Caller of CharDriverState.chr* callback assume errno error conventions.
Translate QIOChannel error to errno (this fixes potential EAGAIN
regression, for ex if a vhost-user backend block, qemu_chr_fe_read_all()
could get error -2 and not wait)
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1457718924-19338-1-git-send-email-marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
One instance of double closing, and invalid close(-1) in some cases
of "goto error".
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
To avoid cluttering the code with #ifdef legs we wrap up the print
statements into a tlb_debug() macro. As access to the virtual TLB can
get quite heavy defining DEBUG_TLB_LOG will ensure all the logs go to
the qemu_log target of CPU_LOG_MMU instead of stderr. This remains
compile time optional as these debug statements haven't been considered
for usefulness for user visible logging.
I've also removed DEBUG_TLB_CHECK which wasn't used.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1458052224-9316-11-git-send-email-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When debugging stuff that occurs over several forks it would be useful
not to keep overwriting the one logfile you've set-up. This allows a
simple %d to be included once in the logfile parameter which is
substituted with getpid().
As the test cases involve checking user output they need
g_test_trap_subprocess() support. As a result they are currently skipped
on Travis builds due to the older glib involved.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Leandro Dorileo <l@dorileo.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1458052224-9316-10-git-send-email-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Each individual architecture needs to use the qemu_log_in_addr_range()
feature for enabling in_asm output as it is part of the frontend.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1458052224-9316-9-git-send-email-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This ensures the code generation debug code will honour -dfilter if set.
For the "exec" tracing I've added a new inline macro for efficiency's
sake.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Aurelien Jarno <aurelien@aureL32.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1458052224-9316-8-git-send-email-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When debugging big programs or system emulation sometimes you want both
the verbosity of cpu,exec et all but don't want to generate lots of logs
for unneeded stuff. This patch adds a new option -dfilter which allows
you to specify interesting address ranges in the form:
-dfilter 0x8000..0x8fff,0xffffffc000080000+0x200,...
Then logging code can use the new qemu_log_in_addr_range() function to
decide if it will output logging information for the given range.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <1458052224-9316-7-git-send-email-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Improve the TB execution logging so that it is easier to identify
what is happening from trace logs:
* move the "Trace" logging of executed TBs into cpu_tb_exec()
so that it is emitted if and only if we actually execute a TB,
and for consistency for the CPU state logging
* log when we link two TBs together via tb_add_jump()
* log when cpu_tb_exec() returns early from a chain of TBs
The new style logging looks like this:
Trace 0x7fb7cc822ca0 [ffffffc0000dce00]
Linking TBs 0x7fb7cc822ca0 [ffffffc0000dce00] index 0 -> 0x7fb7cc823110 [ffffffc0000dce10]
Trace 0x7fb7cc823110 [ffffffc0000dce10]
Trace 0x7fb7cc823420 [ffffffc000302688]
Trace 0x7fb7cc8234a0 [ffffffc000302698]
Trace 0x7fb7cc823520 [ffffffc0003026a4]
Trace 0x7fb7cc823560 [ffffffc0000dce44]
Linking TBs 0x7fb7cc823560 [ffffffc0000dce44] index 1 -> 0x7fb7cc8235d0 [ffffffc0000dce70]
Trace 0x7fb7cc8235d0 [ffffffc0000dce70]
Stopped execution of TB chain before 0x7fb7cc8235d0 [ffffffc0000dce70]
Trace 0x7fb7cc8235d0 [ffffffc0000dce70]
Trace 0x7fb7cc822fd0 [ffffffc0000dd52c]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
[AJB: reword patch title, Abandoned->Stopped]
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1458052224-9316-6-git-send-email-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Make qemu_log_mask() a macro which only calls the function to
do the actual work if the logging is enabled. This avoids making
a function call in possible fast paths where logging is disabled.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This doesn't just dump CPU state on translation but on every block
entrance.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1458052224-9316-4-git-send-email-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
My later debugging patches need access to the origin PC which is held in
the TranslationBlock structure. Pass down the whole structure as it also
holds the information about the code start point.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1458052224-9316-3-git-send-email-alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Move declarations out of qemu-common.h for functions declared in
utils/ files: e.g. include/qemu/path.h for utils/path.c.
Move inline functions out of qemu-common.h and into new files (e.g.
include/qemu/bcd.h)
Signed-off-by: Veronia Bahaa <veroniabahaa@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This patch replaces get_ticks_per_sec() calls with the macro
NANOSECONDS_PER_SECOND. Also, as there are no callers, get_ticks_per_sec()
is then removed. This replacement improves the readability and
understandability of code.
For example,
timer_mod(fdctrl->result_timer,
qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + (get_ticks_per_sec() / 50));
NANOSECONDS_PER_SECOND makes it obvious that qemu_clock_get_ns
matches the unit of the expression on the right side of the plus.
