Commit Graph
1298 Commits
Author SHA1 Message Date
Ian Campbell a73a7a0c64 xl: Remove global domid and enable -Wshadow
Lots of functions loop over a list of domain and others take a domid as
a parameter, shadowing the global one and leading to all sorts of
confusion.

Therefore remove the global domid and explicitly pass it around as
necessary.

Adds a domid to the parameters for many functions and switches many
others from taking a char * domain specifier to taking a domid, pushing
the domid lookup to the toplevel.

Replaces some open-coded domain_qualifier_to_domid error checking with
find_domain.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
[ ijc -- annotate find_domain() with warn_unused_result and fix the
         handful of errors. ]
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-09-17 11:17:02 +01:00
Ian Campbell ead2225b33 xl: prepare to enable Wshadow
Takes care of everything other than the global domid clashes.

Avoid galobal functions
  - stime(2)
  - time(2)

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>
2012-09-17 11:17:01 +01:00
Ian Campbell 4de237a42e libxl: Enable -Wshadow.
It was convenient to invent $(CFLAGS_LIBXL) to do this.

Various renamings to avoid shadowing standard functions:
  - index(3)
  - listen(2)
  - link(2)
  - abort(3)
  - abs(3)

Reduced the scope of some variables to avoid conflicts.

Change to libxc is due to the nested hypercall buf macros in
set_xen_guest_handle (used in libxl) using the same local private vars.

Build tested only.

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>
2012-09-17 11:17:00 +01:00
Ian Campbell 5e61076e8f xl: free libxl context, logger and lockfile using atexit handler
xl frequently just calls exit(3), especially on error. Try to clean
up some of our global state to make tools like valgrind more useful.

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>
2012-09-17 11:16:59 +01:00
Ian Jackson 3e71234b6a libxl: Tolerate xl config files missing trailing newline
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-09-14 10:25:15 +01:00
Ian Jackson 9d3a9e4d73 libxl: Fix missing dependency in api check rule
Without this, the api check cpp run might happen before the various
autogenerated files which are #include by libxl.h are ready.

We need to remove the api-ok file from AUTOINCS to avoid a circular
dependency.  Instead, we list it explicitly as a dependency of the
object files.  The result is that the api check is the last thing to
be done before make considers the preparation done and can start work
on compiling .c files into .o's.

Reported-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Tested-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-09-14 10:02:52 +01:00
Ian Campbell 10a194b1c5 xl: do not leak cpupool names.
Valgrind reports:
==3076== 7 bytes in 1 blocks are definitely lost in loss record 1 of 1
==3076==    at 0x402458C: malloc (vg_replace_malloc.c:270)
==3076==    by 0x406F86D: libxl_cpupoolid_to_name (libxl_utils.c:102)
==3076==    by 0x8058742: parse_config_data (xl_cmdimpl.c:639)
==3076==    by 0x805BD56: create_domain (xl_cmdimpl.c:1838)
==3076==    by 0x805DAED: main_create (xl_cmdimpl.c:3903)
==3076==    by 0x804D39D: main (xl.c:285)

And indeed there are several places where xl uses
libxl_cpupoolid_to_name as a boolean to test if the pool name is
valid and leaks the name if it is. Introduce an is_valid helper and
use that instead.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Juergen Gross<juergen.gross@ts.fujitsu.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-09-14 10:02:50 +01:00
Roger Pau Monne 3c73d5f947 xl: error if vif backend!=0 is used with run_hotplug_scripts
Print an error and exit if backend!=0 is used in conjunction with
run_hotplug_scripts. Currently libxl can only execute hotplug scripts
from the toolstack domain (the same domain xl is running from).

Added a description and workaround of this issue on
xl-network-configuration.

Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-09-14 10:02:49 +01:00
Roger Pau Monne 02fcb50040 libxl: fix usage of backend parameter and run_hotplug_scripts
vif interfaces allows the user to specify the domain that should run
the backend (also known as driver domain) using the 'backend'
parameter. This is not compatible with run_hotplug_scripts=1, since
libxl can only run the hotplug scripts from the Domain 0.

Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-09-14 10:02:48 +01:00
Ian Campbell 393a6e75af libxl: handle errors from xc_sharing_* info functions
On a 32 bit hypervisor xl info currently reports:
sharing_freed_memory   : 72057594037927935
sharing_used_memory    : 72057594037927935

Eat the ENOSYS and turn it into 0. Log and propagate other errors.

