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

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Mon, Nov 03, 2025 at 01:35:07PM +0530, Riana Tauro wrote:
> Hi Rodrigo
> 
> On 10/22/2025 6:08 PM, Riana Tauro wrote:
> > 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
> 
> 
> fwupd tool currently reads the file for runtime survivability (though the
> file has only type). Changing this would break the previous versions of
> fwupd
> 
> https://github.com/fwupd/fwupd/blob/66a0e5cc13b2f9b1391d84186bd6274cc9971299/plugins/intel-gsc/fu-igsc-device.c#L397
> 
> @Frank, is it okay if we change the directory structure now?
> 
> Or else can we have two sysfs entries.?
> 
> 1) survivability_mode - boolean to indicate if device is in survivability
> mode or type of survivability mode

ack

> 
> 2) survivability info for all the other details?
> 
> /sys/bus/pci/devices/0000:03:00.0/survivability_info/
> ├── aux_info
> │   ├── aux_info0
> │   ├── aux_info1
> │   ├── aux_info2
> │   ├── aux_info3
> │   └── aux_info4
> ├── capability_info
> ├── postcode_info
> ├── postcode_overflow_info

ack

That sounds indeed better. We cannot break user-space.

Thank you and again, I'm so sorry for the bad sysfs design.

> 
> Thanks
> Riana
> > 
> > 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
> > > > 
> > 
>