On Wed, Jun 10, 2026 at 11:55:12AM +0800, Richard Cheng wrote:
> On Mon, Jun 08, 2026 at 05:08:19PM +0800, Dave Jiang wrote:
> >
> >
> > On 5/23/26 2:50 AM, Anisa Su wrote:
> > > From: Ira Weiny <[email protected]>
> > >
> > > DCD regions have 0 or more extents. The ability to list those and their
> > > properties is useful to end users.
> > >
> > > Add an option for extent output to region queries. An example of this
> > > is:
> > >
> > > $ ./build/cxl/cxl list -r 8 -Nu
> > > {
> > > "region":"region8",
> > > ...
> > > "type":"dc",
> > > ...
> > > "extents":[
> > > {
> > > "offset":"0x10000000",
> > > "length":"64.00 MiB (67.11 MB)",
> > > "tag":"00000000-0000-0000-0000-000000000000"
> >
> > I think the code emits "uuid". Update commit log.
> > > },
> > > {
> > > "offset":"0x8000000",
> > > "length":"64.00 MiB (67.11 MB)",
> > > "tag":"00000000-0000-0000-0000-000000000000"
> >
> > same here
> >
> > DJ
> >
> > > }
> > > ]
> > > }
> > >
> > > Signed-off-by: Ira Weiny <[email protected]>
> > >
> > > ---
> > > Changes:
> > > [iweiny: s/tag/uuid/]
> > > ---
> > > Documentation/cxl/cxl-list.txt | 29 +++++++++++++++++++++
> > > cxl/filter.h | 3 +++
> > > cxl/json.c | 47 ++++++++++++++++++++++++++++++++++
> > > cxl/json.h | 3 +++
> > > cxl/list.c | 3 +++
> > > util/json.h | 1 +
> > > 6 files changed, 86 insertions(+)
> > >
> > > diff --git a/Documentation/cxl/cxl-list.txt
> > > b/Documentation/cxl/cxl-list.txt
> > > index 193860b..7512687 100644
> > > --- a/Documentation/cxl/cxl-list.txt
> > > +++ b/Documentation/cxl/cxl-list.txt
> > > @@ -426,6 +426,35 @@ OPTIONS
> > > }
> > > ----
> > >
> > > +-N::
> > > +--extents::
> > > + Append Dynamic Capacity extent information.
> > > +----
> > > +13:34:28 > ./build/cxl/cxl list -r 8 -Nu
> > > +{
> > > + "region":"region8",
> > > + "resource":"0xf030000000",
> > > + "size":"512.00 MiB (536.87 MB)",
> > > + "type":"dc",
> > > + "interleave_ways":1,
> > > + "interleave_granularity":256,
> > > + "decode_state":"commit",
> > > + "extents":[
> > > + {
> > > + "offset":"0x10000000",
> > > + "length":"64.00 MiB (67.11 MB)",
> > > + "uuid":"00000000-0000-0000-0000-000000000000"
> > > + },
> > > + {
> > > + "offset":"0x8000000",
> > > + "length":"64.00 MiB (67.11 MB)",
> > > + "uuid":"00000000-0000-0000-0000-000000000000"
> > > + }
> > > + ]
> > > +}
> > > +----
> > > +
> > > +
> > > -r::
> > > --region::
> > > Specify CXL region device name(s), or device id(s), to filter the
> > > listing.
> > > diff --git a/cxl/filter.h b/cxl/filter.h
> > > index 70463c4..30e7fe2 100644
> > > --- a/cxl/filter.h
> > > +++ b/cxl/filter.h
> > > @@ -31,6 +31,7 @@ struct cxl_filter_params {
> > > bool alert_config;
> > > bool dax;
> > > bool media_errors;
> > > + bool extents;
> > > int verbose;
> > > struct log_ctx ctx;
> > > };
> > > @@ -93,6 +94,8 @@ static inline unsigned long cxl_filter_to_flags(struct
> > > cxl_filter_params *param)
> > > flags |= UTIL_JSON_DAX | UTIL_JSON_DAX_DEVS;
> > > if (param->media_errors)
> > > flags |= UTIL_JSON_MEDIA_ERRORS;
> > > + if (param->extents)
> > > + flags |= UTIL_JSON_EXTENTS;
> > > return flags;
> > > }
> > >
> > > diff --git a/cxl/json.c b/cxl/json.c
> > > index e94c809..7922b32 100644
> > > --- a/cxl/json.c
> > > +++ b/cxl/json.c
> > > @@ -1022,6 +1022,50 @@ void util_cxl_mappings_append_json(struct
> > > json_object *jregion,
> > > json_object_object_add(jregion, "mappings", jmappings);
> > > }
> > >
> > > +void util_cxl_extents_append_json(struct json_object *jregion,
> > > + struct cxl_region *region,
> > > + unsigned long flags)
> > > +{
> > > + struct json_object *jextents;
> > > + struct cxl_region_extent *extent;
> > > +
> > > + jextents = json_object_new_array();
> > > + if (!jextents)
> > > + return;
> > > +
> > > + cxl_extent_foreach(region, extent) {
>
> Every region rendered with the flag, including non-DC RAM/PMEM regions.
