How to determine which GPU is assigned to dom0

Run the command in Dom0:

[root@monet ~]# head -n 1 /dev/vga_arbiter
count:9,PCI:
0000:01:03.0,decodes=io+mem,owns=io+mem,locks=none(0:0)

take the text highlighted in red and use it in the below command

[root@monet ~]# lspci -s 0000:01:03.0
01:03.0 VGA compatible controller: Advanced Micro Devices [AMD] nee ATI ES1000 (rev 02)

The result you get should tell you which card is allocated to dom0, above it was an AMD GPU.

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