Commit Graph

635 Commits (4cd42653f5c1df326a2678a84f24a78fb9601277)

Author SHA1 Message Date
Eric Blake e59084b5b2 qobject: Use simpler QDict/QList scalar insertion macros
We now have macros in place to make it less verbose to add a scalar
to QDict and QList, so use them.

Patch created mechanically via:
  spatch --sp-file scripts/coccinelle/qobject.cocci \
    --macro-file scripts/cocci-macro-file.h --dir . --in-place
then touched up manually to fix a couple of '?:' back to original
spacing, as well as avoiding a long line in monitor.c.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20170427215821.19397-7-eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
(cherry picked from commit 46f5ac205a)
* prereq for fc0932f
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
2017-07-31 17:11:11 -05:00
Fam Zheng 8865852e00 async: Introduce aio_co_enter
They start the coroutine on the specified context.

Signed-off-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2017-04-11 20:07:15 +08:00
Fam Zheng ba9e75ceef coroutine: Extract qemu_aio_coroutine_enter
It's a variant of qemu_coroutine_enter with an explicit AioContext
parameter.

Signed-off-by: Fam Zheng <famz@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2017-04-11 20:07:15 +08:00
Peter Maydell 87cc4c6102 * MemoryRegionCache revert
* glib optimization workaround
 * fix "info lapic" segfault on isapc
 * fix QIOChannel memory leak
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQExBAABCAAbBQJY4oOMFBxwYm9uemluaUByZWRoYXQuY29tAAoJEL/70l94x66D
 AsIH/i52nJw41utJCs5AevnQyqNs9RnyMkZLHiVoi6a+pdJqX+0mCw8gV/5FsbPZ
 dtyt1tEuYBSu72adr+/ExE4aIEjwzeyRmnUdOkB+iYPxirHKuf4K/JTuLuvMtaQQ
 Tqj+FU5tx3wx0jlGOm5A7pzjZ680JUex+oaz3d1bZziv3zCyFCIgiZ2m2UAaaPQe
 fsd3fksJvc0gKOUKmdLUpu2m/xP3hAQAfQ4P/ozOfbVh9V2CVNaQ/cl935tNtdFK
 aYN3KleW3/ovb+YSexeNoW7QQH/3ZsjronCW5OmbF4FgHoeoV8MUROfNgu1S2bRU
 Bne9K/6boPzhD8NDEuSy8SXvf7s=
 =EdXr
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* MemoryRegionCache revert
* glib optimization workaround
* fix "info lapic" segfault on isapc
* fix QIOChannel memory leak

# gpg: Signature made Mon 03 Apr 2017 18:17:00 BST
# gpg:                using RSA key 0xBFFBD25F78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>"
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>"
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini/tags/for-upstream:
  main-loop: Acquire main_context lock around os_host_main_loop_wait.
  exec: revert MemoryRegionCache
  nbd: fix memory leak on socket_connect failed
  ipmi: Fix macro issues
  target-i386: fix "info lapic" segfault on isapc
  iscsi: drop unused IscsiAIOCB.qiov field

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-04-04 11:40:55 +01:00
Richard W.M. Jones ecbddbb106 main-loop: Acquire main_context lock around os_host_main_loop_wait.
When running virt-rescue the serial console hangs from time to time.
Virt-rescue runs an ordinary Linux kernel "appliance", but there is
only a single idle process running inside, so the qemu main loop is
largely idle.  With virt-rescue >= 1.37 you may be able to observe the
hang by doing:

  $ virt-rescue -e ^] --scratch
  ><rescue> while true; do ls -l /usr/bin; done

The hang in virt-rescue can be resolved by pressing a key on the
serial console.

Possibly with the same root cause, we also observed hangs during very
early boot of regular Linux VMs with a serial console.  Those hangs
are extremely rare, but you may be able to observe them by running
this command on baremetal for a sufficiently long time:

  $ while libguestfs-test-tool -t 60 >& /tmp/log ; do echo -n . ; done

(Check in /tmp/log that the failure was caused by a hang during early
boot, and not some other reason)

During investigation of this bug, Paolo Bonzini wrote:

> glib is expecting QEMU to use g_main_context_acquire around accesses to
> GMainContext.  However QEMU is not doing that, instead it is taking its
> own mutex.  So we should add g_main_context_acquire and
> g_main_context_release in the two implementations of
> os_host_main_loop_wait; these should undo the effect of Frediano's
> glib patch.

This patch exactly implements Paolo's suggestion in that paragraph.

This fixes the serial console hang in my testing, across 3 different
physical machines (AMD, Intel Core i7 and Intel Xeon), over many hours
of automated testing.  I wasn't able to reproduce the early boot hangs
(but as noted above, these are extremely rare in any case).

