[PATCH v4 5/8] drm/i915: cgroup integration (v3)

[Matt Roper <matthew.d.roper@intel.com>]

Introduce a new DRM_IOCTL_I915_CGROUP_SETPARAM ioctl that will allow
userspace to set i915-specific parameters for individual cgroups.  i915
cgroup data will be registered and later looked up via the new
cgroup_priv infrastructure.

v2:
 - Large rebase/rewrite for new cgroup_priv interface
v3:
 - Another rebase/rewrite for ida-based keys and kref-based storage
 - Access control no longer follows cgroup filesystem permissions;
   instead we restrict access to either DRM master or
   capable(CAP_SYS_RESOURCE).

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
---
 drivers/gpu/drm/i915/Makefile      |   1 +
 drivers/gpu/drm/i915/i915_cgroup.c | 140 +++++++++++++++++++++++++++++++++++++
 drivers/gpu/drm/i915/i915_drv.c    |   7 ++
 drivers/gpu/drm/i915/i915_drv.h    |  25 +++++++
 include/uapi/drm/i915_drm.h        |  12 ++++
 5 files changed, 185 insertions(+)
 create mode 100644 drivers/gpu/drm/i915/i915_cgroup.c

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 552e43e9663f..26031185cf0e 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -48,6 +48,7 @@ i915-y := i915_drv.o \
 i915-$(CONFIG_COMPAT)   += i915_ioc32.o
 i915-$(CONFIG_DEBUG_FS) += i915_debugfs.o intel_pipe_crc.o
 i915-$(CONFIG_PERF_EVENTS) += i915_pmu.o
+i915-$(CONFIG_CGROUPS) += i915_cgroup.o
 
 # GEM code
 i915-y += i915_cmd_parser.o \
diff --git a/drivers/gpu/drm/i915/i915_cgroup.c b/drivers/gpu/drm/i915/i915_cgroup.c
new file mode 100644
index 000000000000..eaa540b65efd
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_cgroup.c
@@ -0,0 +1,140 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * i915_cgroup.c - Linux cgroups integration for i915
+ *
+ * Copyright (C) 2018 Intel Corporation
+ */
+
+#include <linux/cgroup.h>
+
+#include "i915_drv.h"
+
+struct i915_cgroup_data {
+	struct kref ref;
+};
+
+static inline struct i915_cgroup_data *
+cgrp_ref_to_i915(struct kref *ref)
+{
+	return container_of(ref, struct i915_cgroup_data, ref);
+}
+
+static void
+i915_cgroup_free(struct kref *ref)
+{
+	struct i915_cgroup_data *priv;
+
+	priv = cgrp_ref_to_i915(ref);
+	kfree(priv);
+}
+
+int
+i915_cgroup_init(struct drm_i915_private *dev_priv)
+{
+	int ret = 0;
+
+	dev_priv->cgroup_priv_key = cgroup_priv_getkey(i915_cgroup_free);
+	if (dev_priv->cgroup_priv_key < 0) {
+		DRM_DEBUG_DRIVER("Failed to get a cgroup private data key\n");
+		ret = dev_priv->cgroup_priv_key;
+	}
+
+	mutex_init(&dev_priv->cgroup_lock);
+
+	return ret;
+}
+
+void
+i915_cgroup_shutdown(struct drm_i915_private *dev_priv)
+{
+	cgroup_priv_destroykey(dev_priv->cgroup_priv_key);
+}
+
+/*
+ * Return i915 cgroup private data, creating and registering it if one doesn't
+ * already exist for this cgroup.
+ */
+__maybe_unused
+static struct i915_cgroup_data *
+get_or_create_cgroup_data(struct drm_i915_private *dev_priv,
+			  struct cgroup *cgrp)
+{
+	struct kref *ref;
+	struct i915_cgroup_data *priv;
+
+	mutex_lock(&dev_priv->cgroup_lock);
+
+	ref = cgroup_priv_get(cgrp, dev_priv->cgroup_priv_key);
+	if (ref) {
+		priv = cgrp_ref_to_i915(ref);
+	} else {
+		priv = kzalloc(sizeof *priv, GFP_KERNEL);
+		if (!priv) {
+			priv = ERR_PTR(-ENOMEM);
+			goto out;
+		}
+
+		kref_init(&priv->ref);
+		cgroup_priv_install(cgrp, dev_priv->cgroup_priv_key,
+				    &priv->ref);
+	}
+
+out:
+	mutex_unlock(&dev_priv->cgroup_lock);
+
+	return priv;
+}
+
+/**
+ * i915_cgroup_setparam_ioctl - ioctl to alter i915 settings for a cgroup
+ * @dev: DRM device
+ * @data: data pointer for the ioctl
+ * @file_priv: DRM file handle for the ioctl call
+ *
+ * Allows i915-specific parameters to be set for a Linux cgroup.
+ */
+int
+i915_cgroup_setparam_ioctl(struct drm_device *dev,
+			   void *data,
+			   struct drm_file *file)
+{
+	struct drm_i915_cgroup_param *req = data;
+	struct cgroup *cgrp;
+	int ret;
+
+	/* We don't actually support any flags yet. */
+	if (req->flags) {
+		DRM_DEBUG_DRIVER("Invalid flags\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Make sure the file descriptor really is a cgroup fd and is on the
+	 * v2 hierarchy.
+	 */
+	cgrp = cgroup_get_from_fd(req->cgroup_fd);
+	if (IS_ERR(cgrp)) {
+		DRM_DEBUG_DRIVER("Invalid cgroup file descriptor\n");
+		return PTR_ERR(cgrp);
+	}
+
+	/*
+	 * Access control:  For now we grant access via CAP_SYS_RESOURCE _or_
+	 * DRM master status.
+	 */
+	if (!capable(CAP_SYS_RESOURCE) && !drm_is_current_master(file)) {
+		DRM_DEBUG_DRIVER("Insufficient permissions to adjust i915 cgroup settings\n");
+		goto out;
+	}
+
+	switch (req->param) {
+	default:
+		DRM_DEBUG_DRIVER("Invalid cgroup parameter %lld\n", req->param);
+		ret = -EINVAL;
+	}
+
+out:
+	cgroup_put(cgrp);
+
+	return ret;
+}
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 3df5193487f3..99b571cb7ef8 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -1407,6 +1407,10 @@ int i915_driver_load(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	intel_runtime_pm_put(dev_priv);
 
