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

["Tauro, Riana" <riana.tauro@intel.com>]

On 02-09-2026 12:00, Mallesh, Koujalagi wrote:
>
>
> 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?

Thanks. Typo will fix it


>> +	 */
>> +
>> +	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 ().
>

This is 0.. do you mean replace 0 with ret?

> 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 we return err, then we would cause a SBR
which is needed only in cases of system controller's failure to respond 
or belongs to critical bo.
Any invalid address can be ignored.


>> +	}
>> +
>> +	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 {} 

It is 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
>

We do if system controller fails to respond or if it belongs to critical BO.

Thanks
Riana

> 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,
>>   };