[PATCH v3 0/6] CXL Poison List Retrieval & Tracing

[PATCH v3 0/6] CXL Poison List Retrieval & Tracing

[alison.schofield]

From: Alison Schofield <alison.schofield@intel.com>

Add support for retrieving device poison lists and store the returned
error records as kernel trace events.

The handling of the poison list is guided by the CXL 3.0 Specification
Section 8.2.9.8.4.1. [1] 

Example, triggered by memdev:
$ echo 1 > /sys/bus/cxl/devices/mem3/trigger_poison_list
cxl_poison: memdev=mem3 pcidev=cxl_mem.3 region= region_uuid=00000000-0000-0000-0000-000000000000 dpa=0x0 length=0x40 source=Internal flags= overflow_time=0

Example, triggered by region:
$ echo 1 > /sys/bus/cxl/devices/region5/trigger_poison_list
cxl_poison: memdev=mem0 pcidev=cxl_mem.0 region=region5 region_uuid=bfcb7a29-890e-4a41-8236-fe22221fc75c dpa=0x0 length=0x40 source=Internal flags= overflow_time=0
cxl_poison: memdev=mem1 pcidev=cxl_mem.1 region=region5 region_uuid=bfcb7a29-890e-4a41-8236-fe22221fc75c dpa=0x0 length=0x40 source=Internal flags= overflow_time=0

Changes in v3:
- Rebase to 6.1-rc4
- Rebase picked up cxl_dpa_resource_start() (Jonathan)
- Move poison source defines to cxlmem.h from events/cxl.h
- TRACE_printk helper macros display 'Reserved' for illegal poison sources
  rather than failing to parse.
- Add region uuid to the trace event.
- Always get poison, but only parse records if tracing is enabled.(Steve)
  There was a little foresight on not moving the calcs to the event
  definition itself, as Steve also suggested. The DPA->HPA translation
  is coming, and that work seems better kept in the driver itself.
- Remove unused hpa trace field. Add back when hpa is available.
- Remove pid from cxl_poison event. Find in common event field. (Steve)
- cxl_test: Add mock support for get poison

Changes in v2:
- Added per region poison collection 
- Protect poison list w mutex
- Replace range usage w resource
- S/poison_max_mer/poison_max in cxl_dev_state kdoc (Ira)
- Renamed sysfs attribute to 'trigger_poison_list'
- _store() rm chatty dev_err() msgs (Jonathan, Dan)
- _store() use kstrtobool (Jonathan, Dan)
- _store() simplify return (Jonathan)
- cxl_memdev_visible() skip local vars on way enabled_cmds (Jonathan)
- cxl_memdev_visible() use kobj_to_dev() helper (Dan)
- Misc name shortenings and cleanups.
- Replace goto w break in cxl_mem_get_poison() do-while loop.
- Don't error out on FLAGS, record in trace event.
- Add kernel CXL_POISON__LIST_MAX (64) and guard against exceeding (Dan)
- Add current->pid to trace  (Dan)
- Return the poison length as multiple of 64 per spec (Jonathan)
- Mask starting address from record->address (Jonathan)
- Move range selection to sysfs_store and make cxl_mem_get_poison() accept it.
- Get both the volatile & persistent ranges per memdev.
- Add pci device name to trace (Dan)

[1]: https://www.computeexpresslink.org/download-the-specification

Alison Schofield (6):
  trace, cxl: Introduce a TRACE_EVENT for CXL poison records
  cxl/mbox: Add GET_POISON_LIST mailbox command
  cxl/memdev: Add trigger_poison_list sysfs attribute
  cxl/region: Add trigger_poison_list sysfs attribute
  tools/testing/cxl: Mock the max err records field of Identify cmd
  tools/testing/cxl: Mock the Get Poison List mbox command

 Documentation/ABI/testing/sysfs-bus-cxl | 28 +++++++++
 drivers/cxl/core/mbox.c                 | 81 +++++++++++++++++++++++++
 drivers/cxl/core/memdev.c               | 41 +++++++++++++
 drivers/cxl/core/region.c               | 33 ++++++++++
 drivers/cxl/cxlmem.h                    | 51 ++++++++++++++++
 include/trace/events/cxl.h              | 80 ++++++++++++++++++++++++
 tools/testing/cxl/test/mem.c            | 35 +++++++++++
 7 files changed, 349 insertions(+)
 create mode 100644 include/trace/events/cxl.h


base-commit: f0c4d9fc9cc9462659728d168387191387e903cc
-- 
2.37.3

[PATCH v3 1/6] trace, cxl: Introduce a TRACE_EVENT for CXL poison records

[alison.schofield]

From: Alison Schofield <alison.schofield@intel.com>

CXL devices may support the retrieval of a device poison list.
Introduce a trace event that the CXL subsystem can use to log
the poison error records.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 drivers/cxl/cxlmem.h       | 14 +++++++
 include/trace/events/cxl.h | 80 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 94 insertions(+)
 create mode 100644 include/trace/events/cxl.h

diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 88e3a8e54b6a..669868cc1553 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -347,6 +347,20 @@ struct cxl_mbox_set_partition_info {
 
 #define  CXL_SET_PARTITION_IMMEDIATE_FLAG	BIT(0)
 
+/* Get Poison List  CXL 3.0 Spec 8.2.9.8.4.1 */
+
+/* Get Poison List: Payload out flags */
+#define CXL_POISON_FLAG_MORE            BIT(0)
+#define CXL_POISON_FLAG_OVERFLOW        BIT(1)
+#define CXL_POISON_FLAG_SCANNING        BIT(2)
+
+/* Get Poison List: Poison Source */
+#define CXL_POISON_SOURCE_UNKNOWN	0
+#define CXL_POISON_SOURCE_EXTERNAL	1
+#define CXL_POISON_SOURCE_INTERNAL	2
+#define CXL_POISON_SOURCE_INJECTED	3
+#define CXL_POISON_SOURCE_VENDOR	7
+
 /**
  * struct cxl_mem_command - Driver representation of a memory device command
  * @info: Command information as it exists for the UAPI
diff --git a/include/trace/events/cxl.h b/include/trace/events/cxl.h
new file mode 100644
index 000000000000..03428125573f
--- /dev/null
+++ b/include/trace/events/cxl.h
@@ -0,0 +1,80 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM cxl
+
+#if !defined(_CXL_TRACE_H) ||  defined(TRACE_HEADER_MULTI_READ)
+#define _CXL_TRACE_H
+
+#include <linux/tracepoint.h>
+#include <cxlmem.h>
+
+#define __show_poison_source(source)                          \
+	__print_symbolic(source,                              \
+		{ CXL_POISON_SOURCE_UNKNOWN,   "Unknown"  },  \
+		{ CXL_POISON_SOURCE_EXTERNAL,  "External" },  \
+		{ CXL_POISON_SOURCE_INTERNAL,  "Internal" },  \
+		{ CXL_POISON_SOURCE_INJECTED,  "Injected" },  \
+		{ CXL_POISON_SOURCE_VENDOR,    "Vendor"   })
+
+#define show_poison_source(source)			     \
+	(((source > CXL_POISON_SOURCE_INJECTED) &&	     \
+	 (source != CXL_POISON_SOURCE_VENDOR)) ? "Reserved"  \
+	 : __show_poison_source(source))
+
+#define show_poison_flags(flags)                             \
+	__print_flags(flags, "|",                            \
+		{ CXL_POISON_FLAG_MORE,      "More"     },   \
+		{ CXL_POISON_FLAG_OVERFLOW,  "Overflow"  },  \
+		{ CXL_POISON_FLAG_SCANNING,  "Scanning"  })
+
+TRACE_EVENT(cxl_poison,
+
+	    TP_PROTO(const char *memdev, const char *pcidev, const char *region,
+		     const uuid_t *uuid, u64 dpa, u32 length, u8 source,
+		     u8 flags, u64 overflow_t),
+
+	    TP_ARGS(memdev, pcidev, region, uuid, dpa, length, source,
+		    flags, overflow_t),
+
+	    TP_STRUCT__entry(
+		__string(memdev, memdev)
+		__string(pcidev, pcidev)
+		__string(region, region ? region : "")
+		__array(char, uuid, 16)
+		__field(u64, dpa)
+		__field(u32, length)
+		__field(u8, source)
+		__field(u8, flags)
+		__field(u64, overflow_t)
+	    ),
+
+	    TP_fast_assign(
+		__assign_str(memdev, memdev);
+		__assign_str(pcidev, pcidev);
+		__assign_str(region, region ? region : "");
+		if (uuid)
+			memcpy(__entry->uuid, uuid, 16);
+		__entry->dpa = dpa;
+		__entry->length = length;
+		__entry->source = source;
+		__entry->flags = flags;
+		__entry->overflow_t = overflow_t;
+	    ),
+
+	    TP_printk("memdev=%s pcidev=%s region=%s region_uuid=%pU dpa=0x%llx length=0x%x source=%s flags=%s overflow_time=%llu",
+		__get_str(memdev),
+		__get_str(pcidev),
+		__get_str(region),
+		__entry->uuid,
+		__entry->dpa,
+		__entry->length,
+		show_poison_source(__entry->source),
+		show_poison_flags(__entry->flags),
+		__entry->overflow_t)
+);
+#endif /* _CXL_TRACE_H */
+
+/* This part must be outside protection */
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE cxl
+#include <trace/define_trace.h>
-- 
2.37.3

Re: [PATCH v3 1/6] trace, cxl: Introduce a TRACE_EVENT for CXL poison records

[Jonathan Cameron]

On Thu, 10 Nov 2022 19:12:39 -0800
alison.schofield@intel.com wrote:

> From: Alison Schofield <alison.schofield@intel.com>
> 
> CXL devices may support the retrieval of a device poison list.
> Introduce a trace event that the CXL subsystem can use to log
> the poison error records.
> 
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Only thing I wondered a bit about in here is the philosophy of whether it is
useful to include the pcidev and region given they can both be established
fairly easily via other paths..  Meh. Seems reasonable to me to have the
in here so.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> ---
>  drivers/cxl/cxlmem.h       | 14 +++++++
>  include/trace/events/cxl.h | 80 ++++++++++++++++++++++++++++++++++++++
>  2 files changed, 94 insertions(+)
>  create mode 100644 include/trace/events/cxl.h
> 
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index 88e3a8e54b6a..669868cc1553 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -347,6 +347,20 @@ struct cxl_mbox_set_partition_info {
>  
>  #define  CXL_SET_PARTITION_IMMEDIATE_FLAG	BIT(0)
>  
> +/* Get Poison List  CXL 3.0 Spec 8.2.9.8.4.1 */
> +
> +/* Get Poison List: Payload out flags */
> +#define CXL_POISON_FLAG_MORE            BIT(0)
> +#define CXL_POISON_FLAG_OVERFLOW        BIT(1)
> +#define CXL_POISON_FLAG_SCANNING        BIT(2)
> +
> +/* Get Poison List: Poison Source */
> +#define CXL_POISON_SOURCE_UNKNOWN	0
> +#define CXL_POISON_SOURCE_EXTERNAL	1
> +#define CXL_POISON_SOURCE_INTERNAL	2
> +#define CXL_POISON_SOURCE_INJECTED	3
> +#define CXL_POISON_SOURCE_VENDOR	7
> +
>  /**
>   * struct cxl_mem_command - Driver representation of a memory device command
>   * @info: Command information as it exists for the UAPI
> diff --git a/include/trace/events/cxl.h b/include/trace/events/cxl.h
> new file mode 100644
> index 000000000000..03428125573f
> --- /dev/null
> +++ b/include/trace/events/cxl.h
> @@ -0,0 +1,80 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM cxl
> +
> +#if !defined(_CXL_TRACE_H) ||  defined(TRACE_HEADER_MULTI_READ)
> +#define _CXL_TRACE_H
> +
> +#include <linux/tracepoint.h>
> +#include <cxlmem.h>
> +
> +#define __show_poison_source(source)                          \
> +	__print_symbolic(source,                              \
> +		{ CXL_POISON_SOURCE_UNKNOWN,   "Unknown"  },  \
> +		{ CXL_POISON_SOURCE_EXTERNAL,  "External" },  \
> +		{ CXL_POISON_SOURCE_INTERNAL,  "Internal" },  \
> +		{ CXL_POISON_SOURCE_INJECTED,  "Injected" },  \
> +		{ CXL_POISON_SOURCE_VENDOR,    "Vendor"   })
> +
> +#define show_poison_source(source)			     \
> +	(((source > CXL_POISON_SOURCE_INJECTED) &&	     \
> +	 (source != CXL_POISON_SOURCE_VENDOR)) ? "Reserved"  \
> +	 : __show_poison_source(source))
> +
> +#define show_poison_flags(flags)                             \
> +	__print_flags(flags, "|",                            \
> +		{ CXL_POISON_FLAG_MORE,      "More"     },   \
> +		{ CXL_POISON_FLAG_OVERFLOW,  "Overflow"  },  \
> +		{ CXL_POISON_FLAG_SCANNING,  "Scanning"  })
> +
> +TRACE_EVENT(cxl_poison,
> +
> +	    TP_PROTO(const char *memdev, const char *pcidev, const char *region,
> +		     const uuid_t *uuid, u64 dpa, u32 length, u8 source,
> +		     u8 flags, u64 overflow_t),
> +
> +	    TP_ARGS(memdev, pcidev, region, uuid, dpa, length, source,
> +		    flags, overflow_t),
> +
> +	    TP_STRUCT__entry(
> +		__string(memdev, memdev)
> +		__string(pcidev, pcidev)
> +		__string(region, region ? region : "")
> +		__array(char, uuid, 16)
> +		__field(u64, dpa)
> +		__field(u32, length)
> +		__field(u8, source)
> +		__field(u8, flags)
> +		__field(u64, overflow_t)
> +	    ),
> +
> +	    TP_fast_assign(
> +		__assign_str(memdev, memdev);
> +		__assign_str(pcidev, pcidev);
> +		__assign_str(region, region ? region : "");
> +		if (uuid)
> +			memcpy(__entry->uuid, uuid, 16);
> +		__entry->dpa = dpa;
> +		__entry->length = length;
> +		__entry->source = source;
> +		__entry->flags = flags;
> +		__entry->overflow_t = overflow_t;
> +	    ),
> +
> +	    TP_printk("memdev=%s pcidev=%s region=%s region_uuid=%pU dpa=0x%llx length=0x%x source=%s flags=%s overflow_time=%llu",
> +		__get_str(memdev),
> +		__get_str(pcidev),
> +		__get_str(region),
> +		__entry->uuid,
> +		__entry->dpa,
> +		__entry->length,
> +		show_poison_source(__entry->source),
> +		show_poison_flags(__entry->flags),
> +		__entry->overflow_t)
> +);
> +#endif /* _CXL_TRACE_H */
> +
> +/* This part must be outside protection */
> +#undef TRACE_INCLUDE_FILE
> +#define TRACE_INCLUDE_FILE cxl
> +#include <trace/define_trace.h>

RE: [PATCH v3 1/6] trace, cxl: Introduce a TRACE_EVENT for CXL poison records

[Dan Williams]

alison.schofield@ wrote:
> From: Alison Schofield <alison.schofield@intel.com>
> 
> CXL devices may support the retrieval of a device poison list.
> Introduce a trace event that the CXL subsystem can use to log
> the poison error records.
> 
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
> ---
>  drivers/cxl/cxlmem.h       | 14 +++++++
>  include/trace/events/cxl.h | 80 ++++++++++++++++++++++++++++++++++++++
>  2 files changed, 94 insertions(+)
>  create mode 100644 include/trace/events/cxl.h
> 
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index 88e3a8e54b6a..669868cc1553 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -347,6 +347,20 @@ struct cxl_mbox_set_partition_info {
>  
>  #define  CXL_SET_PARTITION_IMMEDIATE_FLAG	BIT(0)
>  
> +/* Get Poison List  CXL 3.0 Spec 8.2.9.8.4.1 */
> +
> +/* Get Poison List: Payload out flags */
> +#define CXL_POISON_FLAG_MORE            BIT(0)
> +#define CXL_POISON_FLAG_OVERFLOW        BIT(1)
> +#define CXL_POISON_FLAG_SCANNING        BIT(2)
> +
> +/* Get Poison List: Poison Source */
> +#define CXL_POISON_SOURCE_UNKNOWN	0
> +#define CXL_POISON_SOURCE_EXTERNAL	1
> +#define CXL_POISON_SOURCE_INTERNAL	2
> +#define CXL_POISON_SOURCE_INJECTED	3
> +#define CXL_POISON_SOURCE_VENDOR	7
> +
>  /**
>   * struct cxl_mem_command - Driver representation of a memory device command
>   * @info: Command information as it exists for the UAPI
> diff --git a/include/trace/events/cxl.h b/include/trace/events/cxl.h
> new file mode 100644
> index 000000000000..03428125573f
> --- /dev/null
> +++ b/include/trace/events/cxl.h
> @@ -0,0 +1,80 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM cxl
> +
> +#if !defined(_CXL_TRACE_H) ||  defined(TRACE_HEADER_MULTI_READ)
> +#define _CXL_TRACE_H
> +
> +#include <linux/tracepoint.h>
> +#include <cxlmem.h>
> +
> +#define __show_poison_source(source)                          \
> +	__print_symbolic(source,                              \
> +		{ CXL_POISON_SOURCE_UNKNOWN,   "Unknown"  },  \
> +		{ CXL_POISON_SOURCE_EXTERNAL,  "External" },  \
> +		{ CXL_POISON_SOURCE_INTERNAL,  "Internal" },  \
> +		{ CXL_POISON_SOURCE_INJECTED,  "Injected" },  \
> +		{ CXL_POISON_SOURCE_VENDOR,    "Vendor"   })
> +
> +#define show_poison_source(source)			     \
> +	(((source > CXL_POISON_SOURCE_INJECTED) &&	     \
> +	 (source != CXL_POISON_SOURCE_VENDOR)) ? "Reserved"  \
> +	 : __show_poison_source(source))
> +
> +#define show_poison_flags(flags)                             \
> +	__print_flags(flags, "|",                            \
> +		{ CXL_POISON_FLAG_MORE,      "More"     },   \
> +		{ CXL_POISON_FLAG_OVERFLOW,  "Overflow"  },  \
> +		{ CXL_POISON_FLAG_SCANNING,  "Scanning"  })
> +
> +TRACE_EVENT(cxl_poison,
> +
> +	    TP_PROTO(const char *memdev, const char *pcidev, const char *region,

Same feedback as on the Events patch, make these arguments a 'struct
device *', 'struct pci_dev *', and 'struct cxl_region *' to maximize
type-safety. Otherwise you could do something like pass "region0",
"mem1", and "0000:64:09.0" in the wrong order and the compiler cannot
help prevent that.

> +		     const uuid_t *uuid, u64 dpa, u32 length, u8 source,
> +		     u8 flags, u64 overflow_t),
> +
> +	    TP_ARGS(memdev, pcidev, region, uuid, dpa, length, source,
> +		    flags, overflow_t),
> +
> +	    TP_STRUCT__entry(
> +		__string(memdev, memdev)
> +		__string(pcidev, pcidev)
> +		__string(region, region ? region : "")
> +		__array(char, uuid, 16)
> +		__field(u64, dpa)
> +		__field(u32, length)
> +		__field(u8, source)
> +		__field(u8, flags)
> +		__field(u64, overflow_t)
> +	    ),
> +
> +	    TP_fast_assign(
> +		__assign_str(memdev, memdev);
> +		__assign_str(pcidev, pcidev);
> +		__assign_str(region, region ? region : "");
> +		if (uuid)
> +			memcpy(__entry->uuid, uuid, 16);
> +		__entry->dpa = dpa;
> +		__entry->length = length;
> +		__entry->source = source;
> +		__entry->flags = flags;
> +		__entry->overflow_t = overflow_t;
> +	    ),
> +
> +	    TP_printk("memdev=%s pcidev=%s region=%s region_uuid=%pU dpa=0x%llx length=0x%x source=%s flags=%s overflow_time=%llu",
> +		__get_str(memdev),
> +		__get_str(pcidev),
> +		__get_str(region),
> +		__entry->uuid,
> +		__entry->dpa,
> +		__entry->length,
> +		show_poison_source(__entry->source),
> +		show_poison_flags(__entry->flags),
> +		__entry->overflow_t)
> +);
> +#endif /* _CXL_TRACE_H */
> +
> +/* This part must be outside protection */
> +#undef TRACE_INCLUDE_FILE
> +#define TRACE_INCLUDE_FILE cxl
> +#include <trace/define_trace.h>
> -- 
> 2.37.3
> 

[PATCH v3 2/6] cxl/mbox: Add GET_POISON_LIST mailbox command

[alison.schofield]

From: Alison Schofield <alison.schofield@intel.com>

CXL devices maintain a list of locations that are poisoned or result
in poison if the addresses are accessed by the host.

Per the spec (CXL 3.0 8.2.9.8.4.1), the device returns this Poison
list as a set of  Media Error Records that include the source of the
error, the starting device physical address and length. The length is
the number of adjacent DPAs in the record and is in units of 64 bytes.

Retrieve the list and log each Media Error Record as a trace event of
type 'cxl_poison'.

When the poison list is requested by region, include the region name
and uuid in the trace event.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 drivers/cxl/core/mbox.c | 81 +++++++++++++++++++++++++++++++++++++++++
 drivers/cxl/cxlmem.h    | 37 +++++++++++++++++++
 2 files changed, 118 insertions(+)

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 0c90f13870a4..88f034e97812 100644
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -9,6 +9,9 @@
 
 #include "core.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/cxl.h>
+
 static bool cxl_raw_allow_all;
 
 /**
@@ -752,6 +755,7 @@ int cxl_dev_state_identify(struct cxl_dev_state *cxlds)
 {
 	/* See CXL 2.0 Table 175 Identify Memory Device Output Payload */
 	struct cxl_mbox_identify id;
+	__le32 val = 0;
 	int rc;
 
 	rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_IDENTIFY, NULL, 0, &id,
@@ -771,6 +775,9 @@ int cxl_dev_state_identify(struct cxl_dev_state *cxlds)
 	cxlds->lsa_size = le32_to_cpu(id.lsa_size);
 	memcpy(cxlds->firmware_version, id.fw_revision, sizeof(id.fw_revision));
 
+	memcpy(&val, id.poison_list_max_mer, 3);
+	cxlds->poison_max = min_t(u32, le32_to_cpu(val), CXL_POISON_LIST_MAX);
+
 	return 0;
 }
 EXPORT_SYMBOL_NS_GPL(cxl_dev_state_identify, CXL);
@@ -835,6 +842,79 @@ int cxl_mem_create_range_info(struct cxl_dev_state *cxlds)
 }
 EXPORT_SYMBOL_NS_GPL(cxl_mem_create_range_info, CXL);
 
