sys/kern/subr_param.c

   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 }