node = 0; node <= highest_node; node++) {
+		char b[20];
+
+		store_size(b, s->numa[node]);
+		printf(" %4s", b);
+	}
+	printf("\n");
+	if (mode) {
+		printf("%-21s ", "Partial slabs");
+		for(node = 0; node <= highest_node; node++) {
+			char b[20];
+
+			store_size(b, s->numa_partial[node]);
+			printf(" %4s", b);
+		}
+		printf("\n");
+	}
+	line++;
+}
+
+static void show_tracking(struct slabinfo *s)
+{
+	printf("\n%s: Kernel object allocation\n", s->name);
+	printf("-----------------------------------------------------------------------\n");
+	if (read_slab_obj(s, "alloc_calls"))
+		printf(buffer);
+	else
+		printf("No Data\n");
+
+	printf("\n%s: Kernel object freeing\n", s->name);
+	printf("------------------------------------------------------------------------\n");
+	if (read_slab_obj(s, "free_calls"))
+		printf(buffer);
+	else
+		printf("No Data\n");
+
+}
+
+static void ops(struct slabinfo *s)
+{
+	if (strcmp(s->name, "*") == 0)
+		return;
+
+	if (read_slab_obj(s, "ops")) {
+		printf("\n%s: kmem_cache operations\n", s->name);
+		printf("--------------------------------------------\n");
+		printf(buffer);
+	} else
+		printf("\n%s has no kmem_cache operations\n", s->name);
+}
+
+static const char *onoff(int x)
+{
+	if (x)
+		return "On ";
+	return "Off";
+}
+
+static void slab_stats(struct slabinfo *s)
+{
+	unsigned long total_alloc;
+	unsigned long total_free;
+	unsigned long total;
+
+	if (!s->alloc_slab)
+		return;
+
+	total_alloc = s->alloc_fastpath + s->alloc_slowpath;
+	total_free = s->free_fastpath + s->free_slowpath;
+
+	if (!total_alloc)
+		return;
+
+	printf("\n");
+	printf("Slab Perf Counter       Alloc     Free %%Al %%Fr\n");
+	printf("--------------------------------------------------\n");
+	printf("Fastpath             %8lu %8lu %3lu %3lu\n",
+		s->alloc_fastpath, s->free_fastpath,
+		s->alloc_fastpath * 100 / total_alloc,
+		s->free_fastpath * 100 / total_free);
+	printf("Slowpath             %8lu %8lu %3lu %3lu\n",
+		total_alloc - s->alloc_fastpath, s->free_slowpath,
+		(total_alloc - s->alloc_fastpath) * 100 / total_alloc,
+		s->free_slowpath * 100 / total_free);
+	printf("Page Alloc           %8lu %8lu %3lu %3lu\n",
+		s->alloc_slab, s->free_slab,
+		s->alloc_slab * 100 / total_alloc,
+		s->free_slab * 100 / total_free);
+	printf("Add partial          %8lu %8lu %3lu %3lu\n",
+		s->deactivate_to_head + s->deactivate_to_tail,
+		s->free_add_partial,
+		(s->deactivate_to_head + s->deactivate_to_tail) * 100 / total_alloc,
+		s->free_add_partial * 100 / total_free);
+	printf("Remove partial       %8lu %8lu %3lu %3lu\n",
+		s->alloc_from_partial, s->free_remove_partial,
+		s->alloc_from_partial * 100 / total_alloc,
+		s->free_remove_partial * 100 / total_free);
+
+	printf("RemoteObj/SlabFrozen %8lu %8lu %3lu %3lu\n",
+		s->deactivate_remote_frees, s->free_frozen,
+		s->deactivate_remote_frees * 100 / total_alloc,
+		s->free_frozen * 100 / total_free);
+
+	printf("Total                %8lu %8lu\n\n", total_alloc, total_free);
+
+	if (s->cpuslab_flush)
+		printf("Flushes %8lu\n", s->cpuslab_flush);
+
+	if (s->alloc_refill)
+		printf("Refill %8lu\n", s->alloc_refill);
+
+	total = s->deactivate_full + s->deactivate_empty +
+			s->deactivate_to_head + s->deactivate_to_tail;
+
+	if (total)
+		printf("Deactivate Full=%lu(%lu%%) Empty=%lu(%lu%%) "
+			"ToHead=%lu(%lu%%) ToTail=%lu(%lu%%)\n",
+			s->deactivate_full, (s->deactivate_full * 100) / total,
+			s->deactivate_empty, (s->deactivate_empty * 100) / total,
+			s->deactivate_to_head, (s->deactivate_to_head * 100) / total,
+			s->deactivate_to_tail, (s->deactivate_to_tail * 100) / total);
+}
+
+static void report(struct slabinfo *s)
+{
+	if (strcmp(s->name, "*") == 0)
+		return;
+
+	printf("\nSlabcache: %-20s  Aliases: %2d Order : %2d Objects: %lu\n",
+		s->name, s->aliases, s->order, s->objects);
+	if (s->hwcache_align)
+		printf("** Hardware cacheline aligned\n");
+	if (s->cache_dma)
+		printf("** Memory is allocated in a special DMA zone\n");
+	if (s->destroy_by_rcu)
+		printf("** Slabs are destroyed via RCU\n");
+	if (s->reclaim_account)
+		printf("** Reclaim accounting active\n");
+
+	printf("\nSizes (bytes)     Slabs              Debug                Memory\n");
+	printf("------------------------------------------------------------------------\n");
+	printf("Object : %7d  Total  : %7ld   Sanity Checks : %s  Total: %7ld\n",
+			s->object_size, s->slabs, onoff(s->sanity_checks),
+			s->slabs * (page_size << s->order));
+	printf("SlabObj: %7d  Full   : %7ld   Redzoning     : %s  Used : %7ld\n",
+			s->slab_size, s->slabs - s->partial - s->cpu_slabs,
+			onoff(s->red_zone), s->objects * s->object_size);
+	printf("SlabSiz: %7d  Partial: %7ld   Poisoning     : %s  Loss : %7ld\n",
+			page_size << s->order, s->partial, onoff(s->poison),
+			s->slabs * (page_size << s->order) - s->objects * s->object_size);
+	printf("Loss   : %7d  CpuSlab: %7d   Tracking      : %s  Lalig: %7ld\n",
