vhost-user: VHOST_USER_SET_MEM_TABLE doesn't contain all regions



vhost-user implementation doesn't provide information about all memory regions, 
and in some cases client is not able to map buffer memory as he is missing 
memory region information for specific address.

Same thing is implemented properly for vhost-net. Below gdb outputs are 
showing memory regions information provided to the vhost-net and vhost-user.



==== memory regions information provided to vhost-net  ====

(gdb) p/x hdev->mem->regions[0]
$21 = {
  guest_phys_addr = 0x100000000,
  memory_size = 0xc0000000,
  userspace_addr = 0x2aab6ac00000,
  flags_padding = 0x0
}
(gdb) p/x hdev->mem->regions[1]
$22 = {
  guest_phys_addr = 0xfffc0000,
  memory_size = 0x40000,
  userspace_addr = 0x7ffff4a00000,
  flags_padding = 0x0
}
(gdb) p/x hdev->mem->regions[2]
$23 = {
  guest_phys_addr = 0x0,
  memory_size = 0xa0000,
  userspace_addr = 0x2aaaaac00000,
  flags_padding = 0x0
}
(gdb) p/x hdev->mem->regions[3]
$24 = {
  guest_phys_addr = 0xc0000,
  memory_size = 0xbff40000,
  userspace_addr = 0x2aaaaacc0000,
  flags_padding = 0x0
}
(gdb)


==== memory regions information provided to vhost-user  ====

(gdb) p/x msg.memory.nregions
$28 = 0x1
(gdb) p/x msg.memory.regions[0]
$29 = {
  guest_phys_addr = 0x0,
  memory_size = 0x180000000,
  userspace_addr = 0x2aaaaac00000
}
(gdb)

Problem fixed in qemu commit 3fd74b84.