xref: /dragonfly/sys/kern/subr_param.c (revision cfd1aba3)
1 /*
2  * Copyright (c) 1980, 1986, 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * (c) UNIX System Laboratories, Inc.
5  * All or some portions of this file are derived from material licensed
6  * to the University of California by American Telephone and Telegraph
7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8  * the permission of UNIX System Laboratories, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)param.c	8.3 (Berkeley) 8/20/94
35  * $FreeBSD: src/sys/kern/subr_param.c,v 1.42.2.10 2002/03/09 21:05:47 silby Exp $
36  */
37 
38 #include "opt_param.h"
39 #include "opt_maxusers.h"
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/malloc.h>
45 #include <sys/sysctl.h>
46 #include <vm/pmap.h>
47 #include <machine/vmparam.h>
48 
49 /*
50  * System parameter formulae.
51  */
52 
53 #ifndef HZ
54 #define	HZ 100
55 #endif
56 #define	NPROC (20 + 16 * maxusers)
57 #ifndef NBUF
58 #define NBUF 0
59 #endif
60 #ifndef MAXFILES
61 #define	MAXFILES (maxproc * 16)
62 #endif
63 #ifndef MAXPOSIXLOCKSPERUID
64 #define MAXPOSIXLOCKSPERUID (maxusers * 64) /* Should be a safe value */
65 #endif
66 
67 static int sysctl_kern_vmm_guest(SYSCTL_HANDLER_ARGS);
68 
69 int	hz;
70 int	stathz;
71 int	profhz;
72 int	ustick;				/* tick interval in microseconds */
73 int	nstick;				/* tick interval in nanoseconds */
74 int	maxusers;			/* base tunable */
75 int	maxproc;			/* maximum # of processes */
76 int	maxprocperuid;			/* max # of procs per user */
77 int	maxfiles;			/* system wide open files limit */
78 int	maxfilesrootres;		/* descriptors reserved for root use */
79 int	minfilesperproc;		/* per-proc min open files (safety) */
80 int	maxfilesperproc;		/* per-proc open files limit */
81 int	maxfilesperuser;		/* per-user open files limit */
82 int	maxposixlocksperuid;		/* max # POSIX locks per uid */
83 int	ncallout;			/* maximum # of timer events */
84 int	mbuf_wait = 32;			/* mbuf sleep time in ticks */
85 long	nbuf;
86 long	nswbuf;
87 long	maxswzone;			/* max swmeta KVA storage */
88 long	maxbcache;			/* max buffer cache KVA storage */
89 enum vmm_guest_type vmm_guest = VMM_GUEST_NONE;	/* Running as VM guest? */
90 u_quad_t	maxtsiz;			/* max text size */
91 u_quad_t	dfldsiz;			/* initial data size limit */
92 u_quad_t	maxdsiz;			/* max data size */
93 u_quad_t	dflssiz;			/* initial stack size limit */
94 u_quad_t	maxssiz;			/* max stack size */
95 u_quad_t	sgrowsiz;			/* amount to grow stack */
96 
97 SYSCTL_PROC(_kern, OID_AUTO, vmm_guest, CTLFLAG_RD | CTLTYPE_STRING,
98     NULL, 0, sysctl_kern_vmm_guest, "A",
99     "Virtual machine guest type");
100 
101 /*
102  * These have to be allocated somewhere; allocating
103  * them here forces loader errors if this file is omitted
104  * (if they've been externed everywhere else; hah!).
