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#ifndef _LINUX_DEBUGOBJECTS_H
#define _LINUX_DEBUGOBJECTS_H

#include <linux/list.h>
#include <linux/spinlock.h>

enum debug_obj_state {
	ODEBUG_STATE_NONE,
	ODEBUG_STATE_INIT,
	ODEBUG_STATE_INACTIVE,
	ODEBUG_STATE_ACTIVE,
	ODEBUG_STATE_DESTROYED,
	ODEBUG_STATE_NOTAVAILABLE,
	ODEBUG_STATE_MAX,
};

struct debug_obj_descr;

/**
 * struct debug_obj - representaion of an tracked object
 * @node:	hlist node to link the object into the tracker list
 * @state:	tracked object state
 * @astate:	current active state
 * @object:	pointer to the real object
 * @descr:	pointer to an object type specific debug description structure
 */
struct debug_obj {
	struct hlist_node	node;
	enum debug_obj_state	state;
	unsigned int		astate;
	void			*object;
	struct debug_obj_descr	*descr;
};

/**
 * struct debug_obj_descr - object type specific debug description structure
 *
 * @name:		name of the object typee
 * @debug_hint:		function returning address, which have associated
 *			kernel symbol, to allow identify the object
 * @fixup_init:		fixup function, which is called when the init check
 *			fails
 * @fixup_activate:	fixup function, which is called when the activate check
 *			fails
 * @fixup_destroy:	fixup function, which is called when the destroy check
 *			fails
 * @fixup_free:		fixup function, which is called when the free check
 *			fails
 */
struct debug_obj_descr {
	const char		*name;
	void *(*debug_hint)	(void *addr);
	int (*fixup_init)	(void *addr, enum debug_obj_state state);
	int (*fixup_activate)	(void *addr, enum debug_obj_state state);
	int (*fixup_destroy)	(void *addr, enum debug_obj_state state);
	int (*fixup_free)	(void *addr, enum debug_obj_state state);
};

#ifdef CONFIG_DEBUG_OBJECTS
extern void debug_object_init      (void *addr, struct debug_obj_descr *descr);
extern void
debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr);
extern void debug_object_activate  (void *addr, struct debug_obj_descr *descr);
extern void debug_object_deactivate(void *addr, struct debug_obj_descr *descr);
extern void debug_object_destroy   (void *addr, struct debug_obj_descr *descr);
extern void debug_object_free      (void *addr, struct debug_obj_descr *descr);

/*
 * Active state:
 * - Set at 0 upon initialization.
 * - Must return to 0 before deactivation.
 */
extern void
debug_object_active_state(void *addr, struct debug_obj_descr *descr,
			  unsigned int expect, unsigned int next);

extern void debug_objects_early_init(void);
extern void debug_objects_mem_init(void);
#else
static inline void
debug_object_init      (void *addr, struct debug_obj_descr *descr) { }
static inline void
debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr) { }
static inline void
debug_object_activate  (void *addr, struct debug_obj_descr *descr) { }
static inline void
debug_object_deactivate(void *addr, struct debug_obj_descr *descr) { }
static inline void
debug_object_destroy   (void *addr, struct debug_obj_descr *descr) { }
static inline void
debug_object_free      (void *addr, struct debug_obj_descr *descr) { }

static inline void debug_objects_early_init(void) { }
static inline void debug_objects_mem_init(void) { }
#endif

#ifdef CONFIG_DEBUG_OBJECTS_FREE
extern void debug_check_no_obj_freed(const void *address, unsigned long size);
#else
static inline void
debug_check_no_obj_freed(const void *address, unsigned long size) { }
#endif

#endif
*/ } /* Gratuitous device reset and go... */ ioctl(device, VFIO_DEVICE_RESET); VFIO User API ------------------------------------------------------------------------------- Please see include/linux/vfio.h for complete API documentation. VFIO bus driver API ------------------------------------------------------------------------------- VFIO bus drivers, such as vfio-pci make use of only a few interfaces into VFIO core. When devices are bound and unbound to the driver, the driver should call vfio_add_group_dev() and vfio_del_group_dev() respectively: extern int vfio_add_group_dev(struct iommu_group *iommu_group, struct device *dev, const struct vfio_device_ops *ops, void *device_data); extern void *vfio_del_group_dev(struct device *dev); vfio_add_group_dev() indicates to the core to begin tracking the specified iommu_group and register the specified dev as owned by a VFIO bus driver. The driver provides an ops structure for callbacks similar to a file operations structure: struct vfio_device_ops { int (*open)(void *device_data); void (*release)(void *device_data); ssize_t (*read)(void *device_data, char __user *buf, size_t count, loff_t *ppos); ssize_t (*write)(void *device_data, const char __user *buf, size_t size, loff_t *ppos); long (*ioctl)(void *device_data, unsigned int cmd, unsigned long arg); int (*mmap)(void *device_data, struct vm_area_struct *vma); }; Each function is passed the device_data that was originally registered in the vfio_add_group_dev() call above. This allows the bus driver an easy place to store its opaque, private data. The open/release callbacks are issued when a new file descriptor is created for a device (via VFIO_GROUP_GET_DEVICE_FD). The ioctl interface provides a direct pass through for VFIO_DEVICE_* ioctls. The read/write/mmap interfaces implement the device region access defined by the device's own VFIO_DEVICE_GET_REGION_INFO ioctl. ------------------------------------------------------------------------------- [1] VFIO was originally an acronym for "Virtual Function I/O" in its initial implementation by Tom Lyon while as Cisco. We've since outgrown the acronym, but it's catchy. [2] "safe" also depends upon a device being "well behaved". It's possible for multi-function devices to have backdoors between functions and even for single function devices to have alternative access to things like PCI config space through MMIO registers. To guard against the former we can include additional precautions in the IOMMU driver to group multi-function PCI devices together (iommu=group_mf). The latter we can't prevent, but the IOMMU should still provide isolation. For PCI, SR-IOV Virtual Functions are the best indicator of "well behaved", as these are designed for virtualization usage models. [3] As always there are trade-offs to virtual machine device assignment that are beyond the scope of VFIO. It's expected that future IOMMU technologies will reduce some, but maybe not all, of these trade-offs. [4] In this case the device is below a PCI bridge, so transactions from either function of the device are indistinguishable to the iommu: -[0000:00]-+-1e.0-[06]--+-0d.0 \-0d.1 00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 90)