+static void cxl_trace_poison(struct cxl_mbox_poison_payload_out *po,
+			     struct cxl_region *cxlr,
+			     const char *memdev_name,
+			     const char *pcidev_name)
+{
+	const char *region_name = cxlr ? dev_name(&cxlr->dev) : NULL;
+	struct cxl_region_params *p = cxlr ? &cxlr->params : NULL;
+	uuid_t *uuid = p ? &p->uuid : NULL;
+	u64 addr, dpa, overflow_t = 0;
+	u8 source;
+	u32 len;
+
+	if (po->flags & CXL_POISON_FLAG_OVERFLOW)
+		overflow_t = le64_to_cpu(po->overflow_timestamp);
+
+	for (int i = 0; i < le16_to_cpu(po->count); i++) {
+		len = le32_to_cpu(po->record[i].length) * CXL_POISON_LEN_MULT;
+		addr = le64_to_cpu(po->record[i].address);
+		source = addr & CXL_POISON_SOURCE_MASK;
+		dpa = addr & CXL_POISON_START_MASK;
+
+		trace_cxl_poison(memdev_name, pcidev_name, region_name, uuid,
+				 dpa, len, source, po->flags, overflow_t);
+	}
+}
+
+int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
+		       struct cxl_region *cxlr)
+{
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	const char *memdev_name = dev_name(&cxlmd->dev);
+	const char *pcidev_name = dev_name(cxlds->dev);
+	struct cxl_mbox_poison_payload_out *po;
+	struct cxl_mbox_poison_payload_in pi;
+	int nr_records = 0;
+	int rc;
+
+	po = kvmalloc(cxlds->payload_size, GFP_KERNEL);
+	if (!po)
+		return -ENOMEM;
+
+	pi.offset = cpu_to_le64(offset);
+	pi.length = cpu_to_le64(len);
+
+	rc = mutex_lock_interruptible(&cxlds->poison_list_mutex);
+	if (rc)
+		goto out;
+
+	do {
+		rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_GET_POISON, &pi,
+				       sizeof(pi), po, cxlds->payload_size);
+		if (rc)
+			break;
+
+		if (trace_cxl_poison_enabled())
+			cxl_trace_poison(po, cxlr, memdev_name, pcidev_name);
+
+		/* Protect against an uncleared _FLAG_MORE */
+		nr_records = nr_records + le16_to_cpu(po->count);
+		if (nr_records >= cxlds->poison_max) {
+			dev_dbg(&cxlmd->dev, "Max Error Records reached: %d\n",
+				nr_records);
+			break;
+		}
+	} while (po->flags & CXL_POISON_FLAG_MORE);
+
+	mutex_unlock(&cxlds->poison_list_mutex);
+out:
+	kvfree(po);
+	return rc;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_mem_get_poison, CXL);
+
 struct cxl_dev_state *cxl_dev_state_create(struct device *dev)
 {
 	struct cxl_dev_state *cxlds;
@@ -846,6 +926,7 @@ struct cxl_dev_state *cxl_dev_state_create(struct device *dev)
 	}
 
 	mutex_init(&cxlds->mbox_mutex);
+	mutex_init(&cxlds->poison_list_mutex);
 	cxlds->dev = dev;
 
 	return cxlds;
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 669868cc1553..49d891347e39 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -192,6 +192,8 @@ struct cxl_endpoint_dvsec_info {
  *                (CXL 2.0 8.2.8.4.3 Mailbox Capabilities Register)
  * @lsa_size: Size of Label Storage Area
  *                (CXL 2.0 8.2.9.5.1.1 Identify Memory Device)
+ * @poison_max: maximum media error records held in device cache
+ * @poison_list_mutex: Mutex to synchronize poison list retrieval
  * @mbox_mutex: Mutex to synchronize mailbox access.
  * @firmware_version: Firmware version for the memory device.
  * @enabled_cmds: Hardware commands found enabled in CEL.
@@ -224,6 +226,8 @@ struct cxl_dev_state {
 
 	size_t payload_size;
 	size_t lsa_size;
+	u32 poison_max;
+	struct mutex poison_list_mutex;  /* Protect reads of poison list */
 	struct mutex mbox_mutex; /* Protects device mailbox and firmware */
 	char firmware_version[0x10];
 	DECLARE_BITMAP(enabled_cmds, CXL_MEM_COMMAND_ID_MAX);
@@ -349,6 +353,37 @@ struct cxl_mbox_set_partition_info {
 
 /* Get Poison List  CXL 3.0 Spec 8.2.9.8.4.1 */
 
+struct cxl_mbox_poison_payload_in {
+	__le64 offset;
+	__le64 length;
+} __packed;
+
+struct cxl_mbox_poison_payload_out {
+	u8 flags;
+	u8 rsvd1;
+	__le64 overflow_timestamp;
+	__le16 count;
+	u8 rsvd2[0x14];
+	struct cxl_poison_record {
+		__le64 address;
+		__le32 length;
+		__le32 rsvd;
+	} __packed record[];
+} __packed;
+
+/*
+ * Get Poison List address field encodes the starting
+ * address of poison, and the source of the poison.
+ */
+#define CXL_POISON_START_MASK		GENMASK_ULL(63, 6)
+#define CXL_POISON_SOURCE_MASK		GENMASK(2, 0)
+
+/* Get Poison List record length is in units of 64 bytes */
+#define CXL_POISON_LEN_MULT	64
+
+/* Kernel defined maximum for a list of poison errors */
+#define CXL_POISON_LIST_MAX	1024
+
 /* Get Poison List: Payload out flags */
 #define CXL_POISON_FLAG_MORE            BIT(0)
 #define CXL_POISON_FLAG_OVERFLOW        BIT(1)
@@ -395,6 +430,8 @@ int cxl_mem_create_range_info(struct cxl_dev_state *cxlds);
 struct cxl_dev_state *cxl_dev_state_create(struct device *dev);
 void set_exclusive_cxl_commands(struct cxl_dev_state *cxlds, unsigned long *cmds);
 void clear_exclusive_cxl_commands(struct cxl_dev_state *cxlds, unsigned long *cmds);
+int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
+		       struct cxl_region *cxlr);
 #ifdef CONFIG_CXL_SUSPEND
 void cxl_mem_active_inc(void);
 void cxl_mem_active_dec(void);
-- 
2.37.3

Re: [PATCH v3 2/6] cxl/mbox: Add GET_POISON_LIST mailbox command

[Jonathan Cameron]

On Thu, 10 Nov 2022 19:12:40 -0800
alison.schofield@intel.com wrote:

> From: Alison Schofield <alison.schofield@intel.com>
> 
> CXL devices maintain a list of locations that are poisoned or result
> in poison if the addresses are accessed by the host.
> 
> Per the spec (CXL 3.0 8.2.9.8.4.1), the device returns this Poison
> list as a set of  Media Error Records that include the source of the
> error, the starting device physical address and length. The length is
> the number of adjacent DPAs in the record and is in units of 64 bytes.
> 
> Retrieve the list and log each Media Error Record as a trace event of
> type 'cxl_poison'.
> 
> When the poison list is requested by region, include the region name
> and uuid in the trace event.
> 
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Hi Alison,

I've forgotten most of previous discussions around versions of this series
so I may well repeat things that were covered earlier!

A few things inline.

Thanks,

Jonathan


> ---
>  drivers/cxl/core/mbox.c | 81 +++++++++++++++++++++++++++++++++++++++++
>  drivers/cxl/cxlmem.h    | 37 +++++++++++++++++++
>  2 files changed, 118 insertions(+)
> 
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index 0c90f13870a4..88f034e97812 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -9,6 +9,9 @@
>  
>  #include "core.h"
>  
> +#define CREATE_TRACE_POINTS
> +#include <trace/events/cxl.h>
> +
>  static bool cxl_raw_allow_all;
>  
>  /**
> @@ -752,6 +755,7 @@ int cxl_dev_state_identify(struct cxl_dev_state *cxlds)
>  {
>  	/* See CXL 2.0 Table 175 Identify Memory Device Output Payload */
>  	struct cxl_mbox_identify id;
> +	__le32 val = 0;
>  	int rc;
>  
>  	rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_IDENTIFY, NULL, 0, &id,
> @@ -771,6 +775,9 @@ int cxl_dev_state_identify(struct cxl_dev_state *cxlds)
>  	cxlds->lsa_size = le32_to_cpu(id.lsa_size);
>  	memcpy(cxlds->firmware_version, id.fw_revision, sizeof(id.fw_revision));
>  
> +	memcpy(&val, id.poison_list_max_mer, 3);

This is ugly.  I've lost track of last discussion about get_unaligned_le24()
and using it on elements of a packed structure.  At very least can we
do a memcpy to a u8[3] array and then use get_unaligned_le24() on that if
we can't use it directly on the structure element?


> +	cxlds->poison_max = min_t(u32, le32_to_cpu(val), CXL_POISON_LIST_MAX);
> +
>  	return 0;
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_dev_state_identify, CXL);
> @@ -835,6 +842,79 @@ int cxl_mem_create_range_info(struct cxl_dev_state *cxlds)
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_mem_create_range_info, CXL);
>  
> +int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
> +		       struct cxl_region *cxlr)
> +{
> +	struct cxl_dev_state *cxlds = cxlmd->cxlds;
> +	const char *memdev_name = dev_name(&cxlmd->dev);
Could just do this where it's used rather than here.

> +	const char *pcidev_name = dev_name(cxlds->dev);
Same with this.

> +	struct cxl_mbox_poison_payload_out *po;
> +	struct cxl_mbox_poison_payload_in pi;
> +	int nr_records = 0;
> +	int rc;
> +
> +	po = kvmalloc(cxlds->payload_size, GFP_KERNEL);
> +	if (!po)
> +		return -ENOMEM;
> +
> +	pi.offset = cpu_to_le64(offset);
> +	pi.length = cpu_to_le64(len);
> +
> +	rc = mutex_lock_interruptible(&cxlds->poison_list_mutex);
> +	if (rc)
> +		goto out;
> +
> +	do {
> +		rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_GET_POISON, &pi,
> +				       sizeof(pi), po, cxlds->payload_size);
> +		if (rc)
> +			break;
> +
> +		if (trace_cxl_poison_enabled())
> +			cxl_trace_poison(po, cxlr, memdev_name, pcidev_name);
> +
> +		/* Protect against an uncleared _FLAG_MORE */
> +		nr_records = nr_records + le16_to_cpu(po->count);
> +		if (nr_records >= cxlds->poison_max) {
> +			dev_dbg(&cxlmd->dev, "Max Error Records reached: %d\n",
> +				nr_records);
> +			break;
> +		}
> +	} while (po->flags & CXL_POISON_FLAG_MORE);
> +
> +	mutex_unlock(&cxlds->poison_list_mutex);
> +out:
> +	kvfree(po);
> +	return rc;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_mem_get_poison, CXL);
> +
>  struct cxl_dev_state *cxl_dev_state_create(struct device *dev)
>  {
>  	struct cxl_dev_state *cxlds;
> @@ -846,6 +926,7 @@ struct cxl_dev_state *cxl_dev_state_create(struct device *dev)
>  	}
>  
>  	mutex_init(&cxlds->mbox_mutex);
> +	mutex_init(&cxlds->poison_list_mutex);
>  	cxlds->dev = dev;
>  
>  	return cxlds;
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index 669868cc1553..49d891347e39 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -192,6 +192,8 @@ struct cxl_endpoint_dvsec_info {
>   *                (CXL 2.0 8.2.8.4.3 Mailbox Capabilities Register)
>   * @lsa_size: Size of Label Storage Area
>   *                (CXL 2.0 8.2.9.5.1.1 Identify Memory Device)
> + * @poison_max: maximum media error records held in device cache
For consistency of capitalization: Maximum 
> + * @poison_list_mutex: Mutex to synchronize poison list retrieval
>   * @mbox_mutex: Mutex to synchronize mailbox access.
>   * @firmware_version: Firmware version for the memory device.
>   * @enabled_cmds: Hardware commands found enabled in CEL.
> @@ -224,6 +226,8 @@ struct cxl_dev_state {
>  

...