+			s->slab_size - s->object_size, s->cpu_slabs, onoff(s->store_user),
+			(s->slab_size - s->object_size) * s->objects);
+	printf("Align  : %7d  Objects: %7d   Tracing       : %s  Lpadd: %7ld\n",
+			s->align, s->objs_per_slab, onoff(s->trace),
+			((page_size << s->order) - s->objs_per_slab * s->slab_size) *
+			s->slabs);
+
+	ops(s);
+	show_tracking(s);
+	slab_numa(s, 1);
+	slab_stats(s);
+}
+
+static void slabcache(struct slabinfo *s)
+{
+	char size_str[20];
+	char dist_str[40];
+	char flags[20];
+	char *p = flags;
+
+	if (strcmp(s->name, "*") == 0)
+		return;
+
+	if (actual_slabs == 1) {
+		report(s);
+		return;
+	}
+
+	if (skip_zero && !show_empty && !s->slabs)
+		return;
+
+	if (show_empty && s->slabs)
+		return;
+
+	store_size(size_str, slab_size(s));
+	snprintf(dist_str, 40, "%lu/%lu/%d", s->slabs - s->cpu_slabs,
+						s->partial, s->cpu_slabs);
+
+	if (!line++)
+		first_line();
+
+	if (s->aliases)
+		*p++ = '*';
+	if (s->cache_dma)
+		*p++ = 'd';
+	if (s->hwcache_align)
+		*p++ = 'A';
+	if (s->poison)
+		*p++ = 'P';
+	if (s->reclaim_account)
+		*p++ = 'a';
+	if (s->red_zone)
+		*p++ = 'Z';
+	if (s->sanity_checks)
+		*p++ = 'F';
+	if (s->store_user)
+		*p++ = 'U';
+	if (s->trace)
+		*p++ = 'T';
+
+	*p = 0;
+	if (show_activity) {
+		unsigned long total_alloc;
+		unsigned long total_free;
+
+		total_alloc = s->alloc_fastpath + s->alloc_slowpath;
+		total_free = s->free_fastpath + s->free_slowpath;
+
+		printf("%-21s %8ld %10ld %10ld %3ld %3ld %5ld %1d\n",
+			s->name, s->objects,
+			total_alloc, total_free,
+			total_alloc ? (s->alloc_fastpath * 100 / total_alloc) : 0,
+			total_free ? (s->free_fastpath * 100 / total_free) : 0,
+			s->order_fallback, s->order);
+	}
+	else
+		printf("%-21s %8ld %7d %8s %14s %4d %1d %3ld %3ld %s\n",
+			s->name, s->objects, s->object_size, size_str, dist_str,
+			s->objs_per_slab, s->order,
+			s->slabs ? (s->partial * 100) / s->slabs : 100,
+			s->slabs ? (s->objects * s->object_size * 100) /
+				(s->slabs * (page_size << s->order)) : 100,
+			flags);
+}
+
+/*
+ * Analyze debug options. Return false if something is amiss.
+ */
+static int debug_opt_scan(char *opt)
+{
+	if (!opt || !opt[0] || strcmp(opt, "-") == 0)
+		return 1;
+
+	if (strcasecmp(opt, "a") == 0) {
+		sanity = 1;
+		poison = 1;
+		redzone = 1;
+		tracking = 1;
+		return 1;
+	}
+
+	for ( ; *opt; opt++)
+		switch (*opt) {
+		case 'F' : case 'f':
+			if (sanity)
+				return 0;
+			sanity = 1;
+			break;
+		case 'P' : case 'p':
+			if (poison)
+				return 0;
+			poison = 1;
+			break;
+
+		case 'Z' : case 'z':
+			if (redzone)
+				return 0;
+			redzone = 1;
+			break;
+
+		case 'U' : case 'u':
+			if (tracking)
+				return 0;
+			tracking = 1;
+			break;
+
+		case 'T' : case 't':
+			if (tracing)
+				return 0;
+			tracing = 1;
+			break;
+		default:
+			return 0;
+		}
+	return 1;
+}
+
+static int slab_empty(struct slabinfo *s)
+{
+	if (s->objects > 0)
+		return 0;
+
+	/*
+	 * We may still have slabs even if there are no objects. Shrinking will
+	 * remove them.
+	 */
+	if (s->slabs != 0)
+		set_obj(s, "shrink", 1);
+
+	return 1;
+}
+
+static void slab_debug(struct slabinfo *s)
+{
+	if (strcmp(s->name, "*") == 0)
+		return;
+
+	if (sanity && !s->sanity_checks) {
+		set_obj(s, "sanity", 1);
+	}
+	if (!sanity && s->sanity_checks) {
+		if (slab_empty(s))
+			set_obj(s, "sanity", 0);
+		else
+			fprintf(stderr, "%s not empty cannot disable sanity checks\n", s->name);
+	}
+	if (redzone && !s->red_zone) {
+		if (slab_empty(s))
+			set_obj(s, "red_zone", 1);
+		else
+			fprintf(stderr, "%s not empty cannot enable redzoning\n", s->name);
+	}
+	if (!redzone && s->red_zone) {
+		if (slab_empty(s))
+			set_obj(s, "red_zone", 0);
+		else
+			fprintf(stderr, "%s not empty cannot disable redzoning\n", s->name);
+	}
+	if (poison && !s->poison) {
+		if (slab_empty(s))
+			set_obj(s, "poison", 1);
+		else
+			fprintf(stderr, "%s not empty cannot enable poisoning\n", s->name);
+	}
+	if (!poison && s->poison) {
+		if (slab_empty(s))
+			set_obj(s, "poison", 0);
+		else
+			fprintf(stderr, "%s not empty cannot disable poisoning\n", s->name);
+	}
+	if (tracking && !s->store_user) {
+		if (slab_empty(s))
+			set_obj(s, "store_user", 1);
+		else
+			fprintf(stderr, "%s not empty cannot enable tracking\n", s->name);
+	}
+	if (!tracking && s->store_user) {
+		if (slab_empty(s))
+			set_obj(s, "store_user", 0);
+		else
+			fprintf(stderr, "%s not empty cannot disable tracking\n", s->name);
+	}
+	if (tracing && !s->trace) {
+		if (slabs == 1)
+			set_obj(s, "trace", 1);
+		else
+			fprintf(stderr, "%s can only enable trace for one slab at a time\n", s->name);
+	}
+	if (!tracing && s->trace)
+		set_obj(s, "trace", 1);
+}
+
+static void totals(void)
+{
+	struct slabinfo *s;
+
+	int used_slabs = 0;
+	char b1[20], b2[20], b3[20], b4[20];
+	unsigned long long max = 1ULL << 63;
+
+	/* Object size */
