xref: /illumos-gate/usr/src/test/bhyve-tests/tests/vmm/datarw_msrs.c (revision 1a2d662a91cee3bf82f41cd47c7ae6f3825d9db2)
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 2023 Oxide Computer Company
14  */
15 
16 #include <stdio.h>
17 #include <unistd.h>
18 #include <stdlib.h>
19 #include <fcntl.h>
20 #include <libgen.h>
21 #include <sys/stat.h>
22 #include <errno.h>
23 #include <err.h>
24 #include <assert.h>
25 #include <sys/sysmacros.h>
26 #include <stdbool.h>
27 
28 #include <sys/vmm.h>
29 #include <sys/vmm_dev.h>
30 #include <sys/vmm_data.h>
31 #include <vmmapi.h>
32 #include <sys/x86_archext.h>
33 #include <sys/controlregs.h>
34 
35 #include "common.h"
36 
37 static void
38 do_data_write(int vmfd, struct vm_data_xfer *vdx)
39 {
40 	if (ioctl(vmfd, VM_DATA_WRITE, vdx) != 0) {
41 		err(EXIT_FAILURE, "valid vmm_data_write failed");
42 	}
43 	if (vdx->vdx_result_len != vdx->vdx_len) {
44 		errx(EXIT_FAILURE, "unexpected vdx_result_len %u != %u",
45 		    vdx->vdx_len, vdx->vdx_result_len);
46 	}
47 }
48 
49 static void
50 do_data_read(int vmfd, struct vm_data_xfer *vdx)
51 {
52 	if (ioctl(vmfd, VM_DATA_READ, vdx) != 0) {
53 		err(EXIT_FAILURE, "valid vmm_data_read failed");
54 	}
55 	if (vdx->vdx_result_len != vdx->vdx_len) {
56 		errx(EXIT_FAILURE, "unexpected vdx_result_len %u != %u",
57 		    vdx->vdx_len, vdx->vdx_result_len);
58 	}
59 }
60 
61 static uint32_t
62 query_data_size(int vmfd, struct vm_data_xfer *vdx)
63 {
64 	vdx->vdx_len = 0;
65 	vdx->vdx_data = NULL;
66 	vdx->vdx_flags = 0;
67 
68 	if (ioctl(vmfd, VM_DATA_READ, vdx) == 0) {
69 		errx(EXIT_FAILURE,
70 		    "expected VM_DATA_READ to fail for size query");
71 	}
72 	if (errno != ENOSPC) {
73 		err(EXIT_FAILURE,
74 		    "expected ENOSPC error for VM_DATA_READ size query");
75 	}
76 	return (vdx->vdx_result_len);
77 }
78 
79 int
80 main(int argc, char *argv[])
81 {
82 	const char *suite_name = basename(argv[0]);
83 	struct vmctx *ctx;
84 	struct vcpu *vcpu;
85 
86 	ctx = create_test_vm(suite_name);
87 	if (ctx == NULL) {
88 		errx(EXIT_FAILURE, "could not open test VM");
89 	}
90 
91 	if ((vcpu = vm_vcpu_open(ctx, 0)) == NULL) {
92 		err(EXIT_FAILURE, "could not open vcpu0");
93 	}
94 
95 	if (vm_activate_cpu(vcpu) != 0) {
96 		err(EXIT_FAILURE, "could not activate vcpu0");
97 	}
98 
99 	const int vmfd = vm_get_device_fd(ctx);
100 
101 	/* Pause the instance before attempting to manipulate vcpu data */
102 	if (ioctl(vmfd, VM_PAUSE, 0) != 0) {
103 		err(EXIT_FAILURE, "VM_PAUSE failed");
104 	}
105 
106 	struct vm_data_xfer vdx = {
107 		.vdx_class = VDC_MSR,
108 		.vdx_version = 1,
109 		.vdx_vcpuid = 0,
110 	};
111 
112 	const uint32_t msr_sz = query_data_size(vmfd, &vdx);
