Re: [PATCH 01/14] drm/xe/pf: Prepare sysfs for SR-IOV admin attributes

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

On Mon, Oct 20, 2025 at 08:24:01PM +0200, Michal Wajdeczko wrote:
> We already have some SR-IOV specific knobs exposed as debugfs
> files to allow low level tuning of the SR-IOV configurations,
> but those files are mainly for the use by the developers and
> debugfs might not be available on the production builds.
> 
> Start building dedicated sysfs sub-tree under xe device, where
> in upcoming patches we will add selected attributes that will
> help provision and manage PF and all VFs:
> 
>   /sys/bus/pci/drivers/xe/BDF/
>   ├── sriov_admin/
>       ├── pf/
>       ├── vf1/
>       ├── vf2/
>       :
>       └── vfN/

Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

> 
> Add all required data types and helper macros that will be used
> by upcoming patches to define actual attributes.
> 
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
> Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> ---
>  drivers/gpu/drm/xe/Makefile            |   1 +
>  drivers/gpu/drm/xe/xe_sriov_pf.c       |   5 +
>  drivers/gpu/drm/xe/xe_sriov_pf_sysfs.c | 295 +++++++++++++++++++++++++
>  drivers/gpu/drm/xe/xe_sriov_pf_sysfs.h |  13 ++
>  drivers/gpu/drm/xe/xe_sriov_pf_types.h |  11 +
>  5 files changed, 325 insertions(+)
>  create mode 100644 drivers/gpu/drm/xe/xe_sriov_pf_sysfs.c
>  create mode 100644 drivers/gpu/drm/xe/xe_sriov_pf_sysfs.h
> 
> diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
> index 82c6b3d29676..e84811783115 100644
> --- a/drivers/gpu/drm/xe/Makefile
> +++ b/drivers/gpu/drm/xe/Makefile
> @@ -178,6 +178,7 @@ xe-$(CONFIG_PCI_IOV) += \
>  	xe_sriov_pf_debugfs.o \
>  	xe_sriov_pf_provision.o \
>  	xe_sriov_pf_service.o \
> +	xe_sriov_pf_sysfs.o \
>  	xe_tile_sriov_pf_debugfs.o
>  
>  # include helpers for tests even when XE is built-in
> diff --git a/drivers/gpu/drm/xe/xe_sriov_pf.c b/drivers/gpu/drm/xe/xe_sriov_pf.c
> index bc1ab9ee31d9..b8af93eb5b5f 100644
> --- a/drivers/gpu/drm/xe/xe_sriov_pf.c
> +++ b/drivers/gpu/drm/xe/xe_sriov_pf.c
> @@ -16,6 +16,7 @@
>  #include "xe_sriov_pf.h"
>  #include "xe_sriov_pf_helpers.h"
>  #include "xe_sriov_pf_service.h"
> +#include "xe_sriov_pf_sysfs.h"
>  #include "xe_sriov_printk.h"
>  
>  static unsigned int wanted_max_vfs(struct xe_device *xe)
> @@ -128,6 +129,10 @@ int xe_sriov_pf_init_late(struct xe_device *xe)
>  			return err;
>  	}
>  
> +	err = xe_sriov_pf_sysfs_init(xe);
> +	if (err)
> +		return err;
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_sysfs.c b/drivers/gpu/drm/xe/xe_sriov_pf_sysfs.c
> new file mode 100644
> index 000000000000..91962155f80b
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_sriov_pf_sysfs.c
> @@ -0,0 +1,295 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2025 Intel Corporation
> + */
> +
> +#include <linux/kobject.h>
> +#include <linux/sysfs.h>
> +
> +#include <drm/drm_managed.h>
> +
> +#include "xe_assert.h"
> +#include "xe_sriov.h"
> +#include "xe_sriov_pf_helpers.h"
> +#include "xe_sriov_pf_sysfs.h"
> +#include "xe_sriov_printk.h"
> +
> +/*
> + * /sys/bus/pci/drivers/xe/BDF/
> + * :
> + * ├── sriov_admin/
> + *     ├── ...
> + *     ├── pf/
> + *     │   ├── ...
> + *     │   └── ...
> + *     ├── vf1/
> + *     │   ├── ...
> + *     │   └── ...