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1435432
Reported-by: Richard W.M. Jones <rjones@redhat.com>
Tested-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Richard W.M. Jones <rjones@redhat.com>
Message-Id: <20170331205133.23906-1-rjones@redhat.com>
[Paolo: this is actually a glib bug: recent glib versions are also
expecting g_main_context_acquire around g_poll---but that is not
documented and probably not even intended].
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-04-03 19:13:12 +02:00
Markus Armbruster 216411b839 sockets: New helper socket_address_crumple()
SocketAddress is a simple union, and simple unions are awkward: they
have their variant members wrapped in a "data" object on the wire, and
require additional indirections in C.  I intend to limit its use to
existing external interfaces.  New ones should use SocketAddressFlat.
I further intend to convert all internal interfaces to
SocketAddressFlat.  This helper should go away then.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1490895797-29094-8-git-send-email-armbru@redhat.com
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-03 17:11:39 +02:00
Markus Armbruster a6c76285f2 io vnc sockets: Clean up SocketAddressKind switches
We have quite a few switches over SocketAddressKind.  Some have case
labels for all enumeration values, others rely on a default label.
Some abort when the value isn't a valid SocketAddressKind, others
report an error then.

Unify as follows.  Always provide case labels for all enumeration
values, to clarify intent.  Abort when the value isn't a valid
SocketAddressKind, because the program state is messed up then.

Improve a few error messages while there.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Message-id: 1490895797-29094-4-git-send-email-armbru@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-03 17:11:39 +02:00
Markus Armbruster ca0b64e5ed nbd sockets vnc: Mark problematic address family tests TODO
Certain features make sense only with certain address families.  For
instance, passing file descriptors requires AF_UNIX.  Testing
SocketAddress's saddr->type == SOCKET_ADDRESS_KIND_UNIX is obvious,
but problematic: it can't recognize AF_UNIX when type ==
SOCKET_ADDRESS_KIND_FD.

Mark such tests of saddr->type TODO.  We may want to check the address
family with getsockname() there.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1490895797-29094-2-git-send-email-armbru@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
2017-04-03 17:11:39 +02:00
Halil Pasic aa26292859 event_notifier: prevent accidental use after close
Let's set the handles to the underlying facilities to their extremal
value so no accidental misuse can happen, and to make it obvious that the
notifier is dysfunctional. E.g. if we just close an fd but do not touch
the int holding the fd eventually a read/write could succeed again when
the fd gets reused, and corrupt the file addressed by the fd.

Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2017-03-29 02:35:23 +03:00
Markus Armbruster 44fdc76455 sockets: Fix socket_address_to_string() hostname truncation
We first snprintf() to a fixed buffer, then g_strdup() the result
*boggle*.

Worse, the size of the fixed buffer INET6_ADDRSTRLEN + 5 + 4 is bogus:
the 4 correctly accounts for '[', ']', ':' and '\0', but
INET6_ADDRSTRLEN is not a suitable limit for inet->host, and 5 is not
one for inet->port!  They are for host and port in *numeric* form
(exploiting that INET6_ADDRSTRLEN > INET_ADDRSTRLEN), but inet->host
can also be a hostname, and inet->port can be a service name, to be
resolved with getaddrinfo().

Fortunately, the only user so far is the "socket" network backend's
net_socket_connected(), which uses it to initialize a NetSocketState's
info_str[].  info_str[] has considerable more space: 256 instead of
55.  So the bug's impact appears to be limited to truncated "info
networks" with the "socket" network backend.

The fix is obvious: use g_strdup_printf().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1490268208-23368-1-git-send-email-armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-28 18:50:38 +02:00
Andrey Shedel 12f8def0e0 win32: replace custom mutex and condition variable with native primitives
The multithreaded TCG implementation exposed deadlocks in the win32
condition variables: as implemented, qemu_cond_broadcast waited on
receivers, whereas the pthreads API it was intended to emulate does
not. This was causing a deadlock because broadcast was called while
holding the IO lock, as well as all possible waiters blocked on the
same lock.

This patch replaces all the custom synchronisation code for mutexes
and condition variables with native Windows primitives (SRWlocks and
condition variables) with the same semantics as their POSIX
equivalents. To enable that, it requires a Windows Vista or newer host
OS.

Signed-off-by: Andrey Shedel <ashedel@microsoft.com>
[AB: edited commit message]
Signed-off-by: Andrew Baumann <Andrew.Baumann@microsoft.com>
Message-Id: <20170324220141.10104-1-Andrew.Baumann@microsoft.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-27 14:41:01 +02:00
Jitendra Kolhe dfd0dcc717 mem-prealloc: fix sysconf(_SC_NPROCESSORS_ONLN) failure case.
This was spotted by Coverity, in case where sysconf(_SC_NPROCESSORS_ONLN)
fails and returns -1. This results in memset_num_threads getting set to -1.
Which we then pass to g_new0().
The patch replaces MAX_MEM_PREALLOC_THREAD_COUNT macro with a function call
get_memset_num_threads() to handle sysconf() failure gracefully. In case
sysconf() fails, we fall back to single threaded.

(Spotted by Coverity, CID 1372465.)

Signed-off-by: Jitendra Kolhe <jitendra.kolhe@hpe.com>
Message-Id: <1490079006-32495-1-git-send-email-jitendra.kolhe@hpe.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-24 11:50:11 +01:00
Markus Armbruster 0ee9ae7c8c keyval: Document issues with 'any' and alternate types
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1490014548-15083-5-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-21 10:42:09 +01:00
Markus Armbruster fae425d74f keyval: Improve some comments
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1490014548-15083-3-git-send-email-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-03-21 10:41:54 +01:00
Paolo Bonzini 53fabd4b86 qemu-ga: obey LISTEN_PID when using systemd socket activation
qemu-ga's socket activation support was not obeying the LISTEN_PID
environment variable, which avoids that a process uses a socket-activation
file descriptor meant for its parent.

