This allows the application to pass a token to libxl in the fd/timeout
registration callbacks, which it receives back in modification or
deregistration callbacks.
It turns out that this is essential for timeout handling, in order to
identify which timeout to change on a modify event.
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: David Scott <dave.scott@eu.citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
The original code works fine on 64-bit, but on 32-bit, the OCaml int (which is
1 bit smaller than the C int) is likely to overflow.
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Ocaml has a heap lock which must be held whenever ocaml code is running. Ocaml
usually drops this lock when it enters a potentially blocking low-level
function, such as writing to a file. Libxl has its own lock, which it may
acquire when being called.
Things get interesting when libxl calls back into ocaml code. There is a risk
of ending up in a deadlock when a thread holds both locks at the same time,
then temporarily drop the ocaml lock, while another thread calls another libxl
function.
To avoid deadlocks, we drop the ocaml heap lock before entering libxl, and
reacquire it in callbacks to ocaml. This way, the ocaml heap lock is never held
together with the libxl lock, except in osevent registration callbacks, and
xentoollog callbacks. If we guarantee to not call any libxl functions inside
those callbacks, we can avoid deadlocks.
This patch handle the dropping and reacquiring of the ocaml heap lock by the
caml_enter_blocking_section and caml_leave_blocking_section functions, and
related macros. We are also careful to not call any functions that access the
ocaml heap while the ocaml heap lock is dropped. This often involves copying
ocaml values to C before dropping the ocaml lock.
The ao_how in aohow_val is now malloc'ed, just to make this function a little
easier to use.
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: David Scott <dave.scott@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Also:
* Reorganise toplevel OCaml functions into modules of Xenlight.
* Factor out the management of ao_how into the function aohow_val. The ao_how
is now malloc'ed, just to make this function a little easier to use.
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: David Scott <dave.scott@eu.citrix.com>
Having bindings to the low-level functions libxl_osevent_register_hooks and
related, allows to run an event loop in OCaml; either one we write ourselves,
or one that is available elsewhere.
The Lwt cooperative threads library (http://ocsigen.org/lwt/), which is quite
popular these days, has an event loop that can be easily extended to poll any
additional fds that we get from libxl. Lwt provides a "lightweight" threading
model, which does not let you run any other (POSIX) threads in your
application, and therefore excludes an event loop implemented in the C
bindings.
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: David Scott <dave.scott@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Libxl functions such as libxl_domain_create_new take large structs
of configuration parameters. Often, we would like to use the default
values for many of these parameters.
The struct and keyed-union types in libxl have init functions, which
fill in the defaults for a given type. This commit provides an OCaml
interface to obtain records of defaults by calling the relevant init
function.
These default records can be used as a base to construct your own
records, and to selectively override parameters where needed.
For example, a Domain_create_info record can now be created as follows:
Xenlight.Domain_create_info.({ default ctx () with
ty = Xenlight.DOMAIN_TYPE_PV;
name = Some vm_name;
uuid = vm_uuid;
})
For types with KeyedUnion fields, such as Domain_build_info, a record
with defaults is obtained by specifying the type key:
Xenlight.Domain_build_info.default ctx ~ty:Xenlight.DOMAIN_TYPE_HVM ()
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: David Scott <dave.scott@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
The libxl IDL is based on C type "char *", and therefore "strings" can
by NULL, or be an actual string. In ocaml, it is common to encode such
things as option types.
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: David Scott <dave.scott@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
In order to avoid newly created OCaml values from being GC'ed, they must be
registered as roots with the GC, before an iteration of the GC may happen. The
Val_* functions potentially allocate new values on the OCaml heap, and may
trigger an iteration of the OCaml GC.
The way to register a value with the GC is to assign it to a variable declared
with a CAMLparam or CAMLlocal macro, which put the value into a struct that
can be reached from a GC root.
This leads to slightly weird looking C code, but avoids hard to find segfaults.
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: David Scott <dave.scott@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Since the context has a logger we can get rid of the logger built into these
bindings and use the xentoollog bindings instead.
The gc is of limited use when most things are freed with libxl_FOO_dispose,
so get rid of that too.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: David Scott <dave.scott@eu.citrix.com>
Rather than allocating a new context for every libxl call begin to
switch to a model where a context is allocated by the caller and may
then be used for multiple calls down into the library.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: David Scott <dave.scott@eu.citrix.com>
* bitmaps
* string_list
* key_value_list
* cpuid_policy_list (left "empty" for now)
None of these are used yet, so no change to the generated code.
Bitmap_val requires a ctx, so leave it as an abort for now.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: David Scott <dave.scott@eu.citrix.com>
A KeyedUnion consists of two fields in the containing struct. First an
enum field ("e") used as a descriminator and second a union ("u")
containing potentially anonymous structs associated with each enum
value.
We map the anonymous structs to structs named after the descriminator
field ("e") and the specific enum values. We then declare an ocaml
variant type name e__union mapping each enum value to its associated
struct.