+	ret = i915_cgroup_init(dev_priv);
+	if (ret < 0)
+		goto out_cleanup_hw;
+
 	i915_welcome_messages(dev_priv);
 
 	return 0;
@@ -1433,6 +1437,8 @@ void i915_driver_unload(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = to_i915(dev);
 	struct pci_dev *pdev = dev_priv->drm.pdev;
 
+	i915_cgroup_shutdown(dev_priv);
+
 	i915_driver_unregister(dev_priv);
 
 	if (i915_gem_suspend(dev_priv))
@@ -2834,6 +2840,7 @@ static const struct drm_ioctl_desc i915_ioctls[] = {
 	DRM_IOCTL_DEF_DRV(I915_PERF_ADD_CONFIG, i915_perf_add_config_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(I915_PERF_REMOVE_CONFIG, i915_perf_remove_config_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
 	DRM_IOCTL_DEF_DRV(I915_QUERY, i915_query_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
+	DRM_IOCTL_DEF_DRV(I915_CGROUP_SETPARAM, i915_cgroup_setparam_ioctl, DRM_UNLOCKED|DRM_RENDER_ALLOW),
 };
 
 static struct drm_driver driver = {
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 6ce7d0662bb6..b1862fe5e1a6 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1738,6 +1738,10 @@ struct drm_i915_private {
 
 	struct intel_ppat ppat;
 
+	/* cgroup private data */
+	int cgroup_priv_key;
+	struct mutex cgroup_lock;
+
 	/* Kernel Modesetting */
 
 	struct intel_crtc *plane_to_crtc_mapping[I915_MAX_PIPES];
@@ -2678,6 +2682,27 @@ intel_ggtt_update_needs_vtd_wa(struct drm_i915_private *dev_priv)
 int intel_sanitize_enable_ppgtt(struct drm_i915_private *dev_priv,
 				int enable_ppgtt);
 
+/* i915_cgroup.c */
+#ifdef CONFIG_CGROUPS
+int i915_cgroup_init(struct drm_i915_private *dev_priv);
+int i915_cgroup_setparam_ioctl(struct drm_device *dev, void *data,
+			       struct drm_file *file);
+void i915_cgroup_shutdown(struct drm_i915_private *dev_priv);
+#else
+static inline int
+i915_cgroup_init(struct drm_i915_private *dev_priv)
+{
+	return 0;
+}
+static inline void i915_cgroup_shutdown(struct drm_i915_private *dev_priv) {}
+static inline int
+i915_cgroup_setparam_ioctl(struct drm_device *dev, void *data,
+			   struct drm_file *file)
+{
+	return -EINVAL;
+}
+#endif
+
 /* i915_drv.c */
 void __printf(3, 4)
 __i915_printk(struct drm_i915_private *dev_priv, const char *level,
diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
index 7f5634ce8e88..735128fa61de 100644
--- a/include/uapi/drm/i915_drm.h
+++ b/include/uapi/drm/i915_drm.h
@@ -319,6 +319,7 @@ typedef struct _drm_i915_sarea {
 #define DRM_I915_PERF_ADD_CONFIG	0x37
 #define DRM_I915_PERF_REMOVE_CONFIG	0x38
 #define DRM_I915_QUERY			0x39
+#define DRM_I915_CGROUP_SETPARAM	0x3a
 
 #define DRM_IOCTL_I915_INIT		DRM_IOW( DRM_COMMAND_BASE + DRM_I915_INIT, drm_i915_init_t)
 #define DRM_IOCTL_I915_FLUSH		DRM_IO ( DRM_COMMAND_BASE + DRM_I915_FLUSH)
@@ -377,6 +378,7 @@ typedef struct _drm_i915_sarea {
 #define DRM_IOCTL_I915_PERF_ADD_CONFIG	DRM_IOW(DRM_COMMAND_BASE + DRM_I915_PERF_ADD_CONFIG, struct drm_i915_perf_oa_config)
 #define DRM_IOCTL_I915_PERF_REMOVE_CONFIG	DRM_IOW(DRM_COMMAND_BASE + DRM_I915_PERF_REMOVE_CONFIG, __u64)
 #define DRM_IOCTL_I915_QUERY			DRM_IOWR(DRM_COMMAND_BASE + DRM_I915_QUERY, struct drm_i915_query)
+#define DRM_IOCTL_I915_CGROUP_SETPARAM		DRM_IOW(DRM_COMMAND_BASE + DRM_I915_CGROUP_SETPARAM, struct drm_i915_cgroup_param)
 
 /* Allow drivers to submit batchbuffers directly to hardware, relying
  * on the security mechanisms provided by hardware.
@@ -1717,6 +1719,16 @@ struct drm_i915_query_topology_info {
 	__u8 data[];
 };
 
+/**
+ * Structure to set i915 parameter on a cgroup.
+ */
+struct drm_i915_cgroup_param {
+	__s32 cgroup_fd;
+	__u32 flags;
+	__u64 param;
+	__s64 value;
+};
+
 #if defined(__cplusplus)
 }
 #endif
-- 
2.14.3

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx