1 // SPDX-License-Identifier: GPL-2.0-only
14  * kvm_stats_read() - Common function to read from the binary statistics
20  * @stats: start address of stats data block for a vm or a vcpu
21  * @size_stats: the size of stats data block pointed by @stats
28  * +-------------+
30  * +-------------+
32  * +-------------+
34  * +-------------+
36  * +-------------+
41  *    and some other necessary information. This is a one-time work for the
43  * 2. Read id string from its offset. This is a one-time work for the lifecycle
46  *    descriptors. This is a one-time work for the lifecycle of the
67 	size_desc = header->num_desc * sizeof(*desc);  in kvm_stats_read()
69 	len = KVM_STATS_NAME_SIZE + size_header + size_desc + size_stats - pos;  in kvm_stats_read()
76 	 * Copy kvm stats header.  in kvm_stats_read()
77 	 * The header is the first block of content userspace usually read out.  in kvm_stats_read()
79 	 * The copy of the header would be skipped if offset is larger than the  in kvm_stats_read()
83 	copylen = size_header - pos;  in kvm_stats_read()
88 			return -EFAULT;  in kvm_stats_read()
89 		remain -= copylen;  in kvm_stats_read()
95 	 * Copy kvm stats header id string.  in kvm_stats_read()
103 	copylen = header->id_offset + KVM_STATS_NAME_SIZE - pos;  in kvm_stats_read()
106 		src = id + pos - header->id_offset;  in kvm_stats_read()
108 			return -EFAULT;  in kvm_stats_read()
109 		remain -= copylen;  in kvm_stats_read()
115 	 * Copy kvm stats descriptors.  in kvm_stats_read()
116 	 * The descriptors copy would be skipped in the typical case that  in kvm_stats_read()
119 	 * (header->header.desc_offset + size_desc) causing copylen <= 0.  in kvm_stats_read()
121 	copylen = header->desc_offset + size_desc - pos;  in kvm_stats_read()
124 		src = (void *)desc + pos - header->desc_offset;  in kvm_stats_read()
126 			return -EFAULT;  in kvm_stats_read()
127 		remain -= copylen;  in kvm_stats_read()
132 	/* Copy kvm stats values */  in kvm_stats_read()
133 	copylen = header->data_offset + size_stats - pos;  in kvm_stats_read()
136 		src = stats + pos - header->data_offset;  in kvm_stats_read()
138 			return -EFAULT;  in kvm_stats_read()