Re: [PATCH v3 2/6] cxl/mbox: Add GET_POISON_LIST mailbox command

[Alison Schofield]

On Wed, Nov 16, 2022 at 12:41:18PM +0000, Jonathan Cameron wrote:
> On Thu, 10 Nov 2022 19:12:40 -0800
> alison.schofield@intel.com wrote:
> 
> > From: Alison Schofield <alison.schofield@intel.com>
> > 
> > CXL devices maintain a list of locations that are poisoned or result
> > in poison if the addresses are accessed by the host.
> > 
> > Per the spec (CXL 3.0 8.2.9.8.4.1), the device returns this Poison
> > list as a set of  Media Error Records that include the source of the
> > error, the starting device physical address and length. The length is
> > the number of adjacent DPAs in the record and is in units of 64 bytes.
> > 
> > Retrieve the list and log each Media Error Record as a trace event of
> > type 'cxl_poison'.
> > 
> > When the poison list is requested by region, include the region name
> > and uuid in the trace event.
> > 
> > Signed-off-by: Alison Schofield <alison.schofield@intel.com>
> Hi Alison,
> 
> I've forgotten most of previous discussions around versions of this series
> so I may well repeat things that were covered earlier!
> 
> A few things inline.
> 
> Thanks,
> 
> Jonathan
Thanks Jonathan. Got 'em all.
> 
> 
> > ---
snip
> > 
> >  
> > +	memcpy(&val, id.poison_list_max_mer, 3);
> 
> This is ugly.  I've lost track of last discussion about get_unaligned_le24()
> and using it on elements of a packed structure.  At very least can we
> do a memcpy to a u8[3] array and then use get_unaligned_le24() on that if
> we can't use it directly on the structure element?
> 

Done, like this -
val = get_unaligned_le24(id.poison_list_max_mer);

> 
snip
> > +
> > +int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
> > +		       struct cxl_region *cxlr)
> > +{
> > +	struct cxl_dev_state *cxlds = cxlmd->cxlds;
> > +	const char *memdev_name = dev_name(&cxlmd->dev);
> Could just do this where it's used rather than here.
> 
> > +	const char *pcidev_name = dev_name(cxlds->dev);
> Same with this.
> 

Done.

> 
snip
> ...
> 
> 

RE: [PATCH v3 2/6] cxl/mbox: Add GET_POISON_LIST mailbox command

[Dan Williams]

alison.schofield@ wrote:
> From: Alison Schofield <alison.schofield@intel.com>
> 
> CXL devices maintain a list of locations that are poisoned or result
> in poison if the addresses are accessed by the host.
> 
> Per the spec (CXL 3.0 8.2.9.8.4.1), the device returns this Poison
> list as a set of  Media Error Records that include the source of the
> error, the starting device physical address and length. The length is
> the number of adjacent DPAs in the record and is in units of 64 bytes.
> 
> Retrieve the list and log each Media Error Record as a trace event of
> type 'cxl_poison'.
> 
> When the poison list is requested by region, include the region name
> and uuid in the trace event.
> 
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
> ---
>  drivers/cxl/core/mbox.c | 81 +++++++++++++++++++++++++++++++++++++++++
>  drivers/cxl/cxlmem.h    | 37 +++++++++++++++++++
>  2 files changed, 118 insertions(+)
> 
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index 0c90f13870a4..88f034e97812 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -9,6 +9,9 @@
>  
>  #include "core.h"
>  
> +#define CREATE_TRACE_POINTS
> +#include <trace/events/cxl.h>
> +
>  static bool cxl_raw_allow_all;
>  
>  /**
> @@ -752,6 +755,7 @@ int cxl_dev_state_identify(struct cxl_dev_state *cxlds)
>  {
>  	/* See CXL 2.0 Table 175 Identify Memory Device Output Payload */
>  	struct cxl_mbox_identify id;
> +	__le32 val = 0;
>  	int rc;
>  
>  	rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_IDENTIFY, NULL, 0, &id,
> @@ -771,6 +775,9 @@ int cxl_dev_state_identify(struct cxl_dev_state *cxlds)
>  	cxlds->lsa_size = le32_to_cpu(id.lsa_size);
>  	memcpy(cxlds->firmware_version, id.fw_revision, sizeof(id.fw_revision));
>  
> +	memcpy(&val, id.poison_list_max_mer, 3);

I see Jonathan already commented on the need for get_unaligned_le24()
here, seconded.


> +	cxlds->poison_max = min_t(u32, le32_to_cpu(val), CXL_POISON_LIST_MAX);
> +
>  	return 0;
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_dev_state_identify, CXL);
> @@ -835,6 +842,79 @@ int cxl_mem_create_range_info(struct cxl_dev_state *cxlds)
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_mem_create_range_info, CXL);
>  
> +static void cxl_trace_poison(struct cxl_mbox_poison_payload_out *po,
> +			     struct cxl_region *cxlr,
> +			     const char *memdev_name,
> +			     const char *pcidev_name)

Type-safety please. Pass a 'struct cxl_memdev *' and 'struct pci_dev *'.
Might need to be 'struct device *' instead of 'struct pci_dev *'
depending on if this needs to be called from cxl_test, but anything is
better than a non-specific string.

> +{
> +	const char *region_name = cxlr ? dev_name(&cxlr->dev) : NULL;

...and push this conversion into the trace point.

> +	struct cxl_region_params *p = cxlr ? &cxlr->params : NULL;
> +	uuid_t *uuid = p ? &p->uuid : NULL;
> +	u64 addr, dpa, overflow_t = 0;
> +	u8 source;
> +	u32 len;
> +
> +	if (po->flags & CXL_POISON_FLAG_OVERFLOW)
> +		overflow_t = le64_to_cpu(po->overflow_timestamp);
> +
> +	for (int i = 0; i < le16_to_cpu(po->count); i++) {
> +		len = le32_to_cpu(po->record[i].length) * CXL_POISON_LEN_MULT;
> +		addr = le64_to_cpu(po->record[i].address);
> +		source = addr & CXL_POISON_SOURCE_MASK;
> +		dpa = addr & CXL_POISON_START_MASK;
> +
> +		trace_cxl_poison(memdev_name, pcidev_name, region_name, uuid,
> +				 dpa, len, source, po->flags, overflow_t);
> +	}
> +}
> +
> +int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
> +		       struct cxl_region *cxlr)
> +{
> +	struct cxl_dev_state *cxlds = cxlmd->cxlds;
> +	const char *memdev_name = dev_name(&cxlmd->dev);
> +	const char *pcidev_name = dev_name(cxlds->dev);
> +	struct cxl_mbox_poison_payload_out *po;
> +	struct cxl_mbox_poison_payload_in pi;
> +	int nr_records = 0;
> +	int rc;
> +
> +	po = kvmalloc(cxlds->payload_size, GFP_KERNEL);
> +	if (!po)
> +		return -ENOMEM;
> +
> +	pi.offset = cpu_to_le64(offset);
> +	pi.length = cpu_to_le64(len);
> +
> +	rc = mutex_lock_interruptible(&cxlds->poison_list_mutex);

So I do not know what this mutex is protecting if there is an allocation
per cxl_mem_get_poison() invocation. Although I suspect that's somewhat
wasteful. Just allocate one buffer at the beginning of time and then use
the lock to protect that buffer.

Although, I wonder if this and Event handling should share locks and one
preallocated buffer? Otherwise I do think it is important for Events and
Poison handling to be able to make forward progress without needing to
allocate up to a megabyte of memory at runtime. The other payload_size
allocations are for one-off things that run at the beginning of time,
but Poison and Events run repeatedly.

> +	if (rc)
> +		goto out;
> +
> +	do {
> +		rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_GET_POISON, &pi,
> +				       sizeof(pi), po, cxlds->payload_size);
> +		if (rc)
> +			break;
> +
> +		if (trace_cxl_poison_enabled())
> +			cxl_trace_poison(po, cxlr, memdev_name, pcidev_name);
> +
> +		/* Protect against an uncleared _FLAG_MORE */
> +		nr_records = nr_records + le16_to_cpu(po->count);
> +		if (nr_records >= cxlds->poison_max) {
> +			dev_dbg(&cxlmd->dev, "Max Error Records reached: %d\n",
> +				nr_records);
> +			break;
> +		}
> +	} while (po->flags & CXL_POISON_FLAG_MORE);
> +
> +	mutex_unlock(&cxlds->poison_list_mutex);
> +out:
> +	kvfree(po);
> +	return rc;
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_mem_get_poison, CXL);
> +
>  struct cxl_dev_state *cxl_dev_state_create(struct device *dev)
>  {
>  	struct cxl_dev_state *cxlds;
> @@ -846,6 +926,7 @@ struct cxl_dev_state *cxl_dev_state_create(struct device *dev)
>  	}
>  
>  	mutex_init(&cxlds->mbox_mutex);
> +	mutex_init(&cxlds->poison_list_mutex);
>  	cxlds->dev = dev;
>  
>  	return cxlds;
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index 669868cc1553..49d891347e39 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -192,6 +192,8 @@ struct cxl_endpoint_dvsec_info {
>   *                (CXL 2.0 8.2.8.4.3 Mailbox Capabilities Register)
>   * @lsa_size: Size of Label Storage Area
>   *                (CXL 2.0 8.2.9.5.1.1 Identify Memory Device)
> + * @poison_max: maximum media error records held in device cache
> + * @poison_list_mutex: Mutex to synchronize poison list retrieval
>   * @mbox_mutex: Mutex to synchronize mailbox access.
>   * @firmware_version: Firmware version for the memory device.
>   * @enabled_cmds: Hardware commands found enabled in CEL.
> @@ -224,6 +226,8 @@ struct cxl_dev_state {
>  
>  	size_t payload_size;
>  	size_t lsa_size;
> +	u32 poison_max;
> +	struct mutex poison_list_mutex;  /* Protect reads of poison list */
>  	struct mutex mbox_mutex; /* Protects device mailbox and firmware */
>  	char firmware_version[0x10];
>  	DECLARE_BITMAP(enabled_cmds, CXL_MEM_COMMAND_ID_MAX);
> @@ -349,6 +353,37 @@ struct cxl_mbox_set_partition_info {
>  
>  /* Get Poison List  CXL 3.0 Spec 8.2.9.8.4.1 */
>  
> +struct cxl_mbox_poison_payload_in {
> +	__le64 offset;
> +	__le64 length;
> +} __packed;
> +
> +struct cxl_mbox_poison_payload_out {
> +	u8 flags;
> +	u8 rsvd1;
> +	__le64 overflow_timestamp;
> +	__le16 count;
> +	u8 rsvd2[0x14];

Let's use decimal values for size.

> +	struct cxl_poison_record {
> +		__le64 address;
> +		__le32 length;
> +		__le32 rsvd;
> +	} __packed record[];
> +} __packed;
> +
> +/*
> + * Get Poison List address field encodes the starting
> + * address of poison, and the source of the poison.
> + */
> +#define CXL_POISON_START_MASK		GENMASK_ULL(63, 6)
> +#define CXL_POISON_SOURCE_MASK		GENMASK(2, 0)
> +
> +/* Get Poison List record length is in units of 64 bytes */
> +#define CXL_POISON_LEN_MULT	64
> +
> +/* Kernel defined maximum for a list of poison errors */
> +#define CXL_POISON_LIST_MAX	1024
> +
>  /* Get Poison List: Payload out flags */
>  #define CXL_POISON_FLAG_MORE            BIT(0)
>  #define CXL_POISON_FLAG_OVERFLOW        BIT(1)
> @@ -395,6 +430,8 @@ int cxl_mem_create_range_info(struct cxl_dev_state *cxlds);
>  struct cxl_dev_state *cxl_dev_state_create(struct device *dev);
>  void set_exclusive_cxl_commands(struct cxl_dev_state *cxlds, unsigned long *cmds);
>  void clear_exclusive_cxl_commands(struct cxl_dev_state *cxlds, unsigned long *cmds);
> +int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
> +		       struct cxl_region *cxlr);
>  #ifdef CONFIG_CXL_SUSPEND
>  void cxl_mem_active_inc(void);
>  void cxl_mem_active_dec(void);
> -- 
> 2.37.3
> 

Re: [PATCH v3 2/6] cxl/mbox: Add GET_POISON_LIST mailbox command

[Alison Schofield]

On Tue, Dec 06, 2022 at 06:41:34PM -0800, Dan Williams wrote:
> alison.schofield@ wrote:
> > From: Alison Schofield <alison.schofield@intel.com>
> > 
> > CXL devices maintain a list of locations that are poisoned or result
> > in poison if the addresses are accessed by the host.
> > 
> > Per the spec (CXL 3.0 8.2.9.8.4.1), the device returns this Poison
> > list as a set of  Media Error Records that include the source of the
> > error, the starting device physical address and length. The length is
> > the number of adjacent DPAs in the record and is in units of 64 bytes.
> > 
> > Retrieve the list and log each Media Error Record as a trace event of
> > type 'cxl_poison'.
> > 
> > When the poison list is requested by region, include the region name
> > and uuid in the trace event.
> > 
> > Signed-off-by: Alison Schofield <alison.schofield@intel.com>
> > ---
> >  drivers/cxl/core/mbox.c | 81 +++++++++++++++++++++++++++++++++++++++++
> >  drivers/cxl/cxlmem.h    | 37 +++++++++++++++++++
> >  2 files changed, 118 insertions(+)
> > 
> > diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> > index 0c90f13870a4..88f034e97812 100644
> > --- a/drivers/cxl/core/mbox.c
> > +++ b/drivers/cxl/core/mbox.c
> > @@ -9,6 +9,9 @@
> >  
> >  #include "core.h"
> >  
> > +#define CREATE_TRACE_POINTS
> > +#include <trace/events/cxl.h>
> > +
> >  static bool cxl_raw_allow_all;
> >  
> >  /**
> > @@ -752,6 +755,7 @@ int cxl_dev_state_identify(struct cxl_dev_state *cxlds)
> >  {
> >  	/* See CXL 2.0 Table 175 Identify Memory Device Output Payload */
> >  	struct cxl_mbox_identify id;
> > +	__le32 val = 0;
> >  	int rc;
> >  
> >  	rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_IDENTIFY, NULL, 0, &id,
> > @@ -771,6 +775,9 @@ int cxl_dev_state_identify(struct cxl_dev_state *cxlds)
> >  	cxlds->lsa_size = le32_to_cpu(id.lsa_size);
> >  	memcpy(cxlds->firmware_version, id.fw_revision, sizeof(id.fw_revision));
> >  
> > +	memcpy(&val, id.poison_list_max_mer, 3);
> 
> I see Jonathan already commented on the need for get_unaligned_le24()
> here, seconded.
> 
Got it.

