Re: [RFC v8 1/1] drm/xe/pf: Restrict device query responses in admin-only PF mode

Michal Wajdeczko
2026-04-02T14:10:06Z

On 4/2/2026 3:19 PM, Satyanarayana K V P wrote:
> When a PF is configured in admin-only mode, it is intended for management
> only and must not expose workload-facing capabilities to userspace.
>
> Limit the exposed ioctl set in admin-only PF mode to XE_DEVICE_QUERY and
> XE_OBSERVATION, and suppress capability-bearing query payloads so that
> the userspace cannot discover execution-related device details in this
> mode.
>
> Enable admin-only mode with:
> echo <B:D:F> | sudo tee /sys/bus/pci/drivers/xe/unbind
> sudo mkdir /sys/kernel/config/xe/<B:D:F>
> echo yes | sudo tee /sys/kernel/config/xe/<B:D:F>/sriov/admin_only_pf
> echo <B:D:F> | sudo tee /sys/bus/pci/drivers/xe/bind
>
> Signed-off-by: Satyanarayana K V P <satyanarayana.k.v.p@intel.com>
> Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Cc: Piotr Piórkowski <piotr.piorkowski@intel.com>
> Cc: Matthew Brost <matthew.brost@intel.com>
> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> Cc: Michał Winiarski <michal.winiarski@intel.com>
> Cc: Dunajski Bartosz <bartosz.dunajski@intel.com>
> Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
> Cc: dri-devel@lists.freedesktop.org
> Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Acked-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
>
> ---
> V7 -> V8:
> - Fixed issues reported by CI.Hooks
> - Updated commit message (Ashutosh)
> - Removed gem_prime_import from admin_only_driver structure (Michal)
>
> V6 -> V7:
> - Allowed xe_observation_ioctl as well with admin-only PF (Ashutosh,
> Michal).
> - Updated commit message with steps to enable admin-only mode (Rodrigo).
>
> V5 -> V6:
> - Updated commit message.
> - Return number of engines and memory regions as zero instead of
> returning query size as zero (Michal Wajdeczko).
> - Allow all other query IOCTLs excepts query_engines and
> query_mem_regions (Michal Wajdeczko).
>
> V4 -> V5:
> - Updated commit message (Matt B).
> - Introduced new driver_admin_only_pf structure (Michal Wajdeczko).
> - Updated all query configs (Michal Wajdeczko).
> - Renamed xe_device_is_admin_only() to xe_device_is_admin_only_pf()
> - Fixed other review comments (Michal Wajdeczko).
>
> V3 -> V4:
> - Suppressed device capabilities in admin-only PF mode. (Wajdeczko)
>
> V2 -> V3:
> - Introduced new helper function xe_debugfs_create_files() to create
> debugfs entries based on admin_only_pf mode or normal mode.
>
> V1 -> V2:
> - Rebased to latest drm-tip.
> - Update update_minor_dev() to debugfs_minor_dev().
> ---
> drivers/gpu/drm/xe/xe_device.c | 60 ++++++++++++++++++++++++++++---
> drivers/gpu/drm/xe/xe_device.h | 1 +
> drivers/gpu/drm/xe/xe_hw_engine.c | 3 ++
> drivers/gpu/drm/xe/xe_query.c | 10 +++++-
> 4 files changed, 69 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index cbce1d0ffe48..eba2fa6dc7d3 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -25,6 +25,7 @@
> #include "regs/xe_regs.h"
> #include "xe_bo.h"
> #include "xe_bo_evict.h"
> +#include "xe_configfs.h"
> #include "xe_debugfs.h"
> #include "xe_defaults.h"
> #include "xe_devcoredump.h"
> @@ -216,6 +217,11 @@ static const struct drm_ioctl_desc xe_ioctls[] = {
> DRM_RENDER_ALLOW),
> };
>
> +static const struct drm_ioctl_desc xe_ioctls_admin_only[] = {
> + DRM_IOCTL_DEF_DRV(XE_DEVICE_QUERY, xe_query_ioctl, DRM_RENDER_ALLOW),
> + DRM_IOCTL_DEF_DRV(XE_OBSERVATION, xe_observation_ioctl, DRM_RENDER_ALLOW),
> +};
> +
> static long xe_drm_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> {
> struct drm_file *file_priv = file->private_data;
> @@ -390,7 +396,7 @@ bool xe_is_xe_file(const struct file *file)
> return file->f_op == &xe_driver_fops;
> }
>
> -static struct drm_driver driver = {
> +static struct drm_driver regular_driver = {
> .driver_features =
> DRIVER_GEM |
> DRIVER_RENDER | DRIVER_SYNCOBJ |
> @@ -415,6 +421,38 @@ static struct drm_driver driver = {
> .patchlevel = DRIVER_PATCHLEVEL,
> };
>
> +static struct drm_driver admin_only_driver = {
> + .driver_features =
> + DRIVER_GEM | DRIVER_RENDER | DRIVER_GEM_GPUVA,
> + .open = xe_file_open,
> + .postclose = xe_file_close,
> +
> + .dumb_create = xe_bo_dumb_create,
> + .dumb_map_offset = drm_gem_ttm_dumb_map_offset,
> +#ifdef CONFIG_PROC_FS
> + .show_fdinfo = xe_drm_client_fdinfo,

do we want to expose memory or engines details here?

