KVM : GPU Passthrough

	Configure GPU Passthrough for Virtual Machines. By this configuration, it's possible to use GPU on Virtual Machines and run GPU Computing. Before configuration, Enable VT-d (Intel) or AMD IOMMU (AMD) on BIOS Setting first.
[1]	Enable IOMMU feature on KVM Host.

root@dlp:~#  vi /etc/default/grub # line 10 : add # for AMD CPU, set [amd_iommu=on] # for Intel CPU, set [intel_iommu=on] GRUB_CMDLINE_LINUX=" intel_iommu=on iommu=pt " root@dlp:~#  update-grub # show PCI identification number and [vendor-ID:device-ID] of Graphic card # PCI number ⇒ it matches [03:00.*] below # vendor-ID:device-ID ⇒ it matches [10de:***] below root@dlp:~#  lspci -nn | grep -i nvidia 81:00.0 VGA compatible controller [0300]: NVIDIA Corporation GA104 [GeForce RTX 3060] [10de:2487] (rev a1) 81:00.1 Audio device [0403]: NVIDIA Corporation GA104 High Definition Audio Controller [10de:228b] (rev a1) root@dlp:~#  vi /etc/modprobe.d/vfio.conf # create new : for [ids=***], specify [Vendor-ID : Device-ID] options vfio-pci ids=10de:2487,10de:228b root@dlp:~#  echo 'vfio-pci' > /etc/modules-load.d/vfio-pci.conf root@dlp:~#  reboot # confirm IOMMU is enabled root@dlp:~#  dmesg | grep -E "DMAR|IOMMU" [ 0.010814] ACPI: DMAR 0x000000007A5C3130 000108 (v01 ALASKA A M I 00000001 INTL 20091013) [ 0.010847] ACPI: Reserving DMAR table memory at [mem 0x7a5c3130-0x7a5c3237] [ 0.027998] DMAR: IOMMU enabled [ 0.099135] DMAR: Host address width 46 [ 0.099137] DMAR: DRHD base: 0x000000fbffc000 flags: 0x0 [ 0.099143] DMAR: dmar0: reg_base_addr fbffc000 ver 1:0 cap d2078c106f0466 ecap f020df [ 0.099146] DMAR: DRHD base: 0x000000c7ffc000 flags: 0x1 [ 0.099151] DMAR: dmar1: reg_base_addr c7ffc000 ver 1:0 cap d2078c106f0466 ecap f020df [ 0.099153] DMAR: RMRR base: 0x0000007dbcf000 end: 0x0000007dbddfff [ 0.099155] DMAR: ATSR flags: 0x0 [ 0.099156] DMAR: RHSA base: 0x000000c7ffc000 proximity domain: 0x0 [ 0.099158] DMAR: RHSA base: 0x000000fbffc000 proximity domain: 0x1 [ 0.099161] DMAR-IR: IOAPIC id 10 under DRHD base 0xfbffc000 IOMMU 0 [ 0.099163] DMAR-IR: IOAPIC id 8 under DRHD base 0xc7ffc000 IOMMU 1 [ 0.099165] DMAR-IR: IOAPIC id 9 under DRHD base 0xc7ffc000 IOMMU 1 [ 0.099166] DMAR-IR: HPET id 0 under DRHD base 0xc7ffc000 [ 0.099168] DMAR-IR: x2apic is disabled because BIOS sets x2apic opt out bit. [ 0.099169] DMAR-IR: Use 'intremap=no_x2apic_optout' to override the BIOS setting. [ 0.100047] DMAR-IR: Enabled IRQ remapping in xapic mode [ 0.468967] DMAR: No SATC found [ 0.468971] DMAR: dmar0: Using Queued invalidation [ 0.468978] DMAR: dmar1: Using Queued invalidation [ 0.480680] DMAR: Intel(R) Virtualization Technology for Directed I/O # confirm vfio_pci is enabled root@dlp:~#  dmesg | grep -i vfio [ 4.102407] VFIO - User Level meta-driver version: 0.3 [ 4.120253] vfio-pci 0000:81:00.0: vgaarb: VGA decodes changed: olddecodes=io+mem,decodes=io+mem:owns=none [ 4.120385] vfio_pci: add [10de:2487[ffffffff:ffffffff]] class 0x000000/00000000 [ 4.144749] vfio_pci: add [10de:228b[ffffffff:ffffffff]] class 0x000000/00000000

[2]	That's OK. For example, create a Debian 13 Virtual machine with GPU. Specify PCI identification number of GPU for [--host-device].

root@dlp:~# virt-install \ --name debian13 \ --ram 8192 \ --disk path=/var/kvm/images/debian13.img,size=30 \ --vcpus=4 \ --os-variant debian13 \ --network bridge=br0 \ --graphics vnc,listen=0.0.0.0,password=password \ --video vga \ --host-device 81:00.0 \ --features kvm_hidden=on \ --machine q35 \ --cdrom /home/debian-13.0.0-amd64-DVD-1.iso

[3]	After creating Virtual machine, Confirm GPU is found on it like follows.

root@debian:~#  lspci | grep -i nvidia 05:00.0 VGA compatible controller: NVIDIA Corporation GA104 [GeForce RTX 3060] (rev a1)