+	unsigned long long min_objsize = max, max_objsize = 0, avg_objsize;
+
+	/* Number of partial slabs in a slabcache */
+	unsigned long long min_partial = max, max_partial = 0,
+				avg_partial, total_partial = 0;
+
+	/* Number of slabs in a slab cache */
+	unsigned long long min_slabs = max, max_slabs = 0,
+				avg_slabs, total_slabs = 0;
+
+	/* Size of the whole slab */
+	unsigned long long min_size = max, max_size = 0,
+				avg_size, total_size = 0;
+
+	/* Bytes used for object storage in a slab */
+	unsigned long long min_used = max, max_used = 0,
+				avg_used, total_used = 0;
+
+	/* Waste: Bytes used for alignment and padding */
+	unsigned long long min_waste = max, max_waste = 0,
+				avg_waste, total_waste = 0;
+	/* Number of objects in a slab */
+	unsigned long long min_objects = max, max_objects = 0,
+				avg_objects, total_objects = 0;
+	/* Waste per object */
+	unsigned long long min_objwaste = max,
+				max_objwaste = 0, avg_objwaste,
+				total_objwaste = 0;
+
+	/* Memory per object */
+	unsigned long long min_memobj = max,
+				max_memobj = 0, avg_memobj,
+				total_objsize = 0;
+
+	/* Percentage of partial slabs per slab */
+	unsigned long min_ppart = 100, max_ppart = 0,
+				avg_ppart, total_ppart = 0;
+
+	/* Number of objects in partial slabs */
+	unsigned long min_partobj = max, max_partobj = 0,
+				avg_partobj, total_partobj = 0;
+
+	/* Percentage of partial objects of all objects in a slab */
+	unsigned long min_ppartobj = 100, max_ppartobj = 0,
+				avg_ppartobj, total_ppartobj = 0;
+
+
+	for (s = slabinfo; s < slabinfo + slabs; s++) {
+		unsigned long long size;
+		unsigned long used;
+		unsigned long long wasted;
+		unsigned long long objwaste;
+		unsigned long percentage_partial_slabs;
+		unsigned long percentage_partial_objs;
+
+		if (!s->slabs || !s->objects)
+			continue;
+
+		used_slabs++;
+
+		size = slab_size(s);
+		used = s->objects * s->object_size;
+		wasted = size - used;
+		objwaste = s->slab_size - s->object_size;
+
+		percentage_partial_slabs = s->partial * 100 / s->slabs;
+		if (percentage_partial_slabs > 100)
+			percentage_partial_slabs = 100;
+
+		percentage_partial_objs = s->objects_partial * 100
+							/ s->objects;
+
+		if (percentage_partial_objs > 100)
+			percentage_partial_objs = 100;
+
+		if (s->object_size < min_objsize)
+			min_objsize = s->object_size;
+		if (s->partial < min_partial)
+			min_partial = s->partial;
+		if (s->slabs < min_slabs)
+			min_slabs = s->slabs;
+		if (size < min_size)
+			min_size = size;
+		if (wasted < min_waste)
+			min_waste = wasted;
+		if (objwaste < min_objwaste)
+			min_objwaste = objwaste;
+		if (s->objects < min_objects)
+			min_objects = s->objects;
+		if (used < min_used)
+			min_used = used;
+		if (s->objects_partial < min_partobj)
+			min_partobj = s->objects_partial;
+		if (percentage_partial_slabs < min_ppart)
+			min_ppart = percentage_partial_slabs;
+		if (percentage_partial_objs < min_ppartobj)
+			min_ppartobj = percentage_partial_objs;
+		if (s->slab_size < min_memobj)
+			min_memobj = s->slab_size;
+
+		if (s->object_size > max_objsize)
+			max_objsize = s->object_size;
+		if (s->partial > max_partial)
+			max_partial = s->partial;
+		if (s->slabs > max_slabs)
+			max_slabs = s->slabs;
+		if (size > max_size)
+			max_size = size;
+		if (wasted > max_waste)
+			max_waste = wasted;
+		if (objwaste > max_objwaste)
+			max_objwaste = objwaste;
+		if (s->objects > max_objects)
+			max_objects = s->objects;
+		if (used > max_used)
+			max_used = used;
+		if (s->objects_partial > max_partobj)
+			max_partobj = s->objects_partial;
+		if (percentage_partial_slabs > max_ppart)
+			max_ppart = percentage_partial_slabs;
+		if (percentage_partial_objs > max_ppartobj)
+			max_ppartobj = percentage_partial_objs;
+		if (s->slab_size > max_memobj)
+			max_memobj = s->slab_size;
+
+		total_partial += s->partial;
+		total_slabs += s->slabs;
+		total_size += size;
+		total_waste += wasted;
+
+		total_objects += s->objects;
+		total_used += used;
+		total_partobj += s->objects_partial;
+		total_ppart += percentage_partial_slabs;
+		total_ppartobj += percentage_partial_objs;
+
+		total_objwaste += s->objects * objwaste;
+		total_objsize += s->objects * s->slab_size;
+	}
+
+	if (!total_objects) {
+		printf("No objects\n");
+		return;
+	}
+	if (!used_slabs) {
+		printf("No slabs\n");
+		return;
+	}
+
+	/* Per slab averages */
+	avg_partial = total_partial / used_slabs;
+	avg_slabs = total_slabs / used_slabs;
+	avg_size = total_size / used_slabs;
+	avg_waste = total_waste / used_slabs;
+
+	avg_objects = total_objects / used_slabs;
+	avg_used = total_used / used_slabs;
+	avg_partobj = total_partobj / used_slabs;
+	avg_ppart = total_ppart / used_slabs;
+	avg_ppartobj = total_ppartobj / used_slabs;
+
+	/* Per object object sizes */
+	avg_objsize = total_used / total_objects;
+	avg_objwaste = total_objwaste / total_objects;
