We can't always guarantee we get to the end of a translator loop.
Although this can happen for a variety of reasons it does happen more
often on x86 system emulation when an instruction spans across to an
un-faulted page. This caused confusion of the instruction tracking
data resulting in apparent reverse execution (at least from the
plugins point of view).
Fix this by moving the reset code to plugin_gen_tb_start so we always
start with a clean slate.
We unconditionally reset tcg_ctx->plugin_insn as the
plugin_insn_append code uses this as a proxy for knowing if plugins
are enabled for the current instruction. Otherwise we can hit a race
where a previously instrumented thread leaves a stale value after the
main thread exits and disables instrumentation.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/824
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220204204335.1689602-27-alex.bennee@linaro.org>
If you really want to trace all memory operations TCG plugins gives
you a more flexible interface for doing so.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Cc: Luis Vilanova <vilanova@imperial.ac.uk>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20220204204335.1689602-19-alex.bennee@linaro.org>
As --enable-profiler isn't defended in CI we missed this breakage.
Move the qmp handler into accel/tcg so we have access to the helpers
we need. While we are at it ensure we gate the feature on CONFIG_TCG.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Reported-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Fixes: 37087fde0e ("qapi: introduce x-query-profile QMP command")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/773
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20220105135009.1584676-23-alex.bennee@linaro.org>
Renaming defines for quad in their various forms so that their signedness is
now explicit.
Done using git grep as suggested by Philippe, with a bit of hand edition to
keep assignments aligned.
Signed-off-by: Frédéric Pétrot <frederic.petrot@univ-grenoble-alpes.fr>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-id: 20220106210108.138226-2-frederic.petrot@univ-grenoble-alpes.fr
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
When we set cpu->cflags_next_tb it is because we want to carefully
control the execution of the next TB. Currently there is a race that
causes the second stage of watchpoint handling to get ignored if an
IRQ is processed before we finish executing the instruction that
triggers the watchpoint. Use the new CF_NOIRQ facility to avoid the
race.
We also suppress IRQs when handling precise self modifying code to
avoid unnecessary bouncing.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: Pavel Dovgalyuk <pavel.dovgalyuk@ispras.ru>
Fixes: https://gitlab.com/qemu-project/qemu/-/issues/245
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211129140932.4115115-3-alex.bennee@linaro.org>
dlopen is never used after it is sought via cc.find_library, because
plugins use gmodule instead; remove the test.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20211110092454.30916-1-pbonzini@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211115142915.3797652-5-alex.bennee@linaro.org>
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>
Currently we make the assumption that the guest frontend loads all
op code bytes sequentially. This mostly holds up for regular fixed
encodings but some architectures like s390x like to re-read the
instruction which causes weirdness to occur. Rather than changing the
frontends make the plugin API a little more ergonomic and able to
handle the re-read case.
Stuff will still get strange if we read ahead of the opcode but so far
no front ends have done that and this patch asserts the case so we can
catch it early if they do.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211026102234.3961636-21-alex.bennee@linaro.org>
This is a counterpart to the HMP "info opcount" command. It is being
added with an "x-" prefix because this QMP command is intended as an
ad hoc debugging tool and will thus not be modelled in QAPI as fully
structured data, nor will it have long term guaranteed stability.
The existing HMP command is rewritten to call the QMP command.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This is a counterpart to the HMP "info jit" command. It is being
added with an "x-" prefix because this QMP command is intended as an
ad hoc debugging tool and will thus not be modelled in QAPI as fully
structured data, nor will it have long term guaranteed stability.
The existing HMP command is rewritten to call the QMP command.
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
To be called from tcg generated code on hosts that support
unaligned accesses natively, in response to an access that
is supposed to be aligned.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Use the new cpu_loop_exit_sigbus for cpu_mmu_lookup.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Use the new cpu_loop_exit_sigbus for atomic_mmu_lookup, which
has access to complete alignment info from the TCGMemOpIdx arg.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This is a new interface to be provided by the os emulator for
raising SIGSEGV on fault. Use the new record_sigsegv target hook.
