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-rw-r--r--share/man/man4/Makefile7
-rw-r--r--share/man/man4/dtrace_callout_execute.468
-rw-r--r--share/man/man4/dtrace_fbt.4323
-rw-r--r--share/man/man4/dtrace_vfs.497
-rw-r--r--share/man/man4/geom_zero.4174
-rw-r--r--share/man/man4/gif.420
-rw-r--r--share/man/man4/tty.41
-rw-r--r--share/man/man4/xen.474
-rw-r--r--share/man/man4/zero.43
9 files changed, 723 insertions, 44 deletions
diff --git a/share/man/man4/Makefile b/share/man/man4/Makefile
index 8802e5fc35d6..5ea51eb02eb0 100644
--- a/share/man/man4/Makefile
+++ b/share/man/man4/Makefile
@@ -172,6 +172,7 @@ MAN= aac.4 \
geom_linux_lvm.4 \
geom_map.4 \
geom_uzip.4 \
+ geom_zero.4 \
gif.4 \
${_gve.4} \
gpio.4 \
@@ -960,6 +961,8 @@ _ccd.4= ccd.4
.if ${MK_CDDL} != "no"
_dtrace_provs= dtrace_audit.4 \
+ dtrace_callout_execute.4 \
+ dtrace_fbt.4 \
dtrace_io.4 \
dtrace_ip.4 \
dtrace_lockstat.4 \
@@ -968,7 +971,8 @@ _dtrace_provs= dtrace_audit.4 \
dtrace_sctp.4 \
dtrace_tcp.4 \
dtrace_udp.4 \
- dtrace_udplite.4
+ dtrace_udplite.4 \
+ dtrace_vfs.4
MLINKS+= dtrace_audit.4 dtaudit.4
.endif
@@ -1065,6 +1069,7 @@ MAN+= \
uvscom.4 \
zyd.4
+MLINKS+=geom_zero.4 gzero.4
MLINKS+=otus.4 if_otus.4
MLINKS+=rsu.4 if_rsu.4
MLINKS+=rtwn_usb.4 if_rtwn_usb.4
diff --git a/share/man/man4/dtrace_callout_execute.4 b/share/man/man4/dtrace_callout_execute.4
new file mode 100644
index 000000000000..1154ed066b97
--- /dev/null
+++ b/share/man/man4/dtrace_callout_execute.4
@@ -0,0 +1,68 @@
+.\"
+.\" Copyright (c) 2025 Mateusz Piotrowski <0mp@FreeBSD.org>
+.\"
+.\" SPDX-License-Identifier: BSD-2-Clause
+.\"
+.Dd November 4, 2025
+.Dt DTRACE_CALLOUT_EXECUTE 4
+.Os
+.Sh NAME
+.Nm dtrace_callout_execute
+.Nd a DTrace provider for the callout API
+.Sh SYNOPSIS
+.Nm callout_execute Ns Cm :kernel::callout_start
+.Nm callout_execute Ns Cm :kernel::callout_end
+.Sh DESCRIPTION
+The
+.Nm callout_execute
+provider allows for tracing the
+.Xr callout 9
+mechanism.
+.Pp
+The
+.Nm callout_execute Ns Cm :kernel::callout_start
+probe fires just before a callout.
+.Pp
+The
+.Nm callout_execute Ns Cm :kernel::callout_end
+probe fires right after a callout.
+.Pp
+The only argument to the
+.Nm callout_execute
+probes,
+.Fa args[0] ,
+is a callout handler
+.Ft struct callout *
+of the invoked callout.
+.Sh EXAMPLES
+.Ss Example 1: Graph of Callout Execution Time
+The following
+.Xr d 7
+script generates a distribution graph of
+.Xr callout 9
+execution times:
+.Bd -literal -offset 2n
+callout_execute:::callout_start
+{
+ self->cstart = timestamp;
+}
+
+callout_execute:::callout_end
+{
+ @length = quantize(timestamp - self->cstart);
+}
+.Ed
+.Sh SEE ALSO
+.Xr dtrace 1 ,
+.Xr tracing 7 ,
+.Xr callout 9 ,
+.Xr SDT 9
+.Sh AUTHORS
+.An -nosplit
+The
+.Nm callout_execute
+provider was written by
+.An Robert N. M. Watson Aq Mt rwatson@FreeBSD.org .
