Re: [Linux-4.19] ThinkPad T470 not booting with "intel_iommu=on"

From: Lu Baolu <baolu.lu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
To: sedat.dilek-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org,
	Joerg Roedel <joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org>
Cc: iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org
Subject: Re: [Linux-4.19] ThinkPad T470 not booting with "intel_iommu=on"
Date: Tue, 16 Oct 2018 14:35:06 +0800	[thread overview]
Message-ID: <95f69db6-becd-adce-5477-264de839bcd8@linux.intel.com> (raw)
In-Reply-To: <CA+icZUXnB2LbB-X_pQeM=OQDEVcWQdUr9TLbG1cXnpwuTe=mNw-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>

Hi Sedat,

Sorry for late reply.

Do you still have this issue with newer rc's (like 4.19-rc8)?

I checked the dmesg log you attached there, it seems that the vt-d was
not on actually.

Best regards,
Lu Baolu

On 9/5/18 8:04 PM, Sedat Dilek wrote:
> Hi Joerg,
> 
> "intel_ioomu=on" was working fine here on my ThinkPad T470 with
> debian/testing AMD64 with Linux v4.17.y and v4.18.y.
> 
> With testing Linux v4.19-rc1 and v4.19-rc2 my machine is not booting -
> black screen.
> These kernels are built with LLVM/Clang v7.0.0rc2 (v4.18.y too).
> 
> Furthermore, I switched from GRUB to systemd-boot v239.
> 
> [ /boot/efi/loader/entries/debian.conf ]
> 
> title Debian GNU/Linux buster/sid [ debian kernel ]
> linux /vmlinuz-4.17.0-3-amd64
> initrd /initrd.img-4.17.0-3-amd64
> options root=UUID=4c2aa544-6e86-44d2-9329-572623867b3d ro intel_iommu=on
> 
> [ /boot/efi/loader/entries/debian-llvmlinux.conf ]
> 
> title Debian GNU/Linux buster/sid [ llvmlinux kernel (EXPERIMENTAL) ]
> linux /vmlinuz-4.19.0-rc2-3-iniza-llvmlinux
> initrd /initrd.img-4.19.0-rc2-3-iniza-llvmlinux
> options root=UUID=4c2aa544-6e86-44d2-9329-572623867b3d ro
> 
> Any hints or hints to debug this?
> Any other kernel boot cheats [1] I can try?
> 
> My kernel-config and dmesg output is attached.
> 
> Thanks in advance.
> 
> Regards,
> - Sedat -
> 
> 
> Documentation/intel_txt.txt
> Documentation/admin-guide/kernel-parameters.txt
> Documentation/Intel-IOMMU.txt
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/admin-guide/kernel-parameters.txt#n1645
> [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/Intel-IOMMU.txt
> [3] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/intel_txt.txt
> 
> 
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