diff --git a/tests/.gitignore b/tests/.gitignore
index a06a8ba..7c0d156 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -48,6 +48,7 @@ test-qapi-types.[ch]
 test-qapi-visit.[ch]
 test-qdev-global-props
 test-qemu-opts
+test-qdist
 test-qga
 test-qmp-commands
 test-qmp-commands.h
diff --git a/tests/Makefile.include b/tests/Makefile.include
index a3e20e3..2948945 100644
--- a/tests/Makefile.include
+++ b/tests/Makefile.include
@@ -70,6 +70,8 @@ check-unit-y += tests/rcutorture$(EXESUF)
 gcov-files-rcutorture-y = util/rcu.c
 check-unit-y += tests/test-rcu-list$(EXESUF)
 gcov-files-test-rcu-list-y = util/rcu.c
+check-unit-y += tests/test-qdist$(EXESUF)
+gcov-files-test-qdist-y = util/qdist.c
 check-unit-y += tests/test-bitops$(EXESUF)
 check-unit-$(CONFIG_HAS_GLIB_SUBPROCESS_TESTS) += tests/test-qdev-global-props$(EXESUF)
 check-unit-y += tests/check-qom-interface$(EXESUF)
@@ -394,7 +396,8 @@ test-obj-y = tests/check-qint.o tests/check-qstring.o tests/check-qdict.o \
 	tests/test-qmp-commands.o tests/test-visitor-serialization.o \
 	tests/test-x86-cpuid.o tests/test-mul64.o tests/test-int128.o \
 	tests/test-opts-visitor.o tests/test-qmp-event.o \
-	tests/rcutorture.o tests/test-rcu-list.o
+	tests/rcutorture.o tests/test-rcu-list.o \
+	tests/test-qdist.o
 
 $(test-obj-y): QEMU_INCLUDES += -Itests
 QEMU_CFLAGS += -I$(SRC_PATH)/tests
@@ -433,6 +436,7 @@ tests/test-cutils$(EXESUF): tests/test-cutils.o util/cutils.o
 tests/test-int128$(EXESUF): tests/test-int128.o
 tests/rcutorture$(EXESUF): tests/rcutorture.o $(test-util-obj-y)
 tests/test-rcu-list$(EXESUF): tests/test-rcu-list.o $(test-util-obj-y)
+tests/test-qdist$(EXESUF): tests/test-qdist.o $(test-util-obj-y)
 
 tests/test-qdev-global-props$(EXESUF): tests/test-qdev-global-props.o \
 	hw/core/qdev.o hw/core/qdev-properties.o hw/core/hotplug.o\
diff --git a/tests/test-qdist.c b/tests/test-qdist.c
new file mode 100644
index 0000000..a67f260
--- /dev/null
+++ b/tests/test-qdist.c
@@ -0,0 +1,384 @@
+/*
+ * Copyright (C) 2016, Emilio G. Cota <cota@braap.org>
+ *
+ * License: GNU GPL, version 2 or later.
+ *   See the COPYING file in the top-level directory.