Mess can for example ensue if a process forks a children before consuming
the socket-activation file descriptor and therefore setting O_CLOEXEC
on it.

Luckily, qemu-nbd also got socket activation code, and its copy does
support LISTEN_PID.  Some extra fixups are needed to ensure that the
code can be used for both, but that's what this patch does.  The
main change is to replace get_listen_fds's "consume" argument with
the FIRST_SOCKET_ACTIVATION_FD macro from the qemu-nbd code.

Cc: "Richard W.M. Jones" <rjones@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-19 11:12:12 +01:00
Paolo Bonzini 6b3cca76dd oslib-posix: fix compilation on OpenBSD
si_band is not found in OpenBSD.   It is marked as obsolescent in
POSIX, so we can delete it without any remorse.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20170317152214.6148-1-pbonzini@redhat.com
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Tested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-03-17 18:27:49 +00:00
Peter Lieven b7a745dc33 thread-pool: add missing qemu_bh_cancel in completion function
commit 3c80ca15 fixed a deadlock scenarion with nested aio_poll invocations.

However, the rescheduling of the completion BH introcuded unnecessary spinning
in the main-loop. On very fast file backends this can even lead to the
"WARNING: I/O thread spun for 1000 iterations" message popping up.

Callgrind reports about 3-4% less instructions with this patch running
qemu-img bench on a ramdisk based VMDK file.

Fixes: 3c80ca158c
Cc: qemu-stable@nongnu.org
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-03-17 12:54:21 +01:00
Daniel P. Berrange 9dc44aa582 os: don't corrupt pre-existing memory-backend data with prealloc
When using a memory-backend object with prealloc turned on, QEMU
will memset() the first byte in every memory page to zero. While
this might have been acceptable for memory backends associated
with RAM, this corrupts application data for NVDIMMs.

Instead of setting every page to zero, read the current byte
value and then just write that same value back, so we are not
corrupting the original data. Directly write the value instead
of memset()ing it, since there's no benefit to memset for a
single byte write.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Message-id: 20170303113255.28262-1-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-03-15 11:55:41 +08:00
Paolo Bonzini 6b8f0187a4 icount: process QEMU_CLOCK_VIRTUAL timers in vCPU thread
icount has become much slower after tcg_cpu_exec has stopped
using the BQL.  There is also a latent bug that is masked by
the slowness.

The slowness happens because every occurrence of a QEMU_CLOCK_VIRTUAL
timer now has to wake up the I/O thread and wait for it.  The rendez-vous
is mediated by the BQL QemuMutex:

- handle_icount_deadline wakes up the I/O thread with BQL taken
- the I/O thread wakes up and waits on the BQL
- the VCPU thread releases the BQL a little later
- the I/O thread raises an interrupt, which calls qemu_cpu_kick
- the VCPU thread notices the interrupt, takes the BQL to
  process it and waits on it

All this back and forth is extremely expensive, causing a 6 to 8-fold
slowdown when icount is turned on.

One may think that the issue is that the VCPU thread is too dependent
on the BQL, but then the latent bug comes in.  I first tried removing
the BQL completely from the x86 cpu_exec, only to see everything break.
The only way to fix it (and make everything slow again) was to add a dummy
BQL lock/unlock pair.

This is because in -icount mode you really have to process the events
before the CPU restarts executing the next instruction.  Therefore, this
series moves the processing of QEMU_CLOCK_VIRTUAL timers straight in
the vCPU thread when running in icount mode.

The required changes include:

- make the timer notification callback wake up TCG's single vCPU thread
  when run from another thread.  By using async_run_on_cpu, the callback
  can override all_cpu_threads_idle() when the CPU is halted.

- move handle_icount_deadline after qemu_tcg_wait_io_event, so that
  the timer notification callback is invoked after the dummy work item
  wakes up the vCPU thread

- make handle_icount_deadline run the timers instead of just waking the
  I/O thread.

- stop processing the timers in the main loop

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-14 13:51:34 +01:00
Paolo Bonzini 3f53bc61a4 cpus: define QEMUTimerListNotifyCB for QEMU system emulation
There is no change for now, because the callback just invokes
qemu_notify_event.

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-14 13:28:29 +01:00
Paolo Bonzini d2528bdc19 qemu-timer: do not include sysemu/cpus.h from util/qemu-timer.h
This dependency is the wrong way, and we will need util/qemu-timer.h from
sysemu/cpus.h in the next patch.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-14 13:28:18 +01:00
Paolo Bonzini 33bef0b994 qemu-timer: fix off-by-one
If the first timer is exactly at the current value of the clock, the
deadline is met and the timer should fire.  This fixes itself on the next
iteration of the loop without icount; with icount, however, execution
of instructions will stop exactly at the deadline and won't proceed.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-14 13:26:42 +01:00
Suramya Shah bd5d983fa8 util: Removed unneeded header from path.c
Signed-off-by: Suramya Shah <shah.suramya@gmail.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170310163948.7567-1-shah.suramya@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-14 13:26:37 +01:00
Jitendra Kolhe 1e356fc14b mem-prealloc: reduce large guest start-up and migration time.
Using "-mem-prealloc" option for a large guest leads to higher guest
start-up and migration time. This is because with "-mem-prealloc" option
qemu tries to map every guest page (create address translations), and
make sure the pages are available during runtime. virsh/libvirt by
default, seems to use "-mem-prealloc" option in case the guest is
configured to use huge pages. The patch tries to map all guest pages
simultaneously by spawning multiple threads. Currently limiting the
change to QEMU library functions on POSIX compliant host only, as we are
not sure if the problem exists on win32. Below are some stats with
"-mem-prealloc" option for guest configured to use huge pages.