I don't have a 32 bit system handy, so tested on x86_64 with a libxc
hacked to return -ENOSYS and -EINVAL.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-09-14 10:02:46 +01:00
Roger Pau Monne 4760e67ccd libxl: fix error message in device_backend_callback
device_backend_callback error path always says "unable to disconnect",
but this can also happen during the connection of a device. Fix the
error message using the information in aodev->action.

Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-09-10 11:13:53 +01:00
Ian Jackson d5047e1a1c libxl: fix api check Makefile
Touch the libxl.api-ok stamp file, and unconditionally put in place
the new _libxl.api-for-check.  This avoids needlessly rerunning the
preprocessor on libxl.h each time we call "make".

Ensure that _libxl.api-for-check gets the CFLAGS used for xl, so that
if it is asked for in a standalone make run it can find xentoollog.h.

Remove *.api-ok on clean.

Also fix .gitignore.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-09-03 11:22:01 +01:00
Ian Campbell 203fbef2fb libxl/xl: implement support for guest ioport and irq permissions.
This is useful for passing legacy ISA devices (e.g. com ports,
parallel ports) to guests.

Supported syntax is as described in
http://cmrg.fifthhorseman.net/wiki/xen#grantingaccesstoserialhardwaretoadomU

I tested this using Xen's 'q' key handler which prints out the I/O
port and IRQ ranges allowed for each domain. e.g.:

(XEN) Rangesets belonging to domain 31:
(XEN)     I/O Ports  { 2e8-2ef, 2f8-2ff }
(XEN)     Interrupts { 3, 5-6 }

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Tested-by: Dieter Bloms <dieter@bloms.de>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-09-03 11:21:59 +01:00
Ian Jackson 50188cde05 libxl: fix double free on some config parser errors
If libxlu_cfg_y.y encountered a config file error, the code generated
by bison would sometimes _both_ run the %destructor _and_ call
xlu__cfg_set_store for the same XLU_ConfigSetting* semantic value.
The result would be a double free.

This appears to be because of the use of a mid-rule action.  There is
some discussion of the problems with destructors and mid-rule action
error handling in "(bison)Mid-Rule Actions".  This area is complex and
best avoided.

So fix the bug by abolishing the use of a mid-rule action, which was
in any case not necessary here.

Also while we are there rename the nonterminal rule "setting" to
"assignment", to avoid confusion with the token type "setting", which
had an identically name in a different namespace.  This was especially
confusing because the nonterminal "setting" did not have "setting" as
the type of its semantic value!  (In fact the nonterminal, now called
"assignment", does not have a value so it does not have a value type.)

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-31 12:24:57 +01:00
Andrew Cooper efbb5c5411 tools/xl: Fix uninitialized variable error.
c/s 25779:4ca40e0559c3 introduced a compilation error for any build
system using -Werror=uninitialized, such as the default CentOS 5.7
version of gcc.

And with good reason, because if the global libxl
default_output_format is neither OUTPUT_FORMAT_SXP nor
OUTPUT_FORMAT_JSON, the variable hand will be used before being
initialised.

The attached patch fixes the warning, and futher fixes the logic to
work correctly when a new OUTPUT_FORMAT is added to xl.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-28 14:46:30 +01:00
Ian Jackson 37d7ccdc2f libxl: Rerun bison
This updates libxlu_cfg_y.[ch] to code generated by bison from
Debian squeeze (1:2.4.1.dfsg-3 i386).

There should be no functional change since there is no change to the
source file, but we will inherit bugfixes and behavioural changes from
the new version of bison.  So this is more a matter of hope than
knowledge.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2012-08-24 12:38:18 +01:00
Ian Jackson e6ec155320 libxl: Rerun flex
This undoes some systematic changes which were made to
libxlu_cfg_l.[ch] along with manually-edited files (eg, whitespace
changes, emacs local variables) and returns these two files to exactly
the output of flex (Debian squeeze 2.5.35-10 i386).

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2012-08-24 12:38:16 +01:00
Ian Jackson 0669c8a4b2 libxl: provide "make realclean" target
This removes all the autogenerated files.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2012-08-24 12:38:14 +01:00
Ian Campbell ac963eb789 xl: make "xl list -l" proper JSON
Bastian Blank reports that the output of this command is just multiple
JSON objects concatenated and is not a single properly formed JSON
object.