+ */
+#include "qemu/osdep.h"
+#include <glib.h>
+#include "qemu/qdist.h"
+
+#include <math.h>
+
+struct entry_desc {
+    double x;
+    unsigned long count;
+
+    /* 0 prints a space, 1-8 prints from qdist_blocks[] */
+    int fill_code;
+};
+
+/* See: https://en.wikipedia.org/wiki/Block_Elements */
+static const gunichar qdist_blocks[] = {
+    0x2581,
+    0x2582,
+    0x2583,
+    0x2584,
+    0x2585,
+    0x2586,
+    0x2587,
+    0x2588
+};
+
+#define QDIST_NR_BLOCK_CODES ARRAY_SIZE(qdist_blocks)
+
+static char *pr_hist(const struct entry_desc *darr, size_t n)
+{
+    GString *s = g_string_new("");
+    size_t i;
+
+    for (i = 0; i < n; i++) {
+        int fill = darr[i].fill_code;
+
+        if (fill) {
+            assert(fill <= QDIST_NR_BLOCK_CODES);
+            g_string_append_unichar(s, qdist_blocks[fill - 1]);
+        } else {
+            g_string_append_c(s, ' ');
+        }
+    }
+    return g_string_free(s, FALSE);
+}
+
+static void
+histogram_check(const struct qdist *dist, const struct entry_desc *darr,
+                size_t n, size_t n_bins)
+{
+    char *pr = qdist_pr_plain(dist, n_bins);
+    char *str = pr_hist(darr, n);
+
+    g_assert_cmpstr(pr, ==, str);
+    g_free(pr);
+    g_free(str);
+}
+
+static void histogram_check_single_full(const struct qdist *dist, size_t n_bins)
+{
+    struct entry_desc desc = { .fill_code = 8 };
+
+    histogram_check(dist, &desc, 1, n_bins);
+}
+
+static void
+entries_check(const struct qdist *dist, const struct entry_desc *darr, size_t n)
+{
+    size_t i;
+
+    for (i = 0; i < n; i++) {
+        struct qdist_entry *e = &dist->entries[i];
+
+        g_assert_cmpuint(e->count, ==, darr[i].count);
+    }
+}
+
+static void
+entries_insert(struct qdist *dist, const struct entry_desc *darr, size_t n)
+{
+    size_t i;
+
+    for (i = 0; i < n; i++) {
+        qdist_add(dist, darr[i].x, darr[i].count);
+    }
+}
+
+static void do_test_bin(const struct entry_desc *a, size_t n_a,
+                        const struct entry_desc *b, size_t n_b)
+{
+    struct qdist qda;
+    struct qdist qdb;
+
+    qdist_init(&qda);
+
+    entries_insert(&qda, a, n_a);
+    qdist_inc(&qda, a[0].x);
+    qdist_add(&qda, a[0].x, -1);
+
+    g_assert_cmpuint(qdist_unique_entries(&qda), ==, n_a);
+    g_assert_cmpfloat(qdist_xmin(&qda), ==, a[0].x);
+    g_assert_cmpfloat(qdist_xmax(&qda), ==, a[n_a - 1].x);
+    histogram_check(&qda, a, n_a, 0);
+    histogram_check(&qda, a, n_a, n_a);
+
+    qdist_bin__internal(&qdb, &qda, n_b);
+    g_assert_cmpuint(qdb.n, ==, n_b);
+    entries_check(&qdb, b, n_b);
+    g_assert_cmpuint(qdist_sample_count(&qda), ==, qdist_sample_count(&qdb));
+    /*
+     * No histogram_check() for $qdb, since we'd rebin it and that is a bug.
+     * Instead, regenerate it from $qda.
+     */
+    histogram_check(&qda, b, n_b, n_b);
+
+    qdist_destroy(&qdb);
+    qdist_destroy(&qda);
+}
+
+static void do_test_pr(uint32_t opt)
+{
+    static const struct entry_desc desc[] = {
+        [0] = { 1, 900, 8 },
+        [1] = { 2, 1, 1 },
+        [2] = { 3, 2, 1 }
+    };
+    static const char border[] = "|";
+    const char *llabel = NULL;
+    const char *rlabel = NULL;
+    struct qdist dist;
+    GString *s;
+    char *str;
