@Peridot, Request from Upstream: For the original 4.13 kernel, I don't see any attachments that have the AMD-Vi messages in question. Were they completion timeouts (like in the later mainline kernel test, which I'll get to in a bit) or I/O page fault messages? Without that information it is hard to determine what the issue really is.
(Just as an FYI, if the IOMMU is disabled in BIOS, then iommu=soft is not necessary on the kernel command line). For the upstream kernel test, since this is a Ryzen system, it's possible that the BIOS does not have a requisite fix for SME and IOMMU (see [1]). On the upstream kernel, if memory encryption is active by default without this BIOS fix, then the result is AMD-Vi completion-wait timeout messages. Try booting with mem_encrypt=off on the kernel command line or build a kernel with CONFIG_AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT=n and see if that allows the kernel to boot. Thanks, Tom [1] https://bugzilla.kernel.org/show_bug.cgi?id=199513 ** Bug watch added: Linux Kernel Bug Tracker #199513 https://bugzilla.kernel.org/show_bug.cgi?id=199513 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1747463 Title: kernel crashes during boot unless IOMMU is disabled on Ryzen 1800X To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/1747463/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
