- reg = &dev->mem->regions[i];
- if (gpa >= reg->guest_phys_addr &&
- gpa < reg->guest_phys_addr + reg->size) {
- return gpa - reg->guest_phys_addr +
- reg->host_user_addr;
+ r = &dev->mem->regions[i];
+ if (gpa >= r->guest_phys_addr &&
+ gpa < r->guest_phys_addr + r->size) {
+
+ if (unlikely(*len > r->guest_phys_addr + r->size - gpa))
+ *len = r->guest_phys_addr + r->size - gpa;
+
+ return gpa - r->guest_phys_addr +
+ r->host_user_addr;