From: Dave Jiang <dave.jiang@intel.com>
To: linux-cxl@vger.kernel.org, nvdimm@lists.linux.dev
Cc: vishal.l.verma@intel.com, Alison Schofield <alison.schofield@intel.com>
Subject: [NDCTL PATCH v6 3/4] ndctl: cxl: add QoS class check for CXL region creation
Date: Wed, 7 Feb 2024 10:19:38 -0700 [thread overview]
Message-ID: <20240207172055.1882900-4-dave.jiang@intel.com> (raw)
In-Reply-To: <20240207172055.1882900-1-dave.jiang@intel.com>
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. Emit a warning if the qos_class
token from the root decoder is different than the mem device qos_class
token. User parameter options are provided to fail instead of just
warning.
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
v6:
- Check return value of create_region_validate_qos_class() (Wonjae)
---
Documentation/cxl/cxl-create-region.txt | 9 ++++
cxl/region.c | 58 ++++++++++++++++++++++++-
2 files changed, 66 insertions(+), 1 deletion(-)
diff --git a/Documentation/cxl/cxl-create-region.txt b/Documentation/cxl/cxl-create-region.txt
index f11a412bddfe..d5e34cf38236 100644
--- a/Documentation/cxl/cxl-create-region.txt
+++ b/Documentation/cxl/cxl-create-region.txt
@@ -105,6 +105,15 @@ include::bus-option.txt[]
supplied, the first cross-host bridge (if available), decoder that
supports the largest interleave will be chosen.
+-e::
+--strict::
+ Enforce strict execution where any potential error will force failure.
+ For example, if qos_class mismatches region creation will fail.
+
+-q::
+--no-enforce-qos::
+ Parameter to bypass qos_class mismatch failure. Will only emit warning.
+
include::human-option.txt[]
include::debug-option.txt[]
diff --git a/cxl/region.c b/cxl/region.c
index 3a762db4800e..0468f5fa06ee 100644
--- a/cxl/region.c
+++ b/cxl/region.c
@@ -32,6 +32,8 @@ static struct region_params {
bool force;
bool human;
bool debug;
+ bool strict;
+ bool no_qos;
} param = {
.ways = INT_MAX,
.granularity = INT_MAX,
@@ -49,6 +51,8 @@ struct parsed_params {
const char **argv;
struct cxl_decoder *root_decoder;
enum cxl_decoder_mode mode;
+ bool strict;
+ bool no_qos;
};
enum region_actions {
@@ -81,7 +85,9 @@ 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('e', "strict", ¶m.strict, "strict execution enforcement"), \
+OPT_BOOLEAN('q', "no-enforce-qos", ¶m.no_qos, "no enforce of qos_class")
static const struct option create_options[] = {
BASE_OPTIONS(),
@@ -360,6 +366,9 @@ static int parse_create_options(struct cxl_ctx *ctx, int count,
}
}
+ p->strict = param.strict;
+ p->no_qos = param.no_qos;
+
return 0;
err:
@@ -467,6 +476,49 @@ 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;
+
+ 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) {
+ if (p->strict && !p->no_qos) {
+ log_err(&rl, "%s QoS Class mismatches %s\n",
+ cxl_decoder_get_devname(p->root_decoder),
+ cxl_memdev_get_devname(memdev));
+
+ return -ENXIO;
+ }
+
+ log_notice(&rl, "%s QoS Class mismatches %s\n",
+ cxl_decoder_get_devname(p->root_decoder),
+ cxl_memdev_get_devname(memdev));
+ }
+ }
+
+ return 0;
+}
+
static int create_region_validate_config(struct cxl_ctx *ctx,
struct parsed_params *p)
{
@@ -507,6 +559,10 @@ found:
return rc;
collect_minsize(ctx, p);
+ rc = create_region_validate_qos_class(ctx, p);
+ if (rc)
+ return rc;
+
return 0;
}
--
2.43.0
next prev parent reply other threads:[~2024-02-07 17:21 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-07 17:19 [NDCTL PATCH v6 0/4] ndctl: Add support of qos_class for CXL CLI Dave Jiang
2024-02-07 17:19 ` [NDCTL PATCH v6 1/4] ndctl: cxl: Add QoS class retrieval for the root decoder Dave Jiang
2024-02-07 20:05 ` Alison Schofield
2024-02-07 20:13 ` Alison Schofield
2024-02-07 20:16 ` Dave Jiang
2024-02-07 20:24 ` Verma, Vishal L
2024-02-07 17:19 ` [NDCTL PATCH v6 2/4] ndctl: cxl: Add QoS class support for the memory device Dave Jiang
2024-02-07 17:19 ` Dave Jiang [this message]
2024-02-07 21:02 ` [NDCTL PATCH v6 3/4] ndctl: cxl: add QoS class check for CXL region creation Verma, Vishal L
2024-02-07 23:32 ` Dave Jiang
2024-02-07 17:19 ` [NDCTL PATCH v6 4/4] ndctl: add test for qos_class in CXL test suite Dave Jiang
2024-02-07 21:05 ` Verma, Vishal L
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