+	avg_partobj = total_partobj * 100 / total_objects;
+	avg_memobj = total_objsize / total_objects;
+
+	printf("Slabcache Totals\n");
+	printf("----------------\n");
+	printf("Slabcaches : %3d      Aliases  : %3d->%-3d Active: %3d\n",
+			slabs, aliases, alias_targets, used_slabs);
+
+	store_size(b1, total_size);store_size(b2, total_waste);
+	store_size(b3, total_waste * 100 / total_used);
+	printf("Memory used: %6s   # Loss   : %6s   MRatio:%6s%%\n", b1, b2, b3);
+
+	store_size(b1, total_objects);store_size(b2, total_partobj);
+	store_size(b3, total_partobj * 100 / total_objects);
+	printf("# Objects  : %6s   # PartObj: %6s   ORatio:%6s%%\n", b1, b2, b3);
+
+	printf("\n");
+	printf("Per Cache    Average         Min         Max       Total\n");
+	printf("---------------------------------------------------------\n");
+
+	store_size(b1, avg_objects);store_size(b2, min_objects);
+	store_size(b3, max_objects);store_size(b4, total_objects);
+	printf("#Objects  %10s  %10s  %10s  %10s\n",
+			b1,	b2,	b3,	b4);
+
+	store_size(b1, avg_slabs);store_size(b2, min_slabs);
+	store_size(b3, max_slabs);store_size(b4, total_slabs);
+	printf("#Slabs    %10s  %10s  %10s  %10s\n",
+			b1,	b2,	b3,	b4);
+
+	store_size(b1, avg_partial);store_size(b2, min_partial);
+	store_size(b3, max_partial);store_size(b4, total_partial);
+	printf("#PartSlab %10s  %10s  %10s  %10s\n",
+			b1,	b2,	b3,	b4);
+	store_size(b1, avg_ppart);store_size(b2, min_ppart);
+	store_size(b3, max_ppart);
+	store_size(b4, total_partial * 100  / total_slabs);
+	printf("%%PartSlab%10s%% %10s%% %10s%% %10s%%\n",
+			b1,	b2,	b3,	b4);
+
+	store_size(b1, avg_partobj);store_size(b2, min_partobj);
+	store_size(b3, max_partobj);
+	store_size(b4, total_partobj);
+	printf("PartObjs  %10s  %10s  %10s  %10s\n",
+			b1,	b2,	b3,	b4);
+
+	store_size(b1, avg_ppartobj);store_size(b2, min_ppartobj);
+	store_size(b3, max_ppartobj);
+	store_size(b4, total_partobj * 100 / total_objects);
+	printf("%% PartObj%10s%% %10s%% %10s%% %10s%%\n",
+			b1,	b2,	b3,	b4);
+
+	store_size(b1, avg_size);store_size(b2, min_size);
+	store_size(b3, max_size);store_size(b4, total_size);
+	printf("Memory    %10s  %10s  %10s  %10s\n",
+			b1,	b2,	b3,	b4);
+
+	store_size(b1, avg_used);store_size(b2, min_used);
+	store_size(b3, max_used);store_size(b4, total_used);
+	printf("Used      %10s  %10s  %10s  %10s\n",
+			b1,	b2,	b3,	b4);
+
+	store_size(b1, avg_waste);store_size(b2, min_waste);
+	store_size(b3, max_waste);store_size(b4, total_waste);
+	printf("Loss      %10s  %10s  %10s  %10s\n",
+			b1,	b2,	b3,	b4);
+
+	printf("\n");
+	printf("Per Object   Average         Min         Max\n");
+	printf("---------------------------------------------\n");
+
+	store_size(b1, avg_memobj);store_size(b2, min_memobj);
+	store_size(b3, max_memobj);
+	printf("Memory    %10s  %10s  %10s\n",
+			b1,	b2,	b3);
+	store_size(b1, avg_objsize);store_size(b2, min_objsize);
+	store_size(b3, max_objsize);
+	printf("User      %10s  %10s  %10s\n",
+			b1,	b2,	b3);
+
+	store_size(b1, avg_objwaste);store_size(b2, min_objwaste);
+	store_size(b3, max_objwaste);
+	printf("Loss      %10s  %10s  %10s\n",
+			b1,	b2,	b3);
+}
+
+static void sort_slabs(void)
+{
+	struct slabinfo *s1,*s2;
+
+	for (s1 = slabinfo; s1 < slabinfo + slabs; s1++) {
+		for (s2 = s1 + 1; s2 < slabinfo + slabs; s2++) {
+			int result;
+
+			if (sort_size)
+				result = slab_size(s1) < slab_size(s2);
+			else if (sort_active)
+				result = slab_activity(s1) < slab_activity(s2);
+			else
+				result = strcasecmp(s1->name, s2->name);
+
+			if (show_inverted)
+				result = -result;
+
+			if (result > 0) {
+				struct slabinfo t;
+
+				memcpy(&t, s1, sizeof(struct slabinfo));
+				memcpy(s1, s2, sizeof(struct slabinfo));
+				memcpy(s2, &t, sizeof(struct slabinfo));
+			}
+		}
+	}
+}
+
+static void sort_aliases(void)
+{
+	struct aliasinfo *a1,*a2;
+
+	for (a1 = aliasinfo; a1 < aliasinfo + aliases; a1++) {
+		for (a2 = a1 + 1; a2 < aliasinfo + aliases; a2++) {
+			char *n1, *n2;
+
+			n1 = a1->name;
+			n2 = a2->name;
+			if (show_alias && !show_inverted) {
+				n1 = a1->ref;
+				n2 = a2->ref;
+			}
+			if (strcasecmp(n1, n2) > 0) {
+				struct aliasinfo t;
+
+				memcpy(&t, a1, sizeof(struct aliasinfo));
+				memcpy(a1, a2, sizeof(struct aliasinfo));
+				memcpy(a2, &t, sizeof(struct aliasinfo));
+			}
+		}
+	}
+}
+
+static void link_slabs(void)
+{
+	struct aliasinfo *a;
+	struct slabinfo *s;
+
+	for (a = aliasinfo; a < aliasinfo + aliases; a++) {
+
+		for (s = slabinfo; s < slabinfo + slabs; s++)
+			if (strcmp(a->ref, s->name) == 0) {
+				a->slab = s;
+				s->refs++;
+				break;
+			}
+		if (s == slabinfo + slabs)
+			fatal("Unresolved alias %s\n", a->ref);
+	}
+}
+
+static void alias(void)
+{
+	struct aliasinfo *a;
+	char *active = NULL;
+
+	sort_aliases();
+	link_slabs();
+
+	for(a = aliasinfo; a < aliasinfo + aliases; a++) {
+
+		if (!show_single_ref && a->slab->refs == 1)
+			continue;
+