------------------------------------------------------------------------
Idle Guest      | Start-up time | Migration time
------------------------------------------------------------------------
Guest stats with 2M HugePage usage - single threaded (existing code)
------------------------------------------------------------------------
64 Core - 4TB   | 54m11.796s    | 75m43.843s
64 Core - 1TB   | 8m56.576s     | 14m29.049s
64 Core - 256GB | 2m11.245s     | 3m26.598s
------------------------------------------------------------------------
Guest stats with 2M HugePage usage - map guest pages using 8 threads
------------------------------------------------------------------------
64 Core - 4TB   | 5m1.027s      | 34m10.565s
64 Core - 1TB   | 1m10.366s     | 8m28.188s
64 Core - 256GB | 0m19.040s     | 2m10.148s
-----------------------------------------------------------------------
Guest stats with 2M HugePage usage - map guest pages using 16 threads
-----------------------------------------------------------------------
64 Core - 4TB   | 1m58.970s     | 31m43.400s
64 Core - 1TB   | 0m39.885s     | 7m55.289s
64 Core - 256GB | 0m11.960s     | 2m0.135s
-----------------------------------------------------------------------

Changed in v2:
 - modify number of memset threads spawned to min(smp_cpus, 16).
 - removed 64GB memory restriction for spawning memset threads.

Changed in v3:
 - limit number of threads spawned based on
   min(sysconf(_SC_NPROCESSORS_ONLN), 16, smp_cpus)
 - implement memset thread specific siglongjmp in SIGBUS signal_handler.

Changed in v4
 - remove sigsetjmp/siglongjmp and SIGBUS unblock/block for main thread
   as main thread no longer touches any pages.
 - simplify code my returning memset_thread_failed status from
   touch_all_pages.

Signed-off-by: Jitendra Kolhe <jitendra.kolhe@hpe.com>
Message-Id: <1487907103-32350-1-git-send-email-jitendra.kolhe@hpe.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-14 13:26:36 +01:00
Markus Armbruster 0b2c1beea4 keyval: Support lists
Additionally permit non-negative integers as key components.  A
dictionary's keys must either be all integers or none.  If all keys
are integers, convert the dictionary to a list.  The set of keys must
be [0,N].

Examples:

* list.1=goner,list.0=null,list.1=eins,list.2=zwei
  is equivalent to JSON [ "null", "eins", "zwei" ]

* a.b.c=1,a.b.0=2
  is inconsistent: a.b.c clashes with a.b.0

* list.0=null,list.2=eins,list.2=zwei
  has a hole: list.1 is missing

Similar design flaw as for objects: there is no way to denote an empty
list.  While interpreting "key absent" as empty list seems natural
(removing a list member from the input string works when there are
multiple ones, so why not when there's just one), it doesn't work:
"key absent" already means "optional list absent", which isn't the
same as "empty list present".

Update the keyval object visitor to use this a.0 syntax in error
messages rather than the usual a[0].

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1488317230-26248-25-git-send-email-armbru@redhat.com>
[Off-by-one fix squashed in, as per Kevin's review]
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
2017-03-07 16:07:48 +01:00
Markus Armbruster f740048323 keyval: Restrict key components to valid QAPI names
Until now, key components are separated by '.'.  This leaves little
room for evolving the syntax, and is incompatible with the __RFQDN_
prefix convention for downstream extensions.

Since key components will be commonly used as QAPI member names by the
QObject input visitor, we can just as well borrow the QAPI naming
rules here: letters, digits, hyphen and period starting with a letter,
with an optional __RFQDN_ prefix for downstream extensions.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <1488317230-26248-20-git-send-email-armbru@redhat.com>
2017-03-07 16:07:47 +01:00
Markus Armbruster d454dbe0ee keyval: New keyval_parse()
keyval_parse() parses KEY=VALUE,... into a QDict.  Works like
qemu_opts_parse(), except:

* Returns a QDict instead of a QemuOpts (d'oh).

* Supports nesting, unlike QemuOpts: a KEY is split into key
  fragments at '.' (dotted key convention; the block layer does
  something similar on top of QemuOpts).  The key fragments are QDict
  keys, and the last one's value is updated to VALUE.

* Each key fragment may be up to 127 bytes long.  qemu_opts_parse()
  limits the entire key to 127 bytes.

* Overlong key fragments are rejected.  qemu_opts_parse() silently
  truncates them.

* Empty key fragments are rejected.  qemu_opts_parse() happily
  accepts empty keys.

* It does not store the returned value.  qemu_opts_parse() stores it
  in the QemuOptsList.