Fix this by wrapping in an array. This turned out to be a bit more
intrusive than I was expecting due to the requirement to keep
supporting the SXP output mode.

Python's json module is happy to parse the result...

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2012-08-23 19:12:28 +01:00
Ian Campbell 7eaccb3cc3 libxl: make domain resume API asynchronous
Although the current implementation has no asynchromous parts I can
envisage it needing to do bits of create/destroy like functionality
which may need async support in the future.

To do this make the meat into an internal libxl__domain_resume
function in order to satisfy the no-internal-callers rule for the
async function.

Since I needed to touch the logging to s/ctx/CTX/ anyway switch to the
LOG* helper macros.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Roger Pau Monne <roger.pau@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2012-08-23 19:00:09 +01:00
Paul Durrant 8cda3b0288 hvm: Remove VM genearation ID device and incr_generationid from build_info.
Microsoft have now published their VM generation ID specification at
https://www.microsoft.com/en-us/download/details.aspx?id=30707.
It differs from the original specification upon which I based my
implementation in several key areas. Particularly, it is no longer
an incrementing 64-bit counter and so this patch is to remove
the incr_generationid field from the build_info and also disable the
ACPI device before 4.2 is released.

I will follow up with further patches to implement the VM generation
ID to the new specification.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Committed-by: Keir Fraser <keir@xen.org>
2012-08-22 22:26:27 +01:00
Jan Beulich 1b7378d1b6 libxl: fix build for gcc prior to 4.3
So far all we (explicitly) require is gcc 3.4 or better, so we
shouldn't be unconditionally using features supported only by much
newer versions.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2012-08-13 18:08:37 +01:00
Ian Campbell 15116f1c25 libxl: write physical-device node if user did not supply a block script
This reverts one of the intentional changes from 25733:353bc0801b11.
That change exposed an issue with the xl migration protocol, which
although safe triggers the hotplug scripts device sharing logic.

For 4.2 we disable this logic by writing the physical-device xenstore
node ourselves if a user did not supply a script. If the user did
supply a script then we continue to rely on it to write the
physical-device node (not least because the script may create the
device and therefore it is not available before we run the script).

This means that to support localhost migration a block hotplug script
needs to be robust against adding a device twice and should not
deactivate the device until it has been removed twice.

This should be revisited for 4.3.

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>
2012-08-07 14:26:29 +01:00
Ian Campbell 6e844c2af0 libxl: support custom block hotplug scripts
These are provided using the "script=" syntax described in
docs/misc/xl-disk-configuration.txt.

The existing hotplug scripts currently conflate two different
concepts, namely that of making a datapath available in the backend
domain (logging into iSCSI LUNs and the like) and that of actually
connecting that datapath to a Xen backend path (e.g. writing
"physical-device" node in xenstore to bring up blkback).

For this reason the script support implemented here is only supported
in conjunction with backendtype=phy.

Eventually we hope to rework the hotplug scripts to separate the to
concepts, but that is not 4.2 material.

In addition there are some other subtleties:

 - Previously in the blktap case we would add "script = .../blktap" to
   the backend flex array, but then jumped to the PHY case which added
   "script = .../block" too. The block one takes precendence since it
   comes second.

   This was, accidentally, correct. The blktap script is for blktap1
   devices and not blktap2 devices. libxl completely manages the
   blktap2 side of things without resorting to hotplug scripts and
   creates a blkback device directly.  Therefore the "block" script is
   always the correct one to call. Custom script are not supported in
   this context.

 - libxl should not write the "physical-device" node. This is the
   responsibility of the block script. Writing the "physical-device"
   node in libxl basically completely short-cuts the standard block
   hotplug script which uses "physical-device" to know if it has run
   already or not.

   In the case of more complex scripts libxl cannot know the right
   value to write here anyway, in particular the device may not exist
   until after the script is called.

   This change has the side effect of re-enabling the checks for
   device sharing aspect of the default block script, which I have tested
   and which now cause libxl to properly abort now that libxl properly
   checks for hotplug script errors.

   There is no sharing check for blktap2 since even if you reuse the
   same vhd the resulting tap device is different. I would have preferred
   to simply write the "physical-device" node for the blktap2 case but
   the hotplug script infrastructure is not currently setup to handle
   LIBXL__DEVICE_KIND_VBD
   devices without a hotplug script (backendtype phy and tap both end
   up as KIND_VBD). Changing this was more surgery than I was happy doing
   for 4.2 and therefore I have simply hardcoded to the block script for
   the LIBXL_DISK_BACKEND_TAP case.

