Mark the suspend callback libxl__domain_suspend_callback as
asynchronous in the helper stub generator (libxl_save_msgs_gen.pl).
We are going to want to provide an asynchronous version of this
function to get rid of the usleeps and waiting loops in the suspend
code.
libxl__domain_suspend_common_callback, the common synchronous core,
which used to be provided directly as the callback function for the
helper machinery, becomes libxl__domain_suspend_callback_common. It
can now take a typesafe parameter.
For now, provide two very similar asynchronous wrappers for it
(normal, and remus). Each is a simple function which contains only
boilerplate, calls the common synchronous core, and returns the
asynchronous response.
Essentially, we have just moved (in the case of suspend callbacks) the
call site of libxl__srm_callout_sendreply. It was in the switch
statement in the autogenerated _libxl_save_msgs_callout.c, and is now
in the handwritten libxl_dom.c.
No functional change.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Cc: Shriram Rajagopalan <rshriram@cs.ubc.ca>
CC: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---
v3: Clarify commit message.
Fix a misformatted CC in the commit message
Do not introduce a whitespace error in libxl_save_msgs_gen.pl
v2: Commit message mentions usleeps, not Remus, as motivation.
libxl_save_msgs_gen.pl has some trailing whitespace. This can make
git complain annoyingly. Remove the trailing whitespace.
(The file also contains tabs. Leave these as they are to avoid a big
and intrusive diff.)
No functional change.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---
v3: New patch in v3 of the series.
Use fcntl F_SETLK, rather than writing our pid into a "lock" file.
That way if we crash we don't leave the lockfile lying about. Callers
now need to keep the fd for our lockfile. (We don't use flock because
we don't want anyone who inherits this fd across fork to end up with a
handle onto the lock.)
While we are here:
* Move the lockfile to /var/run/xen
* De-duplicate the calculation of the pathname
* Compute the buffer size for the pathname so that it will definitely
not overrun (and use the computed value everywhere)
* Fix various error handling bugs
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
xc_suspend_evtchn_init expects to eat the first event on the xce. If
the xce is used for any other purpose then this can break. Document
this fact and rename the function to xc_suspend_evtchn_init_exclusive.
(I haven't checked the call sites for improper shared use of the xce.)
Provide a corresponding xc_suspend_evtchn_init_sane which doesn't try
to eat an event, and instead leaves the caller the ability to
demultiplex.
Also document that xc_await_suspend needs exclusive use of the xce.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
CC: Shriram Rajagopalan <rshriram@cs.ubc.ca>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---
v3: Drop spurious addition of #include <assert.h>
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---
v2: Fix commit message not to refer to libxl_ctx_alloc's gc, done earlier
Change type of port in evtchn_fd_callback to evtchn_port_or_error_t
Clarify comment about use of ctx->xce.
Fix typo in comment.
Special-case paths starting with '@' in libxl__xswait. Attempting to
read these from xenstore gives EINVAL. Callers waiting for (say)
@releaseDomain will be checking for some condition which can be
observed other than by looking at xenstore.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---
v3: New patch in this version of the series.
This is an ao utility for for conveniently doing a timed wait on
xenstore. It handles setting up and cancelling the timeout, and also
conveniently reads the key for you.
No callers yet in this patch.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---
v2: Fix doc comments to refer to correct rc values
Provide a more formal description of the semantics of
libxl__xs_transaction_start, _commit and _abort, in addition to the
usage pattern example.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
The comments for libxl__ev_time_isregistered and the corresponding
watch function even say that these should be const. Make it so.
Also fix libxl__ev_child_inuse and libxl__ev_spawn_inuse.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Change libxl__poller_init and libxl__poller__get to take a libxl__gc*
rather than a libxl_ctx*. The gc is not used for memory allocation
but simply to provide the standard local variable "gc" expected by the
convenience macros. Doing this makes the error logging more
convenient.
Hence, convert the logging calls to use the LOG* convenience macros.
And consequently, change the call sites, and the function bodies to
use CTX rather than ctx.
Also convert a call to malloc() (with error check) in
libxl__poller_get, to libxl__zalloc (no error check needed).
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
CC: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Provide libxl__gc *gc for the second half of libxl_ctx_alloc.
(For the first half of the function, gc is in scope but set to NULL.)
This makes it possible to make gc-requiring calls. For example, it
makes error logging more convenient.
Make use of this by changing the logging calls to use the LOG*
convenience macros.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Otherwise we deference a NULL pointer.
I saw this while experimenting with libvirt on Xen on ARM, xl already checks
that the command line is non NULL and provides "" as a default.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Julien Grall <julien.grall@linaro.org>
Cc: george.dunlap@citrix.com>
The previous patch (dda0b77d "tools/libxc: pass errno to callers of
xc_domain_save") did not jump to the proper label if the domU is HVM.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reviewed-by: Olaf Hering <olaf@aepfle.de>
If libxl_pipe fails we leave the carefd locked, which translates to
the atfork lock remaining held. This would probably cause the process
to deadlock shortly afterwards.
Of course libxl_pipe is very unlikely to fail unless things are
already going very badly. This bug has not been observed anywhere as
far as we are aware.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
CC: George Dunlap <george.dunlap@eu.citrix.com>
This avoids the process being forked while a carefd is recorded in the
list but the actual fd has been closed. If that happened, a
subsequent libxl_postfork_child_noexec would attempt to close the fd
again. If we are lucky that results in a harmless warning; but if we
are unlucky the fd number has been reused and we close an unrelated
fd.