* It does not treat parameter "id" specially.  qemu_opts_parse()
  ignores all but the first "id", and fails when its value isn't
  id_wellformed(), or duplicate (a QemuOpts with the same ID is
  already stored).  It also screws up when a value contains ",id=".

* Implied value is not supported.  qemu_opts_parse() desugars "foo" to
  "foo=on", and "nofoo" to "foo=off".

* An implied key's value can't be empty, and can't contain ','.

I intend to grow this into a saner replacement for QemuOpts.  It'll
take time, though.

Note: keyval_parse() provides no way to do lists, and its key syntax
is incompatible with the __RFQDN_ prefix convention for downstream
extensions, because it blindly splits at '.', even in __RFQDN_.  Both
issues will be addressed later in the series.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <1488317230-26248-4-git-send-email-armbru@redhat.com>
2017-03-07 16:07:46 +01:00
Peter Maydell 17783ac828 ppc patch queuye for 2017-03-03
This will probably be my last pull request before the hard freeze.  It
 has some new work, but that has all been posted in draft before the
 soft freeze, so I think it's reasonable to include in qemu-2.9.
 
 This batch has:
     * A substantial amount of POWER9 work
         * Implements the legacy (hash) MMU for POWER9
 	* Some more preliminaries for implementing the POWER9 radix
           MMU
 	* POWER9 has_work
 	* Basic POWER9 compatibility mode handling
 	* Removal of some premature tests
     * Some cleanups and fixes to the existing MMU code to make the
       POWER9 work simpler
     * A bugfix for TCG multiply adds on power
     * Allow pseries guests to access PCIe extended config space
 
 This also includes a code-motion not strictly in ppc code - moving
 getrampagesize() from ppc code to exec.c.  This will make some future
 VFIO improvements easier, Paolo said it was ok to merge via my tree.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQIcBAABCAAGBQJYuOEEAAoJEGw4ysog2bOSHD0P/jBg/qr/4KnsB1KhnlVrB2sP
 vy2d3bGGlUWr9Z+CK/PMCRB8ekFgQLjidLIXji6mviUocv6m3WsVrnbLF/oOL/IT
 NPMVAffw7q804YVu1Ns9R82d6CIqHTy//bpg69tFMcJmhL9fqPan3wTZZ9JeiyAm
 SikqkAHBSW4SxKqg8ApaSqx5L2QTqyfkClR0sLmgM0JtmfJrbobpQ6bMtdPjUZ9L
 n2gnpO2vaWCa1SEQrRrdELqvcD8PHkSJapWOBXOkpGWxoeov/PYxOgkpdDUW4qYY
 lVLtp1Vd3OB/h3Unqfw32DNiHA5p89hWPX5UybKMgRVL9Cv2/lyY47pcY8XTeNzn
 bv84YRbFJeI+GgoEnghmtq+IM8XiW/cr9rWm9wATKfKGcmmFauumALrsffUpHVCM
 4hSNgBv5t2V9ptZ+MDlM/Ku+zk9GoqwQ+hemdpVtiyhOtGUPGFBn5YLE4c2DHFxV
 +L9JtBnFn8obnssNoz0wL+QvZchT1qUHMhH5CWAanjw9CTDp/YwQ2P01zK+00s9d
 4cB7fUG3WNto5eXXEGMaXeDsUEz8z//hTe3j5sVbnHsXi0R3dhv7iryifmx4bUKU
 H9EwAc+uNUHbvBy7u6IWg0I8P2n00CCO6JqXijQ92zELJ5j0XhzHUI2dOXn+zyEo
 3FZu56LFnSSUBEXuTjq4
 =PcNw
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/dgibson/tags/ppc-for-2.9-20170303' into staging

ppc patch queuye for 2017-03-03

This will probably be my last pull request before the hard freeze.  It
has some new work, but that has all been posted in draft before the
soft freeze, so I think it's reasonable to include in qemu-2.9.

This batch has:
    * A substantial amount of POWER9 work
        * Implements the legacy (hash) MMU for POWER9
	* Some more preliminaries for implementing the POWER9 radix
          MMU
	* POWER9 has_work
	* Basic POWER9 compatibility mode handling
	* Removal of some premature tests
    * Some cleanups and fixes to the existing MMU code to make the
      POWER9 work simpler
    * A bugfix for TCG multiply adds on power
    * Allow pseries guests to access PCIe extended config space

This also includes a code-motion not strictly in ppc code - moving
getrampagesize() from ppc code to exec.c.  This will make some future
VFIO improvements easier, Paolo said it was ok to merge via my tree.