+.Pp
+This manual page was written by
+.An Mateusz Piotrowski Aq Mt 0mp@FreeBSD.org .
diff --git a/share/man/man4/dtrace_fbt.4 b/share/man/man4/dtrace_fbt.4
new file mode 100644
index 000000000000..fc55846f2d0b
--- /dev/null
+++ b/share/man/man4/dtrace_fbt.4
@@ -0,0 +1,323 @@
+.\"
+.\" SPDX-License-Identifier: BSD-2-Clause
+.\"
+.\" Copyright (c) 2025 Mateusz Piotrowski <0mp@FreeBSD.org>
+.\"
+.Dd July 16, 2025
+.Dt DTRACE_FBT 4
+.Os
+.Sh NAME
+.Nm dtrace_fbt
+.Nd a DTrace provider for dynamic kernel tracing based on function boundaries
+.Sh SYNOPSIS
+.Nm fbt Ns Cm \&: Ns Ar module Ns Cm \&: Ns Ar function Ns Cm \&:entry
+.Nm fbt Ns Cm \&: Ns Ar module Ns Cm \&: Ns Ar function Ns Cm \&:return
+.Sh DESCRIPTION
+The Function Boundary Tracing
+.Pq Nm fbt
+provider instruments the entry and return of almost every kernel function
+corresponding to an
+.Xr elf 5
+symbol in the kernel and loaded kernel modules.
+.Pp
+.Nm fbt Ns Cm \&: Ns Ar module Ns Cm \&: Ns Ar function Ns Cm \&:entry
+fires whenever the
+.Ar function
+is called.
+.Nm fbt Ns Cm \&: Ns Ar module Ns Cm \&: Ns Ar function Ns Cm \&:return
+fires when the
+.Ar function
+returns.
+.Pp
+The
+.Ar module
+in the probe description is either the name of the loaded kernel module
+or
+.Ql kernel
+for functions compiled into the kernel.
+.Ss Function Boundary Instrumentation
+The
+.Nm fbt
+will always instrument a function's entry, but
+its return will be intsrumented so long as it can find a
+.Ql ret
+instruction.
+.Pp
+In some cases,
+.Nm fbt
+cannot instrument a function's entry and/or return.
+Refer to subsection
+.Sx Frame Pointer
+for more details.
+.Ss Probe Arguments
+The arguments of the entry probe
+.Pq Nm fbt Ns Cm \&: Ns Ar module Ns Cm \&: Ns Ar function Ns Cm \&:entry
+are the arguments of the traced function call.
+.Bl -column -offset indent "Entry Probe Argument" "Definition"
+.It Sy Entry Probe Argument Ta Sy Definition
+.It Fa args[0] Ta Function's first argument, typed
+.Pq e.g., Xr malloc 9 Ap s Ft size_t Fa size
+.It Fa args[1] Ta Function's second argument, typed
+.Pq e.g., Xr malloc 9 Ap s Ft struct malloc_type Fa *type
+.It Fa args[2] Ta Function's third argument, typed
+.Pq e.g., Xr malloc 9 Ap s Ft int Fa flags
+.It Fa ... Ta ...
+.El
+.Pp
+The arguments of the return probe
+.Pq Nm fbt Ns Cm \&: Ns Ar module Ns Cm \&: Ns Ar function Ns Cm \&:return
+are
+.Fa args[0]
+.Po
+the offset of the firing return instruction within the function;
+useful to tell apart two different return statements in a single function
+.Pc
+and
+.Fa args[1]
+.Pq the return value, if any .
+.Bl -column -offset indent "Return Probe Argument" "Definition"
+.It Sy Return Probe Argument Ta Sy Definition
+.It Fa args[0] Ta Offset of the traced return instruction
+.It Fa args[1] Ta Function's return value
+.Po e.g., a kernel virtual address if returning from a successful
+.Xr malloc 9
+.Pc
+.El
+.Pp
+Subsection
+.Sx Example 2 : Getting Details About Probe's Arguments
+shows how to get probe's argument count and types directly with
+.Xr dtrace 1
+without having to resort to the reading function's source code
+or documentation.