 - libxl__device_disk_set_backend running against a phy device with a
   script cannot stat the device to check its properties since it may
   not exist until the script is run. Therefore I have special cased
   this in disk_try_backend to simply assume that backend == phy is
   always ok if a script was
   configured.  Similarly the other backend types are always rejected
   if a script was configured.

   Note that the reason for implementing the default script behaviour
   in device_disk_add instead of libxl__device_disk_setdefault is
   because we need to be able to tell when the script was
   user-supplied rather than defaulted by libxl in order to correctly
   implement the above. The setdefault function must be idempotent so
   we cannot simply update disk->script.

   I suspect that for 4.3 a script member should be added to
   libxl__device, this would also help in the case above of handling
   devices with no script in a consistent manner. This is not 4.2
   material.

 - When the block script falls through and shells out to a block-$type
   script it used to pass "$node" however the only place this was
   assigned was in the remove+phy case (in which case it contains the
   file:// derived /dev/loopN device), and in that case the script
   exits without falling through to the block-$type case.

   Since libxl never creates a type other than phy this never happens
   in practice anyway and we now call the correct block-$type script
   directly.  But fix it up anyway since it is confusing.

 - The block-nbd and block-enbd scripts which we supply appear to be
   broken WRT the hotplug calling convention, in that they seem to
   expect a command line parameter (perhaps the $node described above)
   rather than reading the appropriate node from xenstore.

   I rather suspect this was broken by 7774:e2e7f47e6f79 in November
   2005. I think it is safe to say no one is using these scripts! I
   haven't fixed this here. It would be good to track down some working
   scripts and either incorproate them or defer to them in their existing
   home (e.g. if they live somewhere useful like the nbd tools
   package).

 - Added a few block script related entries to check-xl-disk-parse
   from http://backdrift.org/xen-block-iscsi-script-with-multipath-support
   and http://lists.linbit.com/pipermail/drbd-user/2008-September/010221.html /
   http://www.drbd.org/users-guide-emb/s-xen-configure-domu.html (and
   snuck in another interesting empty CDROM case)

   This highlighted two bugs in the libxlu disk parser handling of the
   deprecated "<script>:" prefix:

   - It was failing to prefix with "block-" to construct the actual
     script name

   - The regex for matching iscsi or drdb or e?nbd was incorrect

 - Use libxl__abs_path for the nic script too. Just because the
   existing code nearly tricked me into repeating the mistake

I have tested with a custom block script which uses "lvchange -a" to
dynamically add remove the referenced device (simulates iSCSI
login/logout without requiring me to faff around setting up an iSCSI
target). I also tested on a blktap2 system.

I haven't directly tested anything more complex like iscsi: or nbd:
other than what check-xl-disk-parse exercises.

[ Recommit of correct version of 25727:a8d708fcb347, which was mangled
  during commit.  Sorry. -iwj ]

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>
2012-08-06 12:28:03 +01:00
Ian Jackson f94454bf9a Merge backout of 25727:a8d708fcb347 2012-08-06 12:25:06 +01:00
Ian Jackson 6390110d62 Backed out changeset a8d708fcb347
25727:a8d708fcb347 was mangled during commit.  Back it out so that we
can commit it properly.

Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>
2012-08-06 12:24:46 +01:00
Ian Campbell 4f6dda6a14 libxl: fix cleanup of tap devices in libxl__device_destroy
We pass be_path to tapdisk_destroy but we've already deleted it so it
fails to read tapdisk-params. However it appears that we need to
destroy the tap device after tearing down xenstore, to avoid the leak
reported by Greg Wettstein in
<201207312141.q6VLfJje012656@wind.enjellic.com>.

So read the tapdisk-params in the cleanup transaction, before the
remove, and pass that down to destroy_tapdisk instead. tapdisk-params
may of course be NULL if the device isn't a tap device.

There is no need to tear down the tap device from
libxl__initiate_device_remove since this ultimately calls
libxl__device_destroy.

Propagate and log errors from libxl__device_destroy_tapdisk.

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>
2012-08-03 12:25:29 +01:00
Ian Campbell 1a3e84bd85 libxl: support custom block hotplug scripts
These are provided using the "script=" syntax described in
docs/misc/xl-disk-configuration.txt.