This race has not been observed anywhere as far as we are aware.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
CC: George Dunlap <george.dunlap@eu.citrix.com>
It is very common for BIOSes to advertise more cpus than are actually present
on the system, and mark some of them as offline. This is what Xen does to
allow for later CPU hotplug, and what BIOSes common to multiple different
systems do to to save fully rewriting the MADT in memory.
An excerpt from `xl info` might look like:
...
nr_cpus : 2
max_cpu_id : 3
...
Which shows 4 CPUs in the MADT, but only 2 online (as this particular box is
the dual-core rather than the quad-core SKU of its particular brand)
Because of the way Xen exposes this information, a libxl_cputopology array is
bounded by 'nr_cpus', while cpu bitmaps are bounded by 'max_cpu_id + 1'.
The current libxl code has two places which erroneously assume that a
libxl_cputopology array is as long as the number of bits found in a cpu
bitmap, and valgrind complains:
==14961== Invalid read of size 4
==14961== at 0x407AB7F: libxl__get_numa_candidate (libxl_numa.c:230)
==14961== by 0x407030B: libxl__build_pre (libxl_dom.c:167)
==14961== by 0x406246F: libxl__domain_build (libxl_create.c:371)
...
==14961== Address 0x4324788 is 8 bytes after a block of size 24 alloc'd
==14961== at 0x402669D: calloc (in/usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==14961== by 0x4075BB9: libxl__zalloc (libxl_internal.c:83)
==14961== by 0x4052F87: libxl_get_cpu_topology (libxl.c:4408)
==14961== by 0x407A899: libxl__get_numa_candidate (libxl_numa.c:342)
...
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Dario Faggioli <dario.faggioli@citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
libxl_device_events_handler would fail to call AO_ABORT if it failed;
instead it would simply return rc. (This leaves the egc etc. from the
now-abolished stack frame potentially live, and leaves the ctx
locked.)
In xl, this is of no consequence, because xl will immediately exit in
this situation. This is very likely to be true in any other callers
(of which we don't know of any, anyway).
Coverity-ID: 1181840
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
CC: coverity@xenproject.org
menuentry in grub2/grub.cfg uses linux16 and initrd16 commands
instead of linux and initrd. Due to this RHEL 7 (beta) guest failed to
boot after the installation.
In addition to this, RHEL 7 menu entries have two different single-quote
delimited strings on the same line, and the greedy grouping for menuentry
parsing gets both strings, and the options inbetween.
Signed-off-by: Joby Poriyath <joby.poriyath@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Cc: george.dunlap@citrix.com
Callers of xc_domain_save use errno to print diagnostics if the call
fails. But xc_domain_save does not preserve the actual errno in case of
a failure.
This change preserves errno in all cases where code jumps to the label
"out". In addition a new label "exit" is added to catch also code which
used to do just "return 1".
Now libxl_save_helper:complete can print the actual error string.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
While not much of a functional change, this prevents irritating warnings from
valgrind when trying to analyse xc_domain_{save,restore}() themselves.
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
CC: Ian Campbell <Ian.Campbell@citrix.com>
Acked-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
This was part of
[PATCH v2 2/2] xl: Add "seize" option to PCI devices
but I accidentally applied v1.
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
The "seize" option tells the toolstack to attempt to automatically
unbind devices and re-bind them to the pciback driver. This should
make creating VMs that habitually use pass-through (such as driver domain
VMs and gaming VMs) easier to use and manage.
[Whitespace error fixed by iwj.]
Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>
libxl_postfork_child_noexec would nestedly reaquire the non-recursive
"no_forking" mutex: atfork_lock uses it, as does sigchld_user_remove.
The result on Linux is that the process always deadlocks before
returning from this function.
This is used by xl's console child. So, the ultimate effect is that
xl with pygrub does not manage to connect to the pygrub console.
This behaviour was reported by Michael Young in Xen 4.4.0 RC5.
Also, the use of sigchld_user_remove in libxl_postfork_child_noexec is
not correct with SIGCHLD sharing. libxl_postfork_child_noexec is
documented to suffice if called only on one ctx. So deregistering the
ctx it's called on is not sufficient. Instead, we need a new approach
which discards the whole sigchld_user list and unconditionally removes
our SIGCHLD handler if we had one.
Prompted by this, clarify the semantics of
libxl_postfork_child_noexec. Specifically, expand on the meaning of
"quickly" by explaining what operations are not permitted; and
document the fact that the function doesn't reclaim the resources in
the ctxs.
And add a comment in libxl_postfork_child_noexec explaining the
internal concurrency situation.
This is an important bugfix. IMO the bug is a blocker for Xen 4.4.
Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Reported-by: M A Young <m.a.young@durham.ac.uk>
CC: Ian Campbell <Ian.Campbell@citrix.com>
CC: George Dunlap <george.dunlap@eu.citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
Release-acked-by: George Dunlap <george.dunlap@eu.citrix.com>
(cherry picked from commit 5be1e95318)
ARM does not (currently) support migration, so stop offering tasty looking
treats like "xl migrate".
Apart from the UI improvement my intention is to use this in osstest to detect
whether to attempt the save/restore/migrate tests.
Other than the additions of the #define/#ifdef there is a tiny bit of code
motion ("dump-core" in the command list and core_dump_domain in the
implementations) which serves to put ifdeffable bits next to each other.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
Ian Jackson
Ian Campbell
Andrew Cooper
Fabio Fantoni
Lai Jiangshan
Wei Liu
Roger Pau Monne
Joby Poriyath
Olaf Hering
Matthew Daley
George Dunlap
Daniel De Graaf
Jan Beulich