[PATCH 15/26] plugins: extend API to get latest memory value accessed

From: Pierrick Bouvier <pierrick.bouvier(a)linaro.org&gt; This value can be accessed only during a memory callback, using new qemu_plugin_mem_get_value function. Returned value can be extended when QEMU will support accesses wider than 128 bits. Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1719 Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2152 Reviewed-by: Richard Henderson <richard.henderson(a)linaro.org&gt; Reviewed-by: Xingtao Yao <yaoxt.fnst(a)fujitsu.com&gt; Reviewed-by: Alex Bennée <alex.bennee(a)linaro.org&gt; Signed-off-by: Pierrick Bouvier <pierrick.bouvier(a)linaro.org&gt; Message-Id: <20240724194708.1843704-3-pierrick.bouvier(a)linaro.org&gt; Signed-off-by: Alex Bennée <alex.bennee(a)linaro.org&gt; --- include/qemu/qemu-plugin.h | 32 ++++++++++++++++++++++++++++++++ plugins/api.c | 33 +++++++++++++++++++++++++++++++++ plugins/qemu-plugins.symbols | 1 + 3 files changed, 66 insertions(+) diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h index c71c705b69..649ce89815 100644 --- a/include/qemu/qemu-plugin.h +++ b/include/qemu/qemu-plugin.h @@ -262,6 +262,29 @@ enum qemu_plugin_mem_rw { QEMU_PLUGIN_MEM_RW, }; +enum qemu_plugin_mem_value_type { + QEMU_PLUGIN_MEM_VALUE_U8, + QEMU_PLUGIN_MEM_VALUE_U16, + QEMU_PLUGIN_MEM_VALUE_U32, + QEMU_PLUGIN_MEM_VALUE_U64, + QEMU_PLUGIN_MEM_VALUE_U128, +}; + +/* typedef qemu_plugin_mem_value - value accessed during a load/store */ +typedef struct { + enum qemu_plugin_mem_value_type type; + union { + uint8_t u8; + uint16_t u16; + uint32_t u32; + uint64_t u64; + struct { + uint64_t low; + uint64_t high; + } u128; + } data; +} qemu_plugin_mem_value; + /** * enum qemu_plugin_cond - condition to enable callback * @@ -551,6 +574,15 @@ bool qemu_plugin_mem_is_big_endian(qemu_plugin_meminfo_t info); QEMU_PLUGIN_API bool qemu_plugin_mem_is_store(qemu_plugin_meminfo_t info); +/** + * qemu_plugin_mem_get_mem_value() - return last value loaded/stored + * @info: opaque memory transaction handle + * + * Returns: memory value + */ +QEMU_PLUGIN_API +qemu_plugin_mem_value qemu_plugin_mem_get_value(qemu_plugin_meminfo_t info); + /** * qemu_plugin_get_hwaddr() - return handle for memory operation * @info: opaque memory info structure diff --git a/plugins/api.c b/plugins/api.c index 2ff13d09de..3316d4a04d 100644 --- a/plugins/api.c +++ b/plugins/api.c @@ -351,6 +351,39 @@ bool qemu_plugin_mem_is_store(qemu_plugin_meminfo_t info) return get_plugin_meminfo_rw(info) & QEMU_PLUGIN_MEM_W; } +qemu_plugin_mem_value qemu_plugin_mem_get_value(qemu_plugin_meminfo_t info) +{ + uint64_t low = current_cpu->neg.plugin_mem_value_low; + qemu_plugin_mem_value value; + + switch (qemu_plugin_mem_size_shift(info)) { + case 0: + value.type = QEMU_PLUGIN_MEM_VALUE_U8; + value.data.u8 = (uint8_t)low; + break; + case 1: + value.type = QEMU_PLUGIN_MEM_VALUE_U16; + value.data.u16 = (uint16_t)low; + break; + case 2: + value.type = QEMU_PLUGIN_MEM_VALUE_U32; + value.data.u32 = (uint32_t)low; + break; + case 3: + value.type = QEMU_PLUGIN_MEM_VALUE_U64; + value.data.u64 = low; + break; + case 4: + value.type = QEMU_PLUGIN_MEM_VALUE_U128; + value.data.u128.low = low; + value.data.u128.high = current_cpu->neg.plugin_mem_value_high; + break; + default: + g_assert_not_reached(); + } + return value; +} + /* * Virtual Memory queries */ diff --git a/plugins/qemu-plugins.symbols b/plugins/qemu-plugins.symbols index ca773d8d9f..eed9d8abd9 100644 --- a/plugins/qemu-plugins.symbols +++ b/plugins/qemu-plugins.symbols @@ -13,6 +13,7 @@ qemu_plugin_insn_size; qemu_plugin_insn_symbol; qemu_plugin_insn_vaddr; + qemu_plugin_mem_get_value; qemu_plugin_mem_is_big_endian; qemu_plugin_mem_is_sign_extended; qemu_plugin_mem_is_store; -- 2.39.2