# gpg: Signature made Fri 03 Mar 2017 03:20:36 GMT
# gpg:                using RSA key 0x6C38CACA20D9B392
# gpg: Good signature from "David Gibson <david@gibson.dropbear.id.au>"
# gpg:                 aka "David Gibson (Red Hat) <dgibson@redhat.com>"
# gpg:                 aka "David Gibson (ozlabs.org) <dgibson@ozlabs.org>"
# gpg:                 aka "David Gibson (kernel.org) <dwg@kernel.org>"
# Primary key fingerprint: 75F4 6586 AE61 A66C C44E  87DC 6C38 CACA 20D9 B392

* remotes/dgibson/tags/ppc-for-2.9-20170303:
  target/ppc: rewrite f[n]m[add,sub] using float64_muladd
  spapr: Small cleanup of PPC MMU enums
  spapr_pci: Advertise access to PCIe extended config space
  target/ppc: Rework hash mmu page fault code and add defines for clarity
  target/ppc: Move no-execute and guarded page checking into new function
  target/ppc: Add execute permission checking to access authority check
  target/ppc: Add Instruction Authority Mask Register Check
  hw/ppc/spapr: Add POWER9 to pseries cpu models
  target/ppc/POWER9: Add cpu_has_work function for POWER9
  target/ppc/POWER9: Add POWER9 pa-features definition
  target/ppc/POWER9: Add POWER9 mmu fault handler
  target/ppc: Don't gen an SDR1 on POWER9 and rework register creation
  target/ppc: Add patb_entry to sPAPRMachineState
  target/ppc/POWER9: Add POWERPC_MMU_V3 bit
  powernv: Don't test POWER9 CPU yet
  exec, kvm, target-ppc: Move getrampagesize() to common code
  target/ppc: Add POWER9/ISAv3.00 to compat_table

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-03-04 16:31:14 +00:00
Paolo Bonzini d98d407234 cpus: remove ugly cast on sigbus_handler
The cast is there because sigbus_handler is invoked via sigfd_handler.
But it feels just wrong to use struct qemu_signalfd_siginfo in the
prototype of a function that is passed to sigaction.

Instead, do a simple-minded conversion of qemu_signalfd_siginfo to
siginfo_t.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-03 16:40:02 +01:00
Alexey Kardashevskiy 9c60766887 exec, kvm, target-ppc: Move getrampagesize() to common code
getrampagesize() returns the largest supported page size and mainly
used to know if huge pages are enabled.

However is implemented in target-ppc/kvm.c and not available
in TCG or other architectures.

This renames and moves gethugepagesize() to mmap-alloc.c where
fd-based analog of it is already implemented. This renames and moves
getrampagesize() to exec.c as it seems to be the common place for
helpers like this.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
2017-03-03 11:30:59 +11:00
Peter Maydell c9fc677a35 -----BEGIN PGP SIGNATURE-----
iQIcBAABAgAGBQJYto49AAoJENro4Ql1lpzljb8P/RutuV92h/e/RvIQ00gIE1Tk
 Tdma/9HpobMtutScp7xCbSjDCaFBHtk8YFmdbPwcwLpNIg9RGUs5cCTVEPvT8nq3
 XRrUFtCzZua4U4CKLOAbo53bDN2x36r6rHSpX7FaYvC51o47MNFS2fpKJ5R8Rg4s
 v9i9zM6bWGYzNbBnK4XDi251/7r8yK2g3okBEZao5TDwBUCtimbwfXn9E/iB21XD
 HJJRZGIkgCFXebCbPzLfob8NxQi0whuJW6N9XscJOy1AKDTfGT4QUsUUkPUZNRVe
 lbGjoGJnq5XYMO+9OWJzaSf6ecFFQT/Seu5P6xLb3SRgdT9IXISouPt9sOsYlM7R
 U/Sw34gPKb2979gASLs2NPbrTPHBQp0hdL8E01LRFjdGVHuvgZcGr0OdxpbUSkEf
 nJgtBFpLVQdL+qtdQtxgSBZz0/hWMIRcXB++MCPfpWpP9uBUErr4/XQN2rfqLLUM
 UgA/doDMX7Hc9m81mZ+h+Pji+9O8zWjt7NKJXgPeZPsUsMbUe05VzAl3Fp4khEWM
 05hrFB5biQguXkHXBIKO/fWwaftRaatqy0qAvXaiKidcRzQjF9ohlZgWd/CJyAWz
 V4GocO2oZL3rxQXwW6kh3HKlMCWUj563FhT4V5eN8VQE5PWLQQ+ObBkRHWfyayRE
 eEFFYApPQRVibAo9U7mC
 =09RR
 -----END PGP SIGNATURE-----

Merge remote-tracking branch 'remotes/elmarco/tags/leak-pull-request' into staging

# gpg: Signature made Wed 01 Mar 2017 09:02:53 GMT
# gpg:                using RSA key 0xDAE8E10975969CE5
# gpg: Good signature from "Marc-André Lureau <marcandre.lureau@redhat.com>"
# gpg:                 aka "Marc-André Lureau <marcandre.lureau@gmail.com>"
# 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: 87A9 BD93 3F87 C606 D276  F62D DAE8 E109 7596 9CE5

* remotes/elmarco/tags/leak-pull-request: (28 commits)
  tests: fix virtio-blk-test leaks
  tests: add specialized device_find function
  tests: fix usb-test leaks
  tests: allows to run single test in usb-hcd-ehci-test
  usb: release the created buses
  bus: do not unref hotplug handler
  tests: fix virtio-9p-test leaks
  tests: fix virtio-scsi-test leak
  tests: fix e1000e leaks
  tests: fix i440fx-test leaks
  tests: fix e1000-test leak
  tests: fix tco-test leaks
  tests: fix eepro100-test leak
  pc: pcihp: avoid adding ACPI_PCIHP_PROP_BSEL twice
  tests: fix ipmi-bt-test leak
  tests: fix ipmi-kcs-test leak
  tests: fix bios-tables-test leak
  tests: fix hd-geo-test leaks
  tests: fix ide-test leaks
  tests: fix vhost-user-test leaks
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2017-03-02 15:25:37 +00:00
Marc-André Lureau e703dcbaee timer: use an inline function for free
Similarly to allocation, do it from an inline function. This allows
tests to only use the headers for allocation/free of timer.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2017-03-01 00:09:28 +04:00
Markus Armbruster 9e19ad4e49 option: Tweak invalid size error message and unbreak iotest 049
Commit 75cdcd1 neglected to update tests/qemu-iotests/049.out, and
made the error message for negative size worse.  Fix that.

