Comment 4 for bug 1865120

I have a similar issue. seems aarch64 qemu only support when num_pcie_ports=15. guest failed to boot when use num_pcie_ports=16. Following is what i get

when using num_pcie_ports=16, guest OS is stuck at UEFI page with following message

```
UEFI Interactive Shell v2.2
EDK II
UEFI v2.70 (EDK II, 0x00010000)
Mapping table
     BLK1: Alias(s):
          VenHw(F9B94AE2-8BA6-409B-9D56-B9B417F53CB3)
     BLK0: Alias(s):
          VenHw(8047DB4B-7E9C-4C0C-8EBC-DFBBAACACE8F)
Press ESC in 5 seconds to skip startup.nsh or any other key to continue.
```

when using num_pcie_ports=15, the guest OS can be boot successfully, i check the uefi manage, found following

```
UEFI Interactive Shell v2.2
EDK II
UEFI v2.70 (EDK II, 0x00010000)
Mapping table
      FS0: Alias(s):HD1b:;BLK2:
          PciRoot(0x0)/Pci(0x1,0x3)/Pci(0x0,0x0)/HD(1,GPT,8AD1EB5A-1F33-44F8-8A74-EEF37D4802F5,0x800,0x113000)
     BLK6: Alias(s):
          VenHw(F9B94AE2-8BA6-409B-9D56-B9B417F53CB3)
     BLK5: Alias(s):
          VenHw(8047DB4B-7E9C-4C0C-8EBC-DFBBAACACE8F)
     BLK1: Alias(s):
          PciRoot(0x0)/Pci(0x1,0x3)/Pci(0x0,0x0)
     BLK3: Alias(s):
          PciRoot(0x0)/Pci(0x1,0x3)/Pci(0x0,0x0)/HD(2,GPT,1F802CD3-DD0B-4DA7-BF90-B928E443E0F0,0x113800,0x4000)
     BLK4: Alias(s):
          PciRoot(0x0)/Pci(0x1,0x3)/Pci(0x0,0x0)/HD(3,GPT,18DB5C2F-CE88-43D6-8A0F-011E4A1FEE29,0x117800,0x3EE800)
     BLK0: Alias(s):
          PciRoot(0x0)/Pci(0x1,0x1)/Pci(0x0,0x0)/Scsi(0x0,0x0)

Press ESC in 1 seconds to skip startup.nsh or any other key to continue.
Shell>
```

seems when using num_pcie_ports=16, the kvm can not find disks.

the libvirt xml file is attached