113 	const uint32_t msr_count = msr_sz / sizeof (struct vdi_field_entry_v1);
114 
115 	struct vdi_field_entry_v1 *entries =
116 	    calloc(msr_count, sizeof (struct vdi_field_entry_v1));
117 	if (entries == NULL) {
118 		err(EXIT_FAILURE, "could not allocate space for MSR data");
119 	}
120 
121 	/* Attempt to read all the (default) entries */
122 	vdx.vdx_data = entries;
123 	vdx.vdx_len = msr_sz;
124 	do_data_read(vmfd, &vdx);
125 
126 	/* Spot check a few MSRs which we expect to be present */
127 	struct expected_msr {
128 		const char *name;
129 		uint32_t msr;
130 		bool present;
131 	} spot_check[] = {
132 		{ .msr = MSR_AMD_EFER, .name = "EFER" },
133 		{ .msr = REG_TSC, .name = "TSC" },
134 		{ .msr = MSR_AMD_CSTAR, .name = "CSTAR" },
135 		{ .msr = MSR_AMD_KGSBASE, .name = "KGSBASE" },
136 	};
137 	for (uint_t i = 0; i < msr_count; i++) {
138 		for (uint_t j = 0; j < ARRAY_SIZE(spot_check); j++) {
139 			if (spot_check[j].msr == entries[i].vfe_ident) {
140 				spot_check[j].present = true;
141 			}
142 		}
143 	}
144 	for (uint_t j = 0; j < ARRAY_SIZE(spot_check); j++) {
145 		if (!spot_check[j].present) {
146 			errx(EXIT_FAILURE,
147 			    "did not find %s(%x) MSR in VM_DATA_READ results",
148 			    spot_check[j].name, spot_check[j].msr);
149 		}
150 	}
151 
152 	/* Attempt to write those same values back to the instance */
153 	do_data_write(vmfd, &vdx);
154 	free(entries);
155 	entries = NULL;
156 
157 	/* Do a targeted read of a few values */
158 	struct vdi_field_entry_v1 small_list[] = {
159 		{ .vfe_ident = REG_TSC },
160 		{ .vfe_ident = MSR_INTC_SEP_EIP },
161 		{ .vfe_ident = REG_PAT },
162 	};
163 	vdx.vdx_data = small_list;
164 	vdx.vdx_len = sizeof (small_list);
165 	vdx.vdx_flags = VDX_FLAG_READ_COPYIN;
166 	do_data_read(vmfd, &vdx);
167 
168 	/*
169 	 * Test access to DEBUGCTL and LBR-related MSRs on AMD.
170 	 *
171 	 * Because support for these varies between CPUs, they are (currently)
172 	 * not included in the default set of MSRs emitted by a blanket read of
173 	 * MSRs via the vmm-data interface.
174 	 */
175 	if (cpu_vendor_amd()) {
176 		struct vdi_field_entry_v1 dbg_entries[] = {
177 			{ .vfe_ident = MSR_DEBUGCTL },
178 			{ .vfe_ident = MSR_LBR_FROM },
179 			{ .vfe_ident = MSR_LBR_TO },
180 			{ .vfe_ident = MSR_LEX_FROM },
181 			{ .vfe_ident = MSR_LEX_TO },
182 		};
183 
184 		vdx.vdx_data = &dbg_entries;
185 		vdx.vdx_len = sizeof (dbg_entries);
186 		vdx.vdx_flags = VDX_FLAG_READ_COPYIN;
187 
188 		do_data_read(vmfd, &vdx);
189 
190 		vdx.vdx_flags = 0;
191 		do_data_write(vmfd, &vdx);
192 	}
193 
194 
195 	vm_destroy(ctx);
196 	(void) printf("%s\tPASS\n", suite_name);
197 	return (EXIT_SUCCESS);
198 }
199