105  */
106 struct	buf *swbuf;
107 
108 struct vmm_bname {
109 	const char *str;
110 	enum vmm_guest_type type;
111 };
112 
113 static struct vmm_bname vmm_bnames[] = {
114 	{ "QEMU",	VMM_GUEST_QEMU },	/* QEMU */
115 	{ "Plex86",	VMM_GUEST_PLEX86 },	/* Plex86 */
116 	{ "Bochs",	VMM_GUEST_BOCHS },	/* Bochs */
117 	{ "Xen",	VMM_GUEST_XEN },	/* Xen */
118 	{ "BHYVE",	VMM_GUEST_BHYVE },	/* bhyve */
119 	{ "Seabios",	VMM_GUEST_KVM},		/* KVM */
120 	{ NULL, 0 }
121 };
122 
123 static struct vmm_bname vmm_pnames[] = {
124 	{ "VMware Virtual Platform",	VMM_GUEST_VMWARE },	/* VMWare VM */
125 	{ "Virtual Machine",		VMM_GUEST_VPC },	/* M$ VirtualPC */
126 	{ "VirtualBox",			VMM_GUEST_VBOX },	/* Sun VirtualBox */
127 	{ "Parallels Virtual Platform",	VMM_GUEST_PARALLELS },	/* Parallels VM */
128 	{ "KVM",			VMM_GUEST_KVM },	/* KVM */
129 	{ NULL, 0 }
130 };
131 
132 static const char *const vmm_guest_sysctl_names[] = {
133 	"none",
134 	"qemu",
135 	"plex86",
136 	"bochs",
137 	"xen",
138 	"bhyve",
139 	"kvm",
140 	"vmware",
141 	"vpc",
142 	"vbox",
143 	"parallels",
144 	"vkernel",
145 	"unknown",
146 	NULL
147 };
148 CTASSERT(NELEM(vmm_guest_sysctl_names) - 1 == VMM_GUEST_LAST);
149 
150 /*
151  * Detect known Virtual Machine hosts by inspecting the emulated BIOS.
152  */
153 enum vmm_guest_type
154 detect_virtual(void)
155 {
156 	char *sysenv;
157 	int i;
158 
159 	sysenv = kgetenv("smbios.bios.vendor");
160 	if (sysenv != NULL) {
161 		for (i = 0; vmm_bnames[i].str != NULL; i++)
162 			if (strcmp(sysenv, vmm_bnames[i].str) == 0) {
163 				kfreeenv(sysenv);
164 				return (vmm_bnames[i].type);
165 			}
166 		kfreeenv(sysenv);
167 	}
168 	sysenv = kgetenv("smbios.system.product");
169 	if (sysenv != NULL) {
170 		for (i = 0; vmm_pnames[i].str != NULL; i++)
171 			if (strcmp(sysenv, vmm_pnames[i].str) == 0) {
172 				kfreeenv(sysenv);
173 				return (vmm_pnames[i].type);
174 			}
175 		kfreeenv(sysenv);
176 	}
177 	return (VMM_GUEST_NONE);
178 }
179 
180 /*
181  * Boot time overrides that are not scaled against main memory
182  */
183 void
184 init_param1(void)
185 {
186 	hz = HZ;
187 	TUNABLE_INT_FETCH("kern.hz", &hz);
188 	stathz = hz * 128 / 100;
189 	profhz = stathz;
190 	ustick = 1000000 / hz;
191 	nstick = 1000000000 / hz;
192 	/* can adjust 30ms in 60s */
193 	ntp_default_tick_delta = howmany(30000000, 60 * hz);
194 
195 #ifdef VM_SWZONE_SIZE_MAX
196 	maxswzone = VM_SWZONE_SIZE_MAX;
197 #endif
198 	TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone);
199 #ifdef VM_BCACHE_SIZE_MAX
200 	maxbcache = VM_BCACHE_SIZE_MAX;
201 #endif
202 	TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache);
203 	maxtsiz = MAXTSIZ;
204 	TUNABLE_QUAD_FETCH("kern.maxtsiz", &maxtsiz);
205 	dfldsiz = DFLDSIZ;
206 	TUNABLE_QUAD_FETCH("kern.dfldsiz", &dfldsiz);
207 	maxdsiz = MAXDSIZ;
208 	TUNABLE_QUAD_FETCH("kern.maxdsiz", &maxdsiz);
209 	dflssiz = DFLSSIZ;
210 	TUNABLE_QUAD_FETCH("kern.dflssiz", &dflssiz);
211 	maxssiz = MAXSSIZ;
