Hi. Im trying to set intel_iommu=on on kernel parameters at grub but for some reason it doesnt work. I edit /etc/default/grub file and i add the parameter. then i run grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg and then i reboot. when i run virt-host-validate i get QEMU: Checking if IOMMU is enabled by kernel: WARN (IOMMU appears to be disabled in kernel. Add intel_iommu=on to kernel cmdline arguments) when i edit the grub menu durring boot and i put intel_iommu=on and the i run again virt-host-validate i get QEMU: Checking if IOMMU is enabled by kernel: PASS any ideas? I tried editing other variables like GRUB_TIMEOUT and it seems to me that changes are applied. Thanks in advance
> Hi. > Im trying to set intel_iommu=on on kernel parameters at grub but for > some reason it doesnt work. > > I edit /etc/default/grub file and i add the parameter. > > then i run grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg and then i > reboot.When you look at /boot/efi/EFI/centos/grub.cfg, do you see that the parameter has been added? Regards, Simon
Yes i can find intel_iommu=on. For some reason it doesnt take it when i reboot. On Fri, 2020-04-03 at 18:44 +0200, Simon Matter via CentOS wrote:> > Hi. > > Im trying to set intel_iommu=on on kernel parameters at grub but > > for > > some reason it doesnt work. > > > > I edit /etc/default/grub file and i add the parameter. > > > > then i run grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg and then > > i > > reboot. > > When you look at /boot/efi/EFI/centos/grub.cfg, do you see that the > parameter has been added? > > Regards, > Simon > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos
On Fri, Apr 03, 2020 at 07:37:10PM +0300, Georgios wrote:> > Hi. > Im trying to set intel_iommu=on on kernel parameters at grub but for > some reason it doesnt work. > > I edit /etc/default/grub file and i add the parameter. > > then i run grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg and then i > reboot. > > when i run virt-host-validate i get > > QEMU: Checking if IOMMU is enabled by kernel: WARN (IOMMU appears to be > disabled in kernel. Add intel_iommu=on to kernel cmdline arguments) > > when i edit the grub menu durring boot and i put intel_iommu=on and the > i run again virt-host-validate i get > > QEMU: Checking if IOMMU is enabled by kernel: PASS > > > any ideas?This is a libvirtd KVM machine? Are you sure you're using UEFI? -- Jonathan Billings <billings at negate.org>
Yes dmesg | grep "EFI v" [ 0.000000] efi: EFI v2.70 by American Megatrends On Fri, 2020-04-03 at 14:29 -0400, Jonathan Billings wrote:> On Fri, Apr 03, 2020 at 07:37:10PM +0300, Georgios wrote: > > Hi. > > Im trying to set intel_iommu=on on kernel parameters at grub but > > for > > some reason it doesnt work. > > > > I edit /etc/default/grub file and i add the parameter. > > > > then i run grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg and then > > i > > reboot. > > > > when i run virt-host-validate i get > > > > QEMU: Checking if IOMMU is enabled by kernel: WARN (IOMMU appears > > to be > > disabled in kernel. Add intel_iommu=on to kernel cmdline arguments) > > > > when i edit the grub menu durring boot and i put intel_iommu=on and > > the > > i run again virt-host-validate i get > > > > QEMU: Checking if IOMMU is enabled by kernel: PASS > > > > > > any ideas? > > This is a libvirtd KVM machine? Are you sure you're using UEFI? >
I think i might have solve it. For some reason grub2-mkconfig doesnt work. (Have no idea why) I manage to solve it with grubby. sudo grubby --args="intel_iommu=on" --update-kernel=ALL For some reason it works. I dont know if it works if my kernel gets upgraded.