From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- scripts/include/hashtable.h | 98 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 scripts/include/hashtable.h (limited to 'scripts/include/hashtable.h') diff --git a/scripts/include/hashtable.h b/scripts/include/hashtable.h new file mode 100644 index 000000000..45abcb12b --- /dev/null +++ b/scripts/include/hashtable.h @@ -0,0 +1,98 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +#ifndef HASHTABLE_H +#define HASHTABLE_H + +#include "array_size.h" +#include "list.h" + +#define HASH_SIZE(name) (ARRAY_SIZE(name)) + +#define HASHTABLE_DECLARE(name, size) struct hlist_head name[size] + +#define HASHTABLE_DEFINE(name, size) \ + HASHTABLE_DECLARE(name, size) = \ + { [0 ... ((size) - 1)] = HLIST_HEAD_INIT } + +#define hash_head(table, key) (&(table)[(key) % HASH_SIZE(table)]) + +static inline void __hash_init(struct hlist_head *ht, unsigned int sz) +{ + unsigned int i; + + for (i = 0; i < sz; i++) + INIT_HLIST_HEAD(&ht[i]); +} + +/** + * hash_init - initialize a hash table + * @table: hashtable to be initialized + * + * This has to be a macro since HASH_SIZE() will not work on pointers since + * it calculates the size during preprocessing. + */ +#define hash_init(table) __hash_init(table, HASH_SIZE(table)) + +/** + * hash_add - add an object to a hashtable + * @table: hashtable to add to + * @node: the &struct hlist_node of the object to be added + * @key: the key of the object to be added + */ +#define hash_add(table, node, key) \ + hlist_add_head(node, hash_head(table, key)) + +/** + * hash_del - remove an object from a hashtable + * @node: &struct hlist_node of the object to remove + */ +static inline void hash_del(struct hlist_node *node) +{ + hlist_del_init(node); +} + +/** + * hash_for_each - iterate over a hashtable + * @table: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + */ +#define hash_for_each(table, obj, member) \ + for (int _bkt = 0; _bkt < HASH_SIZE(table); _bkt++) \ + hlist_for_each_entry(obj, &table[_bkt], member) + +/** + * hash_for_each_safe - iterate over a hashtable safe against removal of + * hash entry + * @table: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @tmp: a &struct hlist_node used for temporary storage + * @member: the name of the hlist_node within the struct + */ +#define hash_for_each_safe(table, obj, tmp, member) \ + for (int _bkt = 0; _bkt < HASH_SIZE(table); _bkt++) \ + hlist_for_each_entry_safe(obj, tmp, &table[_bkt], member) + +/** + * hash_for_each_possible - iterate over all possible objects hashing to the + * same bucket + * @table: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @member: the name of the hlist_node within the struct + * @key: the key of the objects to iterate over + */ +#define hash_for_each_possible(table, obj, member, key) \ + hlist_for_each_entry(obj, hash_head(table, key), member) + +/** + * hash_for_each_possible_safe - iterate over all possible objects hashing to the + * same bucket safe against removals + * @table: hashtable to iterate + * @obj: the type * to use as a loop cursor for each entry + * @tmp: a &struct hlist_node used for temporary storage + * @member: the name of the hlist_node within the struct + * @key: the key of the objects to iterate over + */ +#define hash_for_each_possible_safe(table, obj, tmp, member, key) \ + hlist_for_each_entry_safe(obj, tmp, hash_head(table, key), member) + +#endif /* HASHTABLE_H */ -- cgit v1.3.1