> + *     ├── vf2/
> + *     :
> + *     └── vfN/
> + */
> +
> +struct xe_sriov_kobj {
> +	struct kobject base;
> +	struct xe_device *xe;
> +	unsigned int vfid;
> +};
> +#define to_xe_sriov_kobj(p) container_of_const((p), struct xe_sriov_kobj, base)
> +
> +struct xe_sriov_dev_attr {
> +	struct attribute attr;
> +	ssize_t (*show)(struct xe_device *xe, char *buf);
> +	ssize_t (*store)(struct xe_device *xe, const char *buf, size_t count);
> +};
> +#define to_xe_sriov_dev_attr(p) container_of_const((p), struct xe_sriov_dev_attr, attr)
> +
> +#define XE_SRIOV_DEV_ATTR(NAME) \
> +struct xe_sriov_dev_attr xe_sriov_dev_attr_##NAME = \
> +	__ATTR(NAME, 0644, xe_sriov_dev_attr_##NAME##_show, xe_sriov_dev_attr_##NAME##_store)
> +
> +#define XE_SRIOV_DEV_ATTR_RO(NAME) \
> +struct xe_sriov_dev_attr xe_sriov_dev_attr_##NAME = \
> +	__ATTR(NAME, 0444, xe_sriov_dev_attr_##NAME##_show, NULL)
> +
> +#define XE_SRIOV_DEV_ATTR_WO(NAME) \
> +struct xe_sriov_dev_attr xe_sriov_dev_attr_##NAME = \
> +	__ATTR(NAME, 0200, NULL, xe_sriov_dev_attr_##NAME##_store)
> +
> +struct xe_sriov_vf_attr {
> +	struct attribute attr;
> +	ssize_t (*show)(struct xe_device *xe, unsigned int vfid, char *buf);
> +	ssize_t (*store)(struct xe_device *xe, unsigned int vfid, const char *buf, size_t count);
> +};
> +#define to_xe_sriov_vf_attr(p) container_of_const((p), struct xe_sriov_vf_attr, attr)
> +
> +#define XE_SRIOV_VF_ATTR(NAME) \
> +struct xe_sriov_vf_attr xe_sriov_vf_attr_##NAME = \
> +	__ATTR(NAME, 0644, xe_sriov_vf_attr_##NAME##_show, xe_sriov_vf_attr_##NAME##_store)
> +
> +#define XE_SRIOV_VF_ATTR_RO(NAME) \
> +struct xe_sriov_vf_attr xe_sriov_vf_attr_##NAME = \
> +	__ATTR(NAME, 0444, xe_sriov_vf_attr_##NAME##_show, NULL)
> +
> +#define XE_SRIOV_VF_ATTR_WO(NAME) \
> +struct xe_sriov_vf_attr xe_sriov_vf_attr_##NAME = \
> +	__ATTR(NAME, 0200, NULL, xe_sriov_vf_attr_##NAME##_store)
> +
> +/* device level attributes go here */
> +
> +static const struct attribute_group *xe_sriov_dev_attr_groups[] = {
> +	NULL
> +};
> +
> +/* and VF-level attributes go here */
> +
> +static const struct attribute_group *xe_sriov_vf_attr_groups[] = {
> +	NULL
> +};
> +
> +/* no user serviceable parts below */
> +
> +static struct kobject *new_xe_sriov_kobj(struct xe_device *xe, unsigned int vfid)
> +{
> +	struct xe_sriov_kobj *vkobj;
> +
> +	xe_sriov_pf_assert_vfid(xe, vfid);
> +
> +	vkobj = kzalloc(sizeof(*vkobj), GFP_KERNEL);
> +	if (!vkobj)
> +		return NULL;
> +
> +	vkobj->xe = xe;
> +	vkobj->vfid = vfid;
> +	return &vkobj->base;
> +}
> +
> +static void release_xe_sriov_kobj(struct kobject *kobj)
> +{
> +	struct xe_sriov_kobj *vkobj = to_xe_sriov_kobj(kobj);
> +
> +	kfree(vkobj);
> +}
> +
> +static ssize_t xe_sriov_dev_attr_show(struct kobject *kobj, struct attribute *attr, char *buf)
> +{
> +	struct xe_sriov_dev_attr *vattr  = to_xe_sriov_dev_attr(attr);
> +	struct xe_sriov_kobj *vkobj = to_xe_sriov_kobj(kobj);
> +	struct xe_device *xe = vkobj->xe;
> +
> +	if (!vattr->show) {
> +		xe_sriov_dbg(xe, "attribute '%s' was not intended to be %s\n",
> +			     attr->name, "readable");
> +		return -EPERM;
> +	}
> +	return vattr->show(xe, buf);
> +}
> +
