diff --git a/block/qcow2-cache.c b/block/qcow2-cache.c index b1aa42477e..d9dafa31e5 100644 --- a/block/qcow2-cache.c +++ b/block/qcow2-cache.c @@ -120,14 +120,20 @@ void qcow2_cache_clean_unused(Qcow2Cache *c) c->cache_clean_lru_counter = c->lru_counter; } -Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables) +Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables, + unsigned table_size) { BDRVQcow2State *s = bs->opaque; Qcow2Cache *c; + assert(num_tables > 0); + assert(is_power_of_2(table_size)); + assert(table_size >= (1 << MIN_CLUSTER_BITS)); + assert(table_size <= s->cluster_size); + c = g_new0(Qcow2Cache, 1); c->size = num_tables; - c->table_size = s->cluster_size; + c->table_size = table_size; c->entries = g_try_new0(Qcow2CachedTable, num_tables); c->table_array = qemu_try_blockalign(bs->file->bs, (size_t) num_tables * c->table_size); diff --git a/block/qcow2.c b/block/qcow2.c index 953254a004..57a517e2bd 100644 --- a/block/qcow2.c +++ b/block/qcow2.c @@ -675,6 +675,11 @@ static QemuOptsList qcow2_runtime_opts = { .type = QEMU_OPT_SIZE, .help = "Maximum L2 table cache size", }, + { + .name = QCOW2_OPT_L2_CACHE_ENTRY_SIZE, + .type = QEMU_OPT_SIZE, + .help = "Size of each entry in the L2 cache", + }, { .name = QCOW2_OPT_REFCOUNT_CACHE_SIZE, .type = QEMU_OPT_SIZE, @@ -747,6 +752,7 @@ static void qcow2_attach_aio_context(BlockDriverState *bs, static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts, uint64_t *l2_cache_size, + uint64_t *l2_cache_entry_size, uint64_t *refcount_cache_size, Error **errp) { BDRVQcow2State *s = bs->opaque; @@ -762,6 +768,9 @@ static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts, *refcount_cache_size = qemu_opt_get_size(opts, QCOW2_OPT_REFCOUNT_CACHE_SIZE, 0); + *l2_cache_entry_size = qemu_opt_get_size( + opts, QCOW2_OPT_L2_CACHE_ENTRY_SIZE, s->cluster_size); + if (combined_cache_size_set) { if (l2_cache_size_set && refcount_cache_size_set) { error_setg(errp, QCOW2_OPT_CACHE_SIZE ", " QCOW2_OPT_L2_CACHE_SIZE @@ -802,6 +811,15 @@ static void read_cache_sizes(BlockDriverState *bs, QemuOpts *opts, / DEFAULT_L2_REFCOUNT_SIZE_RATIO; } } + + if (*l2_cache_entry_size < (1 << MIN_CLUSTER_BITS) || + *l2_cache_entry_size > s->cluster_size || + !is_power_of_2(*l2_cache_entry_size)) { + error_setg(errp, "L2 cache entry size must be a power of two " + "between %d and the cluster size (%d)", + 1 << MIN_CLUSTER_BITS, s->cluster_size); + return; + } } typedef struct Qcow2ReopenState { @@ -824,7 +842,7 @@ static int qcow2_update_options_prepare(BlockDriverState *bs, QemuOpts *opts = NULL; const char *opt_overlap_check, *opt_overlap_check_template; int overlap_check_template = 0; - uint64_t l2_cache_size, refcount_cache_size; + uint64_t l2_cache_size, l2_cache_entry_size, refcount_cache_size; int i; const char *encryptfmt; QDict *encryptopts = NULL; @@ -843,15 +861,15 @@ static int qcow2_update_options_prepare(BlockDriverState *bs, } /* get L2 table/refcount block cache size from command line options */ - read_cache_sizes(bs, opts, &l2_cache_size, &refcount_cache_size, - &local_err); + read_cache_sizes(bs, opts, &l2_cache_size, &l2_cache_entry_size, + &refcount_cache_size, &local_err); if (local_err) { error_propagate(errp, local_err); ret = -EINVAL; goto fail; } - l2_cache_size /= s->cluster_size; + l2_cache_size /= l2_cache_entry_size; if (l2_cache_size < MIN_L2_CACHE_SIZE) { l2_cache_size = MIN_L2_CACHE_SIZE; } @@ -889,9 +907,11 @@ static int qcow2_update_options_prepare(BlockDriverState *bs, } } - r->l2_slice_size = s->cluster_size / sizeof(uint64_t); - r->l2_table_cache = qcow2_cache_create(bs, l2_cache_size); - r->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size); + r->l2_slice_size = l2_cache_entry_size / sizeof(uint64_t); + r->l2_table_cache = qcow2_cache_create(bs, l2_cache_size, + l2_cache_entry_size); + r->refcount_block_cache = qcow2_cache_create(bs, refcount_cache_size, + s->cluster_size); if (r->l2_table_cache == NULL || r->refcount_block_cache == NULL) { error_setg(errp, "Could not allocate metadata caches"); ret = -ENOMEM; diff --git a/block/qcow2.h b/block/qcow2.h index d956a6cdd2..883802241f 100644 --- a/block/qcow2.h +++ b/block/qcow2.h @@ -68,7 +68,7 @@ #define MAX_CLUSTER_BITS 21 /* Must be at least 2 to cover COW */ -#define MIN_L2_CACHE_SIZE 2 /* clusters */ +#define MIN_L2_CACHE_SIZE 2 /* cache entries */ /* Must be at least 4 to cover all cases of refcount table growth */ #define MIN_REFCOUNT_CACHE_SIZE 4 /* clusters */ @@ -100,6 +100,7 @@ #define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2" #define QCOW2_OPT_CACHE_SIZE "cache-size" #define QCOW2_OPT_L2_CACHE_SIZE "l2-cache-size" +#define QCOW2_OPT_L2_CACHE_ENTRY_SIZE "l2-cache-entry-size" #define QCOW2_OPT_REFCOUNT_CACHE_SIZE "refcount-cache-size" #define QCOW2_OPT_CACHE_CLEAN_INTERVAL "cache-clean-interval" @@ -647,7 +648,8 @@ void qcow2_free_snapshots(BlockDriverState *bs); int qcow2_read_snapshots(BlockDriverState *bs); /* qcow2-cache.c functions */ -Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables); +Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables, + unsigned table_size); int qcow2_cache_destroy(Qcow2Cache *c); void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table); diff --git a/qapi/block-core.json b/qapi/block-core.json index 2c107823fe..5c5921bfb7 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -2521,6 +2521,11 @@ # @l2-cache-size: the maximum size of the L2 table cache in # bytes (since 2.2) # +# @l2-cache-entry-size: the size of each entry in the L2 cache in +# bytes. It must be a power of two between 512 +# and the cluster size. The default value is +# the cluster size (since 2.12) +# # @refcount-cache-size: the maximum size of the refcount block cache # in bytes (since 2.2) # @@ -2542,6 +2547,7 @@ '*overlap-check': 'Qcow2OverlapChecks', '*cache-size': 'int', '*l2-cache-size': 'int', + '*l2-cache-entry-size': 'int', '*refcount-cache-size': 'int', '*cache-clean-interval': 'int', '*encrypt': 'BlockdevQcow2Encryption' } }