[linux-block.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;
};

#ifndef CONFIG_HAVE_KVM_DIRTY_RING
/*
 * If CONFIG_HAVE_HVM_DIRTY_RING 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 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 /* CONFIG_HAVE_KVM_DIRTY_RING */

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

/*
 * 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 /* CONFIG_HAVE_KVM_DIRTY_RING */

#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
dc70ec21	30	#ifndef CONFIG_HAVE_KVM_DIRTY_RING
fb04a1ed	31	/*
dc70ec21	32	* If CONFIG_HAVE_HVM_DIRTY_RING not defined, kvm_dirty_ring.o should
fb04a1ed PX	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
fb04a1ed PX	46	static inline int kvm_dirty_ring_reset(struct kvm *kvm,
	47	struct kvm_dirty_ring *ring)
	48	{
	49	return 0;
	50	}
	51
	52	static inline void kvm_dirty_ring_push(struct kvm_dirty_ring *ring,
	53	u32 slot, u64 offset)
	54	{
	55	}
	56
	57	static inline struct page kvm_dirty_ring_get_page(struct kvm_dirty_ring ring,
	58	u32 offset)
	59	{
	60	return NULL;
	61	}
	62
	63	static inline void kvm_dirty_ring_free(struct kvm_dirty_ring *ring)
	64	{
	65	}
	66
	67	static inline bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring)
	68	{
	69	return true;
	70	}
	71
dc70ec21	72	#else /* CONFIG_HAVE_KVM_DIRTY_RING */
fb04a1ed PX	73
	74	u32 kvm_dirty_ring_get_rsvd_entries(void);
	75	int kvm_dirty_ring_alloc(struct kvm_dirty_ring *ring, int index, u32 size);
fb04a1ed PX	76
	77	/*
	78	* called with kvm->slots_lock held, returns the number of
	79	* processed pages.
	80	*/
	81	int kvm_dirty_ring_reset(struct kvm kvm, struct kvm_dirty_ring ring);
	82
	83	/*
	84	* returns =0: successfully pushed
	85	* <0: unable to push, need to wait
	86	*/
	87	void kvm_dirty_ring_push(struct kvm_dirty_ring *ring, u32 slot, u64 offset);
	88
	89	/* for use in vm_operations_struct */
	90	struct page kvm_dirty_ring_get_page(struct kvm_dirty_ring ring, u32 offset);
	91
	92	void kvm_dirty_ring_free(struct kvm_dirty_ring *ring);
	93	bool kvm_dirty_ring_soft_full(struct kvm_dirty_ring *ring);
	94
dc70ec21	95	#endif /* CONFIG_HAVE_KVM_DIRTY_RING */
fb04a1ed PX	96
fb04a1ed PX	97	#endif /* KVM_DIRTY_RING_H */