Re: [RFC PATCH 2/5] drm/xe/xe_ras: Handle page offline requests for device memory ecc errors

["Mallesh, Koujalagi" <mallesh.koujalagi@intel.com>]

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On 25-08-2026 12:06 pm, Riana Tauro wrote:
> This will be integrated with the related address-fault handling flow
> once this patch is merged.
> https://lore.kernel.org/intel-xe/20260818104055.3833974-14-tejas.upadhyay@intel.com/
> Sending for initial comments.
>
> Add basic support for sending page offline/decline requests to system
> controller and use it for device memory ECC error handling.
> Pages that belong to critical BOs cannot be handled by offlining and
> require a SBR (Secondary Bus Reset).
> Pages that are configured for log-only handling are not marked as bad by
> firmware.
>
> For all other valid page addresses, the first occurrence of error
> indicates a poison error and the page is offlined only by software.
> Firmware avoids permanently marking the page as bad. The second occurrence
> of an error indicates a Double-bit ECC error and the firmware
> permanently marks the page as bad.
>
> Cc: Tejas Upadhyay<tejas.upadhyay@intel.com>
> Cc: Himal Prasad Ghimiray<himal.prasad.ghimiray@intel.com>
> Signed-off-by: Riana Tauro<riana.tauro@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_ras.c                   | 121 +++++++++++++++++-
>   drivers/gpu/drm/xe/xe_ras_types.h             |  35 +++++
>   drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h |   2 +
>   3 files changed, 153 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_ras.c b/drivers/gpu/drm/xe/xe_ras.c
> index d25d25f77531..c643c7137a42 100644
> --- a/drivers/gpu/drm/xe/xe_ras.c
> +++ b/drivers/gpu/drm/xe/xe_ras.c
> @@ -3,6 +3,7 @@
>    * Copyright © 2026 Intel Corporation
>    */
>   
> +#include "xe_bo.h"
>   #include "xe_debugfs.h"
>   #include "xe_device.h"
>   #include "xe_drm_ras.h"
> @@ -200,6 +201,115 @@ static inline const char *comp_to_str(u8 component)
>   	return xe_ras_components[component];
>   }
>   
> +static int send_page_offline_cmd(struct xe_device *xe, u64 page_address,
> +				 enum xe_ras_page_action action)
> +{
> +	struct xe_sysctrl_mailbox_command command = {0};
> +	struct xe_ras_page_offline_request request = {0};
> +	struct xe_ras_page_offline_response response = {0};
> +	size_t rlen;
> +	int ret;
> +
> +	if (!xe->info.has_sysctrl)
> +		return 0;
> +
> +	if (action >= XE_RAS_PAGE_ACTION_MAX) {
> +		xe_log_err(xe, DEVICE_MEMORY, -EINVAL, "Invalid page offline action %d\n", action);
> +		return -EINVAL;
> +	}
> +
> +	request.page_address = page_address;
> +	request.action = action;
> +
> +	xe_sysctrl_create_command(&command, XE_SYSCTRL_GROUP_GFSP, XE_SYSCTRL_CMD_PAGE_OFFLINE,
> +				  &request, sizeof(request), &response, sizeof(response));
> +
> +	ret = xe_sysctrl_send_command(&xe->sc, &command, &rlen);
> +	if (ret) {
> +		xe_log_err_fatal(xe, SYSCTRL, ret, "failed to send page offline command\n");
> +		return ret;
> +	}
> +
> +	if (rlen != sizeof(response)) {
> +		xe_log_err(xe, SYSCTRL, -EINVAL,
> +			   "unexpected page offline response length %zu (expected %zu)\n",
> +			   rlen, sizeof(response));
> +		return -EINVAL;
> +	}
> +
> +	ret = ras_status_to_errno(response.status);
> +	if (ret) {
> +		xe_log_err(xe, SYSCTRL, ret, "page offline command failed with status %u\n",
> +			   response.status);
> +		return ret;
> +	}
> +
> +	return ret;
> +}
> +
> +static int handle_page_offline(struct xe_device *xe, u64 page_address, bool send_cmd)
> +{
> +	enum xe_ras_page_action action;
> +	int ret = 0;
> +
> +	if (!IS_ALIGNED(page_address, XE_PAGE_SIZE)) {
> +		xe_log_err(xe, SYSCTRL, -EINVAL, "Unaligned physical page address: 0x%llx\n",
> +			   page_address);
> +		return -EINVAL;
> +	}
> +
> +	/*
> +	 * TODO: Call function to handle address fault
> +	 * ret = xe_ttm_vram_handle_addr_fault(xe, page_address);
> +	 */
> +
> +	/*
> +	 * Handle return code from address fault handling function:
> +	 *  0: Page soft offlined, decline to firmware
> +	 * -EIO: Address belongs to a critical BO/stolen area that cannot be offlined
> +	 * -EOPNOTSUPP: Address is valid and can be offlined but user policy is not to offline
> +	 * -EXIST: Address is soft offlined but yet to be offlined by firmware for second occurrence
nit: -EEXIST?
> +	 */
> +
> +	switch (ret) {
> +	case 0:
> +		action = XE_RAS_PAGE_ACTION_DECLINE;
> +		xe_log_err(xe, DEVICE_MEMORY, 0,

