Commit f4ea95c9ad for qemu.org

commit f4ea95c9ad826859e7dbfd9e0d19c39ffafdd652
Author: Philippe Mathieu-Daudé <philmd@linaro.org>
Date:   Sat Dec 20 12:27:04 2025 +0100

    system/memory: Allow restricting legacy ldst_phys() API usage

    Commit 500131154d6 ("exec.c: Add new address_space_ld*/st*
    functions") added a new API to fix a shortcoming of the
    ld/st*_phys() API, which does blind bus access, not reporting
    failure (and it also allow to provide transaction attributes).

    Later commit 42874d3a8c6 ("Switch non-CPU callers from ld/st*_phys
    to address_space_ld/st*") automatically converted the legacy uses
    to the new API, not precising transaction attributes
    (MEMTXATTRS_UNSPECIFIED) and ignoring the transation result (passing
    NULL pointer as MemTxResult).

    While this is a faithful replacement, without any logical change,
    we later realized better is to not use MEMTXATTRS_UNSPECIFIED or
    NULL MemTxResult, and adapt each call site on a pair basis, looking
    at the device model datasheet to do the correct behavior (which is
    unlikely to ignore transaction failures).

    Since this is quite some work, we defer that to device model
    maintainers. Meanwhile we introduce a definition, to allow a
    target which removed all legacy API call to prohibit further
    legacy API uses, named "TARGET_NOT_USING_LEGACY_LDST_PHYS_API".

    Since all targets should be able to check this definition, we
    take care to not poison it.

    Suggested-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
    Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
    Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
    Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
    Message-Id: <20251224151351.86733-6-philmd@linaro.org>

diff --git a/include/system/memory.h b/include/system/memory.h
index edef51a276..0e8de527d3 100644
--- a/include/system/memory.h
+++ b/include/system/memory.h
@@ -2855,10 +2855,12 @@ MemTxResult address_space_write_rom(AddressSpace *as, hwaddr addr,
 #define ARG1_DECL    AddressSpace *as
 #include "system/memory_ldst.h.inc"

+#ifndef TARGET_NOT_USING_LEGACY_LDST_PHYS_API
 #define SUFFIX
 #define ARG1         as
 #define ARG1_DECL    AddressSpace *as
 #include "system/memory_ldst_phys.h.inc"
+#endif

 struct MemoryRegionCache {
     uint8_t *ptr;
diff --git a/scripts/make-config-poison.sh b/scripts/make-config-poison.sh
index 2b36907e23..937357b353 100755
--- a/scripts/make-config-poison.sh
+++ b/scripts/make-config-poison.sh
@@ -10,6 +10,7 @@ exec sed -n \
   -e' /CONFIG_TCG/d' \
   -e '/CONFIG_USER_ONLY/d' \
   -e '/CONFIG_SOFTMMU/d' \
+  -e '/TARGET_NOT_USING_LEGACY_LDST_PHYS_API/d' \
   -e '/^#define / {' \
   -e    's///' \
   -e    's/ .*//' \