How can enable iommu in AMD CPU during boot?

Motherboard info: sudo dmidecode -t baseboard | grep -B 1 Product Manufacturer: Colorful Technology And Development Co.,LTD Product Name: BATTLE-AX B450M-HD CPU info: sudo dmidecode -t processor | grep Version Version: AMD Athlon 3000G with Radeon Vega Graphics OS info: uname -a Linux debian 5.10.0-22-amd64 #1 SMP Debian 5.10.178-3 (2023-04-22) x86_64 GNU/Linux I have enabled SVM in the bios setting,and set GRUB_CMDLINE_LINUX according to: https://unix.stackexchange.com/questions/263901/kfd-error-getting-iommu-info grep 'GRUB_CMDLINE_LINUX' /etc/default/grub GRUB_CMDLINE_LINUX="quiet amd_iommu=on iommu=pt" Reboot,check booting info on iommu: sudo dmesg | grep "error" [ 4.056168] kfd kfd: error getting iommu info. is the iommu enabled? [ 4.056221] kfd kfd: device 1002:15d8 NOT added due to errors Maybe we can't enable it on AMD CPU because it is not a bug? sudo dmesg | grep -e DMAR -e IOMMU [ 1.191400] AMD-Vi: AMD IOMMUv2 functionality not available on this system - This is not a bug. I have enabled the SVM mode in my motherboard's BIOS,and sudo update-grub,the iommu issue remains after reboot.