kvm tools, qcow: Use big endian order for L2 table entries

Don't keep the in-memory array in CPU byte order to simplify delayed L2 table
writeout.

Cc: Asias He <asias.hejun@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Prasad Joshi <prasadjoshi124@gmail.com>
Cc: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/tools/kvm/disk/qcow.c b/tools/kvm/disk/qcow.c
index 35408ab05694a100e9f397bcb0249bcbc8e7bff1..c851e7f382700d4d079db2a07a481854719dae47 100644 (file)
--- a/tools/kvm/disk/qcow.c
+++ b/tools/kvm/disk/qcow.c
@@ -183,7 +183,6 @@ static struct qcow_l2_table *qcow_read_l2_table(struct qcow *q, u64 offset)
        struct qcow_header *header = q->header;
        struct qcow_l2_table *l2t;
        u64 size;
-       u64 i;
 
        size = 1 << header->l2_bits;
 
@@ -205,10 +204,6 @@ static struct qcow_l2_table *qcow_read_l2_table(struct qcow *q, u64 offset)
        if (cache_table(q, l2t) < 0)
                goto error;
 
-       /* change cached table to CPU's byte-order */
-       for (i = 0; i < size; i++)
-               be64_to_cpus(&l2t->table[i]);
-
        return l2t;
 error:
        free(l2t);
@@ -259,7 +254,7 @@ static ssize_t qcow_read_cluster(struct qcow *q, u64 offset, void *dst, u32 dst_
        if (l2_idx >= l2_table_size)
                goto out_error;
 
-       clust_start = l2_table->table[l2_idx] & ~header->oflag_mask;
+       clust_start = be64_to_cpu(l2_table->table[l2_idx]) & ~header->oflag_mask;
        if (!clust_start)
                goto zero_cluster;
 
@@ -437,7 +432,7 @@ static ssize_t qcow_write_cluster(struct qcow *q, u64 offset, void *buf, u32 src
        if (!f_sz)
                goto error;
 
-       clust_start     = l2t->table[l2t_idx] & ~header->oflag_mask;
+       clust_start     = be64_to_cpu(l2t->table[l2t_idx]) & ~header->oflag_mask;
        if (!clust_start) {
                clust_start     = ALIGN(f_sz, clust_sz);
                update_meta     = true;
@@ -459,7 +454,7 @@ static ssize_t qcow_write_cluster(struct qcow *q, u64 offset, void *buf, u32 src
                }
 
                /* Update the cached level2 entry */
-               l2t->table[l2t_idx] = clust_start;
+               l2t->table[l2t_idx] = cpu_to_be64(clust_start);
        }
 
        mutex_unlock(&q->mutex);