+    char *pr;
+    size_t n;
+
+    n = ARRAY_SIZE(desc);
+    qdist_init(&dist);
+
+    entries_insert(&dist, desc, n);
+    histogram_check(&dist, desc, n, 0);
+
+    s = g_string_new("");
+
+    if (opt & QDIST_PR_LABELS) {
+        unsigned int lopts = opt & (QDIST_PR_NODECIMAL |
+                                    QDIST_PR_PERCENT |
+                                    QDIST_PR_100X |
+                                    QDIST_PR_NOBINRANGE);
+
+        if (lopts == 0) {
+            llabel = "[1.0,1.7)";
+            rlabel = "[2.3,3.0]";
+        } else if (lopts == QDIST_PR_NODECIMAL) {
+            llabel = "[1,2)";
+            rlabel = "[2,3]";
+        } else if (lopts == (QDIST_PR_PERCENT | QDIST_PR_NODECIMAL)) {
+            llabel = "[1,2)%";
+            rlabel = "[2,3]%";
+        } else if (lopts == QDIST_PR_100X) {
+            llabel = "[100.0,166.7)";
+            rlabel = "[233.3,300.0]";
+        } else if (lopts == (QDIST_PR_NOBINRANGE | QDIST_PR_NODECIMAL)) {
+            llabel = "1";
+            rlabel = "3";
+        } else {
+            g_assert_cmpstr("BUG", ==, "This is not meant to be exhaustive");
+        }
+    }
+
+    if (llabel) {
+        g_string_append(s, llabel);
+    }
+    if (opt & QDIST_PR_BORDER) {
+        g_string_append(s, border);
+    }
+
+    str = pr_hist(desc, n);
+    g_string_append(s, str);
+    g_free(str);
+
+    if (opt & QDIST_PR_BORDER) {
+        g_string_append(s, border);
+    }
+    if (rlabel) {
+        g_string_append(s, rlabel);
+    }
+
+    str = g_string_free(s, FALSE);
+    pr = qdist_pr(&dist, n, opt);
+    g_assert_cmpstr(pr, ==, str);
+    g_free(pr);
+    g_free(str);
+
+    qdist_destroy(&dist);
+}
+
+static inline void do_test_pr_label(uint32_t opt)
+{
+    opt |= QDIST_PR_LABELS;
+    do_test_pr(opt);
+}
+
+static void test_pr(void)
+{
+    do_test_pr(0);
+
+    do_test_pr(QDIST_PR_BORDER);
+
+    /* 100X should be ignored because we're not setting LABELS */
+    do_test_pr(QDIST_PR_100X);
+
+    do_test_pr_label(0);
+    do_test_pr_label(QDIST_PR_NODECIMAL);
+    do_test_pr_label(QDIST_PR_PERCENT | QDIST_PR_NODECIMAL);
+    do_test_pr_label(QDIST_PR_100X);
+    do_test_pr_label(QDIST_PR_NOBINRANGE | QDIST_PR_NODECIMAL);
+}
+
+static void test_bin_shrink(void)
+{
+    static const struct entry_desc a[] = {
+        [0] = { 0.0,   42922, 7 },
+        [1] = { 0.25,  47834, 8 },
+        [2] = { 0.50,  26628, 0 },
+        [3] = { 0.625, 597,   4 },
+        [4] = { 0.75,  10298, 1 },
+        [5] = { 0.875, 22,    2 },
+        [6] = { 1.0,   2771,  1 }
+    };
+    static const struct entry_desc b[] = {
+        [0] = { 0.0, 42922, 7 },
+        [1] = { 0.25, 47834, 8 },
+        [2] = { 0.50, 27225, 3 },
+        [3] = { 0.75, 13091, 1 }
+    };
+
+    return do_test_bin(a, ARRAY_SIZE(a), b, ARRAY_SIZE(b));
+}
+
+static void test_bin_expand(void)
+{
+    static const struct entry_desc a[] = {
+        [0] = { 0.0,   11713, 5 },
+        [1] = { 0.25,  20294, 0 },
+        [2] = { 0.50,  17266, 8 },
+        [3] = { 0.625, 1506,  0 },
+        [4] = { 0.75,  10355, 6 },
+        [5] = { 0.833, 2,     1 },
+        [6] = { 0.875, 99,    4 },
+        [7] = { 1.0,   4301,  2 }
+    };
+    static const struct entry_desc b[] = {