+		if (!show_inverted) {
+			if (active) {
+				if (strcmp(a->slab->name, active) == 0) {
+					printf(" %s", a->name);
+					continue;
+				}
+			}
+			printf("\n%-12s <- %s", a->slab->name, a->name);
+			active = a->slab->name;
+		}
+		else
+			printf("%-20s -> %s\n", a->name, a->slab->name);
+	}
+	if (active)
+		printf("\n");
+}
+
+
+static void rename_slabs(void)
+{
+	struct slabinfo *s;
+	struct aliasinfo *a;
+
+	for (s = slabinfo; s < slabinfo + slabs; s++) {
+		if (*s->name != ':')
+			continue;
+
+		if (s->refs > 1 && !show_first_alias)
+			continue;
+
+		a = find_one_alias(s);
+
+		if (a)
+			s->name = a->name;
+		else {
+			s->name = "*";
+			actual_slabs--;
+		}
+	}
+}
+
+static int slab_mismatch(char *slab)
+{
+	return regexec(&pattern, slab, 0, NULL, 0);
+}
+
+static void read_slab_dir(void)
+{
+	DIR *dir;
+	struct dirent *de;
+	struct slabinfo *slab = slabinfo;
+	struct aliasinfo *alias = aliasinfo;
+	char *p;
+	char *t;
+	int count;
+
+	if (chdir("/sys/kernel/slab") && chdir("/sys/slab"))
+		fatal("SYSFS support for SLUB not active\n");
+
+	dir = opendir(".");
+	while ((de = readdir(dir))) {
+		if (de->d_name[0] == '.' ||
+			(de->d_name[0] != ':' && slab_mismatch(de->d_name)))
+				continue;
+		switch (de->d_type) {
+		   case DT_LNK:
+			alias->name = strdup(de->d_name);
+			count = readlink(de->d_name, buffer, sizeof(buffer));
+
+			if (count < 0)
+				fatal("Cannot read symlink %s\n", de->d_name);
+
+			buffer[count] = 0;
+			p = buffer + count;
+			while (p > buffer && p[-1] != '/')
+				p--;
+			alias->ref = strdup(p);
+			alias++;
+			break;
+		   case DT_DIR:
+			if (chdir(de->d_name))
+				fatal("Unable to access slab %s\n", slab->name);
+			slab->name = strdup(de->d_name);
+			slab->alias = 0;
+			slab->refs = 0;
+			slab->aliases = get_obj("aliases");
+			slab->align = get_obj("align");
+			slab->cache_dma = get_obj("cache_dma");
+			slab->cpu_slabs = get_obj("cpu_slabs");
+			slab->destroy_by_rcu = get_obj("destroy_by_rcu");
+			slab->hwcache_align = get_obj("hwcache_align");
+			slab->object_size = get_obj("object_size");
+			slab->objects = get_obj("objects");
+			slab->objects_partial = get_obj("objects_partial");
+			slab->objects_total = get_obj("objects_total");
+			slab->objs_per_slab = get_obj("objs_per_slab");
+			slab->order = get_obj("order");
+			slab->partial = get_obj("partial");
+			slab->partial = get_obj_and_str("partial", &t);
+			decode_numa_list(slab->numa_partial, t);
+			free(t);
+			slab->poison = get_obj("poison");
+			slab->reclaim_account = get_obj("reclaim_account");
+			slab->red_zone = get_obj("red_zone");
+			slab->sanity_checks = get_obj("sanity_checks");
+			slab->slab_size = get_obj("slab_size");
+			slab->slabs = get_obj_and_str("slabs", &t);
+			decode_numa_list(slab->numa, t);
+			free(t);
+			slab->store_user = get_obj("store_user");
+			slab->trace = get_obj("trace");
+			slab->alloc_fastpath = get_obj("alloc_fastpath");
+			slab->alloc_slowpath = get_obj("alloc_slowpath");
+			slab->free_fastpath = get_obj("free_fastpath");
+			slab->free_slowpath = get_obj("free_slowpath");
+			slab->free_frozen= get_obj("free_frozen");
+			slab->free_add_partial = get_obj("free_add_partial");
+			slab->free_remove_partial = get_obj("free_remove_partial");
+			slab->alloc_from_partial = get_obj("alloc_from_partial");
+			slab->alloc_slab = get_obj("alloc_slab");
+			slab->alloc_refill = get_obj("alloc_refill");
+			slab->free_slab = get_obj("free_slab");
+			slab->cpuslab_flush = get_obj("cpuslab_flush");
+			slab->deactivate_full = get_obj("deactivate_full");
+			slab->deactivate_empty = get_obj("deactivate_empty");
+			slab->deactivate_to_head = get_obj("deactivate_to_head");
+			slab->deactivate_to_tail = get_obj("deactivate_to_tail");
+			slab->deactivate_remote_frees = get_obj("deactivate_remote_frees");
+			slab->order_fallback = get_obj("order_fallback");
+			chdir("..");
+			if (slab->name[0] == ':')
+				alias_targets++;
+			slab++;
+			break;
+		   default :
+			fatal("Unknown file type %lx\n", de->d_type);
+		}
+	}
+	closedir(dir);
+	slabs = slab - slabinfo;
+	actual_slabs = slabs;
+	aliases = alias - aliasinfo;
+	if (slabs > MAX_SLABS)
+		fatal("Too many slabs\n");
+	if (aliases > MAX_ALIASES)
+		fatal("Too many aliases\n");
+}
+
+static void output_slabs(void)
+{
+	struct slabinfo *slab;
+
+	for (slab = slabinfo; slab < slabinfo + slabs; slab++) {
+
+		if (slab->alias)
+			continue;
+
+
+		if (show_numa)
+			slab_numa(slab, 0);
+		else if (show_track)
+			show_tracking(slab);
+		else if (validate)
+			slab_validate(slab);
+		else if (shrink)
+			slab_shrink(slab);
+		else if (set_debug)
+			slab_debug(slab);
+		else if (show_ops)
+			ops(slab);
+		else if (show_slab)
+			slabcache(slab);
+		else if (show_report)
+			report(slab);
+	}
+}
+
+struct option opts[] = {
+	{ "aliases", 0, NULL, 'a' },
+	{ "activity", 0, NULL, 'A' },
+	{ "debug", 2, NULL, 'd' },
