The CFMWS provides a QTG ID. The kernel driver creates a root decoder that
represents the CFMWS. A qos_class attribute is exported via sysfs for the root
decoder.
One or more qos_class tokens are retrieved via QTG ID _DSM from the ACPI0017
device for a CXL memory device. The input for the _DSM is the read and write
latency and bandwidth for the path between the device and the CPU. The
numbers are constructed by the kernel driver for the _DSM input. When a
device is probed, QoS class tokens are retrieved. This is useful for a
hot-plugged CXL memory device that does not have regions created.
Add a QoS check during region creation. If --enforce-qos/-Q is set and
the qos_class mismatches, the region creation will fail.
Reviewed-by: Alison Schofield <alison.schofi...@intel.com>
Signed-off-by: Dave Jiang <dave.ji...@intel.com>
---
v7:
- Add qos_class_mismatched to region for cxl list (Vishal)
- Add create_region -Q check (Vishal)
---
Documentation/cxl/cxl-create-region.txt | 6 +++
cxl/json.c | 6 +++
cxl/lib/libcxl.c | 11 +++++
cxl/lib/libcxl.sym | 2 +
cxl/lib/private.h | 1 +
cxl/libcxl.h | 2 +
cxl/region.c | 56 ++++++++++++++++++++++++-
7 files changed, 83 insertions(+), 1 deletion(-)
diff --git a/Documentation/cxl/cxl-create-region.txt
b/Documentation/cxl/cxl-create-region.txt
index f11a412bddfe..b244af60b8a6 100644
--- a/Documentation/cxl/cxl-create-region.txt
+++ b/Documentation/cxl/cxl-create-region.txt
@@ -105,6 +105,12 @@ include::bus-option.txt[]
supplied, the first cross-host bridge (if available), decoder that
supports the largest interleave will be chosen.
+-Q::
+--enforce-qos::
+ Parameter to enforce qos_class mismatch failure. Region create operation
+ will fail of the qos_class of the root decoder and one of the memdev
that
+ backs the region mismatches.
+
include::human-option.txt[]
include::debug-option.txt[]
diff --git a/cxl/json.c b/cxl/json.c
index c8bd8c27447a..27cbacc84f3a 100644
--- a/cxl/json.c
+++ b/cxl/json.c
@@ -1238,6 +1238,12 @@ struct json_object *util_cxl_region_to_json(struct
cxl_region *region,
}
}
+ if (cxl_region_qos_class_mismatched(region)) {
+ jobj = json_object_new_boolean(true);
+ if (jobj)
+ json_object_object_add(jregion, "qos_class_mismatched",
jobj);
+ }
+
json_object_set_userdata(jregion, region, NULL);
diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c
index 6c293f1dfc91..3461c4de2097 100644
--- a/cxl/lib/libcxl.c
+++ b/cxl/lib/libcxl.c
@@ -414,6 +414,17 @@ CXL_EXPORT int cxl_region_is_enabled(struct cxl_region
*region)
return is_enabled(path);
}
+CXL_EXPORT void cxl_region_qos_class_mismatched_set(struct cxl_region *region,
+ bool mismatched)
+{
+ region->qos_mismatched = mismatched;
+}
+
+CXL_EXPORT bool cxl_region_qos_class_mismatched(struct cxl_region *region)
+{
+ return region->qos_mismatched;
+}
+
CXL_EXPORT int cxl_region_disable(struct cxl_region *region)
{
const char *devname = cxl_region_get_devname(region);
diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym
index 465c78dc6c70..47a9c3cafc71 100644
--- a/cxl/lib/libcxl.sym
+++ b/cxl/lib/libcxl.sym
@@ -285,4 +285,6 @@ global:
cxl_root_decoder_get_qos_class;
cxl_memdev_get_pmem_qos_class;
cxl_memdev_get_ram_qos_class;
+ cxl_region_qos_class_mismatched_set;
+ cxl_region_qos_class_mismatched;
} LIBCXL_7;
diff --git a/cxl/lib/private.h b/cxl/lib/private.h
index 07dc8c784f1d..88448d82d53f 100644
--- a/cxl/lib/private.h
+++ b/cxl/lib/private.h
@@ -174,6 +174,7 @@ struct cxl_region {
struct daxctl_region *dax_region;