+        [0] = { 0.0, 11713, 5 },
+        [1] = { 0.0, 0,     0 },
+        [2] = { 0.0, 20294, 8 },
+        [3] = { 0.0, 0,     0 },
+        [4] = { 0.0, 0,     0 },
+        [5] = { 0.0, 17266, 6 },
+        [6] = { 0.0, 1506,  1 },
+        [7] = { 0.0, 10355, 4 },
+        [8] = { 0.0, 101,   1 },
+        [9] = { 0.0, 4301,  2 }
+    };
+
+    return do_test_bin(a, ARRAY_SIZE(a), b, ARRAY_SIZE(b));
+}
+
+static void test_bin_precision(void)
+{
+    static const struct entry_desc a[] = {
+        [0] = { 0, 213549, 8 },
+        [1] = { 1, 70, 1 },
+    };
+    static const struct entry_desc b[] = {
+        [0] = { 0, 213549, 8 },
+        [1] = { 0, 70, 1 },
+    };
+
+    return do_test_bin(a, ARRAY_SIZE(a), b, ARRAY_SIZE(b));
+}
+
+static void test_bin_simple(void)
+{
+    static const struct entry_desc a[] = {
+        [0] = { 10, 101, 8 },
+        [1] = { 11, 0, 0 },
+        [2] = { 12, 2, 1 }
+    };
+    static const struct entry_desc b[] = {
+        [0] = { 0, 101, 8 },
+        [1] = { 0, 0, 0 },
+        [2] = { 0, 0, 0 },
+        [3] = { 0, 0, 0 },
+        [4] = { 0, 2, 1 }
+    };
+
+    return do_test_bin(a, ARRAY_SIZE(a), b, ARRAY_SIZE(b));
+}
+
+static void test_single_full(void)
+{
+    struct qdist dist;
+
+    qdist_init(&dist);
+
+    qdist_add(&dist, 3, 102);
+    g_assert_cmpfloat(qdist_avg(&dist), ==, 3);
+    g_assert_cmpfloat(qdist_xmin(&dist), ==, 3);
+    g_assert_cmpfloat(qdist_xmax(&dist), ==, 3);
+
+    histogram_check_single_full(&dist, 0);
+    histogram_check_single_full(&dist, 1);
+    histogram_check_single_full(&dist, 10);
+
+    qdist_destroy(&dist);
+}
+
+static void test_single_empty(void)
+{
+    struct qdist dist;
+    char *pr;
+
+    qdist_init(&dist);
+
+    qdist_add(&dist, 3, 0);
+    g_assert_cmpuint(qdist_sample_count(&dist), ==, 0);
+    g_assert(isnan(qdist_avg(&dist)));
+    g_assert_cmpfloat(qdist_xmin(&dist), ==, 3);
+    g_assert_cmpfloat(qdist_xmax(&dist), ==, 3);
+
+    pr = qdist_pr_plain(&dist, 0);
+    g_assert_cmpstr(pr, ==, " ");
+    g_free(pr);
+
+    pr = qdist_pr_plain(&dist, 1);
+    g_assert_cmpstr(pr, ==, " ");
+    g_free(pr);
+
+    pr = qdist_pr_plain(&dist, 2);
+    g_assert_cmpstr(pr, ==, " ");
+    g_free(pr);
+
+    qdist_destroy(&dist);
+}
+
+static void test_none(void)
+{
+    struct qdist dist;
+    char *pr;
+
+    qdist_init(&dist);
+
+    g_assert(isnan(qdist_avg(&dist)));
+    g_assert(isnan(qdist_xmin(&dist)));
+    g_assert(isnan(qdist_xmax(&dist)));
+
+    pr = qdist_pr_plain(&dist, 0);
+    g_assert(pr == NULL);
+
+    pr = qdist_pr_plain(&dist, 2);
+    g_assert(pr == NULL);
+
+    qdist_destroy(&dist);
+}
+
+int main(int argc, char *argv[])
+{
+    g_test_init(&argc, &argv, NULL);
+    g_test_add_func("/qdist/none", test_none);
+    g_test_add_func("/qdist/single/empty", test_single_empty);
+    g_test_add_func("/qdist/single/full", test_single_full);
+    g_test_add_func("/qdist/binning/simple", test_bin_simple);
+    g_test_add_func("/qdist/binning/precision", test_bin_precision);
+    g_test_add_func("/qdist/binning/expand", test_bin_expand);
+    g_test_add_func("/qdist/binning/shrink", test_bin_shrink);
+    g_test_add_func("/qdist/pr", test_pr);
+    return g_test_run();
+}