+	{ "display-activity", 0, NULL, 'D' },
+	{ "empty", 0, NULL, 'e' },
+	{ "first-alias", 0, NULL, 'f' },
+	{ "help", 0, NULL, 'h' },
+	{ "inverted", 0, NULL, 'i'},
+	{ "numa", 0, NULL, 'n' },
+	{ "ops", 0, NULL, 'o' },
+	{ "report", 0, NULL, 'r' },
+	{ "shrink", 0, NULL, 's' },
+	{ "slabs", 0, NULL, 'l' },
+	{ "track", 0, NULL, 't'},
+	{ "validate", 0, NULL, 'v' },
+	{ "zero", 0, NULL, 'z' },
+	{ "1ref", 0, NULL, '1'},
+	{ NULL, 0, NULL, 0 }
+};
+
+int main(int argc, char *argv[])
+{
+	int c;
+	int err;
+	char *pattern_source;
+
+	page_size = getpagesize();
+
+	while ((c = getopt_long(argc, argv, "aAd::Defhil1noprstvzTS",
+						opts, NULL)) != -1)
+		switch (c) {
+		case '1':
+			show_single_ref = 1;
+			break;
+		case 'a':
+			show_alias = 1;
+			break;
+		case 'A':
+			sort_active = 1;
+			break;
+		case 'd':
+			set_debug = 1;
+			if (!debug_opt_scan(optarg))
+				fatal("Invalid debug option '%s'\n", optarg);
+			break;
+		case 'D':
+			show_activity = 1;
+			break;
+		case 'e':
+			show_empty = 1;
+			break;
+		case 'f':
+			show_first_alias = 1;
+			break;
+		case 'h':
+			usage();
+			return 0;
+		case 'i':
+			show_inverted = 1;
+			break;
+		case 'n':
+			show_numa = 1;
+			break;
+		case 'o':
+			show_ops = 1;
+			break;
+		case 'r':
+			show_report = 1;
+			break;
+		case 's':
+			shrink = 1;
+			break;
+		case 'l':
+			show_slab = 1;
+			break;
+		case 't':
+			show_track = 1;
+			break;
+		case 'v':
+			validate = 1;
+			break;
+		case 'z':
+			skip_zero = 0;
+			break;
+		case 'T':
+			show_totals = 1;
+			break;
+		case 'S':
+			sort_size = 1;
+			break;
+
+		default:
+			fatal("%s: Invalid option '%c'\n", argv[0], optopt);
+
+	}
+
+	if (!show_slab && !show_alias && !show_track && !show_report
+		&& !validate && !shrink && !set_debug && !show_ops)
+			show_slab = 1;
+
+	if (argc > optind)
+		pattern_source = argv[optind];
+	else
+		pattern_source = ".*";
+
+	err = regcomp(&pattern, pattern_source, REG_ICASE|REG_NOSUB);
+	if (err)
+		fatal("%s: Invalid pattern '%s' code %d\n",
+			argv[0], pattern_source, err);
+	read_slab_dir();
+	if (show_alias)
+		alias();
+	else
+	if (show_totals)
+		totals();
+	else {
+		link_slabs();
+		rename_slabs();
+		sort_slabs();
+		output_slabs();
+	}
+	return 0;
+}
diff --git a/tools/virtio/Makefile b/tools/virtio/Makefile
new file mode 100644
index 000000000000..d1d442ed106a
--- /dev/null
+++ b/tools/virtio/Makefile
@@ -0,0 +1,12 @@
+all: test mod
+test: virtio_test
+virtio_test: virtio_ring.o virtio_test.o
+CFLAGS += -g -O2 -Wall -I. -I ../../usr/include/ -Wno-pointer-sign -fno-strict-overflow  -MMD
+vpath %.c ../../drivers/virtio
+mod:
+	${MAKE} -C `pwd`/../.. M=`pwd`/vhost_test
+.PHONY: all test mod clean
+clean:
+	${RM} *.o vhost_test/*.o vhost_test/.*.cmd \
+              vhost_test/Module.symvers vhost_test/modules.order *.d
+-include *.d
diff --git a/tools/virtio/linux/device.h b/tools/virtio/linux/device.h
new file mode 100644
index 000000000000..4ad7e1df0db5
--- /dev/null
+++ b/tools/virtio/linux/device.h
@@ -0,0 +1,2 @@
+#ifndef LINUX_DEVICE_H
+#endif
diff --git a/tools/virtio/linux/slab.h b/tools/virtio/linux/slab.h
new file mode 100644
index 000000000000..81baeac8ae40
--- /dev/null
+++ b/tools/virtio/linux/slab.h
@@ -0,0 +1,2 @@
+#ifndef LINUX_SLAB_H
+#endif
diff --git a/tools/virtio/linux/virtio.h b/tools/virtio/linux/virtio.h
new file mode 100644
index 000000000000..669bcdd45805
--- /dev/null
+++ b/tools/virtio/linux/virtio.h
@@ -0,0 +1,223 @@
+#ifndef LINUX_VIRTIO_H
+#define LINUX_VIRTIO_H
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+
+#include <linux/types.h>
+#include <errno.h>
+
+typedef unsigned long long dma_addr_t;
+
+struct scatterlist {
+	unsigned long	page_link;
+	unsigned int	offset;
+	unsigned int	length;
+	dma_addr_t	dma_address;
+};
+
+struct page {
+	unsigned long long dummy;
+};
+
+#define BUG_ON(__BUG_ON_cond) assert(!(__BUG_ON_cond))
+
+/* Physical == Virtual */
+#define virt_to_phys(p) ((unsigned long)p)
+#define phys_to_virt(a) ((void *)(unsigned long)(a))
+/* Page address: Virtual / 4K */
+#define virt_to_page(p) ((struct page*)((virt_to_phys(p) / 4096) * \
+					sizeof(struct page)))
+#define offset_in_page(p) (((unsigned long)p) % 4096)
+#define sg_phys(sg) ((sg->page_link & ~0x3) / sizeof(struct page) * 4096 + \
+		     sg->offset)
+static inline void sg_mark_end(struct scatterlist *sg)
+{
+	/*
+	 * Set termination bit, clear potential chain bit
+	 */
+	sg->page_link |= 0x02;
+	sg->page_link &= ~0x01;
+}
+static inline void sg_init_table(struct scatterlist *sgl, unsigned int nents)
+{
+	memset(sgl, 0, sizeof(*sgl) * nents);
+	sg_mark_end(&sgl[nents - 1]);
+}
+static inline void sg_assign_page(struct scatterlist *sg, struct page *page)
+{
+	unsigned long page_link = sg->page_link & 0x3;
+
+	/*
+	 * In order for the low bit stealing approach to work, pages
+	 * must be aligned at a 32-bit boundary as a minimum.
