Hi, I having a problem passing second GPU to my second VM

My Hardware:

GPU1(address 0)

GPU2(address 49)

My Goal:

GPU1 passing to VM1

GPU2 passing to VM2

Current situation:

GPU1 passing to VM1 (Work fine)

GPU2 passing to VM2 (not boot and 1 core always 100% utilize)

Already try:

Swap GPU slot, second GPU always not work

PCIe ACS override, not work

Here is my passing parameter, IOMMU group of second device and 1 core 1 core always 100% utilize

my GPU1 use exactly the same passing parameter, except bus 

<hostdev mode='subsystem' type='pci' managed='yes' xvga='yes'>
      <driver name='vfio'/>
      <source>
        <address domain='0x0000' bus='0x49' slot='0x00' function='0x0'/>
      </source>
      <alias name='hostdev0'/>
      <address type='pci' domain='0x0000' bus='0x04' slot='0x00' function='0x0' multifunction='on'/>
    </hostdev>
    <hostdev mode='subsystem' type='pci' managed='yes'>
      <driver name='vfio'/>
      <source>
        <address domain='0x0000' bus='0x49' slot='0x00' function='0x1'/>
      </source>
      <alias name='hostdev1'/>
      <address type='pci' domain='0x0000' bus='0x04' slot='0x00' function='0x1'/>
    </hostdev>

Why aren't you isolating the 2nd GPU?

Hi, thank for the answer!

I don't know I understand it correctly or not, I have tried isolating the GPU as shown below, now 3080Ti IOMMU is now separated.

I am also added a vbios, but it still doesn't worked

<hostdev mode='subsystem' type='pci' managed='yes' xvga='yes'>
      <driver name='vfio'/>
      <source>
        <address domain='0x0000' bus='0x49' slot='0x00' function='0x0'/>
      </source>
      <rom file='/mnt/user/isos/vbios/RTX3080Ti.rom'/>
      <address type='pci' domain='0x0000' bus='0x04' slot='0x00' function='0x0' multifunction='on'/>
    </hostdev>
    <hostdev mode='subsystem' type='pci' managed='yes'>
      <driver name='vfio'/>
      <source>
        <address domain='0x0000' bus='0x49' slot='0x00' function='0x1'/>
      </source>
      <address type='pci' domain='0x0000' bus='0x04' slot='0x00' function='0x1'/>
    </hostdev>

Here is my boot configuration, where 10de:24b0,10de:228b is my A4000 and  10de:2208,10de:1aef is my 3080Ti

kernel /bzimage
append initrd=/bzroot vfio-pci.ids=10de:24b0,10de:228b,10de:2208,10de:1aef pcie_acs_override=multifunction video=efifb:off

 

Update 

I try create new dummy VM that use OVMF Bios(All of my VM use SEABIOS) and the passthrough WORKED! 

Is there anyway modify my old VM to use OVMF Bios instead?