Reported-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2017-02-28 20:40:31 +01:00
Markus Armbruster 75cdcd1553 option: Fix checking of sizes for overflow and trailing crap
parse_option_size()'s checking for overflow and trailing crap is
wrong.  Has always been that way.  qemu_strtosz() gets it right, so
use that.

This adds support for size suffixes 'P', 'E', and ignores case for all
suffixes, not just 'k'.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1487708048-2131-25-git-send-email-armbru@redhat.com>
2017-02-23 20:35:36 +01:00
Markus Armbruster f46bfdbfc8 util/cutils: Change qemu_strtosz*() from int64_t to uint64_t
This will permit its use in parse_option_size().

Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com> (maintainer:X86)
Cc: Kevin Wolf <kwolf@redhat.com> (supporter:Block layer core)
Cc: Max Reitz <mreitz@redhat.com> (supporter:Block layer core)
Cc: qemu-block@nongnu.org (open list:Block layer core)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1487708048-2131-24-git-send-email-armbru@redhat.com>
2017-02-23 20:35:36 +01:00
Markus Armbruster f17fd4fdf0 util/cutils: Return qemu_strtosz*() error and value separately
This makes qemu_strtosz(), qemu_strtosz_mebi() and
qemu_strtosz_metric() similar to qemu_strtoi64(), except negative
values are rejected.

Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com> (maintainer:X86)
Cc: Kevin Wolf <kwolf@redhat.com> (supporter:Block layer core)
Cc: Max Reitz <mreitz@redhat.com> (supporter:Block layer core)
Cc: qemu-block@nongnu.org (open list:Block layer core)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1487708048-2131-23-git-send-email-armbru@redhat.com>
2017-02-23 20:35:36 +01:00
Markus Armbruster 4fcdf65ae2 util/cutils: Let qemu_strtosz*() optionally reject trailing crap
Change the qemu_strtosz() & friends to return -EINVAL when @endptr is
null and the conversion doesn't consume the string completely.
Matches how qemu_strtol() & friends work.

Only test_qemu_strtosz_simple() passes a null @endptr.  No functional
change there, because its conversion consumes the string.

Simplify callers that use @endptr only to fail when it doesn't point
to '\0' to pass a null @endptr instead.

Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com> (maintainer:X86)
Cc: Kevin Wolf <kwolf@redhat.com> (supporter:Block layer core)
Cc: Max Reitz <mreitz@redhat.com> (supporter:Block layer core)
Cc: qemu-block@nongnu.org (open list:Block layer core)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <1487708048-2131-22-git-send-email-armbru@redhat.com>
2017-02-23 20:35:36 +01:00
Markus Armbruster 17f942560e util/cutils: Drop QEMU_STRTOSZ_DEFSUFFIX_* macros
Writing QEMU_STRTOSZ_DEFSUFFIX_* instead of '*' gains nothing.  Get
rid of these eyesores.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <1487708048-2131-18-git-send-email-armbru@redhat.com>
2017-02-23 20:35:36 +01:00
Markus Armbruster 466dea14e6 util/cutils: New qemu_strtosz()
Most callers of qemu_strtosz_suffix() pass QEMU_STRTOSZ_DEFSUFFIX_B.
Capture the pattern in new qemu_strtosz().

Inline qemu_strtosz_suffix() into its only remaining caller.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1487708048-2131-17-git-send-email-armbru@redhat.com>
2017-02-23 20:35:36 +01:00
Markus Armbruster e591591b32 util/cutils: Rename qemu_strtosz() to qemu_strtosz_MiB()
With qemu_strtosz(), no suffix means mebibytes.  It's used rarely.
I'm going to add a similar function where no suffix means bytes.
Rename qemu_strtosz() to qemu_strtosz_MiB() to make the name
qemu_strtosz() available for the new function.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1487708048-2131-16-git-send-email-armbru@redhat.com>
2017-02-23 20:35:36 +01:00
Markus Armbruster d2734d2629 util/cutils: New qemu_strtosz_metric()
To parse numbers with metric suffixes, we use

    qemu_strtosz_suffix_unit(nptr, &eptr, QEMU_STRTOSZ_DEFSUFFIX_B, 1000)

Capture this in a new function for legibility:

    qemu_strtosz_metric(nptr, &eptr)

Replace test_qemu_strtosz_suffix_unit() by test_qemu_strtosz_metric().