> +static ssize_t xe_sriov_dev_attr_store(struct kobject *kobj, struct attribute *attr,
> +				       const char *buf, size_t count)
> +{
> +	struct xe_sriov_dev_attr *vattr = to_xe_sriov_dev_attr(attr);
> +	struct xe_sriov_kobj *vkobj = to_xe_sriov_kobj(kobj);
> +	struct xe_device *xe = vkobj->xe;
> +
> +	if (!vattr->store) {
> +		xe_sriov_dbg(xe, "attribute '%s' was not intended to be %s\n",
> +			     attr->name, "writable");
> +		return -EPERM;
> +	}
> +	return vattr->store(xe, buf, count);
> +}
> +
> +static ssize_t xe_sriov_vf_attr_show(struct kobject *kobj, struct attribute *attr, char *buf)
> +{
> +	struct xe_sriov_vf_attr *vattr = to_xe_sriov_vf_attr(attr);
> +	struct xe_sriov_kobj *vkobj = to_xe_sriov_kobj(kobj);
> +	struct xe_device *xe = vkobj->xe;
> +	unsigned int vfid = vkobj->vfid;
> +
> +	xe_sriov_pf_assert_vfid(xe, vfid);
> +
> +	if (!vattr->show) {
> +		xe_sriov_dbg(xe, "attribute '%s' was not intended to be %s\n",
> +			     attr->name, "readable");
> +		return -EPERM;
> +	}
> +	return vattr->show(xe, vfid, buf);
> +}
> +
> +static ssize_t xe_sriov_vf_attr_store(struct kobject *kobj, struct attribute *attr,
> +				      const char *buf, size_t count)
> +{
> +	struct xe_sriov_vf_attr *vattr = to_xe_sriov_vf_attr(attr);
> +	struct xe_sriov_kobj *vkobj = to_xe_sriov_kobj(kobj);
> +	struct xe_device *xe = vkobj->xe;
> +	unsigned int vfid = vkobj->vfid;
> +
> +	xe_sriov_pf_assert_vfid(xe, vfid);
> +
> +	if (!vattr->store) {
> +		xe_sriov_dbg(xe, "attribute '%s' was not intended to be %s\n",
> +			     attr->name, "writable");
> +		return -EPERM;
> +	}
> +	return vattr->store(xe, vfid, buf, count);
> +}
> +
> +static const struct sysfs_ops xe_sriov_dev_sysfs_ops = {
> +	.show = xe_sriov_dev_attr_show,
> +	.store = xe_sriov_dev_attr_store,
> +};
> +
> +static const struct sysfs_ops xe_sriov_vf_sysfs_ops = {
> +	.show = xe_sriov_vf_attr_show,
> +	.store = xe_sriov_vf_attr_store,
> +};
> +
> +static const struct kobj_type xe_sriov_dev_ktype = {
> +	.release = release_xe_sriov_kobj,
> +	.sysfs_ops = &xe_sriov_dev_sysfs_ops,
> +	.default_groups = xe_sriov_dev_attr_groups,
> +};
> +
> +static const struct kobj_type xe_sriov_vf_ktype = {
> +	.release = release_xe_sriov_kobj,
> +	.sysfs_ops = &xe_sriov_vf_sysfs_ops,
> +	.default_groups = xe_sriov_vf_attr_groups,
> +};
> +
> +static int pf_sysfs_error(struct xe_device *xe, int err, const char *what)
> +{
> +	if (IS_ENABLED(CONFIG_DRM_XE_DEBUG))
> +		xe_sriov_dbg(xe, "Failed to setup sysfs %s (%pe)\n", what, ERR_PTR(err));
> +	return err;
> +}
> +
> +static void action_put_kobject(void *arg)
> +{
> +	struct kobject *kobj = arg;
> +
> +	kobject_put(kobj);
> +}
> +
> +static int pf_setup_root(struct xe_device *xe)
> +{
> +	struct kobject *parent = &xe->drm.dev->kobj;
> +	struct kobject *root;
> +	int err;
> +
> +	root = new_xe_sriov_kobj(xe, PFID);
> +	if (!root)
> +		return pf_sysfs_error(xe, -ENOMEM, "root obj");
> +
> +	err = devm_add_action_or_reset(xe->drm.dev, action_put_kobject, root);
> +	if (err)
> +		return pf_sysfs_error(xe, err, "root action");
> +
> +	err = kobject_init_and_add(root, &xe_sriov_dev_ktype, parent, "sriov_admin");
> +	if (err)
> +		return pf_sysfs_error(xe, err, "root init");