Signed-off-by: Rutuja Shah <rutu.shah.26@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-common.h should only be included by .c files. Its file comment
explains why: "No header file should depend on qemu-common.h, as this
would easily lead to circular header dependencies."
Several include/crypto/ headers include qemu-common.h, but either need
just qapi-types.h from it, or qemu/bswap.h, or nothing at all. Replace or
drop the include accordingly. tests/test-crypto-secret.c now misses
qemu/module.h, so include it there.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
DMA_transfer_handler is actually an ISA thing, and as such has no
business in qemu-common.h. Move it to hw/isa/isa.h, and rename it to
IsaDmaTransferHandler.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
ParallelIOArg is shared between just qemu-char.c and
hw/char/parallel.c, and as such has no business in qemu-common.h.
Move it to sysemu/char.h.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-common.h should only be included by .c files. Its file comment
explains why: "No header file should depend on qemu-common.h, as this
would easily lead to circular header dependencies."
One of the reasons for headers to include it is QEMU_ALIGN_UP() and
QEMU_ALIGN_DOWN(). Move them next to ROUND_UP() in qemu/osdep.h, to
facilitate removing these ill-advised includes later on.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-common.h should only be included by .c files. Its file comment
explains why: "No header file should depend on qemu-common.h, as this
would easily lead to circular header dependencies."
One of the reasons for headers to include it is HOST_LONG_BITS. Move
that to its more natural home qemu/osdep.h, to facilitate removing
these ill-advised includes later on.
This also lets us use HOST_LONG_BITS in bswap.h instead of duplicating
its definition there to avoid cyclic inclusion.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-common.h should only be included by .c files. Its file comment
explains why: "No header file should depend on qemu-common.h, as this
would easily lead to circular header dependencies."
hw/pci/pci.h includes qemu-common.h, but its users only need pcibus_t
and PCIHostDeviceAddress from it. Move them to hw/pci/pci.h and drop
the ill-advised include. Include hw/pci/pci.h where the moved stuff
is now missing. Except we can't in target-i386/kvm_i386.h, because
that would break the i386-linux-user compile. Add
PCIHostDeviceAddress to qemu/typedefs.h instead.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-common.h should only be included by .c files. Its file comment
explains why: "No header file should depend on qemu-common.h, as this
would easily lead to circular header dependencies."
hw/hw.h includes qemu-common.h, but its users generally need only
hw_error() and qemu/module.h from it. Move the former to hw/hw.h,
include the latter there, and drop the ill-advised include.
hw/misc/cbus.c now misses hw_error(), so include hw/hw.h there.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-common.h should only be included by .c files. Its file comment
explains why: "No header file should depend on qemu-common.h, as this
would easily lead to circular header dependencies."
qemu/iov.h includes qemu-common.h for QEMUIOVector stuff. Move all
that to qemu/iov.h and drop the ill-advised include. Include
qemu/iov.h where the QEMUIOVector stuff is now missing.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Much of fw_cfg.h's contents is #ifndef NO_QEMU_PROTOS. This lets a
few places include it without satisfying the dependencies of the
suppressed code. If you somehow include it with NO_QEMU_PROTOS, any
future includes are ignored. Unnecessarily unclean.
Move the stuff not under NO_QEMU_PROTOS into its own header
fw_cfg_keys.h, and include it as appropriate. Tidy up the moved code
to please checkpatch.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Manually drop redundant includes that scripts/clean-includes misses,
e.g. because they're hidden in generator programs, or they use the
wrong kind of delimiter.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Re-run scripts/clean-includes to apply the previous commit's
corrections and updates. Besides redundant qemu/typedefs.h, this only
finds a redundant config-host.h include in ui/egl-helpers.c. No idea
how that escaped the previous runs.
Some manual whitespace trimming around dropped includes squashed in.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Commit 57cb38b included qapi/error.h into qemu/osdep.h to get the
Error typedef. Since then, we've moved to include qemu/osdep.h
everywhere. Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h. That's in excess of
100KiB of crap most .c files don't actually need.
Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h. Include qapi/error.h in .c files that need it and don't
get it now. Include qapi-types.h in qom/object.h for uint16List.
Update scripts/clean-includes accordingly. Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h. Update the list of includes in the qemu/osdep.h
comment quoted above similarly.
