Public bug reported: While investigating LP: #1955395 by using the -generic kernel image, it appeared that it is impossible to boot the kernel unless the boot parameter swiotlb is set to 512M (swiotlb=262144).
Wnen not set, the kernel tries to adjust the bounce buffer to 1024Mb it fails and later trigger a kernel panic with the following trace : $ grep TLB /tmp/console.log [ 0.003665] software IO TLB: SWIOTLB bounce buffer size adjusted to 1024MB [ 0.034219] kvm-guest: KVM setup pv remote TLB flush [ 0.037063] software IO TLB: Cannot allocate buffer [ 0.223009] Last level iTLB entries: 4KB 512, 2MB 255, 4MB 127 [ 0.223634] Last level dTLB entries: 4KB 512, 2MB 255, 4MB 127, 1GB 0 [ 0.297424] HugeTLB registered 1.00 GiB page size, pre-allocated 0 pages [ 0.297424] HugeTLB registered 2.00 MiB page size, pre-allocated 0 pages [ 1.018860] PCI-DMA: Using software bounce buffering for IO (SWIOTLB) [ 1.019552] software IO TLB: No low mem [ 1.451497] Kernel panic - not syncing: Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer [ 1.491589] ---[ end Kernel panic - not syncing: Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer ]--- The SWIOTLB adjustment comes from the following kernel commit : https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e998879d4fb7991856916972168cf27c0d86ed12 For some reason, the LowMem allocation fails (as seen by the "software IO TLB: No low mem" msg),hence the SWIOTLB adjustment cannot be completed. When booting with the swiotlb=262144 value, we get the following output : $ grep TLB /tmp/console.log [ 0.050908] kvm-guest: KVM setup pv remote TLB flush [ 0.308896] Last level iTLB entries: 4KB 512, 2MB 255, 4MB 127 [ 0.309494] Last level dTLB entries: 4KB 512, 2MB 255, 4MB 127, 1GB 0 [ 0.373162] HugeTLB registered 1.00 GiB page size, pre-allocated 0 pages [ 0.373162] HugeTLB registered 2.00 MiB page size, pre-allocated 0 pages [ 1.071136] PCI-DMA: Using software bounce buffering for IO (SWIOTLB) [ 1.071837] software IO TLB: mapped [mem 0x000000005bebe000-0x000000007bebe000] (512MB) [ 1.529804] software IO TLB: Memory encryption is active and system is using DMA bounce buffers For comparaison, the Fedora 34 kernel (5.15.4-101.fc34.x86_64) with the same adjustment mechanism does correctly adjust the SWIOTLB bounce buffer, without the need to set the swiotlb= value at boot time. The SWIOTLB buffer adjustment has been introduced in kernel 5.11. We can make SEV enabled resources available for testing if needed. ...Louis --- ProblemType: Bug AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 Dec 23 13:32 seq crw-rw---- 1 root audio 116, 33 Dec 23 13:32 timer AplayDevices: Error: [Errno 2] No such file or directory: 'aplay' ApportVersion: 2.20.11-0ubuntu74 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord' AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CRDA: N/A CasperMD5CheckResult: unknown DistroRelease: Ubuntu 22.04 IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig' Lsusb: Error: command ['lsusb'] failed with exit code 1: Lsusb-t: Lsusb-v: Error: command ['lsusb', '-v'] failed with exit code 1: MachineType: Scaleway SCW-ENT1-S Package: linux (not installed) PciMultimedia: ProcEnviron: TERM=screen PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=C.UTF-8 SHELL=/bin/bash ProcFB: ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.13.0-23-generic root=UUID=1f577236-6bf2-48ef-998a-ba45f71aca7f