Jan Kiszka <jan.kis...@siemens.com> writes:
> This introduces device_show, a monitor command that saves the vmstate of
> a qdev device and visualizes it. QMP is also supported. Buffers are cut
> after 16 byte by default, but the full content can be requested via
> '-f'. To pretty-print sub-arrays, vmstate is extended to store the start
> index name.
>
> Signed-off-by: Jan Kiszka <jan.kis...@siemens.com>
Neato! Comments inline.
> ---
> hw/hw.h | 2 +
> hw/qdev.c | 287
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> hw/qdev.h | 2 +
> qemu-monitor.hx | 16 +++
> 4 files changed, 307 insertions(+), 0 deletions(-)
>
> diff --git a/hw/hw.h b/hw/hw.h
> index 328b704..1ff8e40 100644
> --- a/hw/hw.h
> +++ b/hw/hw.h
> @@ -299,6 +299,7 @@ enum VMStateFlags {
>
> typedef struct {
> const char *name;
> + const char *start_index;
> size_t offset;
> size_t size;
> size_t start;
Why is start_index a string?
> @@ -414,6 +415,7 @@ extern const VMStateInfo vmstate_info_unused_buffer;
> .size = sizeof(_type), \
> .flags = VMS_ARRAY, \
> .offset = vmstate_offset_sub_array(_state, _field, _type, _start), \
> + .start_index = (stringify(_start)), \
> }
>
> #define VMSTATE_VARRAY_INT32(_field, _state, _field_num, _version, _info,
> _type) {\
> diff --git a/hw/qdev.c b/hw/qdev.c
> index fe49e71..c989010 100644
> --- a/hw/qdev.c
> +++ b/hw/qdev.c
> @@ -29,6 +29,9 @@
> #include "qdev.h"
> #include "sysemu.h"
> #include "monitor.h"
> +#include "qjson.h"
> +#include "qint.h"
> +#include "qbuffer.h"
>
> static int qdev_hotplug = 0;
>
> @@ -824,3 +827,287 @@ int do_device_del(Monitor *mon, const QDict *qdict,
> QObject **ret_data)
> }
> return qdev_unplug(dev);
> }
> +
> +static int print_array_index(Monitor *mon, const char *start, int index)
> +{
> + char index_str[32];
> + int len;
> +
> + if (start) {
> + len = snprintf(index_str, sizeof(index_str), "[%s+%02x]", start,
> + index);
> + } else {
> + len = snprintf(index_str, sizeof(index_str), "[%02x]", index);
> + }
> + monitor_printf(mon, index_str);
> + return len;
You go via the snprintf() detour just because monitor_printf() doesn't
return the number of characters printed. Wouldn't it be better to fix
that?
> +}
> +
> +#define NAME_COLUMN_WIDTH 23
> +
> +static void print_field(Monitor *mon, const QDict *qfield, int indent);
> +
> +static void print_elem(Monitor *mon, const QObject *qelem, size_t size,
> + int column_pos, int indent)
> +{
> + int64_t data_size;
> + const void *data;
> + int n;
> +
> + if (qobject_type(qelem) == QTYPE_QDICT) {
> + if (column_pos >= 0) {
> + monitor_printf(mon, ".\n");
> + }
> + } else {
> + monitor_printf(mon, ":");
> + column_pos++;
> + if (column_pos < NAME_COLUMN_WIDTH) {
> + monitor_printf(mon, "%*c", NAME_COLUMN_WIDTH - column_pos, ' ');
> + }
> + }
> +
> + switch (qobject_type(qelem)) {
> + case QTYPE_QDICT:
> + print_field(mon, qobject_to_qdict(qelem), indent + 2);
> + break;
> + case QTYPE_QBUFFER:
> + data = qbuffer_get_data(qobject_to_qbuffer(qelem));
> + data_size = qbuffer_get_size(qobject_to_qbuffer(qelem));
> + for (n = 0; n < data_size; ) {
> + monitor_printf(mon, " %02x", *((uint8_t *)data+n));
> + if (++n < size) {
> + if (n % 16 == 0) {
> + monitor_printf(mon, "\n%*c", NAME_COLUMN_WIDTH, ' ');
> + } else if (n % 8 == 0) {
> + monitor_printf(mon, " -");
> + }
> + }
> + }
> + if (data_size < size) {
> + monitor_printf(mon, " ...");
> + }
> + monitor_printf(mon, "\n");
> + break;
> + case QTYPE_QINT:
> + monitor_printf(mon, " %0*x\n", (int)size * 2,
> + (int)qint_get_int(qobject_to_qint(qelem)));
I'm confused. Doesn't casting qint_get_int() to int lose bits?