This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third. Unfortunately, the number depending on
qapi-types.h shrinks only a little. More work is needed for that one.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1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=e8Ym
-----END PGP SIGNATURE-----
Merge remote-tracking branch 'remotes/weil/tags/pull-wxx-20160322' into staging
wxx patch queue
# gpg: Signature made Tue 22 Mar 2016 18:18:36 GMT using RSA key ID 677450AD
# gpg: Good signature from "Stefan Weil <sw@weilnetz.de>"
# gpg: aka "Stefan Weil <stefan.weil@weilnetz.de>"
# gpg: aka "Stefan Weil <stefan.weil@bib.uni-mannheim.de>"
# gpg: WARNING: This key is not certified with sufficiently trusted signatures!
# gpg: It is not certain that the signature belongs to the owner.
# Primary key fingerprint: 4923 6FEA 75C9 5D69 8EC2 B78A E08C 21D5 6774 50AD
* remotes/weil/tags/pull-wxx-20160322:
wxx: Add support for ncurses
Remove unneeded include statements for setjmp.h
Include setjmp.h in qemu/osdep.h (bug fix for w64)
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
We used to support only pdcurses for Windows, but recently Cygwin added
mingw64-i686-ncurses and mingw64-x86_64-ncurses packages which are
supported now, too.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
As soon as setjmp.h is included from qemu/osdep.h, those old include
statements are no longer needed.
Add also setjmp.h to the list in scripts/clean-includes.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
setjmp must be declared before sysemu/os-win32.h
because it is redefined there for 64 bit Windows.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Tested-by: Andrew Baumann <Andrew.Baumann@microsoft.com>
Signed-off-by: Stefan Weil <sw@weilnetz.de>
The code is okay for illustrating how things work and for testing, but
its error handling make it unfit for production use. Print a warning
to protect the innocent.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-41-git-send-email-armbru@redhat.com>
Migration with ivshmem needs to be carefully orchestrated to work.
Exactly one peer (the "master") migrates to the destination, all other
peers need to unplug (and disconnect), migrate, plug back (and
reconnect). This is sort of documented in qemu-doc.
If peers connect on the destination before migration completes, the
shared memory can get messed up. This isn't documented anywhere. Fix
that in qemu-doc.
To avoid messing up register IVPosition on migration, the server must
assign the same ID on source and destination. ivshmem-spec.txt leaves
ID assignment unspecified, however.
Amend ivshmem-spec.txt to require the first client to receive ID zero.
The example ivshmem-server complies: it always assigns the first
unused ID.
For a bit of additional safety, enforce ID zero for the master. This
does nothing when we're not using a server, because the ID is zero for
all peers then.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-40-git-send-email-armbru@redhat.com>
Move code to more sensible places. Use the opportunity to reorder and
document IVShmemState members.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-38-git-send-email-armbru@redhat.com>
ivshmem can be configured with and without interrupt capability
(a.k.a. "doorbell"). The two configurations have largely disjoint
options, which makes for a confusing (and badly checked) user
interface. Moreover, the device can't tell the guest whether its
doorbell is enabled.
Create two new device models ivshmem-plain and ivshmem-doorbell, and
deprecate the old one.
Changes from ivshmem:
* PCI revision is 1 instead of 0. The new revision is fully backwards
compatible for guests. Guests may elect to require at least
revision 1 to make sure they're not exposed to the funny "no shared
memory, yet" state.
* Property "role" replaced by "master". role=master becomes
master=on, role=peer becomes master=off. Default is off instead of
auto.
* Property "use64" is gone. The new devices always have 64 bit BARs.
Changes from ivshmem to ivshmem-plain:
* The Interrupt Pin register in PCI config space is zero (does not use
an interrupt pin) instead of one (uses INTA).
* Property "x-memdev" is renamed to "memdev".
* Properties "shm" and "size" are gone. Use property "memdev"
instead.
* Property "msi" is gone. The new device can't have MSI-X capability.
It can't interrupt anyway.
* Properties "ioeventfd" and "vectors" are gone. They're meaningless
without interrupts anyway.
Changes from ivshmem to ivshmem-doorbell:
* Property "msi" is gone. The new device always has MSI-X capability.
* Property "ioeventfd" defaults to on instead of off.
* Property "size" is gone. The new device can only map all the shared
memory received from the server.
Guests can easily find out whether the device is configured for
interrupts by checking for MSI-X capability.
Note: some code added in sub-optimal places to make the diff easier to
review. The next commit will move it to more sensible places.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-37-git-send-email-armbru@redhat.com>
In preparation of making it a qdev property.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-36-git-send-email-armbru@redhat.com>
ivshmem_realize() puts the shared memory region in a container region.
Used to be necessary to permit delayed mapping of the shared memory.
However, we recently moved to synchronous mapping, in "ivshmem:
Receive shared memory synchronously in realize()" and the commit
following it. The container is redundant since then. Drop it.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1458066895-20632-33-git-send-email-armbru@redhat.com>
ivshmem has its very own code to create and map shared memory.
Replace that with an implicitly created memory backend. Reduces the
number of ways we create BAR 2 from three to two.
The memory-backend-file is currently available only with CONFIG_LINUX,
so this adds a second Linuxism to ivshmem (the other one is eventfd).
