Fix an issue with the dynamic pcpu/vnet data allocators.
We cannot expect that modspace is the last entry in the linker
set and thus that modspace + possible extra space up to PAGE_SIZE
would be contiguous. For the moment do not support more than
*_MODMIN space and ignore the extra space.
Discussed with: jeff, rwatson (briefly)
Reviewed by: jeff
Sponsored by: The FreeBSD Foundation
Sponsored by: CK Software GmbH
Split eventhandler_register() into an internal part and a wrapper function
that provides the allocated and setup eventhandler entry.
Add a new wrapper for VIMAGE that allocates extra space to hold the
callback function and argument in addition to an extra wrapper function.
While the wrapper function goes as normal callback function the
argument points to the extra space allocated holding the original func
and arg that the wrapper function can then call.
Provide an iterator function for the virtual network stack (vnet) that
will call the callback function for each network stack.
Provide a new set of macros for VNET that in the non-VIMAGE case will
just call eventhandler_register() while in the VIMAGE case it will use
vimage_eventhandler_register() passing in the extra iterator function
but will only register once rather than per-vnet.
We need a special macro in case we are interested in the tag returned
as we must check for curvnet and can neither simply assign the
return value, nor not change it in the non-vnet0 case without that.
Discussed with: jhb
Reviewed by: zec (earlier version), jhb
Add DDB support for printing vnet_sysinit and vnet_sysuninit
ordered call lists. Try to lookup function/symbol names and print
those in addition to the pointers, along with the constants for
subsystem and order.
This is useful for debugging vnet teardown ordering issues.
Make it possible to call the actual printing frunction from normal
code at runtime, ie. from vnet_sysuninit(), if DDB support is there.
Add an SDT provider for "vnet"s along with probes for vnet_alloc
and vnet_destroy.
Use the line number rather than NULL as dummy argument.
Note: the fbt provider does not reliably provide :return probes
(depending on optimization levels used at compile time) making
it unusable for scripts to generate complete call-traces with
well defined boundaries over allocations or destructions of
virtual network stacks.
Instead of spamming the console on each curvnet recursion event, print
out each such call graph only once, along with a stack backtrace. This
should make kernels built with VNET_DEBUG reasonably usable again in
busy / production environments.
Introduce a new DDB command "show vnetrcrs" which dumps the whole log
of distinctive curvnet recursion events. This might be useful when
recursion reports get burried / lost too deep in the message buffer.
In the later case stack backtraces are not available.
Reviewed by: bz
Introduce a separate sx lock for protecting lists of vnet sysinit
and sysuninit handlers.
Previously, sx_vnet, which is a lock designated for protecting
the vnet list, was (ab)used for protecting vnet sysinit / sysuninit
handler lists as well. Holding exclusively the sx_vnet lock while
invoking sysinit and / or sysuninit handlers turned out to be
problematic, since some of the handlers may attempt to wake up
another thread and wait for it to walk over the vnet list, hence
acquire a shared lock on sx_vnet, which in turn leads to a deadlock.
Protecting vnet sysinit / sysuninit lists with a separate lock
mitigates this issue, which was first observed with
flowtable_flush() / flowtable_cleaner() in sys/net/flowtable.c.
Reviewed by: rwatson, jhb
MFC after: 3 days
Approved by: re (rwatson)
vnet.c to iterate virtual network stacks without being aware of
the implementation details previously hidden in kern_vimage.c.
Now they are in the same file, so remove this added complexity.
Reviewed by: bz
Approved by: re (vimage blanket)
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks. Minor cleanups are done in the process,
and comments updated to reflect these changes.
Reviewed by: bz
Approved by: re (vimage blanket)
network stacks, VNET_SYSINIT:
- Add VNET_SYSINIT and VNET_SYSUNINIT macros to declare events that will
occur each time a network stack is instantiated and destroyed. In the
!VIMAGE case, these are simply mapped into regular SYSINIT/SYSUNINIT.
For the VIMAGE case, we instead use SYSINIT's to track their order and
properties on registration, using them for each vnet when created/
destroyed, or immediately on module load for already-started vnets.
- Remove vnet_modinfo mechanism that existed to serve this purpose
previously, as well as its dependency scheme: we now just use the
SYSINIT ordering scheme.
- Implement VNET_DOMAIN_SET() to allow protocol domains to declare that
they want init functions to be called for each virtual network stack
rather than just once at boot, compiling down to DOMAIN_SET() in the
non-VIMAGE case.
- Walk all virtualized kernel subsystems and make use of these instead
of modinfo or DOMAIN_SET() for init/uninit events. In some cases,
convert modular components from using modevent to using sysinit (where
appropriate). In some cases, do minor rejuggling of SYSINIT ordering
to make room for or better manage events.
Portions submitted by: jhb (VNET_SYSINIT), bz (cleanup)
Discussed with: jhb, bz, julian, zec
Reviewed by: bz
Approved by: re (VIMAGE blanket)
(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator. Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...). This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.
Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack. Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory. Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.
Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy. Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address. When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.
This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.
Bump __FreeBSD_version and update UPDATING.
Portions submitted by: bz
Reviewed by: bz, zec
Discussed with: gnn, jamie, jeff, jhb, julian, sam
Suggested by: peter
Approved by: re (kensmith)
