[mirror_ubuntu-jammy-kernel.git] / include / linux / kvm_dirty_ring.h

#ifndef KVM_DIRTY_RING_H
#define KVM_DIRTY_RING_H

#include <linux/kvm.h>

/**
 * kvm_dirty_ring: KVM internal dirty ring structure
 *
 * @dirty_index: free running counter that points to the next slot in
 *               dirty_ring->dirty_gfns, where a new dirty page should go
 * @reset_index: free running counter that points to the next dirty page
 *               in dirty_ring->dirty_gfns for which dirty trap needs to
 *               be reenabled
 * @size:        size of the compact list, dirty_ring->dirty_gfns
 * @soft_limit:  when the number of dirty pages in the list reaches this
 *               limit, vcpu that owns this ring should exit to userspace
 *               to allow userspace to harvest all the dirty pages
 * @dirty_gfns:  the array to keep the dirty gfns
 * @index:       index of this dirty ring
 */
struct kvm_dirty_ring {
	u32 dirty_index;
	u32 reset_index;
	u32 size;
	u32 soft_limit;
	struct kvm_dirty_gfn *dirty_gfns;
	int index;
};

#if (KVM_DIRTY_LOG_PAGE_OFFSET == 0)
/*
 * If KVM_DIRTY_LOG_PAGE_OFFSET not defined, kvm_dirty_ring.o should
 * not be included as well, so define these nop functions for the arch.
 */
static inline u32 kvm_dirty_ring_get_rsvd_entries(void)
{
	return 0;
}

static inline int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring,
				       int index, u32 size)
{
	return 0;
}

static inline struct kvm_dirty_ring *kvm_dirty_ring_get(struct kvm *kvm)
{
	return NULL;
}

static inline int kvm_dirty_ring_reset(struct kvm *kvm,
				       struct kvm_dirty_ring *ring)
{
	return 0;
}

static inline void kvm_dirty_ring_push(struct kvm_dirty_ring *ring,
				       u32 slot, u64 offset)
{
}

static inline struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring,
						   u32 offset)
{
	return NULL;
}

static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring)
{
}

static inline bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring)
{
	return true;
}

#else /* KVM_DIRTY_LOG_PAGE_OFFSET == 0 */

u32 kvm_dirty_ring_get_rsvd_entries(void);
int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size);
struct kvm_dirty_ring *kvm_dirty_ring_get(struct kvm *kvm);

/*
 * called with kvm->slots_lock held, returns the number of
 * processed pages.
 */
int kvm_dirty_ring_reset(struct kvm *kvm, struct kvm_dirty_ring *ring);

/*
 * returns =0: successfully pushed
 *         <0: unable to push, need to wait
 */
void kvm_dirty_ring_push(struct kvm_dirty_ring *ring, u32 slot, u64 offset);

/* for use in vm_operations_struct */
struct page *kvm_dirty_ring_get_page(struct kvm_dirty_ring *ring, u32 offset);

void kvm_dirty_ring_free(struct kvm_dirty_ring *ring);
bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring);

#endif /* KVM_DIRTY_LOG_PAGE_OFFSET == 0 */

#endif	/* KVM_DIRTY_RING_H */
Commit	Line	Data
fb04a1ed PX	1	#ifndef KVM_DIRTY_RING_H
	2	#define KVM_DIRTY_RING_H
	3
	4	#include <linux/kvm.h>
	5
	6	/**
	7	* kvm_dirty_ring: KVM internal dirty ring structure
	8	*
	9	* @dirty_index: free running counter that points to the next slot in
	10	* dirty_ring->dirty_gfns, where a new dirty page should go
	11	* @reset_index: free running counter that points to the next dirty page
	12	* in dirty_ring->dirty_gfns for which dirty trap needs to
	13	* be reenabled
	14	* @size: size of the compact list, dirty_ring->dirty_gfns
	15	* @soft_limit: when the number of dirty pages in the list reaches this
	16	* limit, vcpu that owns this ring should exit to userspace
	17	* to allow userspace to harvest all the dirty pages
	18	* @dirty_gfns: the array to keep the dirty gfns
	19	* @index: index of this dirty ring
	20	*/
	21	struct kvm_dirty_ring {
	22	u32 dirty_index;
	23	u32 reset_index;
	24	u32 size;
	25	u32 soft_limit;
	26	struct kvm_dirty_gfn *dirty_gfns;
	27	int index;
	28	};
	29
	30	#if (KVM_DIRTY_LOG_PAGE_OFFSET == 0)
	31	/*
	32	* If KVM_DIRTY_LOG_PAGE_OFFSET not defined, kvm_dirty_ring.o should
	33	* not be included as well, so define these nop functions for the arch.
	34	*/
	35	static inline u32 kvm_dirty_ring_get_rsvd_entries(void)
	36	{
	37	return 0;
	38	}
	39
	40	static inline int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring,
	41	int index, u32 size)
	42	{
	43	return 0;
	44	}
	45
	46	static inline struct kvm_dirty_ring kvm_dirty_ring_get(struct kvm kvm)
	47	{
	48	return NULL;
	49	}
	50
	51	static inline int kvm_dirty_ring_reset(struct kvm *kvm,
	52	struct kvm_dirty_ring *ring)
	53	{
	54	return 0;
	55	}
	56
	57	static inline void kvm_dirty_ring_push(struct kvm_dirty_ring *ring,
	58	u32 slot, u64 offset)
	59	{
	60	}
	61
	62	static inline struct page kvm_dirty_ring_get_page(struct kvm_dirty_ring ring,
	63	u32 offset)
	64	{
65	return NULL;
66	}
67
68	static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring)
69	{
70	}
71
72	static inline bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring)
73	{
74	return true;
75	}
76
77	#else /* KVM_DIRTY_LOG_PAGE_OFFSET == 0 */
78
79	u32 kvm_dirty_ring_get_rsvd_entries(void);
80	int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size);
81	struct kvm_dirty_ring kvm_dirty_ring_get(struct kvm kvm);
82
83	/*
84	* called with kvm->slots_lock held, returns the number of
85	* processed pages.
86	*/
87	int kvm_dirty_ring_reset(struct kvm kvm, struct kvm_dirty_ring ring);
88
89	/*
90	* returns =0: successfully pushed
91	* <0: unable to push, need to wait
92	*/
93	void kvm_dirty_ring_push(struct kvm_dirty_ring *ring, u32 slot, u64 offset);
94
95	/* for use in vm_operations_struct */
96	struct page kvm_dirty_ring_get_page(struct kvm_dirty_ring ring, u32 offset);
97
98	void kvm_dirty_ring_free(struct kvm_dirty_ring *ring);
99	bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring);
100
101	#endif /* KVM_DIRTY_LOG_PAGE_OFFSET == 0 */
102
103	#endif /* KVM_DIRTY_RING_H */