> 
> > +	cxlds->poison_max = min_t(u32, le32_to_cpu(val), CXL_POISON_LIST_MAX);
> > +
> >  	return 0;
> >  }
> >  EXPORT_SYMBOL_NS_GPL(cxl_dev_state_identify, CXL);
> > @@ -835,6 +842,79 @@ int cxl_mem_create_range_info(struct cxl_dev_state *cxlds)
> >  }
> >  EXPORT_SYMBOL_NS_GPL(cxl_mem_create_range_info, CXL);
> >  
> > +static void cxl_trace_poison(struct cxl_mbox_poison_payload_out *po,
> > +			     struct cxl_region *cxlr,
> > +			     const char *memdev_name,
> > +			     const char *pcidev_name)
> 
> Type-safety please. Pass a 'struct cxl_memdev *' and 'struct pci_dev *'.
> Might need to be 'struct device *' instead of 'struct pci_dev *'
> depending on if this needs to be called from cxl_test, but anything is
> better than a non-specific string.
> 
Got it.

> > +{
> > +	const char *region_name = cxlr ? dev_name(&cxlr->dev) : NULL;
> 
> ...and push this conversion into the trace point.
> 
Got that, and also pushed the decode of struct cxl_poison_record to
the trace point like this:

TP_PROTO(const struct device *memdev, const struct pci_dev *pcidev,
                     const struct cxl_region *region,
                     const struct cxl_poison_record *record,
                     u8 flags, __le64 overflow_t),


> > +	struct cxl_region_params *p = cxlr ? &cxlr->params : NULL;
> > +	uuid_t *uuid = p ? &p->uuid : NULL;
> > +	u64 addr, dpa, overflow_t = 0;
> > +	u8 source;
> > +	u32 len;
> > +
> > +	if (po->flags & CXL_POISON_FLAG_OVERFLOW)
> > +		overflow_t = le64_to_cpu(po->overflow_timestamp);
> > +
> > +	for (int i = 0; i < le16_to_cpu(po->count); i++) {
> > +		len = le32_to_cpu(po->record[i].length) * CXL_POISON_LEN_MULT;
> > +		addr = le64_to_cpu(po->record[i].address);
> > +		source = addr & CXL_POISON_SOURCE_MASK;
> > +		dpa = addr & CXL_POISON_START_MASK;
> > +
> > +		trace_cxl_poison(memdev_name, pcidev_name, region_name, uuid,
> > +				 dpa, len, source, po->flags, overflow_t);
> > +	}
> > +}
> > +
> > +int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
> > +		       struct cxl_region *cxlr)
> > +{
> > +	struct cxl_dev_state *cxlds = cxlmd->cxlds;
> > +	const char *memdev_name = dev_name(&cxlmd->dev);
> > +	const char *pcidev_name = dev_name(cxlds->dev);
> > +	struct cxl_mbox_poison_payload_out *po;
> > +	struct cxl_mbox_poison_payload_in pi;
> > +	int nr_records = 0;
> > +	int rc;
> > +
> > +	po = kvmalloc(cxlds->payload_size, GFP_KERNEL);
> > +	if (!po)
> > +		return -ENOMEM;
> > +
> > +	pi.offset = cpu_to_le64(offset);
> > +	pi.length = cpu_to_le64(len);
> > +
> > +	rc = mutex_lock_interruptible(&cxlds->poison_list_mutex);
> 
> So I do not know what this mutex is protecting if there is an allocation
> per cxl_mem_get_poison() invocation. Although I suspect that's somewhat
> wasteful. Just allocate one buffer at the beginning of time and then use
> the lock to protect that buffer.

Intent was a single lock on the device to protect the state of the
poison list retrieval - do not allow > 1 reader. With > 1 reader
software may not know if it retrieved the complete list.

I'm not understanding about protecting a buffer, instead of protecting
the state. Here I try to protect the state.

> 
> Although, I wonder if this and Event handling should share locks and one
> preallocated buffer? Otherwise I do think it is important for Events and
> Poison handling to be able to make forward progress without needing to
> allocate up to a megabyte of memory at runtime. The other payload_size
> allocations are for one-off things that run at the beginning of time,
> but Poison and Events run repeatedly.
> 
> > 
snip

Re: [PATCH v3 2/6] cxl/mbox: Add GET_POISON_LIST mailbox command

[Dan Williams]

Alison Schofield wrote:
> On Tue, Dec 06, 2022 at 06:41:34PM -0800, Dan Williams wrote:
> > alison.schofield@ wrote:
[..]
> > > +int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
> > > +		       struct cxl_region *cxlr)
> > > +{
> > > +	struct cxl_dev_state *cxlds = cxlmd->cxlds;
> > > +	const char *memdev_name = dev_name(&cxlmd->dev);
> > > +	const char *pcidev_name = dev_name(cxlds->dev);
> > > +	struct cxl_mbox_poison_payload_out *po;
> > > +	struct cxl_mbox_poison_payload_in pi;
> > > +	int nr_records = 0;
> > > +	int rc;
> > > +
> > > +	po = kvmalloc(cxlds->payload_size, GFP_KERNEL);
> > > +	if (!po)
> > > +		return -ENOMEM;
> > > +
> > > +	pi.offset = cpu_to_le64(offset);
> > > +	pi.length = cpu_to_le64(len);
> > > +
> > > +	rc = mutex_lock_interruptible(&cxlds->poison_list_mutex);
> > 
> > So I do not know what this mutex is protecting if there is an allocation
> > per cxl_mem_get_poison() invocation. Although I suspect that's somewhat
> > wasteful. Just allocate one buffer at the beginning of time and then use
> > the lock to protect that buffer.
> 
> Intent was a single lock on the device to protect the state of the
> poison list retrieval - do not allow > 1 reader. With > 1 reader
> software may not know if it retrieved the complete list.
> 
> I'm not understanding about protecting a buffer, instead of protecting
> the state. Here I try to protect the state.

Ah, sorry I read cxlds->poison_list_mutex and assumed it was serializing
access to the buffer, not a state machine. I do think it would be
worthwhile to make this a self contained structure with its own kdoc to
explain what is going on, something like:

diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index ab138004f644..02697d1d951c 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -193,6 +193,19 @@ struct cxl_endpoint_dvsec_info {
        struct range dvsec_range[2];
 };
 
+/**
+ * struct cxl_poison_state - summary
+ * @payload: ...
+ * @lock: ...
+ *
+ * A bit more description of why state needs to be held over successive
+ * mbox commands...
+ */
+struct cxl_poison_state {
+       void *payload;
+       struct mutex lock;
+};
+
 /**
  * struct cxl_dev_state - The driver device state
  *
@@ -210,6 +223,7 @@ struct cxl_endpoint_dvsec_info {
  * @lsa_size: Size of Label Storage Area
  *                (CXL 2.0 8.2.9.5.1.1 Identify Memory Device)
  * @mbox_mutex: Mutex to synchronize mailbox access.
+ * @poison: Poison list retrieval and tracing
  * @firmware_version: Firmware version for the memory device.
  * @enabled_cmds: Hardware commands found enabled in CEL.
  * @exclusive_cmds: Commands that are kernel-internal only
@@ -244,6 +258,7 @@ struct cxl_dev_state {
        size_t payload_size;
        size_t lsa_size;
        struct mutex mbox_mutex; /* Protects device mailbox and firmware */
+       struct cxl_poison_state poison;
        char firmware_version[0x10];
        DECLARE_BITMAP(enabled_cmds, CXL_MEM_COMMAND_ID_MAX);
        DECLARE_BITMAP(exclusive_cmds, CXL_MEM_COMMAND_ID_MAX);

Re: [PATCH v3 2/6] cxl/mbox: Add GET_POISON_LIST mailbox command

[Alison Schofield]

On Wed, Dec 07, 2022 at 01:39:58PM -0800, Dan Williams wrote:
> Alison Schofield wrote:
> > On Tue, Dec 06, 2022 at 06:41:34PM -0800, Dan Williams wrote:
> > > alison.schofield@ wrote:
> [..]
> > > > +int cxl_mem_get_poison(struct cxl_memdev *cxlmd, u64 offset, u64 len,
> > > > +		       struct cxl_region *cxlr)
> > > > +{
> > > > +	struct cxl_dev_state *cxlds = cxlmd->cxlds;
> > > > +	const char *memdev_name = dev_name(&cxlmd->dev);
> > > > +	const char *pcidev_name = dev_name(cxlds->dev);
> > > > +	struct cxl_mbox_poison_payload_out *po;
> > > > +	struct cxl_mbox_poison_payload_in pi;
> > > > +	int nr_records = 0;
> > > > +	int rc;
> > > > +
> > > > +	po = kvmalloc(cxlds->payload_size, GFP_KERNEL);
> > > > +	if (!po)
> > > > +		return -ENOMEM;
> > > > +
> > > > +	pi.offset = cpu_to_le64(offset);
> > > > +	pi.length = cpu_to_le64(len);
> > > > +
> > > > +	rc = mutex_lock_interruptible(&cxlds->poison_list_mutex);
> > > 
> > > So I do not know what this mutex is protecting if there is an allocation
> > > per cxl_mem_get_poison() invocation. Although I suspect that's somewhat
> > > wasteful. Just allocate one buffer at the beginning of time and then use
> > > the lock to protect that buffer.
> > 
> > Intent was a single lock on the device to protect the state of the
> > poison list retrieval - do not allow > 1 reader. With > 1 reader
> > software may not know if it retrieved the complete list.
> > 
> > I'm not understanding about protecting a buffer, instead of protecting
> > the state. Here I try to protect the state.
> 
> Ah, sorry I read cxlds->poison_list_mutex and assumed it was serializing
> access to the buffer, not a state machine. I do think it would be
> worthwhile to make this a self contained structure with its own kdoc to
> explain what is going on, something like:
> 

OK thanks, it's getting through to me now. 
Will do !

> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index ab138004f644..02697d1d951c 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -193,6 +193,19 @@ struct cxl_endpoint_dvsec_info {
>         struct range dvsec_range[2];
>  };
>  
> +/**
> + * struct cxl_poison_state - summary
> + * @payload: ...
> + * @lock: ...
> + *
> + * A bit more description of why state needs to be held over successive
> + * mbox commands...
> + */
> +struct cxl_poison_state {
> +       void *payload;
> +       struct mutex lock;
> +};
> +
>  /**
>   * struct cxl_dev_state - The driver device state
>   *
> @@ -210,6 +223,7 @@ struct cxl_endpoint_dvsec_info {
>   * @lsa_size: Size of Label Storage Area
>   *                (CXL 2.0 8.2.9.5.1.1 Identify Memory Device)
>   * @mbox_mutex: Mutex to synchronize mailbox access.
> + * @poison: Poison list retrieval and tracing
>   * @firmware_version: Firmware version for the memory device.
>   * @enabled_cmds: Hardware commands found enabled in CEL.
>   * @exclusive_cmds: Commands that are kernel-internal only
> @@ -244,6 +258,7 @@ struct cxl_dev_state {
>         size_t payload_size;
>         size_t lsa_size;
>         struct mutex mbox_mutex; /* Protects device mailbox and firmware */
> +       struct cxl_poison_state poison;
>         char firmware_version[0x10];
>         DECLARE_BITMAP(enabled_cmds, CXL_MEM_COMMAND_ID_MAX);
>         DECLARE_BITMAP(exclusive_cmds, CXL_MEM_COMMAND_ID_MAX);

[PATCH v3 3/6] cxl/memdev: Add trigger_poison_list sysfs attribute

[alison.schofield]

From: Alison Schofield <alison.schofield@intel.com>

When a boolean 'true' is written to this attribute the memdev driver
retrieves the poison list from the device. The list includes addresses
that are poisoned, or would result in poison if accessed, and the
source of the poison. This attribute is only visible for devices
supporting the capability. The retrieved errors are logged as kernel
trace events with the label 'cxl_poison'.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 Documentation/ABI/testing/sysfs-bus-cxl | 14 +++++++++
 drivers/cxl/core/memdev.c               | 41 +++++++++++++++++++++++++
 2 files changed, 55 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
index 8494ef27e8d2..1c5f4a853ba2 100644
--- a/Documentation/ABI/testing/sysfs-bus-cxl
+++ b/Documentation/ABI/testing/sysfs-bus-cxl
@@ -388,3 +388,17 @@ Description:
 		1), and checks that the hardware accepts the commit request.
 		Reading this value indicates whether the region is committed or
 		not.
+
+
+What:		/sys/bus/cxl/devices/memX/trigger_poison_list
+Date:		November, 2022
+KernelVersion:	v6.2
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		(WO) When a boolean 'true' is written to this attribute the
+		memdev driver retrieves the poison list from the device. The
+		list includes addresses that are poisoned or would result in
+		poison if accessed, and the source of the poison. This
+		attribute is only visible for devices supporting the
+		capability. The retrieved errors are logged as kernel
+		trace events with the label 'cxl_poison'.
diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
index 20ce488a7754..06d265db5127 100644
--- a/drivers/cxl/core/memdev.c
+++ b/drivers/cxl/core/memdev.c
@@ -106,12 +106,45 @@ static ssize_t numa_node_show(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RO(numa_node);
 
+static ssize_t trigger_poison_list_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t len)
+{
+	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
+	struct cxl_dev_state *cxlds = cxlmd->cxlds;
+	u64 offset, length;
+	bool tmp;
+	int rc;
+
+	if (kstrtobool(buf, &tmp))
+		return -EINVAL;
+
+	/* Per CXL Spec, separate the pmem and ram poison list reads */
+	if (resource_size(&cxlds->pmem_res)) {
+		offset = cxlds->pmem_res.start;
+		length = resource_size(&cxlds->pmem_res);
+		rc = cxl_mem_get_poison(cxlmd, offset, length, NULL);
+		if (rc)
+			return rc;
+	}
+	if (resource_size(&cxlds->ram_res)) {
+		offset = cxlds->ram_res.start;
+		length = resource_size(&cxlds->ram_res);
+		rc = cxl_mem_get_poison(cxlmd, offset, length, NULL);
+		if (rc)
+			return rc;
+	}
+	return len;
+}
+static DEVICE_ATTR_WO(trigger_poison_list);
+
 static struct attribute *cxl_memdev_attributes[] = {
 	&dev_attr_serial.attr,
 	&dev_attr_firmware_version.attr,
 	&dev_attr_payload_max.attr,
 	&dev_attr_label_storage_size.attr,
 	&dev_attr_numa_node.attr,
+	&dev_attr_trigger_poison_list.attr,
 	NULL,
 };
 
@@ -130,6 +163,14 @@ static umode_t cxl_memdev_visible(struct kobject *kobj, struct attribute *a,
 {
 	if (!IS_ENABLED(CONFIG_NUMA) && a == &dev_attr_numa_node.attr)
 		return 0;
+
+	if (a == &dev_attr_trigger_poison_list.attr) {
+		struct device *dev = kobj_to_dev(kobj);
+
+		if (!test_bit(CXL_MEM_COMMAND_ID_GET_POISON,
+			      to_cxl_memdev(dev)->cxlds->enabled_cmds))
+			return 0;
+	}
 	return a->mode;
 }
 
-- 
2.37.3

Re: [PATCH v3 3/6] cxl/memdev: Add trigger_poison_list sysfs attribute

[Jonathan Cameron]

On Thu, 10 Nov 2022 19:12:41 -0800
alison.schofield@intel.com wrote:

> From: Alison Schofield <alison.schofield@intel.com>
> 
> When a boolean 'true' is written to this attribute the memdev driver
> retrieves the poison list from the device. The list includes addresses
> that are poisoned, or would result in poison if accessed, and the
> source of the poison. This attribute is only visible for devices
> supporting the capability. The retrieved errors are logged as kernel
> trace events with the label 'cxl_poison'.
> 
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Hi Alison,

A few comments inline.

Jonathan

> ---
>  Documentation/ABI/testing/sysfs-bus-cxl | 14 +++++++++
>  drivers/cxl/core/memdev.c               | 41 +++++++++++++++++++++++++
>  2 files changed, 55 insertions(+)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> index 8494ef27e8d2..1c5f4a853ba2 100644
> --- a/Documentation/ABI/testing/sysfs-bus-cxl
> +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> @@ -388,3 +388,17 @@ Description:
>  		1), and checks that the hardware accepts the commit request.
>  		Reading this value indicates whether the region is committed or
>  		not.
> +
> +
> +What:		/sys/bus/cxl/devices/memX/trigger_poison_list
> +Date:		November, 2022
> +KernelVersion:	v6.2
> +Contact:	linux-cxl@vger.kernel.org
> +Description:
> +		(WO) When a boolean 'true' is written to this attribute the
> +		memdev driver retrieves the poison list from the device. The
> +		list includes addresses that are poisoned or would result in
> +		poison if accessed, and the source of the poison. This

Trivial, but 'includes' kind of implies it might have other things as well.

The list consists of addresses that are... perhaps?

> +		attribute is only visible for devices supporting the
> +		capability. The retrieved errors are logged as kernel
> +		trace events with the label 'cxl_poison'.
> diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
> index 20ce488a7754..06d265db5127 100644
> --- a/drivers/cxl/core/memdev.c
> +++ b/drivers/cxl/core/memdev.c
> @@ -106,12 +106,45 @@ static ssize_t numa_node_show(struct device *dev, struct device_attribute *attr,
>  }
>  static DEVICE_ATTR_RO(numa_node);
>  
> +static ssize_t trigger_poison_list_store(struct device *dev,
> +					 struct device_attribute *attr,
> +					 const char *buf, size_t len)
> +{
> +	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
> +	struct cxl_dev_state *cxlds = cxlmd->cxlds;
> +	u64 offset, length;
> +	bool tmp;
> +	int rc;
> +
> +	if (kstrtobool(buf, &tmp))
> +		return -EINVAL;
> +
> +	/* Per CXL Spec, separate the pmem and ram poison list reads */

Reference?  I assume this is the bit about what happens if the
device doesn't support poison list retrieval for volatile memory?
I can't find anything more specific but maybe I'm looking in wrong place.

> +	if (resource_size(&cxlds->pmem_res)) {
> +		offset = cxlds->pmem_res.start;
> +		length = resource_size(&cxlds->pmem_res);
> +		rc = cxl_mem_get_poison(cxlmd, offset, length, NULL);
> +		if (rc)
> +			return rc;
> +	}
> +	if (resource_size(&cxlds->ram_res)) {
> +		offset = cxlds->ram_res.start;
> +		length = resource_size(&cxlds->ram_res);
> +		rc = cxl_mem_get_poison(cxlmd, offset, length, NULL);
> +		if (rc)
> +			return rc;

Hmm.  So should we handle the return of Invalid Physical Address as an
error or not?  I think not given it's optional to support the poison
list for volatile memory.

> +	}
> +	return len;
> +}
> +static DEVICE_ATTR_WO(trigger_poison_list);
> +
>  static struct attribute *cxl_memdev_attributes[] = {
>  	&dev_attr_serial.attr,
>  	&dev_attr_firmware_version.attr,
>  	&dev_attr_payload_max.attr,
>  	&dev_attr_label_storage_size.attr,
>  	&dev_attr_numa_node.attr,
> +	&dev_attr_trigger_poison_list.attr,
>  	NULL,
>  };
>  
> @@ -130,6 +163,14 @@ static umode_t cxl_memdev_visible(struct kobject *kobj, struct attribute *a,
>  {
>  	if (!IS_ENABLED(CONFIG_NUMA) && a == &dev_attr_numa_node.attr)
>  		return 0;
> +
> +	if (a == &dev_attr_trigger_poison_list.attr) {
> +		struct device *dev = kobj_to_dev(kobj);
> +
> +		if (!test_bit(CXL_MEM_COMMAND_ID_GET_POISON,
> +			      to_cxl_memdev(dev)->cxlds->enabled_cmds))
> +			return 0;
> +	}
>  	return a->mode;
>  }
>  

Re: [PATCH v3 3/6] cxl/memdev: Add trigger_poison_list sysfs attribute

[Alison Schofield]

On Wed, Nov 16, 2022 at 12:48:55PM +0000, Jonathan Cameron wrote:
> On Thu, 10 Nov 2022 19:12:41 -0800
> alison.schofield@intel.com wrote:
> 
> > From: Alison Schofield <alison.schofield@intel.com>
> > 
> > When a boolean 'true' is written to this attribute the memdev driver
> > retrieves the poison list from the device. The list includes addresses
> > that are poisoned, or would result in poison if accessed, and the
> > source of the poison. This attribute is only visible for devices
> > supporting the capability. The retrieved errors are logged as kernel
> > trace events with the label 'cxl_poison'.
> > 
> > Signed-off-by: Alison Schofield <alison.schofield@intel.com>
> Hi Alison,
> 
> A few comments inline.
> 
> Jonathan
> 
> > ---
> >  Documentation/ABI/testing/sysfs-bus-cxl | 14 +++++++++
> >  drivers/cxl/core/memdev.c               | 41 +++++++++++++++++++++++++
> >  2 files changed, 55 insertions(+)
> > 
> > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> > index 8494ef27e8d2..1c5f4a853ba2 100644
> > --- a/Documentation/ABI/testing/sysfs-bus-cxl
> > +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> > @@ -388,3 +388,17 @@ Description:
> >  		1), and checks that the hardware accepts the commit request.
> >  		Reading this value indicates whether the region is committed or
> >  		not.
> > +
> > +
> > +What:		/sys/bus/cxl/devices/memX/trigger_poison_list
> > +Date:		November, 2022
> > +KernelVersion:	v6.2
> > +Contact:	linux-cxl@vger.kernel.org
> > +Description:
> > +		(WO) When a boolean 'true' is written to this attribute the
> > +		memdev driver retrieves the poison list from the device. The
> > +		list includes addresses that are poisoned or would result in
> > +		poison if accessed, and the source of the poison. This
> 
> Trivial, but 'includes' kind of implies it might have other things as well.
> 
> The list consists of addresses that are... perhaps?
> 

Changed that to consists. Now, I will be on the lookout for other
usages of includes with unintended implications ;)


> > +		attribute is only visible for devices supporting the
> > +		capability. The retrieved errors are logged as kernel
> > +		trace events with the label 'cxl_poison'.
> > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
> > index 20ce488a7754..06d265db5127 100644
> > --- a/drivers/cxl/core/memdev.c
> > +++ b/drivers/cxl/core/memdev.c
> > @@ -106,12 +106,45 @@ static ssize_t numa_node_show(struct device *dev, struct device_attribute *attr,
> >  }
> >  static DEVICE_ATTR_RO(numa_node);
> >  
> > +static ssize_t trigger_poison_list_store(struct device *dev,
> > +					 struct device_attribute *attr,
> > +					 const char *buf, size_t len)
> > +{
> > +	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
> > +	struct cxl_dev_state *cxlds = cxlmd->cxlds;
> > +	u64 offset, length;
> > +	bool tmp;
> > +	int rc;
> > +
> > +	if (kstrtobool(buf, &tmp))
> > +		return -EINVAL;
> > +
> > +	/* Per CXL Spec, separate the pmem and ram poison list reads */

/* Per CXL Spec 8.2.9.8.4.1 separate the pmem and ram requests */

Added this ^

> 
> Reference?  I assume this is the bit about what happens if the
> device doesn't support poison list retrieval for volatile memory?
> I can't find anything more specific but maybe I'm looking in wrong place.
> 
Section 8.2.9.8.4.1
Says this: 
The device may reject this command if the requested range spans the
device’s volatile and persistent partitions.

