Re: [PATCH] drm/xe/xe_survivability: Add support for survivability mode v2

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

Hi Rodrigo

On 10/17/2025 12:47 AM, Rodrigo Vivi wrote:
> On Tue, Oct 14, 2025 at 11:02:58AM +0530, Riana Tauro wrote:
>> v2 survivability breadcrumbs introduces a new mode called
>> SPI Flash Descriptor Override mode (FDO). This is enabled by
>> PCODE when MEI itself fails and firmware cannot be updated via
>> MEI using igsc. This mode provides the ability to update
>> the firmware directly via SPI driver.
>>
>> Xe KMD initializes the nvm aux driver if FDO mode is enabled.
>>
>> Userspace should check FDO mode entry in survivability sysfs before
>> using the SPI driver to update firmware.
>>
>> v2 also supports survivability mode for critical boot errors.
>>
>> 	cat /sys/bus/pci/devices/0000\:03\:00.0/survivability_mode
>>
>>                 Capability Info: 0x138320 - 0x2001ae06
>>                 Postcode Info: 0x138324 - 0x0
>>                 Overflow Info: 0x138328 - 0x0
>>                 Auxiliary Info 0: 0x13832c - 0x0
> 
> I am truly sorry here, but although I was the one that designed this,
> looking it now, I realized that this is breaking the sysfs rules
> of one value per file and no fancy format. This is only allowed in
> the debugfs.

Just found the link regarding the "one value per file". When i had tried 
this i found few sysfs having this format, so used the same.

> 
> We need to change this asap, and with help from any tool that
> might be already consuming this.
> 
>>                 FDO Mode: enabled
> 
> After we fix that we can come and add this.
> 
> About our options: I don't believe that debugfs is an option
> without the drm card right?

No debugfs will not work here. And changing the path now will break
any tool using it.

> 
> Perhaps what we need is to transform survivability_mode in
> the directory. Each entry becomes a file in this directory.

Since tools check for presence of survivability_mode file. We
can try this. Will check and respond