> +#endif
> + .ioctls = xe_ioctls_admin_only,
> + .num_ioctls = ARRAY_SIZE(xe_ioctls_admin_only),
> + .fops = &xe_driver_fops,
> + .name = DRIVER_NAME,
> + .desc = DRIVER_DESC,
> + .major = DRIVER_MAJOR,
> + .minor = DRIVER_MINOR,
> + .patchlevel = DRIVER_PATCHLEVEL,
> +};
> +
> +/**
> + * xe_device_is_admin_only() - Check whether device is admin only or not.
> + * @xe: the &xe_device to check
> + *
> + * Return: true if the device is admin only, false otherwise.
> + */
> +bool xe_device_is_admin_only(const struct xe_device *xe)
> +{
> + return xe->drm.driver == &admin_only_driver;
> +}

I'm still looking for patch #2 which would update xe_sriov_pf_admin_only()

> +
> static void xe_device_destroy(struct drm_device *dev, void *dummy)
> {
> struct xe_device *xe = to_xe_device(dev);
> @@ -439,16 +477,25 @@ static void xe_device_destroy(struct drm_device *dev, void *dummy)
> struct xe_device *xe_device_create(struct pci_dev *pdev,
> const struct pci_device_id *ent)
> {
> + struct drm_driver *driver = &regular_driver;
> struct xe_device *xe;
> int err;
>
> - xe_display_driver_set_hooks(&driver);
> +#ifdef CONFIG_PCI_IOV

maybe use if (IS_ENABLED()) to avoid complains about unused static in PCI_IOV=n ?

> + /*
> + * Since XE device is not initialized yet, read from configfs
> + * directly to decide whether we are in admin-only PF mode or not.
> + */
> + if (xe_configfs_admin_only_pf(pdev))
> + driver = &admin_only_driver;
> +#endif

nit: add empty line here

> + xe_display_driver_set_hooks(driver);
>
> - err = aperture_remove_conflicting_pci_devices(pdev, driver.name);
> + err = aperture_remove_conflicting_pci_devices(pdev, driver->name);
> if (err)
> return ERR_PTR(err);
>
> - xe = devm_drm_dev_alloc(&pdev->dev, &driver, struct xe_device, drm);
> + xe = devm_drm_dev_alloc(&pdev->dev, driver, struct xe_device, drm);
> if (IS_ERR(xe))
> return xe;
>
> @@ -708,6 +755,11 @@ int xe_device_probe_early(struct xe_device *xe)
>
> xe_sriov_probe_early(xe);
>
> + if (xe_device_is_admin_only(xe) && !IS_SRIOV_PF(xe)) {
> + xe_err(xe, "Can't run Admin-only mode without SR-IOV PF mode!\n");
> + return -ENODEV;
> + }
> +
> if (IS_SRIOV_VF(xe))
> vf_update_device_info(xe);
>
> diff --git a/drivers/gpu/drm/xe/xe_device.h b/drivers/gpu/drm/xe/xe_device.h
> index e4b9de8d8e95..c220f2f1352f 100644
> --- a/drivers/gpu/drm/xe/xe_device.h
> +++ b/drivers/gpu/drm/xe/xe_device.h
> @@ -43,6 +43,7 @@ static inline struct xe_device *ttm_to_xe_device(struct ttm_device *ttm)
> return container_of(ttm, struct xe_device, ttm);
> }
>
> +bool xe_device_is_admin_only(const struct xe_device *xe);
> struct xe_device *xe_device_create(struct pci_dev *pdev,
> const struct pci_device_id *ent);
> int xe_device_probe_early(struct xe_device *xe);
> diff --git a/drivers/gpu/drm/xe/xe_hw_engine.c b/drivers/gpu/drm/xe/xe_hw_engine.c
> index 337baf0a6e87..2c324acb1dd0 100644
> --- a/drivers/gpu/drm/xe/xe_hw_engine.c
> +++ b/drivers/gpu/drm/xe/xe_hw_engine.c
> @@ -1027,6 +1027,9 @@ bool xe_hw_engine_is_reserved(struct xe_hw_engine *hwe)
> struct xe_gt *gt = hwe->gt;
> struct xe_device *xe = gt_to_xe(gt);
>
> + if (xe_device_is_admin_only(xe))
> + return true;
> +
> if (hwe->class == XE_ENGINE_CLASS_OTHER)
> return true;
>
> diff --git a/drivers/gpu/drm/xe/xe_query.c b/drivers/gpu/drm/xe/xe_query.c
> index d84d6a422c45..b10a281c6ae0 100644
> --- a/drivers/gpu/drm/xe/xe_query.c
> +++ b/drivers/gpu/drm/xe/xe_query.c
> @@ -231,10 +231,13 @@ static size_t calc_mem_regions_size(struct xe_device *xe)
> u32 num_managers = 1;
> int i;
>
> + if (xe_device_is_admin_only(xe))
> + goto out;

or maybe just:
return sizeof(drm_xe_query_mem_regions);

> +
> for (i = XE_PL_VRAM0; i <= XE_PL_VRAM1; ++i)
> if (ttm_manager_type(&xe->ttm, i))
> num_managers++;
> -
> +out:
> return offsetof(struct drm_xe_query_mem_regions, mem_regions[num_managers]);
> }
>
> @@ -273,6 +276,8 @@ static int query_mem_regions(struct xe_device *xe,
> mem_regions->num_mem_regions = 1;

IMO we shouldn't attempt to fill region0 here, and then memset it
but just jump to ...

>
> for (i = XE_PL_VRAM0; i <= XE_PL_VRAM1; ++i) {
> + if (xe_device_is_admin_only(xe))
> + break;
> man = ttm_manager_type(&xe->ttm, i);
> if (man) {
> mem_regions->mem_regions[mem_regions->num_mem_regions].mem_class =
> @@ -297,6 +302,9 @@ static int query_mem_regions(struct xe_device *xe,
> }
> }
>
> + if (xe_device_is_admin_only(xe))
> + memset(mem_regions, 0, size);
> +

... here

> if (!copy_to_user(query_ptr, mem_regions, size))
> ret = 0;
> else