And this -
If the device does not support poison list for volatile ranges and
any location in the requested list maps to volatile, the device
shall return Invalid Physical Address.

And, the device only reports that it supports the Get Poison 
command, in general, not specifically for pmem or volatile.

So, we split the requests along ram and pmem boundaries.

> > +	if (resource_size(&cxlds->pmem_res)) {
> > +		offset = cxlds->pmem_res.start;
> > +		length = resource_size(&cxlds->pmem_res);
> > +		rc = cxl_mem_get_poison(cxlmd, offset, length, NULL);
> > +		if (rc)
> > +			return rc;
> > +	}
> > +	if (resource_size(&cxlds->ram_res)) {
> > +		offset = cxlds->ram_res.start;
> > +		length = resource_size(&cxlds->ram_res);
> > +		rc = cxl_mem_get_poison(cxlmd, offset, length, NULL);
> > +		if (rc)
> > +			return rc;
> 
> Hmm.  So should we handle the return of Invalid Physical Address as an
> error or not?  I think not given it's optional to support the poison
> list for volatile memory.
>
Double hmmm. It wasn't obvious what to do here. Users can look for the
events to see if anything was traced, regardless of the rc. But, if an
'rc' stopped a user from looking for results, that would be bad.

I'll go with no error return on ram failure.

> > +	}
> > +	return len;
> > +}
> > +static DEVICE_ATTR_WO(trigger_poison_list);
> > +
> >  static struct attribute *cxl_memdev_attributes[] = {
> >  	&dev_attr_serial.attr,
> >  	&dev_attr_firmware_version.attr,
> >  	&dev_attr_payload_max.attr,
> >  	&dev_attr_label_storage_size.attr,
> >  	&dev_attr_numa_node.attr,
> > +	&dev_attr_trigger_poison_list.attr,
> >  	NULL,
> >  };
> >  
> > @@ -130,6 +163,14 @@ static umode_t cxl_memdev_visible(struct kobject *kobj, struct attribute *a,
> >  {
> >  	if (!IS_ENABLED(CONFIG_NUMA) && a == &dev_attr_numa_node.attr)
> >  		return 0;
> > +
> > +	if (a == &dev_attr_trigger_poison_list.attr) {
> > +		struct device *dev = kobj_to_dev(kobj);
> > +
> > +		if (!test_bit(CXL_MEM_COMMAND_ID_GET_POISON,
> > +			      to_cxl_memdev(dev)->cxlds->enabled_cmds))
> > +			return 0;
> > +	}
> >  	return a->mode;
> >  }
> >  
> 

[PATCH v3 4/6] cxl/region: Add trigger_poison_list sysfs attribute

[alison.schofield]

From: Alison Schofield <alison.schofield@intel.com>

When a boolean 'true' is written to this attribute the region driver
retrieves the poison list for the capacity each device contributes
to this region. The list includes addresses that are poisoned, or
would result in poison if accessed, and the source of the poison.
The retrieved errors are logged as kernel trace events with the
label 'cxl_poison'.

Devices not supporting the poison list capability are ignored.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 Documentation/ABI/testing/sysfs-bus-cxl | 14 +++++++++++
 drivers/cxl/core/region.c               | 33 +++++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
index 1c5f4a853ba2..54fad3bdcb2b 100644
--- a/Documentation/ABI/testing/sysfs-bus-cxl
+++ b/Documentation/ABI/testing/sysfs-bus-cxl
@@ -402,3 +402,17 @@ Description:
 		attribute is only visible for devices supporting the
 		capability. The retrieved errors are logged as kernel
 		trace events with the label 'cxl_poison'.
+
+
+What:		/sys/bus/cxl/devices/regionZ/trigger_poison_list
+Date:		November, 2022
+KernelVersion:	v6.2
+Contact:	linux-cxl@vger.kernel.org
+Description:
+		(WO) When a boolean 'true' is written to this attribute the
+		region driver retrieves the poison list for the capacity
+		each device contributes to this region. The list includes
+		addresses that are poisoned, or would result in poison if
+		accessed, and the source of the poison. The retrieved
+		errors are logged as kernel trace events with the label
+		'cxl_poison'.
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index f9ae5ad284ff..68821238491e 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -72,6 +72,38 @@ static int is_dup(struct device *match, void *data)
 	return 0;
 }
 
+static ssize_t trigger_poison_list_store(struct device *dev,
+					 struct device_attribute *attr,
+					 const char *buf, size_t len)
+{
+	struct cxl_region *cxlr = to_cxl_region(dev);
+	struct cxl_region_params *p = &cxlr->params;
+	struct cxl_endpoint_decoder *cxled;
+	struct cxl_memdev *cxlmd;
+	u64 offset, length;
+	int rc, i;
+	bool tmp;
+
+	if (kstrtobool(buf, &tmp))
+		return -EINVAL;
+
+	for (i = 0; i <  p->nr_targets; i++) {
+		cxled = p->targets[i];
+		cxlmd = cxled_to_memdev(cxled);
+		if (!test_bit(CXL_MEM_COMMAND_ID_GET_POISON,
+			      cxlmd->cxlds->enabled_cmds))
+			continue;
+
+		offset = cxl_dpa_resource_start(cxled);
+		length = cxl_dpa_size(cxled);
+		rc = cxl_mem_get_poison(cxlmd, offset, length, cxlr);
+		if (rc)
+			return rc;
+	}
+	return len;
+}
+static DEVICE_ATTR_WO(trigger_poison_list);
+
 static ssize_t uuid_store(struct device *dev, struct device_attribute *attr,
 			  const char *buf, size_t len)
 {
@@ -570,6 +602,7 @@ static struct attribute *cxl_region_attrs[] = {
 	&dev_attr_interleave_granularity.attr,
 	&dev_attr_resource.attr,
 	&dev_attr_size.attr,
+	&dev_attr_trigger_poison_list.attr,
 	NULL,
 };
 
-- 
2.37.3

Re: [PATCH v3 4/6] cxl/region: Add trigger_poison_list sysfs attribute

[Jonathan Cameron]

On Thu, 10 Nov 2022 19:12:42 -0800
alison.schofield@intel.com wrote:

> From: Alison Schofield <alison.schofield@intel.com>
> 
> When a boolean 'true' is written to this attribute the region driver
> retrieves the poison list for the capacity each device contributes
> to this region. The list includes addresses that are poisoned, or
> would result in poison if accessed, and the source of the poison.
> The retrieved errors are logged as kernel trace events with the
> label 'cxl_poison'.
> 
> Devices not supporting the poison list capability are ignored.
> 
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Trivial comment inline you might want to consider.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  Documentation/ABI/testing/sysfs-bus-cxl | 14 +++++++++++
>  drivers/cxl/core/region.c               | 33 +++++++++++++++++++++++++
>  2 files changed, 47 insertions(+)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> index 1c5f4a853ba2..54fad3bdcb2b 100644
> --- a/Documentation/ABI/testing/sysfs-bus-cxl
> +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> @@ -402,3 +402,17 @@ Description:
>  		attribute is only visible for devices supporting the
>  		capability. The retrieved errors are logged as kernel
>  		trace events with the label 'cxl_poison'.
> +
> +
> +What:		/sys/bus/cxl/devices/regionZ/trigger_poison_list
> +Date:		November, 2022
> +KernelVersion:	v6.2
> +Contact:	linux-cxl@vger.kernel.org
> +Description:
> +		(WO) When a boolean 'true' is written to this attribute the
> +		region driver retrieves the poison list for the capacity
> +		each device contributes to this region. The list includes
Trivial: Same as in previous patch. "includes" is too vague.

> +		addresses that are poisoned, or would result in poison if
> +		accessed, and the source of the poison. The retrieved
> +		errors are logged as kernel trace events with the label
> +		'cxl_poison'.
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index f9ae5ad284ff..68821238491e 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -72,6 +72,38 @@ static int is_dup(struct device *match, void *data)
>  	return 0;
>  }
>  
> +static ssize_t trigger_poison_list_store(struct device *dev,
> +					 struct device_attribute *attr,
> +					 const char *buf, size_t len)
> +{
> +	struct cxl_region *cxlr = to_cxl_region(dev);
> +	struct cxl_region_params *p = &cxlr->params;
> +	struct cxl_endpoint_decoder *cxled;
> +	struct cxl_memdev *cxlmd;
> +	u64 offset, length;
> +	int rc, i;
> +	bool tmp;
> +
> +	if (kstrtobool(buf, &tmp))
> +		return -EINVAL;
> +
> +	for (i = 0; i <  p->nr_targets; i++) {
> +		cxled = p->targets[i];
> +		cxlmd = cxled_to_memdev(cxled);
> +		if (!test_bit(CXL_MEM_COMMAND_ID_GET_POISON,
> +			      cxlmd->cxlds->enabled_cmds))
> +			continue;
> +
> +		offset = cxl_dpa_resource_start(cxled);
> +		length = cxl_dpa_size(cxled);
> +		rc = cxl_mem_get_poison(cxlmd, offset, length, cxlr);
> +		if (rc)
> +			return rc;
> +	}
> +	return len;
> +}
> +static DEVICE_ATTR_WO(trigger_poison_list);
> +
>  static ssize_t uuid_store(struct device *dev, struct device_attribute *attr,
>  			  const char *buf, size_t len)
>  {
> @@ -570,6 +602,7 @@ static struct attribute *cxl_region_attrs[] = {
>  	&dev_attr_interleave_granularity.attr,
>  	&dev_attr_resource.attr,
>  	&dev_attr_size.attr,
> +	&dev_attr_trigger_poison_list.attr,
>  	NULL,
>  };
>  

Re: [PATCH v3 4/6] cxl/region: Add trigger_poison_list sysfs attribute

[Alison Schofield]

On Wed, Nov 16, 2022 at 12:50:38PM +0000, Jonathan Cameron wrote:
> On Thu, 10 Nov 2022 19:12:42 -0800
> alison.schofield@intel.com wrote:
> 
> > From: Alison Schofield <alison.schofield@intel.com>
> > 
> > When a boolean 'true' is written to this attribute the region driver
> > retrieves the poison list for the capacity each device contributes
> > to this region. The list includes addresses that are poisoned, or
> > would result in poison if accessed, and the source of the poison.
> > The retrieved errors are logged as kernel trace events with the
> > label 'cxl_poison'.
> > 
> > Devices not supporting the poison list capability are ignored.
> > 
> > Signed-off-by: Alison Schofield <alison.schofield@intel.com>
> Trivial comment inline you might want to consider.

