1 /*
2 * This file and its contents are supplied under the terms of the
3 * Common Development and Distribution License ("CDDL"), version 1.0.
4 * You may only use this file in accordance with the terms of version
5 * 1.0 of the CDDL.
6 *
7 * A full copy of the text of the CDDL should have accompanied this
8 * source. A copy of the CDDL is also available via the Internet at
9 * http://www.illumos.org/license/CDDL.
10 */
11
12 /*
13 * Copyright 2022 Oxide Computer Company
14 */
15
16 #include <stdio.h>
17 #include <unistd.h>
18 #include <stdlib.h>
19 #include <strings.h>
20 #include <libgen.h>
21 #include <assert.h>
22 #include <errno.h>
23
24 #include <sys/types.h>
25 #include <sys/sysmacros.h>
26 #include <sys/debug.h>
27 #include <sys/vmm.h>
28 #include <sys/vmm_dev.h>
29 #include <vmmapi.h>
30
31 #include "in_guest.h"
32 #include "test_defs.h"
33
34 typedef struct reading {
35 hrtime_t when;
36 uint32_t value;
37 } reading_t;
38
39 static bool
check_reading(reading_t before,reading_t after,uint_t divisor,uint_t loops,uint_t tick_margin,uint_t ppm_margin)40 check_reading(reading_t before, reading_t after, uint_t divisor, uint_t loops,
41 uint_t tick_margin, uint_t ppm_margin)
42 {
43 const hrtime_t time_delta = after.when - before.when;
44
45
46 /*
47 * The ticks margin should shrink proportionally to how coarsely the
48 * timer clock is being divided.
49 */
50 tick_margin /= divisor;
51
52 /*
53 * The 'before' measurement includes the ticks which occurred between
54 * programming the timer and taking the first reading. The 'after'
55 * measurement includes the number of loops (each consisting of the
56 * target tick count) plus however many ticks had transpired since the
57 * most recent roll-over.
58 */
59 const uint32_t tick_delta =
60 loops * LAPIC_TARGET_TICKS + before.value - after.value;
61 const uint32_t tick_target = loops * LAPIC_TARGET_TICKS;
62
63 /* is the number of ticks OK? */
64 if (tick_delta < tick_target) {
65 if ((tick_target - tick_delta) > tick_margin) {
66 (void) printf("%u ticks outside margin %u\n",
67 tick_delta, tick_target - tick_margin);
68 }
69 } else if ((tick_delta - tick_target) > tick_margin) {
70 (void) printf("%u ticks outside margin %u\n", tick_delta,
71 tick_target + tick_margin);
72 return (false);
73 }
74
75 hrtime_t time_target = (tick_delta * NANOSEC * divisor) / LAPIC_FREQ;
76
77 hrtime_t offset;
78 if (time_delta < time_target) {
79 offset = time_target - time_delta;
80 } else {
81 offset = time_delta - time_target;
82 }
83 uint64_t ppm = (offset * 1000000) / time_target;
84 (void) printf("params: tick_margin=%u ppm_margin=%lu divisor=%u\n",
85 tick_margin, ppm_margin, divisor);
86 (void) printf("%u ticks in %lu ns (error %lu ppm)\n",
87 tick_delta, time_delta, ppm);
88 if (ppm > ppm_margin) {
89 (void) printf("UNACCEPTABLE!\n");
90 return (false);
91 }
92 return (true);
93 }
94
95
96 static void
run_test(struct vcpu * vcpu,uint_t divisor,uint_t loops,struct vm_entry * ventry,struct vm_exit * vexit)97 run_test(struct vcpu *vcpu, uint_t divisor, uint_t loops,
98 struct vm_entry *ventry, struct vm_exit *vexit)
99 {
100 reading_t readings[2];
101 uint_t nread = 0;
102 uint_t nrepeat = 0;
103
104 const uint_t margin_ticks = MAX(1, LAPIC_TARGET_TICKS / 5000);
105 const uint_t margin_ppm = 400;
106
107 do {
108 const enum vm_exit_kind kind =
109 test_run_vcpu(vcpu, ventry, vexit);
110 if (kind == VEK_REENTR) {
111 continue;
112 } else if (kind != VEK_UNHANDLED) {
113 test_fail_vmexit(vexit);
114 }
115
116 /* input the divisor (bits 0-15) and loop count (bits 16-31) */
117 if (vexit_match_inout(vexit, true, IOP_TEST_PARAM0, 2, NULL)) {
118 ventry_fulfill_inout(vexit, ventry, divisor);
119 continue;
120 }
121 /* input the loop count */
122 if (vexit_match_inout(vexit, true, IOP_TEST_PARAM1, 2, NULL)) {
123 ventry_fulfill_inout(vexit, ventry, loops);
124 continue;
125 }
126
127 uint32_t v;
128 if (vexit_match_inout(vexit, false, IOP_TEST_VALUE, 4, &v)) {
129 readings[nread].when = gethrtime();
130 readings[nread].value = v;
131 ventry_fulfill_inout(vexit, ventry, 0);
132
133 nread++;
134 if (nread != 2) {
135 continue;
136 }
137
138 if (check_reading(readings[0], readings[1], divisor,
139 loops, margin_ticks, margin_ppm)) {
140 (void) printf("good result\n");
141 return;
142 } else {
143 nrepeat++;
144 if (nrepeat < 3) {
145 nread = 0;
146 (void) printf("retry %u\n", nrepeat);
147 continue;
148 }
149 test_fail_msg("bad result after %u retries\n",
150 nrepeat);
151 }
152 } else {
153 test_fail_vmexit(vexit);
154 }
155 } while (true);
156 }
157
158 int
main(int argc,char * argv[])159 main(int argc, char *argv[])
160 {
161 const char *test_suite_name = basename(argv[0]);
162 struct vmctx *ctx = NULL;
163 struct vcpu *vcpu;
164 int err;
165
166 ctx = test_initialize(test_suite_name);
167
168 if ((vcpu = vm_vcpu_open(ctx, 0)) == NULL) {
169 test_fail_errno(errno, "Could not open vcpu0");
170 }
171
172 err = test_setup_vcpu(vcpu, MEM_LOC_PAYLOAD, MEM_LOC_STACK);
173 if (err != 0) {
174 test_fail_errno(err, "Could not initialize vcpu0");
175 }
176
177 struct vm_entry ventry = { 0 };
178 struct vm_exit vexit = { 0 };
179
180 run_test(vcpu, 4, 3, &ventry, &vexit);
181 run_test(vcpu, 2, 4, &ventry, &vexit);
182 test_pass();
183 return (0);
184 }
185