The existing hotplug scripts currently conflate two different
concepts, namely that of making a datapath available in the backend
domain (logging into iSCSI LUNs and the like) and that of actually
connecting that datapath to a Xen backend path (e.g. writing
"physical-device" node in xenstore to bring up blkback).

For this reason the script support implemented here is only supported
in conjunction with backendtype=phy.

Eventually we hope to rework the hotplug scripts to separate the to
concepts, but that is not 4.2 material.

In addition there are some other subtleties:

 - Previously in the blktap case we would add "script = .../blktap" to
   the backend flex array, but then jumped to the PHY case which added
   "script = .../block" too. The block one takes precendence since it
   comes second.

   This was, accidentally, correct. The blktap script is for blktap1
   devices and not blktap2 devices. libxl completely manages the
   blktap2 side of things without resorting to hotplug scripts and
   creates a blkback device directly.  Therefore the "block" script is
   always the correct one to call. Custom script are not supported in
   this context.

 - libxl should not write the "physical-device" node. This is the
   responsibility of the block script. Writing the "physical-device"
   node in libxl basically completely short-cuts the standard block
   hotplug script which uses "physical-device" to know if it has run
   already or not.

   In the case of more complex scripts libxl cannot know the right
   value to write here anyway, in particular the device may not exist
   until after the script is called.

   This change has the side effect of re-enabling the checks for
   device sharing aspect of the default block script, which I have tested
   and which now cause libxl to properly abort now that libxl properly
   checks for hotplug script errors.

   There is no sharing check for blktap2 since even if you reuse the
   same vhd the resulting tap device is different. I would have preferred
   to simply write the "physical-device" node for the blktap2 case but
   the hotplug script infrastructure is not currently setup to handle
   LIBXL__DEVICE_KIND_VBD
   devices without a hotplug script (backendtype phy and tap both end
   up as KIND_VBD). Changing this was more surgery than I was happy doing
   for 4.2 and therefore I have simply hardcoded to the block script for
   the LIBXL_DISK_BACKEND_TAP case.

 - libxl__device_disk_set_backend running against a phy device with a
   script cannot stat the device to check its properties since it may
   not exist until the script is run. Therefore I have special cased
   this in disk_try_backend to simply assume that backend == phy is
   always ok if a script was
   configured.  Similarly the other backend types are always rejected
   if a script was configured.

   Note that the reason for implementing the default script behaviour
   in device_disk_add instead of libxl__device_disk_setdefault is
   because we need to be able to tell when the script was
   user-supplied rather than defaulted by libxl in order to correctly
   implement the above. The setdefault function must be idempotent so
   we cannot simply update disk->script.

   I suspect that for 4.3 a script member should be added to
   libxl__device, this would also help in the case above of handling
   devices with no script in a consistent manner. This is not 4.2
   material.

 - When the block script falls through and shells out to a block-$type
   script it used to pass "$node" however the only place this was
   assigned was in the remove+phy case (in which case it contains the
   file:// derived /dev/loopN device), and in that case the script
   exits without falling through to the block-$type case.

   Since libxl never creates a type other than phy this never happens
   in practice anyway and we now call the correct block-$type script
   directly.  But fix it up anyway since it is confusing.

 - The block-nbd and block-enbd scripts which we supply appear to be
   broken WRT the hotplug calling convention, in that they seem to
   expect a command line parameter (perhaps the $node described above)
   rather than reading the appropriate node from xenstore.

   I rather suspect this was broken by 7774:e2e7f47e6f79 in November
   2005. I think it is safe to say no one is using these scripts! I
   haven't fixed this here. It would be good to track down some working
   scripts and either incorproate them or defer to them in their existing
   home (e.g. if they live somewhere useful like the nbd tools
   package).

 - Added a few block script related entries to check-xl-disk-parse
   from http://backdrift.org/xen-block-iscsi-script-with-multipath-support
   and http://lists.linbit.com/pipermail/drbd-user/2008-September/010221.html /
   http://www.drbd.org/users-guide-emb/s-xen-configure-domu.html (and
   snuck in another interesting empty CDROM case)

   This highlighted two bugs in the libxlu disk parser handling of the
   deprecated "<script>:" prefix:

   - It was failing to prefix with "block-" to construct the actual
     script name

   - The regex for matching iscsi or drdb or e?nbd was incorrect

 - Use libxl__abs_path for the nic script too. Just because the
   existing code nearly tricked me into repeating the mistake

I have tested with a custom block script which uses "lvchange -a" to
dynamically add remove the referenced device (simulates iSCSI
login/logout without requiring me to faff around setting up an iSCSI
target). I also tested on a blktap2 system.