+.Sh EXAMPLES
+.Ss Example 1 : Listing Available FBT Probes
+The following example shows how to list all the available
+.Nm fbt
+probes.
+.Bd -literal -offset 2n
+# dtrace -l -P fbt
+ ID PROVIDER MODULE FUNCTION NAME
+[...]
+31868 fbt kernel hammer_time entry
+31869 fbt kernel hammer_time return
+[...]
+.Ed
+.Pp
+Since
+.Fn hammer_time
+is a part of the kernel and not a separate loaded module, the
+.Ar module
+column displays
+.Ql kernel .
+.Ss Example 2 : Getting Details About Probe's Arguments
+The following example shows how to generate a program stability report of
+.Xr malloc 9 Ap s
+entry and return probes.
+Those reports are useful to view
+the probe's number of arguments and their types.
+.Bd -literal -offset 2n
+# dtrace -l -v -n fbt::malloc:entry
+[...]
+ Argument Types
+ args[0]: size_t
+ args[1]: struct malloc_type *
+ args[2]: int
+.Ed
+.Pp
+The count and types of
+.Nm fbt Ns Cm \&::malloc:entry
+arguments
+match the function signature of
+.Xr malloc 9 :
+.Va args[0]
+is
+.Ft size_t ,
+.Va args[1]
+is
+.Ft "struct malloc_type *" ,
+and
+.Va "args[2]"
+is
+.Ft int .
+.Bd -literal -offset 2n
+# dtrace -l -v -n fbt::malloc:return
+[...]
+ Argument Types
+ args[0]: int
+ args[1]: void *
+.Ed
+.Pp
+The
+.Cm return
+probe reports two arguments and their types:
+the return instruction offset
+.Pq the usual Ft int
+and the function's return value, which in this case is
+.Ft void * ,
+as
+.Xr malloc 9
+returns a kernel virtual address.
+.Ss Example 3 : Counting Kernel Slab Memory Allocation by Function
+.Bd -literal -offset 2n
+# dtrace -n 'fbt::kmem*:entry { @[probefunc] = count(); }'
+dtrace: description 'fbt::kmem*:entry ' matched 47 probes
+^C
+ kmem_alloc_contig 1
+ kmem_alloc_contig_domainset 1
+ kmem_cache_reap_active 1
+ kmem_alloc_contig_pages 2
+ kmem_free 2
+ kmem_std_destructor 19
+ kmem_std_constructor 26
+ kmem_cache_free 151
+ kmem_cache_alloc 181
+.Ed
+.Ss Example 4 : Counting Kernel Slab Memory Allocation by Calling Function
+.Bd -literal -offset 2n
+# dtrace -q -n 'fbt::kmem*:entry { @[caller] = count(); } END { printa("%40a %@16d\en", @); }'
+^C
+ kernel`contigmalloc+0x33 1
+ kernel`free+0xd3 1
+ kernel`kmem_alloc_contig+0x29 1
+kernel`kmem_alloc_contig_domainset+0x19a 1
+ zfs.ko`arc_reap_cb_check+0x16 1
+.Ed
+.Ss Example 5 : Counting Kernel malloc()'s by Calling Function
+.Bd -literal -offset 2n
+# dtrace -q -n 'fbt::malloc:entry { @[caller] = count(); } END { printa("%45a %@16d\en", @); }'
+^C
+ kernel`devclass_get_devices+0xa8 1
+ kernel`sys_ioctl+0xb7 1
+ dtrace.ko`dtrace_ioctl+0x15c1 1
+ dtrace.ko`dtrace_ioctl+0x972 2
+ dtrace.ko`dtrace_dof_create+0x35 2
+ kernel`kern_poll_kfds+0x2f0 4
+ kernel`kern_poll_kfds+0x28a 19
+.Ed
+.Ss Example 6 : Counting Kernel malloc()'s by Kernel Stack Trace
+.Bd -literal -offset 2n
+# dtrace -q -n 'fbt::malloc:entry { @[stack()] = count(); }'
+^C
+ dtrace.ko`dtrace_dof_create+0x35
+ dtrace.ko`dtrace_ioctl+0x827
+ kernel`devfs_ioctl+0xd1
+ kernel`VOP_IOCTL_APV+0x2a
+ kernel`vn_ioctl+0xb6
+ kernel`devfs_ioctl_f+0x1e
+ kernel`kern_ioctl+0x286
+ kernel`sys_ioctl+0x12f
+ kernel`amd64_syscall+0x169
+ kernel`0xffffffff81092b0b
+ 2
+.Ed
+.Ss Example 7 : Summarizing vmem_alloc()'s by Arena Name and Size Distribution
+.Bd -literal -offset 2n
+# dtrace -q -n 'fbt::vmem_alloc:entry { @[args[0]->vm_name] = quantize(arg1); }'
+^C
+
+ kernel arena dom
+ value ------------- Distribution ------------- count
+ 2048 | 0
+ 4096 |@@@@@@@@@@@@@@@@@@@@@@@@@@@ 4
+ 8192 |@@@@@@@@@@@@@ 2
+ 16384 | 0
+.Ed
+.Ss Example 8 : Measuring Total Time Spent Executing a Function
+This DTrace script measures the total time spent in
+.Fn vm_page*
+kernel functions.
