xref: /dragonfly/sys/kern/subr_param.c (revision a1626531)
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_DEFAULT
54 #define	HZ_DEFAULT	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 (maxproc * 4)
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_mem;
87 long	nswbuf_kva;
88 long	nswbuf_raw;
89 long	maxswzone;			/* max swmeta KVA storage */
90 long	maxbcache;			/* max buffer cache KVA storage */
91 enum vmm_guest_type vmm_guest = VMM_GUEST_NONE;	/* Running as VM guest? */
92 u_quad_t	maxtsiz;			/* max text size */
93 u_quad_t	dfldsiz;			/* initial data size limit */
94 u_quad_t	maxdsiz;			/* max data size */
95 u_quad_t	dflssiz;			/* initial stack size limit */
96 u_quad_t	maxssiz;			/* max stack size */
97 u_quad_t	sgrowsiz;			/* amount to grow stack */
98 u_quad_t	maxthrssiz;			/* thread stack area */
99 
100 SYSCTL_PROC(_kern, OID_AUTO, vmm_guest, CTLFLAG_RD | CTLTYPE_STRING,
101 	    NULL, 0, sysctl_kern_vmm_guest, "A",
102 	    "Virtual machine guest type");
103 SYSCTL_QUAD(_kern, OID_AUTO, maxssiz, CTLFLAG_RD, &maxssiz, 0,
104 	    "Maximum user stack size");
105 SYSCTL_QUAD(_kern, OID_AUTO, maxthrssiz, CTLFLAG_RD, &maxthrssiz, 0,
106 	    "Nominal threading stack area");
107 
108 /*
109  * These have to be allocated somewhere; allocating
110  * them here forces loader errors if this file is omitted
111  * (if they've been externed everywhere else; hah!).
112  */
113 struct	buf *swbuf_mem;
114 struct	buf *swbuf_kva;
115 struct	buf *swbuf_raw;
116 
117 struct vmm_bname {
118 	const char *str;
119 	enum vmm_guest_type type;
120 };
121 
122 static struct vmm_bname vmm_bnames[] = {
123 	{ "QEMU",	VMM_GUEST_QEMU },	/* QEMU */
124 	{ "Plex86",	VMM_GUEST_PLEX86 },	/* Plex86 */
125 	{ "Bochs",	VMM_GUEST_BOCHS },	/* Bochs */
126 	{ "Xen",	VMM_GUEST_XEN },	/* Xen */
127 	{ "BHYVE",	VMM_GUEST_BHYVE },	/* bhyve */
128 	{ "Seabios",	VMM_GUEST_KVM},		/* KVM */
129 	{ NULL, 0 }
130 };
131 
132 static struct vmm_bname vmm_pnames[] = {
133 	{ "VMware Virtual Platform",	VMM_GUEST_VMWARE },	/* VMWare VM */
134 	{ "Virtual Machine",		VMM_GUEST_HYPERV },	/* MS Hyper-V */
135 	{ "VirtualBox",			VMM_GUEST_VBOX },	/* Sun VirtualBox */
136 	{ "Parallels Virtual Platform",	VMM_GUEST_PARALLELS },	/* Parallels VM */
137 	{ "KVM",			VMM_GUEST_KVM },	/* KVM */
138 	{ NULL, 0 }
139 };
140 
141 static const char *const vmm_guest_sysctl_names[] = {
142 	"none",
143 	"qemu",
144 	"plex86",
145 	"bochs",
146 	"xen",
147 	"bhyve",
148 	"kvm",
149 	"vmware",
150 	"hyperv",
151 	"vbox",
152 	"parallels",
153 	"vkernel",
154 	"unknown",
155 	NULL
156 };
157 CTASSERT(NELEM(vmm_guest_sysctl_names) - 1 == VMM_GUEST_LAST);
158 
159 char		vmm_vendor[16];
160 SYSCTL_STRING(_kern, OID_AUTO, vmm_vendor, CTLFLAG_RD, vmm_vendor, 0,
161     "Virtual machine vendor");
162 
163 /*
164  * Detect known Virtual Machine hosts by inspecting the emulated BIOS.