I haven't directly tested anything more complex like iscsi: or nbd:
other than what check-xl-disk-parse exercises.

[ reran flex/bison -iwj ]

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
2012-08-03 11:59:12 +01:00
Ian Jackson 5b4dce0526 libxl: correct some comments regarding event API and fds
* libxl may indeed register more than one callback for the same fd,
  with some restrictions.  The allowable range of responses to this by
  the application means that this should pose no problems for users.
  But the documentation comment should be fixed.

* Document the relaxed synchronicity semantics of the fd_modify
  registration callback.

* A couple of comments referred to old names for functions.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-03 11:57:10 +01:00
Ian Campbell 662d2991eb libxl: const correctness for libxl__xs_path_cleanup
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>
2012-08-03 09:54:16 +01:00
Ian Jackson 215f2a9aa9 libxl: add a comment re the memory management API instability
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-03 09:54:15 +01:00
Ian Campbell 15c7bb4668 libxl: idl: always initialise the KeyedEnum keyvar in the member init function
Previously we only initialised it if an explicit keyvar_init_val was
given but not if the default was implicitly 0.

In the generated code this only changes the unused libxl_event_init_type
function:

 void libxl_event_init_type(libxl_event *p, libxl_event_type type)
 {
+    assert(!p->type);
+    p->type = type;
     switch (p->type) {
     case LIBXL_EVENT_TYPE_DOMAIN_SHUTDOWN:
         break;

However I think it is wrong that this function is unused, this and
libxl_event_init should be used by libxl__event_new. As it happens
both are just memset to zero but for correctness we should use the
init functions (in case the IDL changes).

In the generator we also need to properly handle init_var == 0 which
the current if statements incorrectly treat as False. This doesn't
actually have any impact on the generated code.

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>
2012-08-03 09:54:14 +01:00
Ian Jackson b8457ba841 libxl: remove an unused numainfo parameter
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Dario Faggioli <dario.faggioli@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-03 09:54:14 +01:00
Ian Jackson 850bec6634 libxl: remus: mark TODOs more clearly
Change the TODOs in the remus code to "REMUS TODO" which will make
them easier to grep for later.  AIUI all of these are essential for
use of remus in production.

Also add a new TODO and a new assert, to check rc on entry to
remus_checkpoint_dm_saved.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-03 09:54:13 +01:00
Ian Jackson 5f672c6210 libxl: do not blunder on if bootloader fails (again)
Do not lose the rc value passed to bootloader_callback.  Do not lose
the rc value from the bl when the local disk detach succeeds.

While we're here rationalise the use of bl->rc to make things clearer.
Set it to zero at the start and always update it conditionally; copy
it into bootloader_callback's argument each time.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-03 09:54:12 +01:00
Ian Jackson bfe1e2bcb4 libxl: rename aodevs to multidev
To be consistent with the new function naming, rename
libxl__ao_devices to libxl__multidev and all variables aodevs to
multidev.

No functional change.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-03 09:54:11 +01:00
Ian Jackson 2928d7465a libxl: abolish useless `start' parameter to libxl__add_*
0 is always passed for this parameter and the code doesn't, actually,
use it, now.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-03 09:54:11 +01:00
Ian Jackson c32293d1dd libxl: fix formatting of DEFINE_DEVICES_ADD
These lines were exactly 80 columns wide, which produces hideous wrap
damage in an 80 column emacs.  Reformat using emacs's C-c \,
which puts the \ in column 72 (by default) where possible.

Whitespace change only.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-03 09:54:10 +01:00
Ian Jackson 258cd4e261 libxl: fix device counting race in libxl__devices_destroy
Don't have a fixed number of devices in the aodevs array, and instead
size it depending on the devices present in xenstore.  Somewhat
formalise the multiple device addition/removal machinery to make this
clearer and easier to do.

As a side-effect we fix a few "lost thread of control" bug which would
occur if there were no devices of a particular kind.  (Various if
statements which checked for there being no devices have become
redundant, but are retained to avoid making the patch bigger.)

Specifically:

 * Users of libxl__ao_devices are no longer expected to know in
   advance how many device operations they are going to do.  Instead
   they can initiate them one at a time, between bracketing calls to
   "begin" and "prepared".

 * The array of aodevs used for this is dynamically sized; to support
   this it's an array of pointers rather than of structs.