I know, it's switch case using ret, please make use of errno as ret from 
xe_ttm_vram_handle_addr_fault ().

and make it consistency across all below xe_log_err.

> +			   "Poison detected at physical address 0x%llx, page software offlined\n",
> +			   page_address);
> +		break;
> +	/* User policy set to decline page offlining */
> +	case -EOPNOTSUPP:
> +		action = XE_RAS_PAGE_ACTION_DECLINE;
> +		break;
> +	case -EIO:
> +		xe_log_err(xe, DEVICE_MEMORY, -EIO,
> +			   "Physical page address belongs to critical BO: 0x%llx\n", page_address);
> +		return ret;
> +	case -EEXIST:
> +		action = XE_RAS_PAGE_ACTION_OFFLINE;
> +		xe_log_err(xe, DEVICE_MEMORY, -EEXIST,
> +			   "Double-bit ECC error detected at physical address 0x%llx, page already software offlined\n",
> +			   page_address);
> +		break;
> +	default:
> +		xe_log_err_fatal(xe, DEVICE_MEMORY, ret, "Failed to handle address fault 0x%llx\n",
> +				 page_address);
> +		return 0;
hmm, In default case, we need to use return ret; right?
> +	}
> +
> +	if (send_cmd) {
> +		ret = send_page_offline_cmd(xe, page_address, action);
> +		if (ret)
> +			xe_log_err_fatal(xe, SYSCTRL, ret,
> +					 "Failed to offline page for physical address 0x%llx\n",
> +					 page_address);
> +		return ret;
'return ret' should be inside {}
> +	}
> +
> +	return 0;
> +}
> +
>   static bool ras_counter_is_valid(struct xe_device *xe, struct xe_ras_error_class *counter)
>   {
>   	u8 severity = counter->common.severity;
> @@ -367,11 +477,12 @@ static u8 handle_soc_internal_errors(struct xe_device *xe, struct xe_ras_error_a
>   static u8 handle_device_memory_errors(struct xe_device *xe, struct xe_ras_error_array *arr)
>   {
>   	struct xe_ras_memory_error *info = (void *)arr->details;
> +	int ret;
>   
>   	/*
>   	 * For memory errors, the recovery action depends on the error category
>   	 *
> -	 * TODO: Double-bit ECC errors: Page offlining
> +	 * Double-bit ECC errors: Page offlining
>   	 * Poison and data parity errors: Log only
>   	 * For any other memory errors, request a reset as recovery mechanism
>   	 */
> @@ -383,10 +494,10 @@ static u8 handle_device_memory_errors(struct xe_device *xe, struct xe_ras_error_
>   		xe_info(xe, "[RAS]: Data parity error detected\n");
>   		break;
>   	case XE_RAS_MEMORY_DB_ECC:
> -		xe_info(xe, "[RAS]: Double-bit ECC error detected at sw address 0x%llx\n",
> -			info->sw_address);
> -		/* TODO: Add page offlining for Double-bit ECC error */
> -		fallthrough;
> +		ret = handle_page_offline(xe, info->sw_address, true);

In case of soft page offline, we need not required reset right? however 
when send_page_offline_cmd

return err that case, reset is required. is that correct behavior?