So given IDL:
foo = Enumeration("foo", [
(0, "BAR"),
(1, "BAZ"),
])
s = Struct("s", [
("u", KeyedUnion(none, foo, "blargle", [
("bar", Struct(...xxx...)),
("baz", Struct(...yyy...)),
])),
])
We generate C:
enum foo { BAR, BAZ };
struct s {
enum foo blargle;
union {
struct { ...xxx... } bar;
struct { ...yyy... } baz;
} u;
}
and map this to ocaml
type foo = BAR | BAZ;
module S = struct
type blargle_bar = ...xxx...;
type blargle_baz = ...yyy...;
type blargle__union = Bar of blargle_bar | Baz of blargle_baz;
type t =
{
blargle : blargle__union;
}
end
These type names are OK because they are already within the namespace
associated with the struct "s".
If the struct associated with bar is empty then we don't bother with
blargle_bar of "of blargle_bar".
No actually change in the generated code since we don't generate any
KeyedUnions yet.
The actual implementation was inspired by
http://www.linux-nantes.org/~fmonnier/ocaml/ocaml-wrapping-c.php#ref_constvrnt
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Rob Hoes <rob.hoes@citrix.com>
Acked-by: David Scott <dave.scott@eu.citrix.com>
This was missed by c/s 23936:cdb34816a40a which renamed xl -> xenlight
[ 23936:cdb34816a40a is 7ceaa0c744 in git -iwj ]
Reported-by: alien@rmail.be
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
configure checks just for ocamlc, but the tools in tools/ocaml depend
also on ocamlfind. On my workstation I have just ocamlc installed, but
no ocamlfind. As a result make will fail.
Update configure.ac to check also for OCAMLFIND, update various
Makefiles and replace hardcoded ocamlfind string with $(OCAMLFIND)
Please rerun autogen.sh after applying this patch.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
Previously device ids in libxl were treated as integers meaning they
were being initialized to 0, which is a valid device id. This patch
makes devid its own type in libxl and initializes it to -1, an invalid
value.
This fixes a bug where if you try to do a xl DEV-attach multiple
time it will continuously try to reattach device 0 instead of
generating a new device id.
Signed-off-by: Matthew Fioravante <matthew.fioravante@jhuapl.edu>
Reviewed-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
This does not make the implementation fully asynchronous but just
updates the API to support asynchrony in the future.
Currently although these functions do not call hotplug scripts etc and
therefore are not "slow" (per the comment about ao machinery in
libxl_internal.h) they do interact with the device model and so are
not quite "fast" either. We can live with this for now.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
Split libxl_device_vfb_add into libxl__device_vfb_add (to be used
inside already running ao's), and make libxl_device_vfb_add a stub
to call libxl__device_vfb_add.
Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
Split libxl_device_vkb_add into libxl__device_vkb_add (to be used
inside already running ao's), and make libxl_device_vkb_add a stub to
call libxl__device_vkb_add.
Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
This patch converts libxl_device_nic_add to an ao operation that
waits for device backend to reach state XenbusStateInitWait and then
marks the operation as completed. This is not really useful now, but
will be used by latter patches that will launch hotplug scripts after
we reached the desired xenbus state.
Calls to libxl_device_nic_add have also been moved to occur after the
device model has been launched, so when hotplug scripts are called
from this functions the interfaces already exists.
As usual, libxl_device_nic_add callers have been modified, and the
internal function libxl__device_disk_add has been used if the call was
inside an already running ao.
Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
This patch converts libxl_device_disk_add to an ao operation that
waits for device backend to reach state XenbusStateInitWait and then
marks the operation as completed. This is not really useful now, but
will be used by later patches that will launch hotplug scripts after
we reached the desired xenbus state.
As usual, libxl_device_disk_add callers have been modified, and the
internal function libxl__device_disk_add has been used if the call was
inside an already running ao.
Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
[ ijc -- drop hunk modifying libxl_cdrom_insert which is not needed after
25670:3666e9712eaf "libxl: make libxl_cdrom_insert async" ]
Committed-by: Ian Campbell <ian.campbell@citrix.com>
Introduce a new structure to track state of device backends, that will
be used in following patches on this series.
This structure if used for both device creation and device
destruction and removes libxl__ao_device_remove.
Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
These renamed a type and the associated functions and the ocaml bindings were
not updated to suit.
This also highlighted that libxl_domain_sched_params should not be DIR_IN since
it is also use as an output struct.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
This type is a but like a "boolean" but with a third state "default" (so really
I suppose it's a tristate).
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
In preparation for introducing a schedule parameter-based structure,
rename libxl_sched_{credit,credit2,sedf} to libxl_sched_{}_domain.
No functional changes.
v2: Wrap long lines while I'm at it
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Keir Fraser <keir@xen.org>
send_trigger already included all the operations covered by button_press.
Rework send_trigger to take an enum instead of a string.
I stopped short at removing the xl "button-press" command but instead have
marked it as deprecated.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Committed-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Originally libxltypes.py provided the infrastructure and libxl.idl provided the
specific types.
In 23887:a543e10211f7 libxl.idl became libxl_types.idl (to allow for
libxl_types_internal.idl) which means we now have libxl_types.FOO and
libxltypes.FOO providing different things and annoying people in tab
completion.
Rename the infrastructure as idl.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Committed-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Don Slutz
Rob Hoes
Andrew Cooper
Olaf Hering
Ian Campbell
Matthew Fioravante
Roger Pau Monne
George Dunlap