165  */
166 enum vmm_guest_type
167 detect_virtual(void)
168 {
169 	char *sysenv;
170 	int i;
171 
172 	sysenv = kgetenv("smbios.bios.vendor");
173 	if (sysenv != NULL) {
174 		for (i = 0; vmm_bnames[i].str != NULL; i++)
175 			if (strcmp(sysenv, vmm_bnames[i].str) == 0) {
176 				kfreeenv(sysenv);
177 				return (vmm_bnames[i].type);
178 			}
179 		kfreeenv(sysenv);
180 	}
181 	sysenv = kgetenv("smbios.system.product");
182 	if (sysenv != NULL) {
183 		for (i = 0; vmm_pnames[i].str != NULL; i++)
184 			if (strcmp(sysenv, vmm_pnames[i].str) == 0) {
185 				kfreeenv(sysenv);
186 				return (vmm_pnames[i].type);
187 			}
188 		kfreeenv(sysenv);
189 	}
190 	return (VMM_GUEST_NONE);
191 }
192 
193 /*
194  * Boot time overrides that are not scaled against main memory
195  */
196 void
197 init_param1(void)
198 {
199 	hz = HZ_DEFAULT;
200 	TUNABLE_INT_FETCH("kern.hz", &hz);
201 	stathz = hz + 1;
202 	TUNABLE_INT_FETCH("kern.stathz", &stathz);
203 	profhz = stathz;
204 	ustick = 1000000 / hz;
205 	nstick = 1000000000 / hz;
206 	/* can adjust 30ms in 60s */
207 	ntp_default_tick_delta = howmany(30000000, 60 * hz);
208 
209 #ifdef VM_SWZONE_SIZE_MAX
210 	maxswzone = VM_SWZONE_SIZE_MAX;
211 #endif
212 	TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone);
213 #ifdef VM_BCACHE_SIZE_MAX
214 	maxbcache = VM_BCACHE_SIZE_MAX;
215 #endif
216 	TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache);
217 	maxtsiz = MAXTSIZ;
218 	TUNABLE_QUAD_FETCH("kern.maxtsiz", &maxtsiz);
219 	dfldsiz = DFLDSIZ;
220 	TUNABLE_QUAD_FETCH("kern.dfldsiz", &dfldsiz);
221 	maxdsiz = MAXDSIZ;
222 	TUNABLE_QUAD_FETCH("kern.maxdsiz", &maxdsiz);
223 	dflssiz = DFLSSIZ;
224 	TUNABLE_QUAD_FETCH("kern.dflssiz", &dflssiz);
225 	maxssiz = MAXSSIZ;
226 	TUNABLE_QUAD_FETCH("kern.maxssiz", &maxssiz);
227 	sgrowsiz = SGROWSIZ;
228 	TUNABLE_QUAD_FETCH("kern.sgrowsiz", &sgrowsiz);
229 	maxthrssiz = MAXTHRSSIZ;
230 	TUNABLE_QUAD_FETCH("kern.maxthrssiz", &maxthrssiz);
231 }
232 
233 /*
234  * Boot time overrides that are scaled against main memory
235  */
236 void
237 init_param2(int physpages)
238 {
239 	size_t limsize;
240 
241 	/*
242 	 * Calculate manually becaus the VM page queues / system is not set
243 	 * up yet.
244 	 */
245 	limsize = (size_t)physpages * PAGE_SIZE;
246 	if (limsize > KvaSize)
247 		limsize = KvaSize;
248 	if (maxswzone > limsize / 2)	/* maxswzone size (1/2 of phys mem) */
249 		maxswzone = limsize / 2;
250 
251 	limsize /= 1024 * 1024;		/* smaller of KVM or physmem in MB */
252 
253 	/* Base parameters */
254 	maxusers = MAXUSERS;
255 	TUNABLE_INT_FETCH("kern.maxusers", &maxusers);
256 	if (maxusers == 0) {
257 		maxusers = limsize / 8;		/* ~384 per 3G */
258 		if (maxusers < 32)
259 			maxusers = 32;
260 		/* no upper limit */
261 	}
262 
263 	/*
264 	 * The following can be overridden after boot via sysctl.  Note:
265 	 * unless overridden, these macros are ultimately based on maxusers.
266 	 *
267 	 * Limit maxproc so that kmap entries cannot be exhausted by
268 	 * processes.  This limitation can be a bit problematic because
269 	 * processes can have a wide range of complexity.
270 	 */
271 	maxproc = NPROC;
272 	TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
273 	if (maxproc < 32)
274 		maxproc = 32;
275 	if (maxproc > limsize * 40)
276 		maxproc = limsize * 40;
277 
278 	/*
279 	 * Maximum number of open files
280 	 */
281 	maxfiles = MAXFILES;
282 	TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
283 	if (maxfiles < 128)
284 		maxfiles = 128;
285 
286 	/*
287 	 * Limit file descriptors so no single user can exhaust the
288 	 * system.
289 	 *
290 	 * WARNING: Do not set minfilesperproc too high or the user
291 	 *	    can exhaust the system with a combination of fork()
292 	 *	    and open().  Actual worst case is:
293 	 *
294 	 *	    (minfilesperproc * maxprocperuid) + maxfilesperuser
295 	 */
296 	maxprocperuid = maxproc / 4;
297 	if (maxprocperuid < 128)
298 		maxprocperuid = maxproc / 2;
299 	minfilesperproc = 8;
300 	maxfilesperproc = maxfiles / 4;
301 	maxfilesperuser = maxfilesperproc * 2;
302 	maxfilesrootres = maxfiles / 20;
303 
304 	/*
305 	 * Severe hack to try to prevent pipe() descriptors from
306 	 * blowing away kernel memory.
307 	 */
308 	if (KvaSize <= (vm_offset_t)(1536LL * 1024 * 1024) &&
309 	    maxfilesperuser > 20000) {
310 		maxfilesperuser = 20000;
311 	}
312 
313 	maxposixlocksperuid = MAXPOSIXLOCKSPERUID;
314 	TUNABLE_INT_FETCH("kern.maxposixlocksperuid", &maxposixlocksperuid);
315 
316 	/*
317 	 * Unless overridden, NBUF is typically 0 (auto-sized later).
318 	 */
319 	nbuf = NBUF;
320 	TUNABLE_LONG_FETCH("kern.nbuf", &nbuf);
321 
322 	/*
323 	 * Calculate the size of the callout wheel.  Limit to approximately
324 	 * 5 minutes worth of table (maxproc would have to be pretty huge),
325 	 * as more is not likely to gain us anything.
326 	 */
327 	ncallout = 16 + maxproc + maxfiles;
328 	if (ncallout > 5*60*hz)
329 		ncallout = 5*60*hz;
330 	TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
331 }
332 
333 /*
334  * Sysctl stringifying handler for kern.vmm_guest.
335  */
336 static int
337 sysctl_kern_vmm_guest(SYSCTL_HANDLER_ARGS)
338 {
339 	return (SYSCTL_OUT(req, vmm_guest_sysctl_names[vmm_guest],
340 	    strlen(vmm_guest_sysctl_names[vmm_guest])));
341 }
342