struct kmod_module *module;
struct list_head mappings;
+ bool qos_mismatched;
};
struct cxl_memdev_mapping {
diff --git a/cxl/libcxl.h b/cxl/libcxl.h
index a180f01cb05e..7795496cdbbd 100644
--- a/cxl/libcxl.h
+++ b/cxl/libcxl.h
@@ -335,6 +335,8 @@ int cxl_region_clear_target(struct cxl_region *region, int
position);
int cxl_region_clear_all_targets(struct cxl_region *region);
int cxl_region_decode_commit(struct cxl_region *region);
int cxl_region_decode_reset(struct cxl_region *region);
+void cxl_region_qos_class_mismatched_set(struct cxl_region *region, bool
mismatched);
+bool cxl_region_qos_class_mismatched(struct cxl_region *region);
#define cxl_region_foreach(decoder, region)
\
for (region = cxl_region_get_first(decoder); region != NULL; \
diff --git a/cxl/region.c b/cxl/region.c
index 3a762db4800e..76df177ef246 100644
--- a/cxl/region.c
+++ b/cxl/region.c
@@ -32,6 +32,7 @@ static struct region_params {
bool force;
bool human;
bool debug;
+ bool qos_enforce;
} param = {
.ways = INT_MAX,
.granularity = INT_MAX,
@@ -49,6 +50,8 @@ struct parsed_params {
const char **argv;
struct cxl_decoder *root_decoder;
enum cxl_decoder_mode mode;
+ bool qos_enforce;
+ bool qos_mismatched;
};
enum region_actions {
@@ -81,7 +84,8 @@ OPT_STRING('U', "uuid", ¶m.uuid, \
"region uuid", "uuid for the new region (default: autogenerate)"), \
OPT_BOOLEAN('m', "memdevs", ¶m.memdevs, \
"non-option arguments are memdevs"), \
-OPT_BOOLEAN('u', "human", ¶m.human, "use human friendly number formats")
+OPT_BOOLEAN('u', "human", ¶m.human, "use human friendly number formats"), \
+OPT_BOOLEAN('Q', "enforce-qos", ¶m.qos_enforce, "enforce of qos_class
matching")
static const struct option create_options[] = {
BASE_OPTIONS(),
@@ -360,6 +364,8 @@ static int parse_create_options(struct cxl_ctx *ctx, int
count,
}
}
+ p->qos_enforce = param.qos_enforce;
+
return 0;
err:
@@ -467,6 +473,49 @@ static void set_type_from_decoder(struct cxl_ctx *ctx,
struct parsed_params *p)
p->mode = CXL_DECODER_MODE_PMEM;
}
+static int create_region_validate_qos_class(struct cxl_ctx *ctx,
+ struct parsed_params *p)
+{
+ int root_qos_class;
+ int qos_class;
+ int i;
+
+ if (!p->qos_enforce)
+ return 0;
+
+ root_qos_class = cxl_root_decoder_get_qos_class(p->root_decoder);
+ if (root_qos_class == CXL_QOS_CLASS_NONE)
+ return 0;
+
+ for (i = 0; i < p->ways; i++) {
+ struct json_object *jobj =
+ json_object_array_get_idx(p->memdevs, i);
+ struct cxl_memdev *memdev = json_object_get_userdata(jobj);
+
+ if (p->mode == CXL_DECODER_MODE_RAM)
+ qos_class = cxl_memdev_get_ram_qos_class(memdev);
+ else
+ qos_class = cxl_memdev_get_pmem_qos_class(memdev);
+
+ /* No qos_class entries. Possibly no kernel support */
+ if (qos_class == CXL_QOS_CLASS_NONE)
+ break;
+
+ if (qos_class != root_qos_class) {
+ p->qos_mismatched = true;
+ if (p->qos_enforce) {
+ log_err(&rl, "%s QoS Class mismatches %s\n",
+
cxl_decoder_get_devname(p->root_decoder),
+ cxl_memdev_get_devname(memdev));
+
+ return -ENXIO;
+ }
+ }
+ }
+
+ return 0;
+}
+
static int create_region_validate_config(struct cxl_ctx *ctx,
struct parsed_params *p)
{
@@ -507,6 +556,10 @@ found:
return rc;
collect_minsize(ctx, p);
+ rc = create_region_validate_qos_class(ctx, p);
+ if (rc)
+ return rc;
+
return 0;
}
@@ -654,6 +707,7 @@ static int create_region(struct cxl_ctx *ctx, int *count,
return -EOPNOTSUPP;
}
+ cxl_region_qos_class_mismatched_set(region, p->qos_mismatched);
devname = cxl_region_get_devname(region);
rc = cxl_region_determine_granularity(region, p);
--
2.43.0
