In cpu_exec_step_atomic, we did not set CF_LAST_IO, which lead
to a loop with cpu_io_recompile.

But since 18a536f1 ("Always require can_do_io") we no longer
need a flag to indicate when the last insn should have can_do_io set,
so remove the flag entirely.

Reported-by: Clément Chigot <chigot@adacore.com>
Tested-by: Clément Chigot <chigot@adacore.com>
Reviewed-by: Claudio Fontana <cfontana@suse.de>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1961


Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

The softmmu/ directory contains files specific to system
emulation. Rename it as system/. Update meson rules, the
MAINTAINERS file and all the documentation and comments.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20231004090629.37473-14-philmd@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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>

CPU watchpoints can be use by non-TCG accelerators.

KVM uses them:

  $ git grep CPUWatchpoint|fgrep kvm
  target/arm/kvm64.c:1558:        CPUWatchpoint *wp = find_hw_watchpoint(cs, debug_exit->far);
  target/i386/kvm/kvm.c:5216:static CPUWatchpoint hw_watchpoint;
  target/ppc/kvm.c:443:static CPUWatchpoint hw_watchpoint;
  target/s390x/kvm/kvm.c:139:static CPUWatchpoint hw_watchpoint;

See for example commit e4482ab7 ("target-arm: kvm - add support
for HW assisted debug"):

     This adds basic support for HW assisted debug. The ioctl interface
     to KVM allows us to pass an implementation defined number of break
     and watch point registers. [...]

This partially reverts commit 2609ec28.

Fixes: 2609ec28 ("softmmu: Extract watchpoint API from physmem.c")
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230328173117.15226-4-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

cpu_watchpoint_insert() calls error_report() which is declared
in "qemu/error-report.h". When moving this code in commit 2609ec28
("softmmu: Extract watchpoint API from physmem.c") we neglected to
include this header. This works so far because it is indirectly
included by TCG headers -> "qemu/plugin.h" -> "qemu/error-report.h".

Currently cpu_watchpoint_insert() is only built with the TCG
accelerator. When building it with other ones (or without TCG)
we get:

  softmmu/watchpoint.c:38:9: error: implicit declaration of function 'error_report' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
        error_report("tried to set invalid watchpoint at %"
        ^

Include "qemu/error-report.h" in order to fix this for non-TCG
builds.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230328173117.15226-3-philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Atomic operations are read-modify-write, and we'd like to
be able to test both read and write with one call.  This is
easy enough, with BP_MEM_READ | BP_MEM_WRITE.

Add BP_HIT_SHIFT to make it easy to set BP_WATCHPOINT_HIT_*.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

The watchpoint API is specific to TCG system emulation.

Move it to a new compile unit. The inlined stubs are used
for user-mode and non-TCG accelerators.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20221209141254.68662-1-philmd@linaro.org>