xref: /illumos-gate/usr/src/test/bhyve-tests/tests/kdev/vhpet_freq.c (revision 32640292339b07090f10ce34d455f98711077343)
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 tick_margin,uint_t ppm_margin)40 check_reading(reading_t before, reading_t after, uint_t tick_margin,
41     uint_t ppm_margin)
42 {
43 	hrtime_t time_delta = after.when - before.when;
44 	uint32_t tick_delta;
45 
46 	if (after.value < before.value) {
47 		/* handle rollover */
48 		tick_delta = (UINT32_MAX - before.value) + after.value;
49 	} else {
50 		tick_delta = after.value - before.value;
51 	}
52 
53 	/* is the number of ticks OK? */
54 	if (tick_delta < HPET_TARGET_TICKS) {
55 		test_fail_msg("inadequate passage of ticks %u < %u\n",
56 		    tick_delta, HPET_TARGET_TICKS);
57 	} else if ((tick_delta - HPET_TARGET_TICKS) > tick_margin) {
58 		(void) printf("%u ticks outside margin %u\n", tick_delta,
59 		    HPET_TARGET_TICKS + tick_margin);
60 		return (false);
61 	}
62 
63 	hrtime_t time_target = (tick_delta * NANOSEC) / HPET_FREQ;
64 
65 	hrtime_t offset;
66 	if (time_delta < time_target) {
67 		offset = time_target - time_delta;
68 	} else {
69 		offset = time_delta - time_target;
70 	}
71 	uint64_t ppm = (offset * 1000000) / time_target;
72 	(void) printf("margin limits: ticks=%u ppm=%lu\n",
73 	    tick_margin, ppm_margin);
74 	(void) printf("%u ticks in %lu ns (error %lu ppm)\n",
75 	    tick_delta, time_delta, ppm);
76 	if (ppm > ppm_margin) {
77 		(void) printf("UNACCEPTABLE!\n");
78 		return (false);
79 	}
80 	return (true);
81 }
82 
83 int
main(int argc,char * argv[])84 main(int argc, char *argv[])
85 {
86 	const char *test_suite_name = basename(argv[0]);
87 	struct vmctx *ctx = NULL;
88 	struct vcpu *vcpu;
89 	int err;
90 
91 	ctx = test_initialize(test_suite_name);
92 
93 	if ((vcpu = vm_vcpu_open(ctx, 0)) == NULL) {
94 		test_fail_errno(errno, "Could not open vcpu0");
95 	}
96 
97 	err = test_setup_vcpu(vcpu, MEM_LOC_PAYLOAD, MEM_LOC_STACK);
98 	if (err != 0) {
99 		test_fail_errno(err, "Could not initialize vcpu0");
100 	}
101 
102 	struct vm_entry ventry = { 0 };
103 	struct vm_exit vexit = { 0 };
104 	reading_t readings[2];
105 	uint_t nread = 0;
106 	uint_t nrepeat = 0;
107 
108 	const uint_t margin_ticks = MAX(1, HPET_TARGET_TICKS / 10000);
109 	const uint_t margin_ppm = 400;
110 
111 	do {
112 		const enum vm_exit_kind kind =
113 		    test_run_vcpu(vcpu, &ventry, &vexit);
114 		if (kind == VEK_REENTR) {
115 			continue;
116 		} else if (kind != VEK_UNHANDLED) {
117 			test_fail_vmexit(&vexit);
118 		}
119 
120 		uint32_t v;
121 		if (vexit_match_inout(&vexit, false, IOP_TEST_VALUE, 4, &v)) {
122 			readings[nread].when = gethrtime();
123 			readings[nread].value = v;
124 
125 			ventry_fulfill_inout(&vexit, &ventry, 0);
126 
127 			nread++;
128 			if (nread != 2) {
129 				continue;
130 			}
131 
132 			if (check_reading(readings[0], readings[1],
133 			    margin_ticks, margin_ppm)) {
134 				test_pass();
135 			} else {
136 				nrepeat++;
137 				if (nrepeat < 3) {
138 					nread = 0;
139 					(void) printf("retry %u\n", nrepeat);
140 					continue;
141 				}
142 				test_fail_msg("bad result after %u retries\n",
143 				    nrepeat);
144 			}
145 		} else {
146 			test_fail_vmexit(&vexit);
147 		}
148 
149 	} while (true);
150 
151 	return (0);
152 }
153