device: 0.497
network: 0.484
PID: 0.461
vnc: 0.365
VMM: 0.333
ppc: 0.299
socket: 0.278
kernel: 0.258
register: 0.234
hypervisor: 0.230
graphic: 0.222
virtual: 0.221
arm: 0.217
architecture: 0.206
risc-v: 0.206
i386: 0.191
TCG: 0.168
x86: 0.168
debug: 0.149
boot: 0.147
performance: 0.136
semantic: 0.132
KVM: 0.131
peripherals: 0.131
files: 0.124
permissions: 0.123
user-level: 0.109
mistranslation: 0.108
assembly: 0.079

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.