> + break;
> + default:
> + assert(0);
> + }
> +}
> +
> +static void print_field(Monitor *mon, const QDict *qfield, int indent)
> +{
> + const char *name = qdict_get_str(qfield, "name");
> + const char *start = qdict_get_try_str(qfield, "start");
> + int64_t size = qdict_get_int(qfield, "size");
> + QList *qlist = qdict_get_qlist(qfield, "elems");
> + QListEntry *entry, *sub_entry;
> + QList *sub_list;
> + int elem_no = 0;
> +
> + QLIST_FOREACH_ENTRY(qlist, entry) {
> + QObject *qelem = qlist_entry_obj(entry);
> + int pos = indent + strlen(name);
> +
> + if (qobject_type(qelem) == QTYPE_QLIST) {
> + monitor_printf(mon, "%*c%s", indent, ' ', name);
> + pos += print_array_index(mon, start, elem_no);
> + sub_list = qobject_to_qlist(qelem);
> + QLIST_FOREACH_ENTRY(sub_list, sub_entry) {
> + print_elem(mon, qlist_entry_obj(sub_entry), size, pos,
> + indent + 2);
> + pos = -1;
> + }
> + } else {
> + if (elem_no == 0) {
> + monitor_printf(mon, "%*c%s", indent, ' ', name);
> + } else {
> + pos = -1;
> + }
> + print_elem(mon, qelem, size, pos, indent);
> + }
> + elem_no++;
> + }
> +}
> +
> +void device_user_print(Monitor *mon, const QObject *data)
> +{
> + QDict *qdict = qobject_to_qdict(data);
> + QList *qlist = qdict_get_qlist(qdict, "fields");
> + QListEntry *entry;
> +
> + monitor_printf(mon, "dev: %s, id \"%s\"\n",
> + qdict_get_str(qdict, "device"),
> + qdict_get_str(qdict, "id"));
> +
> + QLIST_FOREACH_ENTRY(qlist, entry) {
> + print_field(mon, qobject_to_qdict(qlist_entry_obj(entry)), 2);
> + }
> +}
> +
> +static void parse_vmstate(const VMStateDescription *vmsd, void *opaque,
> + QList *qlist, int full_buffers)
> +{
> + VMStateField *field = vmsd->fields;
> +
> + if (vmsd->pre_save) {
> + vmsd->pre_save(opaque);
> + }
> + while(field->name) {
> + if (!field->field_exists ||
> + field->field_exists(opaque, vmsd->version_id)) {
> + void *base_addr = opaque + field->offset;
> + int i, n_elems = 1;
> + int is_array = 1;
> + size_t size = field->size;
> + QDict *qfield = qdict_new();
> + QList *qelems = qlist_new();
> +
> + qlist_append_obj(qlist, QOBJECT(qfield));
> +
> + qdict_put_obj(qfield, "name",
> + QOBJECT(qstring_from_str(field->name)));
> + qdict_put_obj(qfield, "elems", QOBJECT(qelems));
> +
> + if (field->flags & VMS_VBUFFER) {
> + size = *(int32_t *)(opaque + field->size_offset);
> + if (field->flags & VMS_MULTIPLY) {
> + size *= field->size;
> + }
> + }
> + qdict_put_obj(qfield, "size", QOBJECT(qint_from_int(size)));
> + if (field->start_index) {
> + qdict_put_obj(qfield, "start",
> + QOBJECT(qstring_from_str(field->start_index)));
> + }
> +
> + if (field->flags & VMS_ARRAY) {
> + n_elems = field->num;
> + } else if (field->flags & VMS_VARRAY_INT32) {
> + n_elems = *(int32_t *)(opaque + field->num_offset);
> + } else if (field->flags & VMS_VARRAY_UINT16) {
> + n_elems = *(uint16_t *)(opaque + field->num_offset);
> + } else {
> + is_array = 0;
> + }
> + if (field->flags & VMS_POINTER) {
> + base_addr = *(void **)base_addr + field->start;
> + }
> + for (i = 0; i < n_elems; i++) {
> + void *addr = base_addr + size * i;
> + QList *sub_elems = qelems;
> + int val;
> +
> + if (is_array) {
> + sub_elems = qlist_new();
> + qlist_append_obj(qelems, QOBJECT(sub_elems));
> + }
> + if (field->flags & VMS_ARRAY_OF_POINTER) {
> + addr = *(void **)addr;
> + }
> + if (field->flags & VMS_STRUCT) {
> + parse_vmstate(field->vmsd, addr, sub_elems,
> full_buffers);
> + } else {
> + if (field->flags & (VMS_BUFFER | VMS_VBUFFER)) {
> + if (!full_buffers && size > 16) {
> + size = 16;
> + }
