Adding an mdev causes one core to be 100% for 70 seconds before tianocore logo appears and boot starts.

[Pesc0]

As the title says, adding an mdev (nvidia vgpu) to the libvirt xml causes this behavior.
Removing the mdev boot is normal again. Using seabios + mdev boot is normal.

This line gets logged right away on VM start

qemu-system-x86_64: -device {"driver":"vfio-pci","id":"hostdev0","sysfsdev":"/sys/bus/mdev/devices/802167a6-39e5-425c-a85f-acf0aefcdead","display":"off","bus":"pci.6","addr":"0x0"}: warning: vfio 802167a6-39e5-425c-a85f-acf0aefcdead: Could not enable error recovery for the device

This is the VM xml

<domain type="kvm">
  <name>win10</name>
  <uuid>d12e1c54-bd91-4f71-b8ec-0677f4cbbe74</uuid>
  <metadata>
    <libosinfo:libosinfo xmlns:libosinfo="http://libosinfo.org/xmlns/libvirt/domain/1.0">
      <libosinfo:os id="http://microsoft.com/win/10"/>
    </libosinfo:libosinfo>
  </metadata>
  <memory unit="KiB">8388608</memory>
  <currentMemory unit="KiB">2097152</currentMemory>
  <vcpu placement="static">4</vcpu>
  <cputune>
    <vcpupin vcpu="0" cpuset="0"/>
    <vcpupin vcpu="1" cpuset="1"/>
    <vcpupin vcpu="2" cpuset="2"/>
    <vcpupin vcpu="3" cpuset="3"/>
  </cputune>
  <sysinfo type="smbios">
    <bios>
      <entry name="vendor">LENOVO</entry>
    </bios>
    <system>
      <entry name="manufacturer">Fedora</entry>
      <entry name="product">Virt-Manager</entry>
      <entry name="version">0.9.4</entry>
    </system>
    <baseBoard>
      <entry name="manufacturer">LENOVO</entry>
      <entry name="product">20BE0061MC</entry>
      <entry name="version">0B98401 Pro</entry>
      <entry name="serial">W1KS427111E</entry>
    </baseBoard>
    <chassis>
      <entry name="manufacturer">Dell Inc.</entry>
      <entry name="version">2.12</entry>
      <entry name="serial">65X0XF2</entry>
      <entry name="asset">40000101</entry>
      <entry name="sku">Type3Sku1</entry>
    </chassis>
    <oemStrings>
      <entry>myappname:some arbitrary data</entry>
      <entry>otherappname:more arbitrary data</entry>
    </oemStrings>
  </sysinfo>
  <os firmware="efi">
    <type arch="x86_64" machine="pc-q35-8.2">hvm</type>
    <firmware>
      <feature enabled="no" name="enrolled-keys"/>
      <feature enabled="yes" name="secure-boot"/>
    </firmware>
    <loader readonly="yes" secure="yes" type="pflash">/usr/share/edk2/x64/OVMF_CODE.secboot.4m.fd</loader>
    <nvram template="/usr/share/edk2/x64/OVMF_VARS.4m.fd">/var/lib/libvirt/qemu/nvram/win10_VARS.fd</nvram>
    <boot dev="hd"/>
    <smbios mode="sysinfo"/>
  </os>
  <features>
    <acpi/>
    <apic/>
    <hyperv mode="custom">
      <relaxed state="on"/>
      <vapic state="on"/>
      <spinlocks state="on" retries="8191"/>
      <vendor_id state="on" value="randomid"/>
    </hyperv>
    <kvm>
      <hidden state="on"/>
    </kvm>
    <vmport state="off"/>
    <smm state="on"/>
  </features>
  <cpu mode="host-passthrough" check="none" migratable="on">
    <topology sockets="1" dies="1" clusters="1" cores="4" threads="1"/>
  </cpu>
  <clock offset="localtime">
    <timer name="rtc" tickpolicy="catchup"/>
    <timer name="pit" tickpolicy="delay"/>
    <timer name="hpet" present="yes"/>
    <timer name="hypervclock" present="yes"/>
  </clock>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>destroy</on_crash>
  <pm>
    <suspend-to-mem enabled="no"/>
    <suspend-to-disk enabled="no"/>
  </pm>
  <devices>
    <emulator>/usr/bin/qemu-system-x86_64</emulator>
    <disk type="file" device="disk">
      <driver name="qemu" type="qcow2"/>
      <source file="/home/user/Virt/SSD/libvirtVMs/win10_SSD.qcow2"/>
      <target dev="vda" bus="virtio"/>
      <address type="pci" domain="0x0000" bus="0x08" slot="0x00" function="0x0"/>
    </disk>
    <disk type="file" device="disk">
      <driver name="qemu" type="qcow2"/>
      <source file="/home/user/Virt/HDD/libvirtVMs/win10_HDD.qcow2"/>
      <target dev="vdb" bus="virtio"/>
      <address type="pci" domain="0x0000" bus="0x0a" slot="0x00" function="0x0"/>
    </disk>
    <controller type="usb" index="0" model="qemu-xhci" ports="15">
      <address type="pci" domain="0x0000" bus="0x02" slot="0x00" function="0x0"/>
    </controller>
    <controller type="pci" index="0" model="pcie-root"/>
    <controller type="pci" index="1" model="pcie-root-port">
      <model name="pcie-root-port"/>
      <target chassis="1" port="0x10"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x0" multifunction="on"/>
    </controller>
    <controller type="pci" index="2" model="pcie-root-port">
      <model name="pcie-root-port"/>
      <target chassis="2" port="0x11"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x1"/>
    </controller>
    <controller type="pci" index="3" model="pcie-root-port">
      <model name="pcie-root-port"/>
      <target chassis="3" port="0x12"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x2"/>
    </controller>
    <controller type="pci" index="4" model="pcie-root-port">