Should we ever need to make it portable to systems where
memory-backend-file can't be made to serve, we could create a
memory-backend-shmem that allocates memory with shm_open().
Bonus fix: shared memory files are now created with permissions 0655
instead of 0777.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1458066895-20632-32-git-send-email-armbru@redhat.com>
If size_t is narrower than 64 bits, passing uint64_t ivshmem_size to
mmap() truncates. Reject such sizes.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-31-git-send-email-armbru@redhat.com>
Short reads from a UNIX domain sockets are exceedingly unlikely when
the other side always sends eight bytes and we always read eight
bytes. We cope with them anyway. However, the code doing that is
rather convoluted. Dumb it down radically.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-30-git-send-email-armbru@redhat.com>
The chardev must be capable of transmitting SCM_RIGHTS ancillary
messages. We check it by comparing CharDriverState member filename to
"unix:". That's almost as brittle as it is disgusting.
When the actual transmission all happened asynchronously, this check
was all we could do in realize(), and thus better than nothing. But
now we receive at least one SCM_RIGHTS synchronously in realize(),
it's not worth its keep anymore. Drop it.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-29-git-send-email-armbru@redhat.com>
The protocol specification (ivshmem-spec.txt, formerly
ivshmem_device_spec.txt) has always required the ID message to be sent
right at the beginning, and ivshmem-server has always complied. The
device, however, accepts it out of order. If an interrupt setup
arrived before it, though, it would be misinterpreted as connect
notification. Fix the latent bug by relying on the spec and
ivshmem-server's actual behavior.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-28-git-send-email-armbru@redhat.com>
This kills off the funny state described in the previous commit.
Simplify ivshmem_io_read() accordingly, and update documentation.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1458066895-20632-27-git-send-email-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
When configured for interrupts (property "chardev" given), we receive
the shared memory from an ivshmem server. We do so asynchronously
after realize() completes, by setting up callbacks with
qemu_chr_add_handlers().
Keeping server I/O out of realize() that way avoids delays due to a
slow server. This is probably relevant only for hot plug.
However, this funny "no shared memory, yet" state of the device also
causes a raft of issues that are hard or impossible to work around:
* The guest is exposed to this state: when we enter and leave it its
shared memory contents is apruptly replaced, and device register
IVPosition changes.
This is a known issue. We document that guests should not access
the shared memory after device initialization until the IVPosition
register becomes non-negative.
For cold plug, the funny state is unlikely to be visible in
practice, because we normally receive the shared memory long before
the guest gets around to mess with the device.
For hot plug, the timing is tighter, but the relative slowness of
PCI device configuration has a good chance to hide the funny state.
In either case, guests complying with the documented procedure are
safe.
* Migration becomes racy.
If migration completes before the shared memory setup completes on
the source, shared memory contents is silently lost. Fortunately,
migration is rather unlikely to win this race.
If the shared memory's ramblock arrives at the destination before
shared memory setup completes, migration fails.
There is no known way for a management application to wait for
shared memory setup to complete.
All you can do is retry failed migration. You can improve your
chances by leaving more time between running the destination QEMU
and the migrate command.
To mitigate silent memory loss, you need to ensure the server
initializes shared memory exactly the same on source and
destination.
These issues are entirely undocumented so far.
I'd expect the server to be almost always fast enough to hide these
issues. But then rare catastrophic races are in a way the worst kind.
This is way more trouble than I'm willing to take from any device.
Kill the funny state by receiving shared memory synchronously in
realize(). If your hot plug hangs, go kill your ivshmem server.
For easier review, this commit only makes the receive synchronous, it
doesn't add the necessary error propagation. Without that, the funny
state persists. The next commit will do that, and kill it off for
real.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-26-git-send-email-armbru@redhat.com>
close_peer_eventfds() cleans up three things: ioeventfd triggers if
they exist, eventfds, and the array to store them.
Commit 98609cd (v1.2.0) fixed it not to clean up ioeventfd triggers
when they don't exist (property ioeventfd=off, which is the default).
Unfortunately, the fix also made it skip cleanup of the eventfds and
the array then. This is a memory and file descriptor leak on unplug.
Additionally, the reset of nb_eventfds is skipped. Doesn't matter on
unplug. On peer disconnect, however, this permanently wedges the
interrupt vectors used for that peer's ID. The eventfds stay behind,
but aren't connected to a peer anymore. When the ID gets recycled for
a new peer, the new peer's eventfds get assigned to vectors after the
old ones. Commonly, the device's number of vectors matches the
server's, so the new ones get dropped with a "Too many eventfd
received" message. Interrupts either don't work (common case) or go
to the wrong vector.
Fix by narrowing the conditional to just the ioeventfd trigger
cleanup.
While there, move the "invalid" peer check to the only caller where it
can actually happen, and tighten it to reject own ID.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-25-git-send-email-armbru@redhat.com>
