From 9505f85e2d3343f2c8502b34600a6abae257bfb6 Mon Sep 17 00:00:00 2001 From: Pierrick Bouvier Date: Mon, 16 Sep 2024 09:53:47 +0100 Subject: plugins: extend API to get latest memory value accessed MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Xingtao Yao Reviewed-by: Alex Bennée Signed-off-by: Pierrick Bouvier Message-Id: <20240724194708.1843704-3-pierrick.bouvier@linaro.org> Signed-off-by: Alex Bennée Message-Id: <20240916085400.1046925-6-alex.bennee@linaro.org> --- plugins/api.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'plugins/api.c') 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 */ -- cgit 1.4.1 From 595cd9ce2ec9330882c991a647d5bc2a5640f380 Mon Sep 17 00:00:00 2001 From: Rowan Hart Date: Mon, 16 Sep 2024 09:53:58 +0100 Subject: plugins: add plugin API to read guest memory MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Rowan Hart Reviewed-by: Pierrick Bouvier Message-Id: <20240827215329.248434-2-rowanbhart@gmail.com> [AJB: tweaked cpu_memory_rw_debug call] Signed-off-by: Alex Bennée Message-Id: <20240916085400.1046925-17-alex.bennee@linaro.org> --- include/qemu/qemu-plugin.h | 32 +++++++++++++++++++++++++++++++- plugins/api.c | 20 ++++++++++++++++++++ plugins/qemu-plugins.symbols | 1 + 3 files changed, 52 insertions(+), 1 deletion(-) (limited to 'plugins/api.c') diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h index 649ce89815..622c9a0232 100644 --- a/include/qemu/qemu-plugin.h +++ b/include/qemu/qemu-plugin.h @@ -57,11 +57,19 @@ typedef uint64_t qemu_plugin_id_t; * - Remove qemu_plugin_register_vcpu_{tb, insn, mem}_exec_inline. * Those functions are replaced by *_per_vcpu variants, which guarantee * thread-safety for operations. + * + * version 3: + * - modified arguments and return value of qemu_plugin_insn_data to copy + * the data into a user-provided buffer instead of returning a pointer + * to the data. + * + * version 4: + * - added qemu_plugin_read_memory_vaddr */ extern QEMU_PLUGIN_EXPORT int qemu_plugin_version; -#define QEMU_PLUGIN_VERSION 3 +#define QEMU_PLUGIN_VERSION 4 /** * struct qemu_info_t - system information for plugins @@ -884,6 +892,28 @@ typedef struct { QEMU_PLUGIN_API GArray *qemu_plugin_get_registers(void); +/** + * qemu_plugin_read_memory_vaddr() - read from memory using a virtual address + * + * @addr: A virtual address to read from + * @data: A byte array to store data into + * @len: The number of bytes to read, starting from @addr + * + * @len bytes of data is read starting at @addr and stored into @data. If @data + * is not large enough to hold @len bytes, it will be expanded to the necessary + * size, reallocating if necessary. @len must be greater than 0. + * + * This function does not ensure writes are flushed prior to reading, so + * callers should take care when calling this function in plugin callbacks to + * avoid attempting to read data which may not yet be written and should use + * the memory callback API instead. + * + * Returns true on success and false on failure. + */ +QEMU_PLUGIN_API +bool qemu_plugin_read_memory_vaddr(uint64_t addr, + GByteArray *data, size_t len); + /** * qemu_plugin_read_register() - read register for current vCPU * diff --git a/plugins/api.c b/plugins/api.c index 3316d4a04d..24ea64e2de 100644 --- a/plugins/api.c +++ b/plugins/api.c @@ -560,6 +560,26 @@ GArray *qemu_plugin_get_registers(void) return create_register_handles(regs); } +bool qemu_plugin_read_memory_vaddr(vaddr addr, GByteArray *data, size_t len) +{ + g_assert(current_cpu); + + if (len == 0) { + return false; + } + + g_byte_array_set_size(data, len); + + int result = cpu_memory_rw_debug(current_cpu, addr, data->data, + data->len, false); + + if (result < 0) { + return false; + } + + return true; +} + int qemu_plugin_read_register(struct qemu_plugin_register *reg, GByteArray *buf) { g_assert(current_cpu); diff --git a/plugins/qemu-plugins.symbols b/plugins/qemu-plugins.symbols index eed9d8abd9..032661f9ea 100644 --- a/plugins/qemu-plugins.symbols +++ b/plugins/qemu-plugins.symbols @@ -21,6 +21,7 @@ qemu_plugin_num_vcpus; qemu_plugin_outs; qemu_plugin_path_to_binary; + qemu_plugin_read_memory_vaddr; qemu_plugin_read_register; qemu_plugin_register_atexit_cb; qemu_plugin_register_flush_cb; -- cgit 1.4.1