212 	TUNABLE_QUAD_FETCH("kern.maxssiz", &maxssiz);
213 	sgrowsiz = SGROWSIZ;
214 	TUNABLE_QUAD_FETCH("kern.sgrowsiz", &sgrowsiz);
215 }
216 
217 /*
218  * Boot time overrides that are scaled against main memory
219  */
220 void
221 init_param2(int physpages)
222 {
223 	size_t limsize;
224 
225 	/*
226 	 * Calculate manually becaus the VM page queues / system is not set up yet
227 	 */
228 	limsize = (size_t)physpages * PAGE_SIZE;
229 	if (limsize > KvaSize)
230 		limsize = KvaSize;
231 	limsize /= 1024 * 1024;		/* smaller of KVM or physmem in MB */
232 
233 	/* Base parameters */
234 	maxusers = MAXUSERS;
235 	TUNABLE_INT_FETCH("kern.maxusers", &maxusers);
236 	if (maxusers == 0) {
237 		maxusers = limsize / 8;		/* ~384 per 3G */
238 		if (maxusers < 32)
239 			maxusers = 32;
240 		/* no upper limit */
241 	}
242 
243 	/*
244 	 * The following can be overridden after boot via sysctl.  Note:
245 	 * unless overriden, these macros are ultimately based on maxusers.
246 	 *
247 	 * Limit maxproc so that kmap entries cannot be exhausted by
248 	 * processes.
249 	 */
250 	maxproc = NPROC;
251 	TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
252 	if (maxproc < 32)
253 		maxproc = 32;
254 	if (maxproc > limsize * 21)
255 		maxproc = limsize * 21;
256 
257 	/*
258 	 * Maximum number of open files
259 	 */
260 	maxfiles = MAXFILES;
261 	TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
262 	if (maxfiles < 128)
263 		maxfiles = 128;
264 
265 	/*
266 	 * Limit file descriptors so no single user can exhaust the
267 	 * system.
268 	 *
269 	 * WARNING: Do not set minfilesperproc too high or the user
270 	 *	    can exhaust the system with a combination of fork()
271 	 *	    and open().  Actual worst case is:
272 	 *
273 	 *	    (minfilesperproc * maxprocperuid) + maxfilesperuser
274 	 */
275 	maxprocperuid = maxproc / 4;
276 	if (maxprocperuid < 128)
277 		maxprocperuid = maxproc / 2;
278 	minfilesperproc = 8;
279 	maxfilesperproc = maxfiles / 4;
280 	maxfilesperuser = maxfilesperproc * 2;
281 	maxfilesrootres = maxfiles / 20;
282 
283 	/*
284 	 * Severe hack to try to prevent pipe() descriptors from
285 	 * blowing away kernel memory.
286 	 */
287 	if (KvaSize <= (vm_offset_t)(1536LL * 1024 * 1024) &&
288 	    maxfilesperuser > 20000) {
289 		maxfilesperuser = 20000;
290 	}
291 
292 	maxposixlocksperuid = MAXPOSIXLOCKSPERUID;
293 	TUNABLE_INT_FETCH("kern.maxposixlocksperuid", &maxposixlocksperuid);
294 
295 	/*
296 	 * Unless overriden, NBUF is typically 0 (auto-sized later).
297 	 */
298 	nbuf = NBUF;
299 	TUNABLE_LONG_FETCH("kern.nbuf", &nbuf);
300 
301 	ncallout = 16 + maxproc + maxfiles;
302 	TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
303 }
304 
305 /*
306  * Sysctl stringifying handler for kern.vmm_guest.
307  */
308 static int
309 sysctl_kern_vmm_guest(SYSCTL_HANDLER_ARGS)
310 {
311 	return (SYSCTL_OUT(req, vmm_guest_sysctl_names[vmm_guest],
312 	    strlen(vmm_guest_sysctl_names[vmm_guest])));
313 }
314