+The
+.Fn quantize
+aggregation organizes the measurements into power-of-two buckets,
+providing a time distribution in nanoseconds for each function.
+.Bd -literal -offset 2n
+fbt::vm_page*:entry {
+ self->start = timestamp;
+}
+
+fbt::vm_page*:return /self->start/ {
+ @[probefunc] = quantize(timestamp - self->start);
+ self->start = 0;
+}
+.Ed
+.Sh SEE ALSO
+.Xr dtrace 1 ,
+.Xr tracing 7
+.Rs
+.%A Brendan Gregg
+.%A Jim Mauro
+.%B DTrace: Dynamic Tracing in Oracle Solaris, Mac OS X and FreeBSD
+.%I Prentice Hall
+.%P pp. 898\(en903
+.%D 2011
+.%U https://www.brendangregg.com/dtracebook/
+.Re
+.Rs
+.%B The illumos Dynamic Tracing Guide
+.%O Chapter fbt Provider
+.%D 2008
+.%U https://illumos.org/books/dtrace/chp-fbt.html#chp-fbt
+.Re
+.Sh AUTHORS
+This manual page was written by
+.An Mateusz Piotrowski Aq Mt 0mp@FreeBSD.org .
+.Sh CAVEATS
+.Ss Stability and Portability
+.Nm fbt
+probes are by definition tightly coupled to kernel code; if the code underlying
+a script changes, the script may fail to run or may produce incorrect results.
+Scripts written for one version of
+.Fx
+might not work on others,
+and almost certainly will not work on other operating systems.
+.Pp
+Individual
+.Nm fbt
+probes often do not correspond nicely to logical system events.
+For example, consider a DTrace script which prints the destination
+address of every IP packet as the kernel hands them over
+to the network card driver (NIC).
+An
+.Nm fbt Ns -based
+implementation of such a script is a discouragingly difficult task:
+it involves instrumenting at least four different functions in different parts
+of the IPv4 and IPv6 code.
+At the same time, with the
+.Xr dtrace_ip 4
+provider the script is a simple one-liner:
+.Dl dtrace -n 'ip:::send {printf("%s", args[2]->ip_daddr);}'
+.Pp
+Make sure to review available
+.Xr dtrace 1
+providers first
+before implementing a custom script with the
+.Nm fbt
+provider.
+If none of the DTrace providers offer the desired probes,
+consider adding new statically-defined tracing probes
+.Pq Xr SDT 9 .
+.Ss Frame Pointer
+Inline functions are not instrumentable by
+.Nm fbt
+as they lack a frame pointer.
+A developer might explicitly disable inlining by adding the
+.Ql __noinline
+attribute to a function definition,
+but of course this requires a recompilation of the kernel.
+Building the kernel with
+.Fl fno-omit-frame-pointer
+is another way of preserving frame pointers.
+Note, that sometimes compilers will omit the frame pointer in leaf functions,
+even when configured with
+.Fl fno-omit-frame-pointer .
+.Pp
+Function returns via a tail call are also not instrumentable by
+.Nm fbt .
+As a result,
+a function might have an entry probe
+and a mix of instrumented and uninstrumentable returns.
