Commit Graph

14 Commits

Author SHA1 Message Date
Richard Henderson
d7ec12f83c tcg: Split out tcg init functions to tcg/startup.h
The tcg/tcg.h header is a big bucket, containing stuff related to
the translators and the JIT backend.  The places that initialize
tcg or create new threads do not need all of that, so split out
these three functions to a new header.

Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-10-04 11:03:54 -07:00
Richard Henderson
464dacf609 accel/tcg: Move can_do_io to CPUNegativeOffsetState
Minimize the displacement to can_do_io, since it may
be touched at the start of each TranslationBlock.
It fits into other padding within the substructure.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-10-03 08:01:02 -07:00
Nicholas Piggin
0e5903436d accel/tcg: mttcg remove false-negative halted assertion
mttcg asserts that an execution ending with EXCP_HALTED must have
cpu->halted. However between the event or instruction that sets
cpu->halted and requests exit and the assertion here, an
asynchronous event could clear cpu->halted.

This leads to crashes running AIX on ppc/pseries because it uses
H_CEDE/H_PROD hcalls, where H_CEDE sets self->halted = 1 and
H_PROD sets other cpu->halted = 0 and kicks it.

H_PROD could be turned into an interrupt to wake, but several other
places in ppc, sparc, and semihosting follow what looks like a similar
pattern setting halted = 0 directly. So remove this assertion.

Reported-by: Ivan Warren <ivan@vmfacility.fr>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20230829010658.8252-1-npiggin@gmail.com>
[rth: Keep the case label and adjust the comment.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-09-15 05:26:50 -07:00
Philippe Mathieu-Daudé
af03d22a0a accel: Remove unused hThread variable on TCG/WHPX
On Windows hosts, cpu->hThread is assigned but never accessed:
remove it.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230624174121.11508-4-philmd@linaro.org>
2023-06-28 13:55:35 +02:00
Paolo Bonzini
06831001ac atomics: eliminate mb_read/mb_set
qatomic_mb_read and qatomic_mb_set were the very first atomic primitives
introduced for QEMU; their semantics are unclear and they provide a false
sense of safety.

The last use of qatomic_mb_read() has been removed, so delete it.
qatomic_mb_set() instead can survive as an optimized
qatomic_set()+smp_mb(), similar to Linux's smp_store_mb(), but
rename it to qatomic_set_mb() to match the order of the two
operations.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2023-06-06 09:42:14 +02:00
Richard Henderson
e5b4906377 *: Add missing includes of tcg/tcg.h
This had been pulled in from exec/cpu_ldst.h, via exec/exec-all.h,
but the include of tcg.h will be removed.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2023-06-05 12:04:28 -07:00
Peter Maydell
0585105c80 Revert "accel/tcg: Init TCG cflags in vCPU thread handler"
Commit a82fd5a4ec was intended to be a code cleanup, but
unfortunately it has a bug. It moves the initialization of the
TCG cflags from the "start a new vcpu" function to the
thread handler; this is fine when each vcpu has its own thread,
but when we are doing round-robin of vcpus on a single thread
we end up only initializing the cflags for CPU 0, not for any
of the others.

The most obvious effect of this bug is that running in icount
mode with more than one CPU is broken; typically the guest
hangs shortly after it brings up the secondary CPUs.

This reverts commit a82fd5a4ec.

Cc: qemu-stable@nongnu.org
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20221021163409.3674911-1-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-10-25 22:01:14 +10:00
Philippe Mathieu-Daudé
a82fd5a4ec accel/tcg: Init TCG cflags in vCPU thread handler
Move TCG cflags initialization to thread handler.
Remove the duplicated assert checks.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220323171751.78612-6-philippe.mathieu.daude@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2022-06-20 13:11:36 -07:00
Marc-André Lureau
0f9668e0c1 Remove qemu-common.h include from most units
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20220323155743.1585078-33-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-04-06 14:31:55 +02:00
Markus Armbruster
b21e238037 Use g_new() & friends where that makes obvious sense
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>
2022-03-21 15:44:44 +01:00
Philippe Mathieu-Daudé
03ff4f8df9 misc: Add missing "sysemu/cpu-timers.h" include
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220207075426.81934-18-f4bug@amsat.org>
2022-03-06 13:15:42 +01:00
Greg Kurz
dd47a8f654 accel/tcg: Register a force_rcu notifier
A TCG vCPU doing a busy loop systematicaly hangs the QEMU monitor
if the user passes 'device_add' without argument. This is because
drain_cpu_all() which is called from qmp_device_add() cannot return
if readers don't exit read-side critical sections. That is typically
what busy-looping TCG vCPUs do:

int cpu_exec(CPUState *cpu)
{
[...]
    rcu_read_lock();
[...]
    while (!cpu_handle_exception(cpu, &ret)) {
        // Busy loop keeps vCPU here
    }
[...]
    rcu_read_unlock();

    return ret;
}

For MTTCG, have all vCPU threads register a force_rcu notifier that will
kick them out of the loop using async_run_on_cpu(). The notifier is called
with the rcu_registry_lock mutex held, using async_run_on_cpu() ensures
there are no deadlocks.

For RR, a single thread runs all vCPUs. Just register a single notifier
that kicks the current vCPU to the next one.

For MTTCG:
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>

For RR:
Suggested-by: Richard Henderson <richard.henderson@linaro.org>

Fixes: 7bed89958b ("device_core: use drain_call_rcu in in qmp_device_add")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/650
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211109183523.47726-3-groug@kaod.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-11-10 13:20:15 +01:00
Richard Henderson
6cc9d67c6f accel/tcg: Precompute curr_cflags into cpu->tcg_cflags
The primary motivation is to remove a dozen insns along
the fast-path in tb_lookup.  As a byproduct, this allows
us to completely remove parallel_cpus.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-03-06 11:53:57 -08:00
Claudio Fontana
b86f59c715 accel: replace struct CpusAccel with AccelOpsClass
This will allow us to centralize the registration of
the cpus.c module accelerator operations (in accel/accel-softmmu.c),
and trigger it automatically using object hierarchy lookup from the
new accel_init_interfaces() initialization step, depending just on
which accelerators are available in the code.

Rename all tcg-cpus.c, kvm-cpus.c, etc to tcg-accel-ops.c,
kvm-accel-ops.c, etc, matching the object type names.

Signed-off-by: Claudio Fontana <cfontana@suse.de>
Message-Id: <20210204163931.7358-18-cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-02-05 10:24:15 -10:00