> + qlist_append_obj(sub_elems,
> + QOBJECT(qbuffer_from_data(addr,
> + size)));
> + } else {
> + switch (size) {
> + case 1:
> + val = *(uint8_t *)addr;
> + break;
> + case 2:
> + val = *(uint16_t *)addr;
> + break;
> + case 4:
> + val = *(uint32_t *)addr;
> + break;
> + case 8:
> + val = *(uint64_t *)addr;
> + break;
> + default:
> + assert(0);
> + }
> + qlist_append_obj(sub_elems,
> + QOBJECT(qint_from_int(val)));
> + }
> + }
> + }
> + }
> + field++;
> + }
> +}
> +
> +static DeviceState *qdev_find(const char *path)
> +{
> + const char *dev_name;
> + DeviceState *dev;
> + char *bus_path;
> + BusState *bus;
> +
> + dev_name = strrchr(path, '/');
> + if (!dev_name) {
> + bus = main_system_bus;
> + dev_name = path;
> + } else {
> + dev_name++;
> + bus_path = qemu_strdup(path);
> + bus_path[dev_name - path] = 0;
> +
> + bus = qbus_find(bus_path);
> + qemu_free(bus_path);
> +
> + if (!bus) {
> + /* qbus_find already reported the error */
> + return NULL;
> + }
> + }
> + dev = qbus_find_dev(bus, dev_name);
> + if (!dev) {
> + qerror_report(QERR_DEVICE_NOT_FOUND, dev_name);
> + if (!monitor_cur_is_qmp()) {
> + qbus_list_dev(bus);
> + }
> + }
> + return dev;
> +}
> +
> +int do_device_show(Monitor *mon, const QDict *qdict, QObject **ret_data)
Command documentation missing.
> +{
> + const char *path = qdict_get_str(qdict, "path");
> + const VMStateDescription *vmsd;
> + DeviceState *dev;
> + QList *qlist;
> +
> + dev = qdev_find_recursive(main_system_bus, path);
> + if (!dev) {
> + dev = qdev_find(path);
> + if (!dev) {
> + return -1;
> + }
> + }
This is inconsistent with how do_device_del() looks up devices by ID.
Let's agree on one lookup, put it into a function, and use it
everywhere.
> +
> + vmsd = dev->info->vmsd;
> + if (!vmsd) {
> + qerror_report(QERR_UNDEFINED_ERROR);
> + if (!monitor_cur_is_qmp()) {
> + error_printf_unless_qmp("Device '%s' does not support state "
> + "dumping\n", path);
> + }
Please use a suitable QERR_. Define one if necessary.
> + return -1;
> + }
> +
> + *ret_data = qobject_from_jsonf("{ 'device': %s, 'id': %s }",
> + dev->info->name, dev->id ? : "");
> + qlist = qlist_new();
> + parse_vmstate(vmsd, dev, qlist, qdict_get_int(qdict, "full"));
> + qdict_put_obj(qobject_to_qdict(*ret_data), "fields", QOBJECT(qlist));
> +
> + return 0;
> +}
> diff --git a/hw/qdev.h b/hw/qdev.h
> index d8fbc73..f8436ec 100644
> --- a/hw/qdev.h
> +++ b/hw/qdev.h
> @@ -177,6 +177,8 @@ void do_info_qtree(Monitor *mon);
> void do_info_qdm(Monitor *mon);
> int do_device_add(Monitor *mon, const QDict *qdict, QObject **ret_data);
> int do_device_del(Monitor *mon, const QDict *qdict, QObject **ret_data);
> +void device_user_print(Monitor *mon, const QObject *data);
> +int do_device_show(Monitor *mon, const QDict *qdict, QObject **ret_data);
>
> /*** qdev-properties.c ***/
>
> diff --git a/qemu-monitor.hx b/qemu-monitor.hx
> index a8f194c..449f012 100644
> --- a/qemu-monitor.hx
> +++ b/qemu-monitor.hx
> @@ -599,6 +599,22 @@ Remove device @var{id}.
> ETEXI
>
> {
> + .name = "device_show",
> + .args_type = "path:s,full:-f",
> + .params = "device [-f]",
> + .help = "show device state (specify -f for full buffer
> dumping)",
> + .user_print = device_user_print,
> + .mhandler.cmd_new = do_device_show,
> + },
> +
> +STEXI
> +...@item device_show @var{id} [...@code{-f}]
> +
> +Show state of device @var{id} in a human-readable form. Buffers are cut after
> +16 bytes unless a full dump is requested via @code{-f}
> +ETEXI
> +
> + {
> .name = "cpu",
> .args_type = "index:i",
> .params = "index",