Rename qemu_strtosz_suffix_unit() to do_strtosz() and give it internal
linkage.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1487708048-2131-15-git-send-email-armbru@redhat.com>
2017-02-23 20:35:36 +01:00
Markus Armbruster 3403e5eb88 option: Fix to reject invalid and overflowing numbers
parse_option_number() fails to check for these errors after
strtoull().  Has always been broken.  Fix that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1487708048-2131-10-git-send-email-armbru@redhat.com>
2017-02-23 20:35:35 +01:00
Markus Armbruster 4baef2679e util/cutils: Clean up control flow around qemu_strtol() a bit
Reorder check_strtox_error() to make it obvious that we always store
through a non-null @endptr.

Transform

    if (some error) {
        error case ...
        err = value for error case;
    } else {
        normal case ...
        err = value for normal case;
    }
    return err;

to

    if (some error) {
        error case ...
        return value for error case;
    }
    normal case ...
    return value for normal case;

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1487708048-2131-9-git-send-email-armbru@redhat.com>
2017-02-23 20:35:35 +01:00
Markus Armbruster 717adf9609 util/cutils: Clean up variable names around qemu_strtol()
Name same things the same, different things differently.

* qemu_strtol()'s parameter @nptr is called @p in
  check_strtox_error().  Rename the latter.

* qemu_strtol()'s parameter @endptr is called @next in
  check_strtox_error().  Rename the latter.

* qemu_strtol()'s variable @p is called @endptr in
  check_strtox_error().  Rename both to @ep.

* qemu_strtol()'s variable @err is *negative* errno,
  check_strtox_error()'s parameter @err is *positive*.  Rename the
  latter to @libc_errno.

Same for qemu_strtoul(), qemu_strtoi64(), qemu_strtou64(), of course.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1487708048-2131-8-git-send-email-armbru@redhat.com>
2017-02-23 20:35:35 +01:00
Markus Armbruster b30d188677 util/cutils: Rename qemu_strtoll(), qemu_strtoull()
The name qemu_strtoll() suggests conversion to long long, but it
actually converts to int64_t.  Rename to qemu_strtoi64().

The name qemu_strtoull() suggests conversion to unsigned long long,
but it actually converts to uint64_t.  Rename to qemu_strtou64().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <1487708048-2131-7-git-send-email-armbru@redhat.com>
2017-02-23 20:35:35 +01:00
Markus Armbruster 4295f879be util/cutils: Rewrite documentation of qemu_strtol() & friends
Fixes the following documentation bugs:

* Fails to document that null @nptr is safe.

* Fails to document that we return -EINVAL when no conversion could be
  performed (commit 47d4be1).

* Confuses long long with int64_t, and unsigned long long with
  uint64_t.

* Claims the unsigned conversions can underflow.  They can't.

While there, mark problematic assumptions that int64_t is long long,
and uint64_t is unsigned long long with FIXME comments.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <1487708048-2131-6-git-send-email-armbru@redhat.com>
2017-02-23 20:35:35 +01:00
Markus Armbruster 8ee8409eff option: Assert value string isn't null
Plenty of code relies on QemuOpt member @str not being null, including
qemu_opts_print(), qemu_opts_to_qdict(), and callbacks passed to
qemu_opt_foreach().

Begs the question whether it can be null.  Only opt_set() creates
QemuOpt.  It sets member @str to its argument @value.  Passing null
for @value would plant a time bomb.  Callers:

* opts_do_parse() can't pass null.

* qemu_opt_set() passes its argument @value.  Callers:

  - qemu_opts_from_qdict_1() can't pass null

  - qemu_opts_set() passes its argument @value, but none of its
    callers pass null.

  - Many more outside qemu-option.c, but they shouldn't pass null,
    either.

Assert member @str isn't null, so that misuse is caught right away.

Simplify parse_option_bool(), parse_option_number() and
parse_option_size() accordingly.  Best viewed with whitespace changes
ignored.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1487708048-2131-3-git-send-email-armbru@redhat.com>
2017-02-23 20:35:35 +01:00
Paolo Bonzini a7b91d35ba coroutine-lock: make CoRwlock thread-safe and fair
This adds a CoMutex around the existing CoQueue.  Because the write-side
can just take CoMutex, the old "writer" field is not necessary anymore.
Instead of removing it altogether, count the number of pending writers
during a read-side critical section and forbid further readers from
entering.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213181244.16297-7-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21 11:39:40 +00:00
Paolo Bonzini 1ace7ceac5 coroutine-lock: add mutex argument to CoQueue APIs
All that CoQueue needs in order to become thread-safe is help
from an external mutex.  Add this to the API.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213181244.16297-6-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21 11:39:40 +00:00
Paolo Bonzini 480cff6322 coroutine-lock: add limited spinning to CoMutex
Running a very small critical section on pthread_mutex_t and CoMutex
shows that pthread_mutex_t is much faster because it doesn't actually
go to sleep.  What happens is that the critical section is shorter
than the latency of entering the kernel and thus FUTEX_WAIT always
fails.  With CoMutex there is no such latency but you still want to
avoid wait and wakeup.  So introduce it artificially.

This only works with one waiters; because CoMutex is fair, it will
always have more waits and wakeups than a pthread_mutex_t.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Message-id: 20170213181244.16297-3-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2017-02-21 11:39:40 +00:00