Thanks
Riana

> 
> Sorry,
> Rodrigo.
> 
>>
>> Signed-off-by: Riana Tauro <riana.tauro@intel.com>
>> ---
>>   drivers/gpu/drm/xe/xe_pcode_api.h             |  2 ++
>>   drivers/gpu/drm/xe/xe_survivability_mode.c    | 32 +++++++++++++++++--
>>   .../gpu/drm/xe/xe_survivability_mode_types.h  |  6 ++++
>>   3 files changed, 38 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_pcode_api.h b/drivers/gpu/drm/xe/xe_pcode_api.h
>> index 92bfcba51e19..d41f07f9194d 100644
>> --- a/drivers/gpu/drm/xe/xe_pcode_api.h
>> +++ b/drivers/gpu/drm/xe/xe_pcode_api.h
>> @@ -77,11 +77,13 @@
>>   
>>   #define PCODE_SCRATCH(x)		XE_REG(0x138320 + ((x) * 4))
>>   /* PCODE_SCRATCH0 */
>> +#define   BREADCRUMB_VERSION		REG_GENMASK(31, 29)
>>   #define   AUXINFO_REG_OFFSET		REG_GENMASK(17, 15)
>>   #define   OVERFLOW_REG_OFFSET		REG_GENMASK(14, 12)
>>   #define   HISTORY_TRACKING		REG_BIT(11)
>>   #define   OVERFLOW_SUPPORT		REG_BIT(10)
>>   #define   AUXINFO_SUPPORT		REG_BIT(9)
>> +#define   FDO_MODE			REG_BIT(4)
>>   #define   BOOT_STATUS			REG_GENMASK(3, 1)
>>   #define      CRITICAL_FAILURE		4
>>   #define      NON_CRITICAL_FAILURE	7
>> diff --git a/drivers/gpu/drm/xe/xe_survivability_mode.c b/drivers/gpu/drm/xe/xe_survivability_mode.c
>> index 1662bfddd4bc..1c9421651548 100644
>> --- a/drivers/gpu/drm/xe/xe_survivability_mode.c
>> +++ b/drivers/gpu/drm/xe/xe_survivability_mode.c
>> @@ -16,6 +16,7 @@
>>   #include "xe_heci_gsc.h"
>>   #include "xe_i2c.h"
>>   #include "xe_mmio.h"
>> +#include "xe_nvm.h"
>>   #include "xe_pcode_api.h"
>>   #include "xe_vsec.h"
>>   
>> @@ -61,6 +62,12 @@
>>    *	Provides history of previous failures
>>    * Auxiliary Information
>>    *	Certain failures may have information in addition to postcode information
>> + * FDO Mode
>> + *	To allow recovery in scenarios where MEI itself fails, a new SPI Flash Descriptor
>> + *	Override (FDO) mode is added in v2 survivability breadcrumbs. This mode is enabled
>> + *	by PCODE and provides the ability to directly update the firmware via SPI Driver without
>> + *	any dependency on MEI.
>> + *	Xe KMD initializes the nvm aux driver if FDO mode is enabled.
>>    *
>>    * Runtime Survivability
>>    * =====================
>> @@ -105,6 +112,11 @@ static void populate_survivability_info(struct xe_device *xe)
>>   	set_survivability_info(mmio, info, id, "Capability Info");
>>   	reg_value = info[id].value;
>>   
>> +	survivability->version = REG_FIELD_GET(BREADCRUMB_VERSION, reg_value);
>> +	/* FDO mode is exposed only from version 2 */
>> +	if (survivability->version >= 2)
>> +		survivability->fdo_mode = REG_FIELD_GET(FDO_MODE, reg_value);
>> +
>>   	if (reg_value & HISTORY_TRACKING) {
>>   		id++;
>>   		set_survivability_info(mmio, info, id, "Postcode Info");
>> @@ -171,6 +183,9 @@ static ssize_t survivability_mode_show(struct device *dev,
>>   					       info[index].reg, info[index].value);
>>   	}
>>   
>> +	if (survivability->version >= 2)
>> +		count += sysfs_emit_at(buff, count, "FDO Mode: %s\n",
>> +				       str_enabled_disabled(survivability->fdo_mode));
>>   	return count;
>>   }
>>   
>> @@ -179,9 +194,13 @@ static DEVICE_ATTR_ADMIN_RO(survivability_mode);
>>   static void xe_survivability_mode_fini(void *arg)
>>   {
>>   	struct xe_device *xe = arg;
>> +	struct xe_survivability *survivability = &xe->survivability;
>>   	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
>>   	struct device *dev = &pdev->dev;
>>   
>> +	if (survivability->fdo_mode)
>> +		xe_nvm_fini(xe);
>> +
>>   	sysfs_remove_file(&dev->kobj, &dev_attr_survivability_mode.attr);
>>   }
>>   
>> @@ -230,11 +249,18 @@ static int enable_boot_survivability_mode(struct pci_dev *pdev)
>>   	if (ret)
>>   		goto err;
>>   
>> +	if (survivability->fdo_mode) {
>> +		ret = xe_nvm_init(xe);
>> +		if (ret)
>> +			goto err;
>> +	}
>> +
>>   	dev_err(dev, "In Survivability Mode\n");
>>   
>>   	return 0;
>>   
>>   err:
>> +	dev_err(dev, "Failed to enable Survivability Mode\n");
>>   	survivability->mode = false;
>>   	return ret;
>>   }
>> @@ -365,8 +391,10 @@ int xe_survivability_mode_boot_enable(struct xe_device *xe)
>>   	if (ret)
>>   		return ret;
>>   
>> -	/* Log breadcrumbs but do not enter survivability mode for Critical boot errors */
>> -	if (survivability->boot_status == CRITICAL_FAILURE) {
>> +	/*
>> +	 * v2 supports survivability mode for critical errors
>> +	 */
>> +	if (survivability->version < 2  && survivability->boot_status == CRITICAL_FAILURE) {
>>   		log_survivability_info(pdev);
>>   		return -ENXIO;
>>   	}
>> diff --git a/drivers/gpu/drm/xe/xe_survivability_mode_types.h b/drivers/gpu/drm/xe/xe_survivability_mode_types.h
>> index cd65a5d167c9..379d90759c28 100644
>> --- a/drivers/gpu/drm/xe/xe_survivability_mode_types.h
>> +++ b/drivers/gpu/drm/xe/xe_survivability_mode_types.h
>> @@ -38,6 +38,12 @@ struct xe_survivability {
>>   
>>   	/** @type: survivability type */
>>   	enum xe_survivability_type type;
>> +
>> +	/** @fdo_mode: indicates if FDO mode is enabled */
>> +	bool fdo_mode;
>> +
>> +	/** @version: breadcrumb version of survivability mode  */
>> +	u8 version;
>>   };
>>   
>>   #endif /* _XE_SURVIVABILITY_MODE_TYPES_H_ */
>> -- 
>> 2.47.1
>>