 * Users of libxl__ao_devices are presented with a more opaque interface.
   They are are no longer expected to, themselves,
      - look into the array of aodevs (this is now private)
      - know that the individual addition/removal completions are
        handled by libxl__ao_devices_callback (this callback function
        is now a private function for the multidev machinery)
      - ever deal with populating the contents of an aodevs

 * The doc comments relating to some of the members of
   libxl__ao_device are clarified.  (And the member `aodevs' is moved
   to put it with the other members with the same status.)

 * The multidev machinery allocates an aodev to represent the
   operation of preparing all of the other operations.  See
   the comment in libxl__multidev_begin.

A wrinkle is that the functions are called "multidev" but the structs
are called "libxl__ao_devices" and "aodevs".  I have given these
functions this name to distinguish them from "libxl__ao_device" and
"aodev" and so forth by more than just the use of the plural "s"
suffix.

In the next patch we will rename the structs.

Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@eu.citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-03 09:54:09 +01:00
Ian Jackson 7253e0fd1a libxl: react correctly to bootloader pty master POLLHUP
Receive POLLHUP on the bootloader master pty is not an error.
Hopefully it means that the bootloader has exited and therefore the
pty slave side has no process group any more.  (At least NetBSD
indicates POLLHUP on the master in this case.)

So send the bootloader SIGTERM; if it has already exited then this has
no effect (except that on some versions of NetBSD it erroneously
returns ESRCH and we print a harmless warning) and we will then
collect the bootloader's exit status and be satisfied.

However, we remember that we have done this so that if we got POLLHUP
for some other reason than that the bootloader exited we report
something resembling a useful message.

In order to implement this we need to provide a way for users of
datacopier to handle POLLHUP rather than treating it as fatal.

We rename bootloader_abort to bootloader_stop since it now no longer
only applies to error situations.

Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-03 09:54:08 +01:00
Ian Jackson 2dc6e6ef99 libxl: unify libxl__device_destroy and device_hotplug_done
device_hotplug_done contains an open-coded but improved version of
libxl__device_destroy.  So move the contents of device_hotplug_done
into libxl__device_destroy, deleting the old code, and replace it at
its old location with a function call.

Add the missing call to libxl__xs_transaction_abort (which was present
in neither version and technically speaking is always a no-op with
this code as it stands at the moment because no-one does "goto out"
other than after libxl__xs_transaction_start or _commit).

Also fix the error handling: the rc from the destroy should be
propagated into the aodev.

Reported-by: Ian Campbell <Ian.Campbell@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-03 09:54:07 +01:00
Ian Campbell f9e84f5c78 libxl: only read script once in libxl__hotplug_*
instead of duplicating the error handling etc in get_hotplug_env just pass the
script already read by the caller down.

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>
2012-08-03 09:54:06 +01:00
Ian Campbell 01580ccdb2 libxl: prefix *.for-check with _ to mark it as a generated file.
Keeps it out of my greps etc.

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>
2012-08-03 09:54:05 +01:00
Ian Campbell 6e6a6f3614 libxl: make libxl_device_pci_{add,remove,destroy} interfaces asynchronous
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>
2012-08-03 09:54:03 +01:00
Ian Jackson 2862bf5b6c libxl: enforce prohibitions of internal callers
libxl_internal.h says:

 * Functions using LIBXL__INIT_EGC may *not* generally be called from
 * within libxl, because libxl__egc_cleanup may call back into the
 * application. ...

and

 *                    ...  [Functions which take an ao_how] MAY NOT
 * be called from inside libxl, because they can cause reentrancy
 * callbacks.

However, this was not enforced.  Particularly the latter restriction
is easy to overlook, especially since during the transition period to
the new event system we have bent this rule a couple of times, and the
bad pattern simply involves passing 0 or NULL for the ao_how.

So use the compiler to enforce this property, as follows:

 - Mark all functions which take a libxl_asyncop_how, or which
   use EGC_INIT or LIBXL__INIT_EGC, with a new annotation
   LIBXL_EXTERNAL_CALLERS_ONLY in the public header.

 - Change the documentation comment for asynch operations and egcs to
   say that this should always be done.

 - Arrange that if libxl.h is included via libxl_internal.h,
   LIBXL_EXTERNAL_CALLERS_ONLY expands to __attribute__((warning(...))),
   which generates a message like this:
      libxl.c:1772: warning: call to 'libxl_device_disk_remove'
             declared with attribute warning:
             may not be called from within libxl
   Otherwise, the annotation expands to nothing, so external
   callers are unaffected.