+	 */
+	BUG_ON((unsigned long) page & 0x03);
+	sg->page_link = page_link | (unsigned long) page;
+}
+
+static inline void sg_set_page(struct scatterlist *sg, struct page *page,
+			       unsigned int len, unsigned int offset)
+{
+	sg_assign_page(sg, page);
+	sg->offset = offset;
+	sg->length = len;
+}
+
+static inline void sg_set_buf(struct scatterlist *sg, const void *buf,
+			      unsigned int buflen)
+{
+	sg_set_page(sg, virt_to_page(buf), buflen, offset_in_page(buf));
+}
+
+static inline void sg_init_one(struct scatterlist *sg, const void *buf, unsigned int buflen)
+{
+	sg_init_table(sg, 1);
+	sg_set_buf(sg, buf, buflen);
+}
+
+typedef __u16 u16;
+
+typedef enum {
+	GFP_KERNEL,
+	GFP_ATOMIC,
+} gfp_t;
+typedef enum {
+	IRQ_NONE,
+	IRQ_HANDLED
+} irqreturn_t;
+
+static inline void *kmalloc(size_t s, gfp_t gfp)
+{
+	return malloc(s);
+}
+
+static inline void kfree(void *p)
+{
+	free(p);
+}
+
+#define container_of(ptr, type, member) ({			\
+	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
+	(type *)( (char *)__mptr - offsetof(type,member) );})
+
+#define uninitialized_var(x) x = x
+
+# ifndef likely
+#  define likely(x)	(__builtin_expect(!!(x), 1))
+# endif
+# ifndef unlikely
+#  define unlikely(x)	(__builtin_expect(!!(x), 0))
+# endif
+
+#define pr_err(format, ...) fprintf (stderr, format, ## __VA_ARGS__)
+#ifdef DEBUG
+#define pr_debug(format, ...) fprintf (stderr, format, ## __VA_ARGS__)
+#else
+#define pr_debug(format, ...) do {} while (0)
+#endif
+#define dev_err(dev, format, ...) fprintf (stderr, format, ## __VA_ARGS__)
+#define dev_warn(dev, format, ...) fprintf (stderr, format, ## __VA_ARGS__)
+
+/* TODO: empty stubs for now. Broken but enough for virtio_ring.c */
+#define list_add_tail(a, b) do {} while (0)
+#define list_del(a) do {} while (0)
+
+#define BIT_WORD(nr)		((nr) / BITS_PER_LONG)
+#define BITS_PER_BYTE		8
+#define BITS_PER_LONG (sizeof(long) * BITS_PER_BYTE)
+#define BIT_MASK(nr)		(1UL << ((nr) % BITS_PER_LONG))
+/* TODO: Not atomic as it should be:
+ * we don't use this for anything important. */
+static inline void clear_bit(int nr, volatile unsigned long *addr)
+{
+	unsigned long mask = BIT_MASK(nr);
+	unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
+
+	*p &= ~mask;
+}
+
+static inline int test_bit(int nr, const volatile unsigned long *addr)
+{
+        return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1)));
+}
+
+/* The only feature we care to support */
+#define virtio_has_feature(dev, feature) \
+	test_bit((feature), (dev)->features)
+/* end of stubs */
+
+struct virtio_device {
+	void *dev;
+	unsigned long features[1];
+};
+
+struct virtqueue {
+	/* TODO: commented as list macros are empty stubs for now.
+	 * Broken but enough for virtio_ring.c
+	 * struct list_head list; */
+	void (*callback)(struct virtqueue *vq);
+	const char *name;
+	struct virtio_device *vdev;
+	void *priv;
+};
+
+#define EXPORT_SYMBOL_GPL(__EXPORT_SYMBOL_GPL_name) \
+	void __EXPORT_SYMBOL_GPL##__EXPORT_SYMBOL_GPL_name() { \
+}
+#define MODULE_LICENSE(__MODULE_LICENSE_value) \
+	const char *__MODULE_LICENSE_name = __MODULE_LICENSE_value
+
+#define CONFIG_SMP
+
+#if defined(__i386__) || defined(__x86_64__)
+#define barrier() asm volatile("" ::: "memory")
+#define mb() __sync_synchronize()
+
+#define smp_mb()	mb()
+# define smp_rmb()	barrier()
+# define smp_wmb()	barrier()
+#else
+#error Please fill in barrier macros
+#endif
+
+/* Interfaces exported by virtio_ring. */
+int virtqueue_add_buf_gfp(struct virtqueue *vq,
+			  struct scatterlist sg[],
+			  unsigned int out_num,
+			  unsigned int in_num,
+			  void *data,
+			  gfp_t gfp);
+
+static inline int virtqueue_add_buf(struct virtqueue *vq,
+				    struct scatterlist sg[],
+				    unsigned int out_num,
+				    unsigned int in_num,
+				    void *data)
+{
+	return virtqueue_add_buf_gfp(vq, sg, out_num, in_num, data, GFP_ATOMIC);
+}
+
+void virtqueue_kick(struct virtqueue *vq);
+
+void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
+
+void virtqueue_disable_cb(struct virtqueue *vq);
+
+bool virtqueue_enable_cb(struct virtqueue *vq);
+
+void *virtqueue_detach_unused_buf(struct virtqueue *vq);
+struct virtqueue *vring_new_virtqueue(unsigned int num,
+				      unsigned int vring_align,
+				      struct virtio_device *vdev,
+				      void *pages,
+				      void (*notify)(struct virtqueue *vq),
+				      void (*callback)(struct virtqueue *vq),
+				      const char *name);
+void vring_del_virtqueue(struct virtqueue *vq);
+
+#endif
diff --git a/tools/virtio/vhost_test/Makefile b/tools/virtio/vhost_test/Makefile
new file mode 100644
index 000000000000..a1d35b81b314
--- /dev/null
+++ b/tools/virtio/vhost_test/Makefile
@@ -0,0 +1,2 @@
+obj-m += vhost_test.o
+EXTRA_CFLAGS += -Idrivers/vhost
diff --git a/tools/virtio/vhost_test/vhost_test.c b/tools/virtio/vhost_test/vhost_test.c
new file mode 100644
index 000000000000..18735189e62b
--- /dev/null
+++ b/tools/virtio/vhost_test/vhost_test.c
@@ -0,0 +1 @@
+#include "test.c"
diff --git a/tools/virtio/virtio_test.c b/tools/virtio/virtio_test.c
new file mode 100644
index 000000000000..df0c6d2c3860
--- /dev/null
+++ b/tools/virtio/virtio_test.c
@@ -0,0 +1,248 @@
+#define _GNU_SOURCE
+#include <getopt.h>
+#include <string.h>
+#include <poll.h>
+#include <sys/eventfd.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <unistd.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <fcntl.h>
+#include <linux/vhost.h>
+#include <linux/virtio.h>
+#include <linux/virtio_ring.h>
+#include "../../drivers/vhost/test.h"
+
+struct vq_info {
+	int kick;
+	int call;
+	int num;
+	int idx;
+	void *ring;
+	/* copy used for control */
+	struct vring vring;