+.Ss Tracing DTrace
+The
+.Nm fbt
+provider cannot attach to functions inside DTrace provider kernel modules.
diff --git a/share/man/man4/dtrace_vfs.4 b/share/man/man4/dtrace_vfs.4
new file mode 100644
index 000000000000..528d5da42f3d
--- /dev/null
+++ b/share/man/man4/dtrace_vfs.4
@@ -0,0 +1,97 @@
+.\"
+.\" Copyright (c) 2025 Mateusz Piotrowski <0mp@FreeBSD.org>
+.\"
+.\" SPDX-License-Identifier: BSD-2-Clause
+.\"
+.Dd November 3, 2025
+.Dt DTRACE_VFS 4
+.Os
+.Sh NAME
+.Nm dtrace_vfs
+.Nd a DTrace provider for Virtual File System
+.Sh SYNOPSIS
+.Sm off
+.Nm vfs Cm : fplookup : Ar function Cm : Ar name
+.Nm vfs Cm : namecache : Ar function Cm : Ar name
+.Nm vfs Cm : namei : Ar function Cm : Ar name
+.Nm vfs Cm : vop : Ar function Cm : Ar name
+.Sm on
+.Sh DESCRIPTION
+The DTrace
+.Nm vfs
+provider allows users to trace events in the
+.Xr VFS 9
+layer, the kernel interface for file systems on
+.Fx .
+.Pp
+Run
+.Ql dtrace -l -P vfs
+to list all
+.Nm vfs
+probes.
+Add
+.Fl v
+to generate program stability reports,
+which contain information about the number of probe arguments and their types.
+.Pp
+The
+.Cm fplookup
+module defines a single probe,
+.Fn vfs:fplookup:lookup:done "struct nameidata *ndp" "int line" "bool status_code" ,
+that instruments the fast path lookup code in
+.Xr VFS 9 .
+.Pp
+The
+.Cm namecache
+module provides probes related to the
+.Xr VFS 9
+cache.
+Consult the source code in
+.Pa src/sys/kern/vfs_cache.c
+for more details.
+.Pp
+The
+.Cm namei
+module manages probes related to pathname translation and lookup operations.
+Refer to
+.Xr namei 9
+to learn more.
+.Pp
+The
+.Cm vop
+module contains probes related to the functions responsible for
+.Xr vnode 9
+operations.
+.Sh COMPATIBILITY
+This provider is specific to
+.Fx .
+.Sh EXAMPLES
+Check what lookups failed to be handled in a lockless manner:
+.Bd -literal -offset 2n
+# dtrace -n 'vfs:fplookup:lookup:done { @[arg1, arg2] = count(); }'
+.Ed
+.Sh SEE ALSO
+.Xr dtrace 1 ,
+.Xr d 7 ,
+.Xr SDT 9 ,
+.Xr namei 9 ,
+.Xr VFS 9
+.Rs
+.%A Brendan Gregg
+.%A Jim Mauro
+.%B DTrace: Dynamic Tracing in Oracle Solaris, Mac OS X and FreeBSD
+.%I Prentice Hall
+.%P pp. 335\(en351
+.%D 2011
+.%U https://www.brendangregg.com/dtracebook/
+.Re
+.Sh AUTHORS
+.An -nosplit
+The
+.Fx
+.Nm vfs
+provider was written by
+.An Robert Watson Aq Mt rwatson@FreeBSD.org .
+.Pp
+This manual page was written by
+.An Mateusz Piotrowski Aq Mt 0mp@FreeBSD.org .
diff --git a/share/man/man4/geom_zero.4 b/share/man/man4/geom_zero.4
new file mode 100644
index 000000000000..8da09b1473c9
--- /dev/null
+++ b/share/man/man4/geom_zero.4
@@ -0,0 +1,174 @@
+.\"
+.\" Copyright (c) 2019 Greg White <gkwhite@gmail.com>. All rights reserved.
+.\" Copyright (c) 2025 Mateusz Piotrowski <0mp@FreeBSD.org>
+.\"
+.\" SPDX-License-Identifier: BSD-2-Clause
+.\"
+.Dd November 9, 2025
+.Dt GEOM_ZERO 4
+.Os
+.Sh NAME
+.Nm gzero ,
+.Nm geom_zero
+.Nd GEOM-based zero disk/block device
+.Sh SYNOPSIS
+.Cd "options GEOM_ZERO"
+.Pp
+In
+.Xr loader.conf 5
+or
+.Xr sysctl.conf 5 :
+.Cd kern.geom.zero.byte
+.Cd kern.geom.zero.clear
+.Sh DESCRIPTION
+.Nm
+is a
+.Xr GEOM 4
+device simulating a one-exabyte disk.
