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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 $
38 #include "opt_param.h"
39 #include "opt_maxusers.h"
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>
47 #include <machine/vmparam.h>
50 * System parameter formulae.
54 #define HZ_DEFAULT 100
56 #define NPROC (20 + 16 * maxusers)
61 #define MAXFILES (maxproc * 16)
63 #ifndef MAXPOSIXLOCKSPERUID
64 #define MAXPOSIXLOCKSPERUID (maxproc * 4)
67 static int sysctl_kern_vmm_guest(SYSCTL_HANDLER_ARGS);
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 */
88 long maxswzone; /* max swmeta KVA storage */
89 long maxbcache; /* max buffer cache KVA storage */
90 enum vmm_guest_type vmm_guest = VMM_GUEST_NONE; /* Running as VM guest? */
91 u_quad_t maxtsiz; /* max text size */
92 u_quad_t dfldsiz; /* initial data size limit */
93 u_quad_t maxdsiz; /* max data size */
94 u_quad_t dflssiz; /* initial stack size limit */
95 u_quad_t maxssiz; /* max stack size */
96 u_quad_t sgrowsiz; /* amount to grow stack */
97 u_quad_t maxthrssiz; /* thread stack area */
99 SYSCTL_PROC(_kern, OID_AUTO, vmm_guest, CTLFLAG_RD | CTLTYPE_STRING,
100 NULL, 0, sysctl_kern_vmm_guest, "A",
101 "Virtual machine guest type");
102 SYSCTL_QUAD(_kern, OID_AUTO, maxssiz, CTLFLAG_RD, &maxssiz, 0,
103 "Maximum user stack size");
104 SYSCTL_QUAD(_kern, OID_AUTO, maxthrssiz, CTLFLAG_RD, &maxthrssiz, 0,
105 "Nominal threading stack area");
108 * These have to be allocated somewhere; allocating
109 * them here forces loader errors if this file is omitted
110 * (if they've been externed everywhere else; hah!).
112 struct buf *swbuf_mem;
113 struct buf *swbuf_kva;
114 struct buf *swbuf_raw;
118 enum vmm_guest_type type;
121 static struct vmm_bname vmm_bnames[] = {
122 { "QEMU", VMM_GUEST_QEMU }, /* QEMU */
123 { "Plex86", VMM_GUEST_PLEX86 }, /* Plex86 */
124 { "Bochs", VMM_GUEST_BOCHS }, /* Bochs */
125 { "Xen", VMM_GUEST_XEN }, /* Xen */
126 { "BHYVE", VMM_GUEST_BHYVE }, /* bhyve */
127 { "Seabios", VMM_GUEST_KVM}, /* KVM */
131 static struct vmm_bname vmm_pnames[] = {
132 { "VMware Virtual Platform", VMM_GUEST_VMWARE }, /* VMWare VM */
133 { "Virtual Machine", VMM_GUEST_HYPERV }, /* MS Hyper-V */
134 { "VirtualBox", VMM_GUEST_VBOX }, /* Sun VirtualBox */
135 { "Parallels Virtual Platform", VMM_GUEST_PARALLELS }, /* Parallels VM */
136 { "KVM", VMM_GUEST_KVM }, /* KVM */
140 static const char *const vmm_guest_sysctl_names[] = {
157 CTASSERT(NELEM(vmm_guest_sysctl_names) - 1 == VMM_GUEST_LAST);
160 SYSCTL_STRING(_kern, OID_AUTO, vmm_vendor, CTLFLAG_RD, vmm_vendor, 0,
161 "Virtual machine vendor");
164 * Detect known Virtual Machine hosts by inspecting the emulated BIOS.
