Re: [PATCH v6 1/7] libcxl: add interfaces for GET_POISON_LIST mailbox commands

[Dave Jiang <dave.jiang@intel.com>]

On 1/17/24 17:28, 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 3.1 8.2.9.9.4.1), the device returns the Poison
> List as a set of  Media Error Records that include the source of the
> error, the starting device physical address and length.
> 
> Trigger the retrieval of the poison list by writing to the memory
> device sysfs attribute: trigger_poison_list. The CXL driver only
> offers triggering per memdev, so the trigger by region interface
> offered here is a convenience API that triggers a poison list
> retrieval for each memdev contributing to a region.
> 
> int cxl_memdev_trigger_poison_list(struct cxl_memdev *memdev);
> int cxl_region_trigger_poison_list(struct cxl_region *region);
> 
> The resulting poison records are logged as kernel trace events
> named 'cxl_poison'.
> 
> Signed-off-by: Alison Schofield <alison.schofield@intel.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  cxl/lib/libcxl.c   | 47 ++++++++++++++++++++++++++++++++++++++++++++++
>  cxl/lib/libcxl.sym |  6 ++++++
>  cxl/libcxl.h       |  2 ++
>  3 files changed, 55 insertions(+)
> 
> diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c
> index af4ca44eae19..cc95c2d7c94a 100644
> --- a/cxl/lib/libcxl.c
> +++ b/cxl/lib/libcxl.c
> @@ -1647,6 +1647,53 @@ CXL_EXPORT int cxl_memdev_disable_invalidate(struct cxl_memdev *memdev)
>  	return 0;
>  }
>  
> +CXL_EXPORT int cxl_memdev_trigger_poison_list(struct cxl_memdev *memdev)
> +{
> +	struct cxl_ctx *ctx = cxl_memdev_get_ctx(memdev);
> +	char *path = memdev->dev_buf;
> +	int len = memdev->buf_len, rc;
> +
> +	if (snprintf(path, len, "%s/trigger_poison_list",
> +		     memdev->dev_path) >= len) {
> +		err(ctx, "%s: buffer too small\n",
> +		    cxl_memdev_get_devname(memdev));
> +		return -ENXIO;
> +	}
> +	rc = sysfs_write_attr(ctx, path, "1\n");
> +	if (rc < 0) {
> +		fprintf(stderr,
> +			"%s: Failed write sysfs attr trigger_poison_list\n",
> +			cxl_memdev_get_devname(memdev));
> +		return rc;
> +	}
> +	return 0;
> +}
> +
> +CXL_EXPORT int cxl_region_trigger_poison_list(struct cxl_region *region)
> +{
> +	struct cxl_memdev_mapping *mapping;
> +	int rc;
> +
> +	cxl_mapping_foreach(region, mapping) {
> +		struct cxl_decoder *decoder;
> +		struct cxl_memdev *memdev;
> +
> +		decoder = cxl_mapping_get_decoder(mapping);
> +		if (!decoder)
> +			continue;
> +
> +		memdev = cxl_decoder_get_memdev(decoder);
> +		if (!memdev)
> +			continue;
> +
> +		rc = cxl_memdev_trigger_poison_list(memdev);
> +		if (rc)
> +			return rc;
> +	}
> +
> +	return 0;
> +}
> +
>  CXL_EXPORT int cxl_memdev_enable(struct cxl_memdev *memdev)
>  {
>  	struct cxl_ctx *ctx = cxl_memdev_get_ctx(memdev);
> diff --git a/cxl/lib/libcxl.sym b/cxl/lib/libcxl.sym
> index 8fa1cca3d0d7..277b7e21d6a6 100644
> --- a/cxl/lib/libcxl.sym
> +++ b/cxl/lib/libcxl.sym
> @@ -264,3 +264,9 @@ global:
>  	cxl_memdev_update_fw;
>  	cxl_memdev_cancel_fw_update;
>  } LIBCXL_5;
> +
> +LIBCXL_7 {
> +global:
> +	cxl_memdev_trigger_poison_list;
> +	cxl_region_trigger_poison_list;
> +} LIBCXL_6;
> diff --git a/cxl/libcxl.h b/cxl/libcxl.h
> index 0f4f4b2648fb..ecdffe36df2c 100644
> --- a/cxl/libcxl.h
> +++ b/cxl/libcxl.h
> @@ -460,6 +460,8 @@ enum cxl_setpartition_mode {
>  
>  int cxl_cmd_partition_set_mode(struct cxl_cmd *cmd,
>  		enum cxl_setpartition_mode mode);
> +int cxl_memdev_trigger_poison_list(struct cxl_memdev *memdev);
> +int cxl_region_trigger_poison_list(struct cxl_region *region);
>  
>  #ifdef __cplusplus
>  } /* extern "C" */