+It throws away any data written to it,
+and returns the value of
+.Va kern.geom.zero.byte
+for every byte read from it.
+.Pp
+.Nm
+differs from
+.Xr zero 4 ,
+which is a regular character device and has an infinite length,
+while
+.Pa /dev/gzero
+is a
+.Xr GEOM 4
+provider of large, but limited, size.
+.Pp
+Consult
+.Xr geom 8
+for instructions on how to use the supported commands of the
+.Xr GEOM 4
+.Nm ZERO
+class.
+.Pp
+.Nm
+is useful for benchmarking performance of GEOM and GEOM classes
+where compression of the data does not affect the results
+.Po blocks from
+.Pa /dev/gzero
+compress exceptionally well
+.Pc .
+Examples of such benchmarks include
+comparing the speed of two disk encryption algorithms and
+comparing a hardware versus software implementation
+of a single encryption algorithm.
+.Sh MIB VARIABLES
+The following variables are available as both
+.Xr sysctl 8
+variables and
+.Xr loader 8
+tunables:
+.Bl -tag -width "kern.geom.zero.clear"
+.It Va kern.geom.zero.byte
+This variable sets the fill byte of the
+.Nm
+device.
+Default:
+.Ql 0 .
+.It Va kern.geom.zero.clear
+This variable controls the clearing of the read data buffer.
+If set to
+.Ql 0 ,
+.Nm
+will not copy any data into the read data buffers
+and just return the read data buffers as they are without modifying them.
+In particular, it will not not fill the read buffer with the value of
+.Va kern.geom.zero.byte .
+This is useful for read benchmarking to reduce the measurement noise
+caused by extra memory initialization.
+Default:
+.Ql 1 .
+.El
+.Sh FILES
+.Bl -tag -width /dev/gzero
+.It Pa /dev/gzero
+The
+.Nm
+device.
+.El
+.Sh EXAMPLES
+Create the
+.Pa /dev/gzero
+device by loading the
+.Nm geom_zero
+kernel module:
+.Bd -literal -offset indent
+# geom zero load
+.Ed
+.Pp
+Show information about the
+.Nm
+device:
+.Bd -literal -offset indent
+# geom zero list
+Geom name: gzero
+Providers:
+1. Name: gzero
+ Mediasize: 1152921504606846976 (1.0E)
+ Sectorsize: 512
+ Mode: r0w0egzero0
+.Ed
+.Pp
+Set the fill byte of the
+.Nm
+device to 70
+.Po decimal for letter
+.Dq F
+in
+.Xr ascii 7
+.Pc :
+.Bd -literal -offset indent
+# sysctl kern.geom.zero.byte=70
+kern.geom.zero.byte: 0 -> 70
+# head -c 1 /dev/gzero
+F
+.Ed
+.Pp
+Benchmark read and write throughput of
+.Xr geli 8 Ap s
+default encryption algorithm with a 4-KiB sector size:
+.Bd -literal -offset indent
+# geom zero load
+# geli onetime -s 4096 gzero
+# sysctl kern.geom.zero.clear=0
+# dd if=/dev/gzero.eli of=/dev/zero bs=4k count=$((1024 * 256))
+262144+0 records in
+262144+0 records out
+1073741824 bytes transferred in 1.258195 secs (853398307 bytes/sec)
+# dd if=/dev/zero of=/dev/gzero.eli bs=4k count=$((1024 * 256))
+262144+0 records in
+262144+0 records out
+1073741824 bytes transferred in 1.663118 secs (645619658 bytes/sec)
+.Ed
+.Sh SEE ALSO
+.Xr GEOM 4 ,
+.Xr zero 4 ,
+.Xr geom 8 ,
+.Xr sysctl 8 ,
+.Xr bio 9
+.Sh HISTORY
+A
+.Nm
+device first appeared in
+.Fx 6 .
