| Message ID | 20240828063224.291503-2-rowanbhart@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | plugins: add API to read guest CPU memory from hwaddr | expand |
> + qemu_plugin_read_cpu_memory_hwaddr; > + qemu_plugin_read_io_memory_hwaddr; This second symbol name should be removed, I initially wanted to implement for IO as well but there is no good generic way I can see to access a list of IO AddressSpace to read from.
Hi Rowan, thanks for this good complement on the virt address read function. However, to be able to merge a new plugins API function, we must have a concrete usage of it, through one of the existing plugin. What could be a good demonstration of value brought by being able to read a physical address? Thanks, Pierrick On 8/27/24 23:32, Rowan Hart wrote: > Signed-off-by: Rowan Hart <rowanbhart@gmail.com> > --- > include/qemu/qemu-plugin.h | 22 ++++++++++++++++++++++ > plugins/api.c | 17 +++++++++++++++++ > plugins/qemu-plugins.symbols | 2 ++ > 3 files changed, 41 insertions(+) > > diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h > index c71c705b69..25f39c0960 100644 > --- a/include/qemu/qemu-plugin.h > +++ b/include/qemu/qemu-plugin.h > @@ -868,6 +868,28 @@ QEMU_PLUGIN_API > int qemu_plugin_read_register(struct qemu_plugin_register *handle, > GByteArray *buf); > > +/** > + * qemu_plugin_read_cpu_memory_hwaddr() - read CPU memory from hwaddr > + * > + * @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_cpu_memory_hwaddr(uint64_t addr, > + GByteArray *data, size_t len); > + > /** > * qemu_plugin_scoreboard_new() - alloc a new scoreboard > * > diff --git a/plugins/api.c b/plugins/api.c > index 2ff13d09de..c87bed6641 100644 > --- a/plugins/api.c > +++ b/plugins/api.c > @@ -527,6 +527,22 @@ GArray *qemu_plugin_get_registers(void) > return create_register_handles(regs); > } > > +bool qemu_plugin_read_cpu_memory_hwaddr(uint64_t addr, > + GByteArray *data, uint64_t len) > +{ > +#ifndef CONFIG_USER_ONLY > + if (len == 0) { > + return false; > + } > + > + g_byte_array_set_size(data, len); > + cpu_physical_memory_rw(addr, (void *)data->data, len, 0); > + return true; > +#else > + return false; > +#endif > +} > + > int qemu_plugin_read_register(struct qemu_plugin_register *reg, GByteArray *buf) > { > g_assert(current_cpu); > @@ -534,6 +550,7 @@ int qemu_plugin_read_register(struct qemu_plugin_register *reg, GByteArray *buf) > return gdb_read_register(current_cpu, buf, GPOINTER_TO_INT(reg) - 1); > } > > + > struct qemu_plugin_scoreboard *qemu_plugin_scoreboard_new(size_t element_size) > { > return plugin_scoreboard_new(element_size); > diff --git a/plugins/qemu-plugins.symbols b/plugins/qemu-plugins.symbols > index ca773d8d9f..5d9cfd71bb 100644 > --- a/plugins/qemu-plugins.symbols > +++ b/plugins/qemu-plugins.symbols > @@ -20,6 +20,8 @@ > qemu_plugin_num_vcpus; > qemu_plugin_outs; > qemu_plugin_path_to_binary; > + qemu_plugin_read_cpu_memory_hwaddr; > + qemu_plugin_read_io_memory_hwaddr; As you mentioned, you can remove the second one for v2. > qemu_plugin_read_register; > qemu_plugin_register_atexit_cb; > qemu_plugin_register_flush_cb;
And by the way, feel free to integrate this with your other series (as it's a very similar topic) in a v3, so we can review both at the same time. Thanks, Pierrick On 8/30/24 12:30, Pierrick Bouvier wrote: > Hi Rowan, > > thanks for this good complement on the virt address read function. > > However, to be able to merge a new plugins API function, we must have a > concrete usage of it, through one of the existing plugin. > What could be a good demonstration of value brought by being able to > read a physical address? > > Thanks, > Pierrick > > On 8/27/24 23:32, Rowan Hart wrote: >> Signed-off-by: Rowan Hart <rowanbhart@gmail.com> >> --- >> include/qemu/qemu-plugin.h | 22 ++++++++++++++++++++++ >> plugins/api.c | 17 +++++++++++++++++ >> plugins/qemu-plugins.symbols | 2 ++ >> 3 files changed, 41 insertions(+) >> >> diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h >> index c71c705b69..25f39c0960 100644 >> --- a/include/qemu/qemu-plugin.h >> +++ b/include/qemu/qemu-plugin.h >> @@ -868,6 +868,28 @@ QEMU_PLUGIN_API >> int qemu_plugin_read_register(struct qemu_plugin_register *handle, >> GByteArray *buf); >> >> +/** >> + * qemu_plugin_read_cpu_memory_hwaddr() - read CPU memory from hwaddr >> + * >> + * @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_cpu_memory_hwaddr(uint64_t addr, >> + GByteArray *data, size_t len); >> + >> /** >> * qemu_plugin_scoreboard_new() - alloc a new scoreboard >> * >> diff --git a/plugins/api.c b/plugins/api.c >> index 2ff13d09de..c87bed6641 100644 >> --- a/plugins/api.c >> +++ b/plugins/api.c >> @@ -527,6 +527,22 @@ GArray *qemu_plugin_get_registers(void) >> return create_register_handles(regs); >> } >> >> +bool qemu_plugin_read_cpu_memory_hwaddr(uint64_t addr, >> + GByteArray *data, uint64_t len) >> +{ >> +#ifndef CONFIG_USER_ONLY >> + if (len == 0) { >> + return false; >> + } >> + >> + g_byte_array_set_size(data, len); >> + cpu_physical_memory_rw(addr, (void *)data->data, len, 0); >> + return true; >> +#else >> + return false; >> +#endif >> +} >> + >> int qemu_plugin_read_register(struct qemu_plugin_register *reg, GByteArray *buf) >> { >> g_assert(current_cpu); >> @@ -534,6 +550,7 @@ int qemu_plugin_read_register(struct qemu_plugin_register *reg, GByteArray *buf) >> return gdb_read_register(current_cpu, buf, GPOINTER_TO_INT(reg) - 1); >> } >> >> + >> struct qemu_plugin_scoreboard *qemu_plugin_scoreboard_new(size_t element_size) >> { >> return plugin_scoreboard_new(element_size); >> diff --git a/plugins/qemu-plugins.symbols b/plugins/qemu-plugins.symbols >> index ca773d8d9f..5d9cfd71bb 100644 >> --- a/plugins/qemu-plugins.symbols >> +++ b/plugins/qemu-plugins.symbols >> @@ -20,6 +20,8 @@ >> qemu_plugin_num_vcpus; >> qemu_plugin_outs; >> qemu_plugin_path_to_binary; >> + qemu_plugin_read_cpu_memory_hwaddr; >> + qemu_plugin_read_io_memory_hwaddr; > > As you mentioned, you can remove the second one for v2. > >> qemu_plugin_read_register; >> qemu_plugin_register_atexit_cb; >> qemu_plugin_register_flush_cb;
diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h index c71c705b69..25f39c0960 100644 --- a/include/qemu/qemu-plugin.h +++ b/include/qemu/qemu-plugin.h @@ -868,6 +868,28 @@ QEMU_PLUGIN_API int qemu_plugin_read_register(struct qemu_plugin_register *handle, GByteArray *buf); +/** + * qemu_plugin_read_cpu_memory_hwaddr() - read CPU memory from hwaddr + * + * @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_cpu_memory_hwaddr(uint64_t addr, + GByteArray *data, size_t len); + /** * qemu_plugin_scoreboard_new() - alloc a new scoreboard * diff --git a/plugins/api.c b/plugins/api.c index 2ff13d09de..c87bed6641 100644 --- a/plugins/api.c +++ b/plugins/api.c @@ -527,6 +527,22 @@ GArray *qemu_plugin_get_registers(void) return create_register_handles(regs); } +bool qemu_plugin_read_cpu_memory_hwaddr(uint64_t addr, + GByteArray *data, uint64_t len) +{ +#ifndef CONFIG_USER_ONLY + if (len == 0) { + return false; + } + + g_byte_array_set_size(data, len); + cpu_physical_memory_rw(addr, (void *)data->data, len, 0); + return true; +#else + return false; +#endif +} + int qemu_plugin_read_register(struct qemu_plugin_register *reg, GByteArray *buf) { g_assert(current_cpu); @@ -534,6 +550,7 @@ int qemu_plugin_read_register(struct qemu_plugin_register *reg, GByteArray *buf) return gdb_read_register(current_cpu, buf, GPOINTER_TO_INT(reg) - 1); } + struct qemu_plugin_scoreboard *qemu_plugin_scoreboard_new(size_t element_size) { return plugin_scoreboard_new(element_size); diff --git a/plugins/qemu-plugins.symbols b/plugins/qemu-plugins.symbols index ca773d8d9f..5d9cfd71bb 100644 --- a/plugins/qemu-plugins.symbols +++ b/plugins/qemu-plugins.symbols @@ -20,6 +20,8 @@ qemu_plugin_num_vcpus; qemu_plugin_outs; qemu_plugin_path_to_binary; + qemu_plugin_read_cpu_memory_hwaddr; + qemu_plugin_read_io_memory_hwaddr; qemu_plugin_read_register; qemu_plugin_register_atexit_cb; qemu_plugin_register_flush_cb;
Signed-off-by: Rowan Hart <rowanbhart@gmail.com> --- include/qemu/qemu-plugin.h | 22 ++++++++++++++++++++++ plugins/api.c | 17 +++++++++++++++++ plugins/qemu-plugins.symbols | 2 ++ 3 files changed, 41 insertions(+)