Thanks,

-/Mallesh

> +		if (ret)
> +			return XE_RAS_RECOVERY_ACTION_RESET;
> +		break;
>   	default:
>   		return XE_RAS_RECOVERY_ACTION_RESET;
>   	}
> diff --git a/drivers/gpu/drm/xe/xe_ras_types.h b/drivers/gpu/drm/xe/xe_ras_types.h
> index 99b2466e2062..2fac968879b6 100644
> --- a/drivers/gpu/drm/xe/xe_ras_types.h
> +++ b/drivers/gpu/drm/xe/xe_ras_types.h
> @@ -17,6 +17,19 @@
>   #define XE_RAS_MEMORY_POISON			BIT(2)
>   #define XE_RAS_MEMORY_DATA_PARITY		BIT(5)
>   
> +/**
> + * enum xe_ras_page_action - Page offline actions for page offline request
> + *
> + * @XE_RAS_PAGE_ACTION_OFFLINE: Instruct firmware to offline the page
> + * @XE_RAS_PAGE_ACTION_DECLINE: Instruct firmware to remove the page from queue
> + * @XE_RAS_PAGE_ACTION_MAX: Max value
> + */
> +enum xe_ras_page_action {
> +	XE_RAS_PAGE_ACTION_OFFLINE,
> +	XE_RAS_PAGE_ACTION_DECLINE,
> +	XE_RAS_PAGE_ACTION_MAX
> +};
> +
>   /**
>    * enum xe_ras_recovery_action - RAS recovery actions
>    *
> @@ -245,6 +258,28 @@ struct xe_ras_memory_error {
>   	u32 reserved2[10];
>   } __packed;
>   
> +/**
> + * struct xe_ras_page_offline_request - Request for page offline command
> + */
> +struct xe_ras_page_offline_request {
> +	/** @page_address: Page address (4KB aligned) */
> +	u64 page_address;
> +	/** @action: Action to be performed, see &enum xe_ras_page_action */
> +	u32 action;
> +	/** @reserved: Reserved for future use */
> +	u32 reserved;
> +} __packed;
> +
> +/**
> + * struct xe_ras_page_offline_response - Response from page offline command
> + */
> +struct xe_ras_page_offline_response {
> +	/** @status: Status of the page offline request */
> +	u32 status;
> +	/** @reserved: Reserved for future use */
> +	u32 reserved;
> +} __packed;
> +
>   /**
>    * struct xe_ras_get_health_request - Request structure for obtaining gpu health
>    */
> diff --git a/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h b/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h
> index d0341538ad05..3363f48da2b7 100644
> --- a/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h
> +++ b/drivers/gpu/drm/xe/xe_sysctrl_mailbox_types.h
> @@ -26,6 +26,7 @@ enum xe_sysctrl_group {
>    * @XE_SYSCTRL_CMD_GET_COUNTER: Get error counter value
>    * @XE_SYSCTRL_CMD_CLEAR_COUNTER: Clear error counter value
>    * @XE_SYSCTRL_CMD_GET_PENDING_EVENT: Retrieve pending event
> + * @XE_SYSCTRL_CMD_PAGE_OFFLINE: Instruct firmware to offline/decline a page
>    * @XE_SYSCTRL_CMD_GET_HEALTH: Retrieve gpu health
>    * @XE_SYSCTRL_CMD_SET_HEALTH: Set gpu health
>    */
> @@ -34,6 +35,7 @@ enum xe_sysctrl_gfsp_cmd {
>   	XE_SYSCTRL_CMD_GET_COUNTER		= 0x03,
>   	XE_SYSCTRL_CMD_CLEAR_COUNTER		= 0x04,
>   	XE_SYSCTRL_CMD_GET_PENDING_EVENT	= 0x07,
> +	XE_SYSCTRL_CMD_PAGE_OFFLINE             = 0x08,
>   	XE_SYSCTRL_CMD_GET_HEALTH		= 0x0B,
>   	XE_SYSCTRL_CMD_SET_HEALTH		= 0x0C,
>   };

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