+.Sh AUTHORS
+.An -nosplit
+The
+.Nm
+device was written by
+.An Paweł Jakub Dawidek Aq Mt pjd@FreeBSD.org .
+.Pp
+The
+.Nm
+manual page was originally written by
+.An Greg White Aq Mt gkwhite@gmail.com
+and rewritten by
+.An Mateusz Piotrowski Aq Mt 0mp@FreeBSD.org
+before landing in
+.Fx .
diff --git a/share/man/man4/gif.4 b/share/man/man4/gif.4
index 959510451011..03fc712bf2a6 100644
--- a/share/man/man4/gif.4
+++ b/share/man/man4/gif.4
@@ -27,7 +27,7 @@
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
-.Dd October 21, 2018
+.Dd August 27, 2025
.Dt GIF 4
.Os
.Sh NAME
@@ -54,6 +54,16 @@ does not perform GRE encapsulation; use
.Xr gre 4
for GRE encapsulation.
.Pp
+The
+.Nm
+interface can also tunnel Ethernet traffic over IPv4 or IPv6
+when combined with a
+.Xr if_bridge 4
+interface using EtherIP protocol.
+See
+.Xr if_bridge 4
+for detailed setup.
+.Pp
Each
.Nm
interface is created at runtime using interface cloning.
@@ -169,6 +179,7 @@ variable
to the desired level of nesting.
.Sh SEE ALSO
.Xr gre 4 ,
+.Xr if_bridge 4 ,
.Xr inet 4 ,
.Xr inet6 4 ,
.Xr ifconfig 8
@@ -188,6 +199,13 @@ to the desired level of nesting.
.%D December 1999
.%O draft-ietf-ipsec-ecn-02.txt
.Re
+.Rs
+.%A R. Housley
+.%A S. Hollenbeck
+.%T EtherIP: Tunneling Ethernet Frames in IP Datagrams
+.%R RFC 3378
+.%D September 2002
+.Re
.\"
.Sh HISTORY
The
diff --git a/share/man/man4/tty.4 b/share/man/man4/tty.4
index 7c86be6aa62b..8d4ce0cb20bd 100644
--- a/share/man/man4/tty.4
+++ b/share/man/man4/tty.4
@@ -374,6 +374,7 @@ variables.
.Xr stty 1 ,
.Xr ioctl 2 ,
.Xr ng_tty 4 ,
+.Xr pts 4 ,
.Xr pty 4 ,
.Xr termios 4 ,
.Xr getty 8
diff --git a/share/man/man4/xen.4 b/share/man/man4/xen.4
index 6660ab3c268b..15312866dae6 100644
--- a/share/man/man4/xen.4
+++ b/share/man/man4/xen.4
@@ -26,19 +26,19 @@
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
-.Dd April 30, 2015
+.Dd January 8, 2024
.Dt XEN 4
.Os
.Sh NAME
.Nm xen
-.Nd Xen Hypervisor Guest (DomU) Support
+.Nd Xen Hypervisor Support
.Sh SYNOPSIS
-To compile hardware-assisted virtualization (HVM) Xen guest support with
-para-virtualized drivers into an amd64 or i386 kernel,
-place the following lines in your kernel configuration file:
-.Bd -ragged -offset indent
-.Cd "options XENHVM"
-.Cd "device xenpci"
+FreeBSD supports running both as a Xen guest and host on amd64 hardware.
+Guest support is limited to HVM and PVH modes, while host support is limited to
+PVH mode only.
+.Pp
+Xen support is built by default in the i386 and amd64 GENERIC kernels; note
+however that host mode is only available on amd64.
.Ed
.Sh DESCRIPTION
The Xen Hypervisor allows multiple virtual machines to be run on a single
@@ -52,20 +52,18 @@ to access resources such as virtual network interfaces and disk devices.
.Pp
With later instruction set extensions from AMD and Intel to support fully
virtualizable instructions, unmodified virtual memory systems can also be
-supported; this is referred to as hardware-assisted virtualization (HVM).
+supported; this is referred to as hardware-assisted virtualization (HVM and PVH).
HVM configurations may either rely on transparently emulated hardware
peripherals, or para-virtualized drivers, which are aware of virtualization,
and hence able to optimize certain behaviors to improve performance or
semantics.
+PVH configurations rely on para-virtualized drivers exclusively for IO.
