There was not mention QEMUTimer created with timer_new*() must
be released with timer_free() instead of g_free(), because then
active timers are removed from the active list. Update the
documentation mentioning timer_free().
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
qemu_clock_get_main_loop_timerlist and timerlist_get_clock have been
unused since they were originally added in
ff83c66ecc ("aio / timers: Split QEMUClock into QEMUClock and QEMUTimerList")
Remove them.
Signed-off-by: Dr. David Alan Gilbert <dave@treblig.org>
Reviewed-by: Bernhard Beschow <shentey@gmail.com>
Message-ID: <20240919144124.309646-1-dave@treblig.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
g_new(T, n) is neater than g_malloc(sizeof(T) * n). It's also safer,
for two reasons. One, it catches multiplication overflowing size_t.
Two, it returns T * rather than void *, which lets the compiler catch
more type errors.
This commit only touches allocations with size arguments of the form
sizeof(T).
Patch created mechanically with:
$ spatch --in-place --sp-file scripts/coccinelle/use-g_new-etc.cocci \
--macro-file scripts/cocci-macro-file.h FILES...
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20220315144156.1595462-4-armbru@redhat.com>
Reviewed-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
The pseries machines introduced the concept of 'unplug timeout' for CPU
hotunplugs. The idea was to circunvent a deficiency in the pSeries
specification (PAPR), that currently does not define a proper way for
the hotunplug to fail. If the guest refuses to release the CPU (see [1]
for an example) there is no way for QEMU to detect the failure.
Further discussions about how to send a QAPI event to inform about the
hotunplug timeout [2] exposed problems that weren't predicted back when
the idea was developed. Other QEMU machines don't have any type of
hotunplug timeout mechanism for any device, e.g. ACPI based machines
have a way to make hotunplug errors visible to the hypervisor. This
would make this timeout mechanism exclusive to pSeries, which is not
ideal.
The real problem is that a QAPI event that reports hotunplug timeouts
puts the management layer (namely Libvirt) in a weird spot. We're not
telling that the hotunplug failed, because we can't be 100% sure of
that, and yet we're resetting the unplug state back, preventing any
DEVICE_DEL events to reach out in case the guest decides to release the
device. Libvirt would need to inspect the guest itself to see if the
device was released or not, otherwise the internal domain states will be
inconsistent. Moreover, Libvirt already has an 'unplug timeout'
concept, and a QEMU side timeout would need to be juggled together with
the existing Libvirt timeout.
All this considered, this solution ended up creating more trouble than
it solved. This patch reverts the 3 commits that introduced the timeout
mechanism for CPU hotplugs in pSeries machines.
This reverts commit 4515a5f786
"qemu_timer.c: add timer_deadline_ms() helper"
This reverts commit d1c2e3ce3d
"spapr_drc.c: add hotunplug timeout for CPUs"
This reverts commit 51254ffb32
"spapr_drc.c: introduce unplug_timeout_timer"
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1911414
[2] https://lists.gnu.org/archive/html/qemu-devel/2021-03/msg04682.html
CC: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210401000437.131140-2-danielhb413@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Since 5f8e93c3e2 ("util/qemu-timer: Make timer_free() imply timer_del()", 2021-01-08)
it is not possible anymore to pass a NULL pointer to timer_free(). Previously
it would do nothing as it would simply pass NULL down to g_free().
Rectify this, which also fixes "-chardev braille" when there is no device.
Reported-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The pSeries machine is using QEMUTimer internals to return the timeout
in seconds for a timer object, in hw/ppc/spapr.c, function
spapr_drc_unplug_timeout_remaining_sec().
Create a helper in qemu-timer.c to retrieve the deadline for a QEMUTimer
object, in ms, to avoid exposing timer internals to the PPC code.
CC: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20210301124133.23800-2-danielhb413@gmail.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Currently timer_free() is a simple wrapper for g_free(). This means
that the timer being freed must not be currently active, as otherwise
QEMU might crash later when the active list is processed and still
has a pointer to freed memory on it. As a result almost all calls to
timer_free() are preceded by a timer_del() call, as can be seen in
the output of
git grep -B1 '\<timer_free\>'
This is unfortunate API design as it makes it easy to accidentally
misuse (by forgetting the timer_del()), and the correct use is
annoyingly verbose.
Make timer_free() imply a timer_del().
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201215154107.3255-2-peter.maydell@linaro.org
refactoring of cpus.c continues with cpu timer state extraction.
cpu-timers: responsible for the softmmu cpu timers state,
including cpu clocks and ticks.
icount: counts the TCG instructions executed. As such it is specific to
the TCG accelerator. Therefore, it is built only under CONFIG_TCG.
One complication is due to qtest, which uses an icount field to warp time
as part of qtest (qtest_clock_warp).
In order to solve this problem, provide a separate counter for qtest.
This requires fixing assumptions scattered in the code that
qtest_enabled() implies icount_enabled(), checking each specific case.