Reviewed by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split host_signal_pc and host_signal_write out of user-exec.c.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split host_signal_pc and host_signal_write out of user-exec.c.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split host_signal_pc and host_signal_write out of user-exec.c.
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split host_signal_pc and host_signal_write out of user-exec.c.
Drop the *BSD code, to be re-created under bsd-user/ later.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split host_signal_pc and host_signal_write out of user-exec.c.
Drop the *BSD code, to be re-created under bsd-user/ later.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split host_signal_pc and host_signal_write out of user-exec.c.
Drop the *BSD code, to be re-created under bsd-user/ later.
Drop the Solaris code as completely unused.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split host_signal_pc and host_signal_write out of user-exec.c.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split host_signal_pc and host_signal_write out of user-exec.c.
Drop the *BSD code, to be re-created under bsd-user/ later.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split host_signal_pc and host_signal_write out of user-exec.c.
Drop the *BSD code, to be re-created under bsd-user/ later.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Remove the comment about siglongjmp. We do use sigsetjmp
in the main cpu loop, but we do not save the signal mask
as most exits from the cpu loop do not require them.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This is the major portion of handle_cpu_signal which is specific
to tcg, handling the page protections for the translations.
Most of the rest will migrate to linux-user/ shortly.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
v2: Pass guest address to handle_sigsegv_accerr_write.
Currently there are only two places that require we reset this
value before exiting to the main loop, but that will change.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split out a function to adjust the raw signal pc into a
value that could be passed to cpu_restore_state.
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
v2: Adjust pc in place; return MMUAccessType.
Currently the change in cpu_tb_exec is masked by the debug exception
being raised by the translators. But this allows us to remove that code.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
These functions have been replaced by cpu_*_mmu as the
most proper interface to use from target code.
Hide these declarations from code that should not use them.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
These functions are much closer to the softmmu helper
functions, in that they take the complete MemOpIdx,
and from that they may enforce required alignment.
The previous cpu_ldst.h functions did not have alignment info,
and so did not enforce it. Retain this by adding MO_UNALN to
the MemOp that we create in calling the new functions.
Note that we are not yet enforcing alignment for user-only,
but we now have the information with which to do so.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Coverity doesn't know enough about how we have arranged our plugin TCG
ops to know we will always have incremented insn_idx before injecting
the callback. Let us assert it for the benefit of Coverity and protect
ourselves from accidentally breaking the assumption and triggering
harder to grok errors deeper in the code if we attempt a negative
indexed array lookup.
However to get to this point we re-factor the code and remove the
second hand instruction boundary detection in favour of scanning the
full set of ops and using the existing INDEX_op_insn_start to cleanly
detect when the instruction has started. As we no longer need the
plugin specific list of ops we delete that.
My initial benchmarks shows no discernible impact of dropping the
plugin specific ops list.
Fixes: Coverity 1459509
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Cc: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20210917162332.3511179-12-alex.bennee@linaro.org>
There is no point in encoding load/store within a bit of
the memory trace info operand. Represent atomic operations
as a single read-modify-write tracepoint. Use MemOpIdx
instead of inventing a form specifically for traces.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Use the MemOpIdx directly, rather than the rearrangement
of the same bits currently done by the trace infrastructure.
Pass in enum qemu_plugin_mem_rw so that we are able to treat
read-modify-write operations as a single operation.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We will shortly use the MemOpIdx directly, but in the meantime
re-compute the trace meminfo.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We (will) often have the complete MemOpIdx handy, so use that.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We're about to move this out of tcg.h, so rename it
as we did when moving MemOp.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We are already inconsistent about whether or not
MO_SIGN is set in trace_mem_get_info. Dropping it
entirely allows some simplification.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Commit 372579427a ("tcg: enable thread-per-vCPU") added the following
comment describing EXCP_HALTED in qemu_tcg_cpu_thread_fn():
case EXCP_HALTED:
/* during start-up the vCPU is reset and the thread is
* kicked several times. If we don't ensure we go back
* to sleep in the halted state we won't cleanly
* start-up when the vCPU is enabled.