.Pp
.Fx
-supports hardware-assisted virtualization (HVM) on both i386 and amd64
-kernels.
-.Pp
Para-virtualized device drivers are required in order to support certain
functionality, such as processing management requests, returning idle
physical memory pages to the hypervisor, etc.
-.Ss Xen DomU device drivers
+.Ss Xen device drivers
These para-virtualized drivers are supported:
.Bl -hang -offset indent -width blkfront
.It Nm balloon
@@ -87,6 +85,10 @@ suspend, crash, and halt requests.
Expose Xen events via the
.Pa /dev/xen/evtchn
special device.
+.It Nm gntdev
+Allow access to the grant table interface via the
+.Pa /dev/xen/gntdev
+special device.
.It Nm netback
Export local network interfaces to other Xen domains where they can be
imported via
@@ -94,35 +96,30 @@ imported via
.It Nm netfront
Import network interfaces from other Xen domains as local network interfaces,
which may be used for IPv4, IPv6, etc.
-.It Nm pcifront
-Allow physical PCI devices to be passed through into a PV domain.
+.It Nm privcmd
+Allow issuing hypercalls via the
+.Pa /dev/xen/privcmd
+special device.
+.It Nm timer
+Implementation of a one-shot high resolution per-CPU timer using the hypercall
+interface.
+.It Nm acpi cpu
+When running as a host forwards power management related information from ACPI
+to the hypervisor for better performance management.
.It Nm xenpci
Represents the Xen PCI device, an emulated PCI device that is exposed to
HVM domains.
This device allows detection of the Xen hypervisor, and provides interrupt
and shared memory services required to interact with the hypervisor.
+.It Nm xenstore
+Information storage space shared between domains.
.El
-.Ss Performance considerations
-In general, PV drivers will perform better than emulated hardware, and are
-the recommended configuration for HVM installations.
-.Pp
-Using a hypervisor introduces a second layer of scheduling that may limit the
-effectiveness of certain
-.Fx
-scheduling optimisations.
-Among these is adaptive locking, which is no longer able to determine whether
-a thread holding a lock is in execution.
-It is recommended that adaptive locking be disabled when using Xen:
-.Bd -unfilled -offset indent
-.Cd "options NO_ADAPTIVE_MUTEXES"
-.Cd "options NO_ADAPTIVE_RWLOCKS"
-.Cd "options NO_ADAPTIVE_SX"
-.Ed
.Sh HISTORY
Support for
.Nm
first appeared in
.Fx 8.1 .
+Support for host mode was added in 11.0 .
.Sh AUTHORS
.An -nosplit
.Fx
@@ -133,15 +130,10 @@ and
Further refinements were made by
.An Justin Gibbs Aq Mt gibbs@FreeBSD.org ,
.An Adrian Chadd Aq Mt adrian@FreeBSD.org ,
+.An Colin Percival Aq Mt cperciva@FreeBSD.org ,
and
-.An Colin Percival Aq Mt cperciva@FreeBSD.org .
+.An Roger Pau Monné Aq Mt royger@FreeBSD.org .
This manual page was written by
-.An Robert Watson Aq Mt rwatson@FreeBSD.org .
-.Sh BUGS
-.Fx
-is only able to run as a Xen guest (DomU) and not as a Xen host (Dom0).
-.Pp
-As of this release, Xen PV DomU support is not heavily tested; instability
-has been reported during VM migration of PV kernels.
-.Pp
-Certain PV driver features, such as the balloon driver, are under-exercised.
+.An Robert Watson Aq Mt rwatson@FreeBSD.org ,
+and
+.An Roger Pau Monné Aq Mt royger@FreeBSD.org .
diff --git a/share/man/man4/zero.4 b/share/man/man4/zero.4
index f1cd52d455d1..85651d53d342 100644
--- a/share/man/man4/zero.4
+++ b/share/man/man4/zero.4
@@ -29,7 +29,7 @@
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
-.Dd April 7, 1996
+.Dd November 9, 2025
.Dt ZERO 4
.Os
.Sh NAME
@@ -48,6 +48,7 @@ supply of null bytes when read.
.El
.Sh SEE ALSO
.Xr full 4 ,
+.Xr gzero 4 ,
.Xr null 4
.Sh HISTORY
A
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