+	struct virtqueue *vq;
+};
+
+struct vdev_info {
+	struct virtio_device vdev;
+	int control;
+	struct pollfd fds[1];
+	struct vq_info vqs[1];
+	int nvqs;
+	void *buf;
+	size_t buf_size;
+	struct vhost_memory *mem;
+};
+
+void vq_notify(struct virtqueue *vq)
+{
+	struct vq_info *info = vq->priv;
+	unsigned long long v = 1;
+	int r;
+	r = write(info->kick, &v, sizeof v);
+	assert(r == sizeof v);
+}
+
+void vq_callback(struct virtqueue *vq)
+{
+}
+
+
+void vhost_vq_setup(struct vdev_info *dev, struct vq_info *info)
+{
+	struct vhost_vring_state state = { .index = info->idx };
+	struct vhost_vring_file file = { .index = info->idx };
+	unsigned long long features = dev->vdev.features[0];
+	struct vhost_vring_addr addr = {
+		.index = info->idx,
+		.desc_user_addr = (uint64_t)(unsigned long)info->vring.desc,
+		.avail_user_addr = (uint64_t)(unsigned long)info->vring.avail,
+		.used_user_addr = (uint64_t)(unsigned long)info->vring.used,
+	};
+	int r;
+	r = ioctl(dev->control, VHOST_SET_FEATURES, &features);
+	assert(r >= 0);
+	state.num = info->vring.num;
+	r = ioctl(dev->control, VHOST_SET_VRING_NUM, &state);
+	assert(r >= 0);
+	state.num = 0;
+	r = ioctl(dev->control, VHOST_SET_VRING_BASE, &state);
+	assert(r >= 0);
+	r = ioctl(dev->control, VHOST_SET_VRING_ADDR, &addr);
+	assert(r >= 0);
+	file.fd = info->kick;
+	r = ioctl(dev->control, VHOST_SET_VRING_KICK, &file);
+	assert(r >= 0);
+	file.fd = info->call;
+	r = ioctl(dev->control, VHOST_SET_VRING_CALL, &file);
+	assert(r >= 0);
+}
+
+static void vq_info_add(struct vdev_info *dev, int num)
+{
+	struct vq_info *info = &dev->vqs[dev->nvqs];
+	int r;
+	info->idx = dev->nvqs;
+	info->kick = eventfd(0, EFD_NONBLOCK);
+	info->call = eventfd(0, EFD_NONBLOCK);
+	r = posix_memalign(&info->ring, 4096, vring_size(num, 4096));
+	assert(r >= 0);
+	memset(info->ring, 0, vring_size(num, 4096));
+	vring_init(&info->vring, num, info->ring, 4096);
+	info->vq = vring_new_virtqueue(info->vring.num, 4096, &dev->vdev, info->ring,
+				       vq_notify, vq_callback, "test");
+	assert(info->vq);
+	info->vq->priv = info;
+	vhost_vq_setup(dev, info);
+	dev->fds[info->idx].fd = info->call;
+	dev->fds[info->idx].events = POLLIN;
+	dev->nvqs++;
+}
+
+static void vdev_info_init(struct vdev_info* dev, unsigned long long features)
+{
+	int r;
+	memset(dev, 0, sizeof *dev);
+	dev->vdev.features[0] = features;
+	dev->vdev.features[1] = features >> 32;
+	dev->buf_size = 1024;
+	dev->buf = malloc(dev->buf_size);
+	assert(dev->buf);
+        dev->control = open("/dev/vhost-test", O_RDWR);
+	assert(dev->control >= 0);
+	r = ioctl(dev->control, VHOST_SET_OWNER, NULL);
+	assert(r >= 0);
+	dev->mem = malloc(offsetof(struct vhost_memory, regions) +
+			  sizeof dev->mem->regions[0]);
+	assert(dev->mem);
+	memset(dev->mem, 0, offsetof(struct vhost_memory, regions) +
+                          sizeof dev->mem->regions[0]);
+	dev->mem->nregions = 1;
+	dev->mem->regions[0].guest_phys_addr = (long)dev->buf;
+	dev->mem->regions[0].userspace_addr = (long)dev->buf;
+	dev->mem->regions[0].memory_size = dev->buf_size;
+	r = ioctl(dev->control, VHOST_SET_MEM_TABLE, dev->mem);
+	assert(r >= 0);
+}
+
+/* TODO: this is pretty bad: we get a cache line bounce
+ * for the wait queue on poll and another one on read,
+ * plus the read which is there just to clear the
+ * current state. */
+static void wait_for_interrupt(struct vdev_info *dev)
+{
+	int i;
+	unsigned long long val;
+	poll(dev->fds, dev->nvqs, -1);
+	for (i = 0; i < dev->nvqs; ++i)
+		if (dev->fds[i].revents & POLLIN) {
+			read(dev->fds[i].fd, &val, sizeof val);
+		}
+}
+
+static void run_test(struct vdev_info *dev, struct vq_info *vq, int bufs)
+{
+	struct scatterlist sl;
+	long started = 0, completed = 0;
+	long completed_before;
+	int r, test = 1;
+	unsigned len;
+	long long spurious = 0;
+	r = ioctl(dev->control, VHOST_TEST_RUN, &test);
+	assert(r >= 0);
+	for (;;) {
+		virtqueue_disable_cb(vq->vq);
+		completed_before = completed;
+		do {
+			if (started < bufs) {
+				sg_init_one(&sl, dev->buf, dev->buf_size);
+				r = virtqueue_add_buf(vq->vq, &sl, 1, 0,
+						      dev->buf + started);
+				if (likely(r >= 0)) {
+					++started;
+					virtqueue_kick(vq->vq);
+				}
+			} else
+				r = -1;
+
+			/* Flush out completed bufs if any */
+			if (virtqueue_get_buf(vq->vq, &len)) {
+				++completed;
+				r = 0;
+			}
+
+		} while (r >= 0);
+		if (completed == completed_before)
+			++spurious;
+		assert(completed <= bufs);
+		assert(started <= bufs);
+		if (completed == bufs)
+			break;
+		if (virtqueue_enable_cb(vq->vq)) {
+			wait_for_interrupt(dev);
+		}
+	}
+	test = 0;
+	r = ioctl(dev->control, VHOST_TEST_RUN, &test);
+	assert(r >= 0);
+	fprintf(stderr, "spurious wakeus: 0x%llx\n", spurious);
+}
+
+const char optstring[] = "h";
+const struct option longopts[] = {
+	{
+		.name = "help",
+		.val = 'h',
+	},
+	{
+		.name = "indirect",
+		.val = 'I',
+	},
+	{
+		.name = "no-indirect",
+		.val = 'i',
+	},
+	{
+	}
+};
+
+static void help()
+{
+	fprintf(stderr, "Usage: virtio_test [--help] [--no-indirect]\n");
+}
+
+int main(int argc, char **argv)
+{
+	struct vdev_info dev;
+	unsigned long long features = 1ULL << VIRTIO_RING_F_INDIRECT_DESC;
+	int o;
+
+	for (;;) {
+		o = getopt_long(argc, argv, optstring, longopts, NULL);
+		switch (o) {
+		case -1:
+			goto done;
+		case '?':
+			help();
+			exit(2);
+		case 'h':
+			help();
+			goto done;
+		case 'i':
+			features &= ~(1ULL << VIRTIO_RING_F_INDIRECT_DESC);
+			break;
+		default:
+			assert(0);
+			break;
+		}
+	}
+
+done:
+	vdev_info_init(&dev, features);
+	vq_info_add(&dev, 256);
+	run_test(&dev, &dev.vqs[0], 0x100000);
+	return 0;
+}