*
* cpu->halted should ensure we sleep in wait_io_event
*/
g_assert(cpu->halted);
break;
qemu_wait_io_event() is sysemu-specific, so we can restrict the
cpu_handle_halt() call in cpu_exec() to system emulation.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210912172731.789788-2-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
x86_64 dotnet/runtime uses cmpxchg for code patching. When running it
under s390x qemu-linux user, cpu_signal_handler() does not recognize
this as a write and does not restore PAGE_WRITE cleared by
tb_page_add(), incorrectly forwarding the signal to the guest code.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210803221606.150103-1-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
All targets call TCGCPUOps::cpu_exec_interrupt() from sysemu code.
Move its declaration to restrict it to system emulation.
Extend the code guarded.
Restrict the static inlined need_replay_interrupt() method to
avoid a "defined but not used" warning.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210911165434.531552-24-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
do_interrupt() is sysemu specific. However due to some X86
specific hack, it is also used in user-mode emulation, which
is why it couldn't be restricted to CONFIG_SOFTMMU (see the
comment around added in commit 7827168471: "cpu: tcg_ops:
move to tcg-cpu-ops.h, keep a pointer in CPUClass").
Keep the hack but rename the handler as fake_user_interrupt()
and restrict do_interrupt() to sysemu.
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210911165434.531552-6-f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The TCG_KICK_PERIOD macro is already defined in tcg-accel-ops-rr.h.
Remove it from tcg-accel-ops-rr.c.
Signed-off-by: Luc Michel <lmichel@kalray.eu>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210811141229.12470-1-lmichel@kalray.eu>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
translate_insn() implementations fetch instruction bytes piecemeal,
which can cause qemu-user to generate inconsistent translations if
another thread modifies them concurrently [1].
Fix by making pages containing translated instruction non-writable
right before loading instruction bytes from them.
[1] https://lists.nongnu.org/archive/html/qemu-devel/2021-08/msg00644.html
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20210805204835.158918-1-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This crept in as either a cut-and-paste error, or rebase error.
Fixes: cfec388518 ("atomic_template: add inline trace/plugin helpers")
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20210729004647.282017-24-richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
From clang-13:
accel/tcg/cpu-exec.c:783:15: error: variable 'cc' set but not used \
[-Werror,-Wunused-but-set-variable]
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
In cpu_loop_exec_tb(), we decide whether to look for a TB with
exactly insns_left instructions in it using the condition
(!cpu->icount_extra && insns_left > 0 && insns_left < tb->icount)
The check for icount_extra == 0 is unnecessary, because we just set
insns_left = MIN(0xffff, cpu->icount_budget);
icount_extra = icount_budget - insns_left;
and so icount_extra can only be non-zero if icount_budget > 0xffff
and insns_left == 0xffff. But in that case insns_left >= tb->icount
because 0xffff is much larger than TCG_MAX_INSNS, so the condition
will be false anyway.
Remove the unnecessary check, and instead assert:
* that we are only going to execute a partial TB here if the
icount budget has run out (ie icount_extra == 0)
* that the number of insns we're going to execute does fit into
the CF_COUNT_MASK
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210725174405.24568-3-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
In cpu_loop_exec_tb() we were bounding the number of insns we might
try to execute in a TB using CF_COUNT_MASK. This is incorrect,
because we can validly put up to 0xffff into icount_decr.u16.low. In
particular, since commit 78ff82bb1b reduced CF_COUNT_MASK to
511 this meant that we would incorrectly only try to execute 511
instructions in a 512-instruction TB, which could result in QEMU
hanging when in icount mode.
Use the actual maximum value, which is 0xffff. (This brings this code
in to line with the similar logic in icount_prepare_for_run() in
tcg-accel-ops-icount.c.)
Fixes: 78ff82bb1b
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/499
Message-Id: <20210725174405.24568-2-peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Set CF_SINGLE_STEP when single-stepping is enabled.
This avoids the need to flush all tb's when turning
single-stepping on or off.
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The access internal to tb_cflags() is atomic.
Avoid re-reading it as such for the multiple uses.
Tested-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