> They all get a spurious "extents": [].
> I would suggest guarding on cxl_extent_get_first(region) != NULL before
> adding the key.
>
> What do you think?
>
Good point, thanks for catching that! Now checks
cxl_extent_get_first(region) != NULL at top of function
> Best regards,
> Richard Cheng.
>
Thanks,
Anisa
> > > + struct json_object *jextent, *jobj;
> > > + unsigned long long val;
> > > + char uuid_str[40];
> > > + uuid_t uuid;
> > > +
> > > + jextent = json_object_new_object();
> > > + if (!jextent)
> > > + continue;
> > > +
> > > + val = cxl_extent_get_offset(extent);
> > > + jobj = util_json_object_hex(val, flags);
> > > + if (jobj)
> > > + json_object_object_add(jextent, "offset", jobj);
> > > +
> > > + val = cxl_extent_get_length(extent);
> > > + jobj = util_json_object_size(val, flags);
> > > + if (jobj)
> > > + json_object_object_add(jextent, "length", jobj);
> > > +
> > > + cxl_extent_get_uuid(extent, uuid);
> > > + uuid_unparse(uuid, uuid_str);
> > > + jobj = json_object_new_string(uuid_str);
> > > + if (jobj)
> > > + json_object_object_add(jextent, "uuid", jobj);
> > > +
> > > + json_object_array_add(jextents, jextent);
> > > + json_object_set_userdata(jextent, extent, NULL);
> > > + }
> > > +
> > > + json_object_object_add(jregion, "extents", jextents);
> > > +}
> > > +
> > > struct json_object *util_cxl_region_to_json(struct cxl_region *region,
> > > unsigned long flags)
> > > {
> > > @@ -1126,6 +1170,9 @@ struct json_object *util_cxl_region_to_json(struct
> > > cxl_region *region,
> > > }
> > > }
> > >
> > > + if (flags & UTIL_JSON_EXTENTS)
> > > + util_cxl_extents_append_json(jregion, region, flags);
> > > +
> > > if (cxl_region_qos_class_mismatch(region)) {
> > > jobj = json_object_new_boolean(true);
> > > if (jobj)
> > > diff --git a/cxl/json.h b/cxl/json.h
> > > index eb7572b..f9c07ab 100644
> > > --- a/cxl/json.h
> > > +++ b/cxl/json.h
> > > @@ -20,6 +20,9 @@ struct json_object *util_cxl_region_to_json(struct
> > > cxl_region *region,
> > > void util_cxl_mappings_append_json(struct json_object *jregion,
> > > struct cxl_region *region,
> > > unsigned long flags);
> > > +void util_cxl_extents_append_json(struct json_object *jregion,
> > > + struct cxl_region *region,
> > > + unsigned long flags);
> > > void util_cxl_targets_append_json(struct json_object *jdecoder,
> > > struct cxl_decoder *decoder,
> > > const char *ident, const char *serial,
> > > diff --git a/cxl/list.c b/cxl/list.c
> > > index 0b25d78..47d1351 100644
> > > --- a/cxl/list.c
> > > +++ b/cxl/list.c
> > > @@ -59,6 +59,8 @@ static const struct option options[] = {
> > > "include alert configuration information"),
> > > OPT_BOOLEAN('L', "media-errors", ¶m.media_errors,
> > > "include media-error information "),
> > > + OPT_BOOLEAN('N', "extents", ¶m.extents,
> > > + "include extent information (Dynamic Capacity regions
> > > only)"),
> > > OPT_INCR('v', "verbose", ¶m.verbose, "increase output detail"),
> > > #ifdef ENABLE_DEBUG
> > > OPT_BOOLEAN(0, "debug", &debug, "debug list walk"),
> > > @@ -135,6 +137,7 @@ int cmd_list(int argc, const char **argv, struct
> > > cxl_ctx *ctx)
> > > param.decoders = true;
> > > param.targets = true;
> > > param.regions = true;
> > > + param.extents = true;
> > > /*fallthrough*/
> > > case 0:
> > > break;
> > > diff --git a/util/json.h b/util/json.h
> > > index 560f845..79ae324 100644
> > > --- a/util/json.h
> > > +++ b/util/json.h
> > > @@ -21,6 +21,7 @@ enum util_json_flags {
> > > UTIL_JSON_TARGETS = (1 << 11),
> > > UTIL_JSON_PARTITION = (1 << 12),
> > > UTIL_JSON_ALERT_CONFIG = (1 << 13),
> > > + UTIL_JSON_EXTENTS = (1 << 14),
> > > };
> > >
> > > void util_display_json_array(FILE *f_out, struct json_object *jarray,
> >
> >