> +
> +	xe_assert(xe, IS_SRIOV_PF(xe));
> +	xe_assert(xe, !xe->sriov.pf.sysfs.root);
> +	xe->sriov.pf.sysfs.root = root;
> +	return 0;
> +}
> +
> +static int pf_setup_tree(struct xe_device *xe)
> +{
> +	unsigned int totalvfs = xe_sriov_pf_get_totalvfs(xe);
> +	struct kobject *root, *kobj;
> +	unsigned int n;
> +	int err;
> +
> +	xe_assert(xe, IS_SRIOV_PF(xe));
> +	root = xe->sriov.pf.sysfs.root;
> +
> +	for (n = 0; n <= totalvfs; n++) {
> +		kobj = new_xe_sriov_kobj(xe, VFID(n));
> +		if (!kobj)
> +			return pf_sysfs_error(xe, -ENOMEM, "tree obj");
> +
> +		err = devm_add_action_or_reset(xe->drm.dev, action_put_kobject, root);
> +		if (err)
> +			return pf_sysfs_error(xe, err, "tree action");
> +
> +		if (n)
> +			err = kobject_init_and_add(kobj, &xe_sriov_vf_ktype,
> +						   root, "vf%u", n);
> +		else
> +			err = kobject_init_and_add(kobj, &xe_sriov_vf_ktype,
> +						   root, "pf");
> +		if (err)
> +			return pf_sysfs_error(xe, err, "tree init");
> +
> +		xe_assert(xe, !xe->sriov.pf.vfs[n].kobj);
> +		xe->sriov.pf.vfs[n].kobj = kobj;
> +	}
> +
> +	return 0;
> +}
> +
> +/**
> + * xe_sriov_pf_sysfs_init() - Setup PF's SR-IOV sysfs tree.
> + * @xe: the PF &xe_device to setup sysfs
> + *
> + * This function will create additional nodes that will represent PF and VFs
> + * devices, each populated with SR-IOV Xe specific attributes.
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +int xe_sriov_pf_sysfs_init(struct xe_device *xe)
> +{
> +	int err;
> +
> +	err = pf_setup_root(xe);
> +	if (err)
> +		return err;
> +
> +	err = pf_setup_tree(xe);
> +	if (err)
> +		return err;
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_sysfs.h b/drivers/gpu/drm/xe/xe_sriov_pf_sysfs.h
> new file mode 100644
> index 000000000000..1e6698cc29d3
> --- /dev/null
> +++ b/drivers/gpu/drm/xe/xe_sriov_pf_sysfs.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright © 2025 Intel Corporation
> + */
> +
> +#ifndef _XE_SRIOV_PF_SYSFS_H_
> +#define _XE_SRIOV_PF_SYSFS_H_
> +
> +struct xe_device;
> +
> +int xe_sriov_pf_sysfs_init(struct xe_device *xe);
> +
> +#endif
> diff --git a/drivers/gpu/drm/xe/xe_sriov_pf_types.h b/drivers/gpu/drm/xe/xe_sriov_pf_types.h
> index c753cd59aed2..b3cd9797194b 100644
> --- a/drivers/gpu/drm/xe/xe_sriov_pf_types.h
> +++ b/drivers/gpu/drm/xe/xe_sriov_pf_types.h
> @@ -12,10 +12,15 @@
>  #include "xe_sriov_pf_provision_types.h"
>  #include "xe_sriov_pf_service_types.h"
>  
> +struct kobject;
> +
>  /**
>   * struct xe_sriov_metadata - per-VF device level metadata
>   */
>  struct xe_sriov_metadata {
> +	/** @kobj: kobject representing VF in PF's SR-IOV sysfs tree. */
> +	struct kobject *kobj;
> +
>  	/** @version: negotiated VF/PF ABI version */
>  	struct xe_sriov_pf_service_version version;
>  };
> @@ -42,6 +47,12 @@ struct xe_device_pf {
>  	/** @service: device level service data. */
>  	struct xe_sriov_pf_service service;
>  
> +	/** @sysfs: device level sysfs data. */
> +	struct {
> +		/** @sysfs.root: the root kobject for all SR-IOV entries in sysfs. */
> +		struct kobject *root;
> +	} sysfs;
> +
>  	/** @vfs: metadata for all VFs. */
>  	struct xe_sriov_metadata *vfs;
>  };
> -- 
> 2.47.1
>