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[remove redundant initialization with qemu_spice_init]
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
[fix lingering calls to icount_get]
Signed-off-by: Claudio Fontana <cfontana@suse.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Some older parts of QEMU's codebase assume that CLOCK_MONOTONIC
might not be defined by the host OS, and have workarounds to
deal with this. However, more recently (notably in commit
50290c002c for qemu-img in mid-2019, but also much
earlier in 2011 in commit 22795174a3 for ui/spice-display.c)
we've written code that assumes CLOCK_MONOTONIC is always
defined. The only host OS anybody's ever noticed this on
is OSX 10.11 and earlier, which we don't support.
So we can assume that all our host OSes have the #define,
and we can remove some now-unnecessary ifdefs.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200201172252.6605-1-peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
icount-based record/replay uses qemu_clock_deadline_ns_all to measure
the period until vCPU may be interrupted.
This function takes in account the virtual timers, because they belong
to the virtual devices that may generate interrupt request or affect
the virtual machine state.
However, there are a subset of virtual timers, that are marked with
'external' flag. These do not change the virtual machine state and
only based on virtual clock. Calculating the deadling using the external
timers breaks the determinism, because they do not belong to the replayed
part of the virtual machine.
This patch fixes the deadline calculation for this case by adding
new parameter for skipping the external timers when it is needed.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
--
v2 changes:
- added new parameter for timer attribute mask
Message-Id: <156404426682.18669.17014100602930969222.stgit@pasha-Precision-3630-Tower>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
No header includes qemu-common.h after this commit, as prescribed by
qemu-common.h's file comment.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-5-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
include/hw/arm/xlnx-zynqmp.h hw/arm/nrf51_soc.c hw/arm/msf2-soc.c
block/qcow2-refcount.c block/qcow2-cluster.c block/qcow2-cache.c
target/arm/cpu.h target/lm32/cpu.h target/m68k/cpu.h target/mips/cpu.h
target/moxie/cpu.h target/nios2/cpu.h target/openrisc/cpu.h
target/riscv/cpu.h target/tilegx/cpu.h target/tricore/cpu.h
target/unicore32/cpu.h target/xtensa/cpu.h; bsd-user/main.c and
net/tap-bsd.c fixed up]
Attributes are simple flags, associated with individual timers for their
whole lifetime. They intended to be used to mark individual timers for
special handling when they fire.
New/init functions family in timer interface updated and refactored (new
'attribute' argument added, timer_list replaced with timer_list_group+type
combinations, comments improved to avoid info duplication). Also existing
aio interface extended with attribute-enabled variants of functions,
which create/initialize timers.
Signed-off-by: Artem Pisarenko <artem.k.pisarenko@gmail.com>
Message-Id: <f47b81dbce734e9806f9516eba8ca588e6321c2f.1539764043.git.artem.k.pisarenko@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
That patch series introduced new virtual clock type for use in external
subsystems. It breaks desired behavior in non-record/replay usage
scenarios due to a small change to existing behavior. Processing of
virtual timers belonging to new clock type is kicked off to the main
loop, which makes these timers asynchronous with vCPU thread and,
in icount mode, with whole guest execution. This breaks expected
determinism in non-record/replay icount mode of emulation where these
"external subsystems" are isolated from the host (i.e. they are
external only to guest core, not to the entire emulation environment).
Example for slirp ("user" backend for network device):
User runs qemu in icount mode with rtc clock=vm without any external
communication interfaces but with "-netdev user,restrict=on". It expects
deterministic execution, because network services are emulated inside
qemu and isolated from host. There are no reasons to get reply from DHCP
server with different delay or something like that.
The next patches revert reimplements the same changes in a better way.
This reverts commit 87f4fe7653.
This reverts commit 775a412bf8.
This reverts commit 9888091404.
Signed-off-by: Artem Pisarenko <artem.k.pisarenko@gmail.com>
Message-Id: <18b1e7c8f155fe26976f91be06bde98eef6f8751.1539764043.git.artem.k.pisarenko@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When we implemented per-vCPU TCG contexts, we forgot to also
distribute the tcg_time counter, which has remained as a global
accessed without any serialization, leading to potentially missed
counts.
Fix it by distributing the field over the TCG contexts, embedding
it into TCGProfile with a field called "cpu_exec_time", which is more
descriptive than "tcg_time". Add a function to query this value
directly, and for completeness, fill in the field in
tcg_profile_snapshot, even though its callers do not use it.
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <20181010144853.13005-5-cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Slirp and VNC modules use virtual clock for processing some events that
are related to the guest execution speed.
But virtual clock-related events are consideres to be deterministic and
are recorded/replayed by icount mechanism. But slirp and VNC lie outside
the recorded guest core (which includes CPU and peripherals).
Therefore slirp and VNC are external for the guest, but should work at
guest speed.
This patch introduces new virtual clock which can be used for external
subsystems for running timers that are synchronized with the guest.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgaluk@ispras.ru>
Message-Id: <20180912082002.3228.82417.stgit@pasha-VirtualBox>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