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) {
177 return (vmm_bnames[i].type);
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) {
186 return (vmm_pnames[i].type);
190 return (VMM_GUEST_NONE);
194 * Boot time overrides that are not scaled against main memory
200 TUNABLE_INT_FETCH("kern.hz", &hz);
202 TUNABLE_INT_FETCH("kern.stathz", &stathz);
204 ustick = 1000000 / hz;
205 nstick = 1000000000 / hz;
206 /* can adjust 30ms in 60s */
207 ntp_default_tick_delta = howmany(30000000, 60 * hz);
209 #ifdef VM_SWZONE_SIZE_MAX
210 maxswzone = VM_SWZONE_SIZE_MAX;
212 TUNABLE_LONG_FETCH("kern.maxswzone", &maxswzone);
213 #ifdef VM_BCACHE_SIZE_MAX
214 maxbcache = VM_BCACHE_SIZE_MAX;
216 TUNABLE_LONG_FETCH("kern.maxbcache", &maxbcache);
218 TUNABLE_QUAD_FETCH("kern.maxtsiz", &maxtsiz);
220 TUNABLE_QUAD_FETCH("kern.dfldsiz", &dfldsiz);
222 TUNABLE_QUAD_FETCH("kern.maxdsiz", &maxdsiz);
224 TUNABLE_QUAD_FETCH("kern.dflssiz", &dflssiz);
226 TUNABLE_QUAD_FETCH("kern.maxssiz", &maxssiz);
228 TUNABLE_QUAD_FETCH("kern.sgrowsiz", &sgrowsiz);
229 maxthrssiz = MAXTHRSSIZ;
230 TUNABLE_QUAD_FETCH("kern.maxthrssiz", &maxthrssiz);
234 * Boot time overrides that are scaled against main memory
237 init_param2(int physpages)
242 * Calculate manually becaus the VM page queues / system is not set
245 limsize = (size_t)physpages * PAGE_SIZE;
246 if (limsize > KvaSize)
248 if (maxswzone > limsize / 2) /* maxswzone size (1/2 of phys mem) */
249 maxswzone = limsize / 2;
251 limsize /= 1024 * 1024; /* smaller of KVM or physmem in MB */
253 /* Base parameters */
255 TUNABLE_INT_FETCH("kern.maxusers", &maxusers);
257 maxusers = limsize / 8; /* ~384 per 3G */
264 * The following can be overridden after boot via sysctl. Note:
265 * unless overridden, these macros are ultimately based on maxusers.
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.
272 TUNABLE_INT_FETCH("kern.maxproc", &maxproc);
275 if (maxproc > limsize * 40)
276 maxproc = limsize * 40;
279 * Maximum number of open files
282 TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
287 * Limit file descriptors so no single user can exhaust the
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:
294 * (minfilesperproc * maxprocperuid) + maxfilesperuser
296 maxprocperuid = maxproc / 4;
297 if (maxprocperuid < 128)
298 maxprocperuid = maxproc / 2;
300 maxfilesperproc = maxfiles / 4;
301 maxfilesperuser = maxfilesperproc * 2;
302 maxfilesrootres = maxfiles / 20;
305 * Severe hack to try to prevent pipe() descriptors from
306 * blowing away kernel memory.
308 if (KvaSize <= (vm_offset_t)(1536LL * 1024 * 1024) &&
309 maxfilesperuser > 20000) {
310 maxfilesperuser = 20000;
313 maxposixlocksperuid = MAXPOSIXLOCKSPERUID;
314 TUNABLE_INT_FETCH("kern.maxposixlocksperuid", &maxposixlocksperuid);
317 * Unless overridden, NBUF is typically 0 (auto-sized later).
320 TUNABLE_LONG_FETCH("kern.nbuf", &nbuf);
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.
327 ncallout = 16 + maxproc + maxfiles;
328 if (ncallout > 5*60*hz)
330 TUNABLE_INT_FETCH("kern.ncallout", &ncallout);
334 * Sysctl stringifying handler for kern.vmm_guest.
337 sysctl_kern_vmm_guest(SYSCTL_HANDLER_ARGS)
339 return (SYSCTL_OUT(req, vmm_guest_sysctl_names[vmm_guest],
340 strlen(vmm_guest_sysctl_names[vmm_guest])));