Thanks, got it!  I will 'include' your tag going forward.
> 
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> > ---
> >  Documentation/ABI/testing/sysfs-bus-cxl | 14 +++++++++++
> >  drivers/cxl/core/region.c               | 33 +++++++++++++++++++++++++
> >  2 files changed, 47 insertions(+)
> > 
> > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl
> > index 1c5f4a853ba2..54fad3bdcb2b 100644
> > --- a/Documentation/ABI/testing/sysfs-bus-cxl
> > +++ b/Documentation/ABI/testing/sysfs-bus-cxl
> > @@ -402,3 +402,17 @@ Description:
> >  		attribute is only visible for devices supporting the
> >  		capability. The retrieved errors are logged as kernel
> >  		trace events with the label 'cxl_poison'.
> > +
> > +
> > +What:		/sys/bus/cxl/devices/regionZ/trigger_poison_list
> > +Date:		November, 2022
> > +KernelVersion:	v6.2
> > +Contact:	linux-cxl@vger.kernel.org
> > +Description:
> > +		(WO) When a boolean 'true' is written to this attribute the
> > +		region driver retrieves the poison list for the capacity
> > +		each device contributes to this region. The list includes
> Trivial: Same as in previous patch. "includes" is too vague.
> 
> > +		addresses that are poisoned, or would result in poison if
> > +		accessed, and the source of the poison. The retrieved
> > +		errors are logged as kernel trace events with the label
> > +		'cxl_poison'.
> > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> > index f9ae5ad284ff..68821238491e 100644
> > --- a/drivers/cxl/core/region.c
> > +++ b/drivers/cxl/core/region.c
> > @@ -72,6 +72,38 @@ static int is_dup(struct device *match, void *data)
> >  	return 0;
> >  }
> >  
> > +static ssize_t trigger_poison_list_store(struct device *dev,
> > +					 struct device_attribute *attr,
> > +					 const char *buf, size_t len)
> > +{
> > +	struct cxl_region *cxlr = to_cxl_region(dev);
> > +	struct cxl_region_params *p = &cxlr->params;
> > +	struct cxl_endpoint_decoder *cxled;
> > +	struct cxl_memdev *cxlmd;
> > +	u64 offset, length;
> > +	int rc, i;
> > +	bool tmp;
> > +
> > +	if (kstrtobool(buf, &tmp))
> > +		return -EINVAL;
> > +
> > +	for (i = 0; i <  p->nr_targets; i++) {
> > +		cxled = p->targets[i];
> > +		cxlmd = cxled_to_memdev(cxled);
> > +		if (!test_bit(CXL_MEM_COMMAND_ID_GET_POISON,
> > +			      cxlmd->cxlds->enabled_cmds))
> > +			continue;
> > +
> > +		offset = cxl_dpa_resource_start(cxled);
> > +		length = cxl_dpa_size(cxled);
> > +		rc = cxl_mem_get_poison(cxlmd, offset, length, cxlr);
> > +		if (rc)
> > +			return rc;
> > +	}
> > +	return len;
> > +}
> > +static DEVICE_ATTR_WO(trigger_poison_list);
> > +
> >  static ssize_t uuid_store(struct device *dev, struct device_attribute *attr,
> >  			  const char *buf, size_t len)
> >  {
> > @@ -570,6 +602,7 @@ static struct attribute *cxl_region_attrs[] = {
> >  	&dev_attr_interleave_granularity.attr,
> >  	&dev_attr_resource.attr,
> >  	&dev_attr_size.attr,
> > +	&dev_attr_trigger_poison_list.attr,
> >  	NULL,
> >  };
> >  
> 

[PATCH v3 5/6] tools/testing/cxl: Mock the max err records field of Identify cmd

[alison.schofield]

From: Alison Schofield <alison.schofield@intel.com>

The CXL mbox command Identify reports the maximum media error
records that a device will report. Mock it here for testing
the GET POISON LIST mbox command.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 tools/testing/cxl/test/mem.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
index aa2df3a15051..f0704d090073 100644
--- a/tools/testing/cxl/test/mem.c
+++ b/tools/testing/cxl/test/mem.c
@@ -111,6 +111,10 @@ static int mock_id(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
 			cpu_to_le64(DEV_SIZE / CXL_CAPACITY_MULTIPLIER),
 	};
 
+	__le32 val = cpu_to_le32(SZ_64);
+
+	memcpy(id.poison_list_max_mer, &val, 3);
+
 	if (cmd->size_out < sizeof(id))
 		return -EINVAL;
 
-- 
2.37.3

Re: [PATCH v3 5/6] tools/testing/cxl: Mock the max err records field of Identify cmd

[Jonathan Cameron]

On Thu, 10 Nov 2022 19:12:43 -0800
alison.schofield@intel.com wrote:

> From: Alison Schofield <alison.schofield@intel.com>
> 
> The CXL mbox command Identify reports the maximum media error
> records that a device will report. Mock it here for testing
> the GET POISON LIST mbox command.
> 
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
> ---
>  tools/testing/cxl/test/mem.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
> index aa2df3a15051..f0704d090073 100644
> --- a/tools/testing/cxl/test/mem.c
> +++ b/tools/testing/cxl/test/mem.c
> @@ -111,6 +111,10 @@ static int mock_id(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
>  			cpu_to_le64(DEV_SIZE / CXL_CAPACITY_MULTIPLIER),
>  	};
>  
> +	__le32 val = cpu_to_le32(SZ_64);
> +
> +	memcpy(id.poison_list_max_mer, &val, 3);
As in other direction, can we do this with a buffer of the right size if
we can't do a put_unaligned_le24() directly.

> +
>  	if (cmd->size_out < sizeof(id))
>  		return -EINVAL;
>  

Re: [PATCH v3 5/6] tools/testing/cxl: Mock the max err records field of Identify cmd

[Alison Schofield]

On Wed, Nov 16, 2022 at 12:51:45PM +0000, Jonathan Cameron wrote:
> On Thu, 10 Nov 2022 19:12:43 -0800
> alison.schofield@intel.com wrote:
> 
> > From: Alison Schofield <alison.schofield@intel.com>
> > 
> > The CXL mbox command Identify reports the maximum media error
> > records that a device will report. Mock it here for testing
> > the GET POISON LIST mbox command.
> > 
> > Signed-off-by: Alison Schofield <alison.schofield@intel.com>
> > ---
> >  tools/testing/cxl/test/mem.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> > 
> > diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
> > index aa2df3a15051..f0704d090073 100644
> > --- a/tools/testing/cxl/test/mem.c
> > +++ b/tools/testing/cxl/test/mem.c
> > @@ -111,6 +111,10 @@ static int mock_id(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
> >  			cpu_to_le64(DEV_SIZE / CXL_CAPACITY_MULTIPLIER),
> >  	};
> >  
> > +	__le32 val = cpu_to_le32(SZ_64);
> > +
> > +	memcpy(id.poison_list_max_mer, &val, 3);
> As in other direction, can we do this with a buffer of the right size if
> we can't do a put_unaligned_le24() directly.
> 
Yes. Got it, thanks!

> > +
> >  	if (cmd->size_out < sizeof(id))
> >  		return -EINVAL;
> >  
> 

[PATCH v3 6/6] tools/testing/cxl: Mock the Get Poison List mbox command

[alison.schofield]

From: Alison Schofield <alison.schofield@intel.com>

Return fake poison error records when the get poison list mbox
command is issued. This supports testing the kernel tracing
and cxl list capabilities for media errors.

Signed-off-by: Alison Schofield <alison.schofield@intel.com>
---
 tools/testing/cxl/test/mem.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
index f0704d090073..f729e055605d 100644
--- a/tools/testing/cxl/test/mem.c
+++ b/tools/testing/cxl/test/mem.c
@@ -38,6 +38,10 @@ static struct cxl_cel_entry mock_cel[] = {
 		.opcode = cpu_to_le16(CXL_MBOX_OP_GET_HEALTH_INFO),
 		.effect = cpu_to_le16(0),
 	},
+	{
+		.opcode = cpu_to_le16(CXL_MBOX_OP_GET_POISON),
+		.effect = cpu_to_le16(0),
+	},
 };
 
 /* See CXL 2.0 Table 181 Get Health Info Output Payload */
@@ -207,6 +211,30 @@ static int mock_health_info(struct cxl_dev_state *cxlds,
 	return 0;
 }
 
+static int mock_get_poison(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
+{
+	struct {
+		struct cxl_mbox_poison_payload_out poison_out;
+		struct cxl_poison_record record;
+	} mock_poison_list = {
+		.poison_out = {
+			.count = cpu_to_le16(1),
+		},
+		.record = {
+			/* .address encodes DPA and poison source bits */
+			.address = cpu_to_le64(CXL_POISON_SOURCE_INTERNAL),
+			.length = cpu_to_le32(1),
+		},
+	};
+
+	if (cmd->size_out < sizeof(mock_poison_list))
+		return -EINVAL;
+
+	memcpy(cmd->payload_out, &mock_poison_list, sizeof(mock_poison_list));
+	cmd->size_out = sizeof(mock_poison_list);
+	return 0;
+}
+
 static int cxl_mock_mbox_send(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
 {
 	struct device *dev = cxlds->dev;
@@ -234,6 +262,9 @@ static int cxl_mock_mbox_send(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *
 	case CXL_MBOX_OP_GET_HEALTH_INFO:
 		rc = mock_health_info(cxlds, cmd);
 		break;
+	case CXL_MBOX_OP_GET_POISON:
+		rc = mock_get_poison(cxlds, cmd);
+		break;
 	default:
 		break;
 	}
-- 
2.37.3

Re: [PATCH v3 6/6] tools/testing/cxl: Mock the Get Poison List mbox command

[Jonathan Cameron]

On Thu, 10 Nov 2022 19:12:44 -0800
alison.schofield@intel.com wrote:

> From: Alison Schofield <alison.schofield@intel.com>
> 
> Return fake poison error records when the get poison list mbox
> command is issued. This supports testing the kernel tracing
> and cxl list capabilities for media errors.
> 
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  tools/testing/cxl/test/mem.c | 31 +++++++++++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
> 
> diff --git a/tools/testing/cxl/test/mem.c b/tools/testing/cxl/test/mem.c
> index f0704d090073..f729e055605d 100644
> --- a/tools/testing/cxl/test/mem.c
> +++ b/tools/testing/cxl/test/mem.c
> @@ -38,6 +38,10 @@ static struct cxl_cel_entry mock_cel[] = {
>  		.opcode = cpu_to_le16(CXL_MBOX_OP_GET_HEALTH_INFO),
>  		.effect = cpu_to_le16(0),
>  	},
> +	{
> +		.opcode = cpu_to_le16(CXL_MBOX_OP_GET_POISON),
> +		.effect = cpu_to_le16(0),
> +	},
>  };
>  
>  /* See CXL 2.0 Table 181 Get Health Info Output Payload */
> @@ -207,6 +211,30 @@ static int mock_health_info(struct cxl_dev_state *cxlds,
>  	return 0;
>  }
>  
> +static int mock_get_poison(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
> +{
> +	struct {
> +		struct cxl_mbox_poison_payload_out poison_out;
> +		struct cxl_poison_record record;
> +	} mock_poison_list = {
> +		.poison_out = {
> +			.count = cpu_to_le16(1),
> +		},
> +		.record = {
> +			/* .address encodes DPA and poison source bits */
> +			.address = cpu_to_le64(CXL_POISON_SOURCE_INTERNAL),
> +			.length = cpu_to_le32(1),
> +		},
> +	};
> +
> +	if (cmd->size_out < sizeof(mock_poison_list))
> +		return -EINVAL;
> +
> +	memcpy(cmd->payload_out, &mock_poison_list, sizeof(mock_poison_list));
> +	cmd->size_out = sizeof(mock_poison_list);
> +	return 0;
> +}
> +
>  static int cxl_mock_mbox_send(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *cmd)
>  {
>  	struct device *dev = cxlds->dev;
> @@ -234,6 +262,9 @@ static int cxl_mock_mbox_send(struct cxl_dev_state *cxlds, struct cxl_mbox_cmd *
>  	case CXL_MBOX_OP_GET_HEALTH_INFO:
>  		rc = mock_health_info(cxlds, cmd);
>  		break;
> +	case CXL_MBOX_OP_GET_POISON:
> +		rc = mock_get_poison(cxlds, cmd);
> +		break;
>  	default:
>  		break;
>  	}