      <model name="pcie-root-port"/>
      <target chassis="4" port="0x13"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x3"/>
    </controller>
    <controller type="pci" index="5" model="pcie-root-port">
      <model name="pcie-root-port"/>
      <target chassis="5" port="0x14"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x4"/>
    </controller>
    <controller type="pci" index="6" model="pcie-root-port">
      <model name="pcie-root-port"/>
      <target chassis="6" port="0x15"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x5"/>
    </controller>
    <controller type="pci" index="7" model="pcie-root-port">
      <model name="pcie-root-port"/>
      <target chassis="7" port="0x16"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x6"/>
    </controller>
    <controller type="pci" index="8" model="pcie-root-port">
      <model name="pcie-root-port"/>
      <target chassis="8" port="0x17"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x02" function="0x7"/>
    </controller>
    <controller type="pci" index="9" model="pcie-root-port">
      <model name="pcie-root-port"/>
      <target chassis="9" port="0x18"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x03" function="0x0" multifunction="on"/>
    </controller>
    <controller type="pci" index="10" model="pcie-root-port">
      <model name="pcie-root-port"/>
      <target chassis="10" port="0x19"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x03" function="0x1"/>
    </controller>
    <controller type="pci" index="11" model="pcie-root-port">
      <model name="pcie-root-port"/>
      <target chassis="11" port="0x1a"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x03" function="0x2"/>
    </controller>
    <controller type="pci" index="12" model="pcie-root-port">
      <model name="pcie-root-port"/>
      <target chassis="12" port="0x1b"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x03" function="0x3"/>
    </controller>
    <controller type="pci" index="13" model="pcie-root-port">
      <model name="pcie-root-port"/>
      <target chassis="13" port="0x1c"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x03" function="0x4"/>
    </controller>
    <controller type="pci" index="14" model="pcie-root-port">
      <model name="pcie-root-port"/>
      <target chassis="14" port="0x1d"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x03" function="0x5"/>
    </controller>
    <controller type="pci" index="15" model="pcie-root-port">
      <model name="pcie-root-port"/>
      <target chassis="15" port="0x1e"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x03" function="0x6"/>
    </controller>
    <controller type="pci" index="16" model="pcie-to-pci-bridge">
      <model name="pcie-pci-bridge"/>
      <address type="pci" domain="0x0000" bus="0x05" slot="0x00" function="0x0"/>
    </controller>
    <controller type="sata" index="0">
      <address type="pci" domain="0x0000" bus="0x00" slot="0x1f" function="0x2"/>
    </controller>
    <controller type="virtio-serial" index="0">
      <address type="pci" domain="0x0000" bus="0x03" slot="0x00" function="0x0"/>
    </controller>
    <interface type="user">
      <mac address="52:54:00:75:5e:dd"/>
      <model type="virtio"/>
      <address type="pci" domain="0x0000" bus="0x01" slot="0x00" function="0x0"/>
    </interface>
    <channel type="spicevmc">
      <target type="virtio" name="com.redhat.spice.0"/>
      <address type="virtio-serial" controller="0" bus="0" port="1"/>
    </channel>
    <input type="mouse" bus="virtio">
      <address type="pci" domain="0x0000" bus="0x09" slot="0x00" function="0x0"/>
    </input>
    <input type="keyboard" bus="virtio">
      <address type="pci" domain="0x0000" bus="0x04" slot="0x00" function="0x0"/>
    </input>
    <input type="mouse" bus="ps2"/>
    <input type="keyboard" bus="ps2"/>
    <graphics type="spice" autoport="yes">
      <listen type="address"/>
      <image compression="off"/>
    </graphics>
    <sound model="ich9">
      <audio id="1"/>
      <address type="pci" domain="0x0000" bus="0x00" slot="0x1b" function="0x0"/>
    </sound>
    <audio id="1" type="spice"/>
    <video>
      <model type="none"/>
    </video>
    <hostdev mode="subsystem" type="mdev" managed="yes" model="vfio-pci" display="off" ramfb="off">
      <source>
        <address uuid="802167a6-39e5-425c-a85f-acf0aefcdead"/>
      </source>
      <address type="pci" domain="0x0000" bus="0x06" slot="0x00" function="0x0"/>
    </hostdev>
    <watchdog model="itco" action="reset"/>
    <memballoon model="none"/>
    <shmem name="looking-glass">
      <model type="ivshmem-plain"/>
      <size unit="M">128</size>
      <address type="pci" domain="0x0000" bus="0x10" slot="0x01" function="0x0"/>
    </shmem>
  </devices>
</domain>

This is the only thing I could find online: https://edk2.groups.io/g/devel/topic/100367559?p=%2C%2C%2C20%2C0%2C0%2C0%3A%3A%2C%2C%2C0%2C0%2C0%2C100367559

Please let me know if you need any other information or logs.