 - Forbid inclusion of both libxl.h and libxl_internal.h unless
   libxl_internal.h came first, so that the above check doesn't have
   any loopholes.  Files which include libxl_internal.h should not
   include libxl.h as well.

   This is enforced explicitly using #error.  However, in practice
   with the current tree it just changes the error message when this
   mistake is made; otherwise we would carry on to immediately
   following #define which would cause the compiler to complain that
   LIBXL_EXTERNAL_CALLERS_ONLY was redefined.  Then the developer
   might be tempted to add a #ifndef which would be wrong - it would
   leave the affected translation unit unprotected by the new
   enforcement regime.  So let's be explicit.

 - Fix the one source of files which violate the above principle, the
   output from the idl compiler, by removing the redundant inclusion
   of libxl.h from the output.

Also introduce a new script "check-libxl-api-rules" which contains
some ad-hoc regexps to spot and complain when libxl.h contains
functions which mention libxl_asyncop_how but not
LIBXL_EXTERNAL_CALLERS_ONLY.  This isn't a full C parser but is likely
to get the common cases right and err on the side of complaining.

While we are here, the invocation of perl for the bsd queue.h seddery
to $(PERL).

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Roger Pau Monne <roger.pau@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-01 12:46:52 +01:00
Olaf Hering fe074860b5 libxl: fix unitialized variables in libxl__primary_console_find
gcc 4.5 as shipped with openSuSE 11.4 does not recognize the case of
LIBXL_DOMAIN_TYPE_INVALID properly:

cc1: warnings being treated as errors
libxl.c: In function 'libxl_primary_console_exec':
libxl.c:1408:14: error: 'domid' may be used uninitialized in this function
libxl.c:1409:9: error: 'cons_num' may be used uninitialized in this function
libxl.c:1410:24: error: 'type' may be used uninitialized in this function
libxl.c: In function 'libxl_primary_console_get_tty':
libxl.c:1421:14: error: 'domid' may be used uninitialized in this function
libxl.c:1422:9: error: 'cons_num' may be used uninitialized in this function
libxl.c:1423:24: error: 'type' may be used uninitialized in this function
make[3]: *** [libxl.o] Error 1

Fix this by adding a default case.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-01 12:46:49 +01:00
Roger Pau Monne 7c3e7ad39c libxl: call hotplug scripts from xl for NetBSD
Add the missing NetBSD functions to call hotplug scripts, and disable
xenbackendd if libxl/disable_udev is not set.

Signed-off-by: Roger Pau Monne <roger.pau@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Christoph Egger <Christoph.Egger@amd.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-08-01 12:46:47 +01:00
Ian Jackson 60975d1b58 libxl: fix reentrancy hazard in fd event processing
In afterpoll_internal, the callback functions may register and
deregister events arbitrarily.  This means that we need to consider
the reentrancy-safety of the event machinery state variables.

Most of the code is safe but the fd handling is not.  Fix this by
arranging to restart the fd scan loop every time we call one of these
callback functions.

For this loop to terminate, we modify afterpoll_check_fd so that it
returns only once for each of afterpoll's efds.

Another possible solution would be simply to return from
afterpoll_internal after calling efd->func.  That would be a small and
more obviously correct change but would prevent the process from
handling more than one fd event with a single call to poll.

This is apropos of a report from Roger Pau Monne to me (pers.comm.)
of this crash on NetBSD:

  Program terminated with signal 11, Segmentation fault.
  #0  0x00007f7ff743131b in afterpoll_check_fd (poller=<optimized out>, fds=0x7f7ff7b241c0, nfds=7, fd=-1, events=1)
      at libxl_event.c:856
  856             if (fds[slot].fd != fd)

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Reported-by: Roger Pau Monne <roger.pau@citrix.com>
Tested-by: Roger Pau Monne <roger.pau@citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
Committed-by: Ian Campbell <ian.campbell@citrix.com>
2012-07-26 17:22:39 +01:00
Roger Pau Monne d82a726d15 libxl: convert libxl_device_vfb_add to an async operation
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>
2012-07-26 16:47:37 +01:00
Roger Pau Monne 2c5f57a308 libxl: convert libxl_device_vkb_add to an async operation
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>
2012-07-26 16:47:36 +01:00