ro console=tty1 console=ttyS0 swiotlb=262144 ProcVersionSignature: Ubuntu 5.13.0-23.23-generic 5.13.19 RelatedPackageVersions: linux-restricted-modules-5.13.0-23-generic N/A linux-backports-modules-5.13.0-23-generic N/A linux-firmware N/A RfKill: Error: [Errno 2] No such file or directory: 'rfkill' Tags: jammy uec-images Uname: Linux 5.13.0-23-generic x86_64 UpgradeStatus: No upgrade log present (probably fresh install) UserGroups: N/A _MarkForUpload: True dmi.bios.date: 02/06/2015 dmi.bios.release: 0.0 dmi.bios.vendor: EFI Development Kit II / OVMF dmi.bios.version: 0.0.0 dmi.chassis.type: 1 dmi.chassis.vendor: QEMU dmi.chassis.version: pc-q35-3.0 dmi.modalias: dmi:bvnEFIDevelopmentKitII/OVMF:bvr0.0.0:bd02/06/2015:br0.0:svnScaleway:pnSCW-ENT1-S:pvrpc-q35-3.0:cvnQEMU:ct1:cvrpc-q35-3.0:sku: dmi.product.name: SCW-ENT1-S dmi.product.version: pc-q35-3.0 dmi.sys.vendor: Scaleway ** Affects: linux (Ubuntu) Importance: Undecided Status: Confirmed ** Tags: apport-collected jammy uec-images ** Tags added: apport-collected jammy uec-images ** Description changed: While investigating LP: #1955395 by using the -generic kernel image, it appeared that it is impossible to boot the kernel unless the boot parameter swiotlb is set to 512M (swiotlb=262144). Wnen not set, the kernel tries to adjust the bounce buffer to 1024Mb it fails and later trigger a kernel panic with the following trace : $ grep TLB /tmp/console.log [ 0.003665] software IO TLB: SWIOTLB bounce buffer size adjusted to 1024MB [ 0.034219] kvm-guest: KVM setup pv remote TLB flush [ 0.037063] software IO TLB: Cannot allocate buffer [ 0.223009] Last level iTLB entries: 4KB 512, 2MB 255, 4MB 127 [ 0.223634] Last level dTLB entries: 4KB 512, 2MB 255, 4MB 127, 1GB 0 [ 0.297424] HugeTLB registered 1.00 GiB page size, pre-allocated 0 pages [ 0.297424] HugeTLB registered 2.00 MiB page size, pre-allocated 0 pages [ 1.018860] PCI-DMA: Using software bounce buffering for IO (SWIOTLB) [ 1.019552] software IO TLB: No low mem [ 1.451497] Kernel panic - not syncing: Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer [ 1.491589] ---[ end Kernel panic - not syncing: Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer ]--- The SWIOTLB adjustment comes from the following kernel commit : https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=e998879d4fb7991856916972168cf27c0d86ed12 For some reason, the LowMem allocation fails (as seen by the "software IO TLB: No low mem" msg),hence the SWIOTLB adjustment cannot be completed. When booting with the swiotlb=262144 value, we get the following output : $ grep TLB /tmp/console.log [ 0.050908] kvm-guest: KVM setup pv remote TLB flush [ 0.308896] Last level iTLB entries: 4KB 512, 2MB 255, 4MB 127 [ 0.309494] Last level dTLB entries: 4KB 512, 2MB 255, 4MB 127, 1GB 0 [ 0.373162] HugeTLB registered 1.00 GiB page size, pre-allocated 0 pages [ 0.373162] HugeTLB registered 2.00 MiB page size, pre-allocated 0 pages [ 1.071136] PCI-DMA: Using software bounce buffering for IO (SWIOTLB) [ 1.071837] software IO TLB: mapped [mem 0x000000005bebe000-0x000000007bebe000] (512MB) [ 1.529804] software IO TLB: Memory encryption is active and system is using DMA bounce buffers For comparaison, the Fedora 34 kernel (5.15.4-101.fc34.x86_64) with the same adjustment mechanism does correctly adjust the SWIOTLB bounce buffer, without the need to set the swiotlb= value at boot time. The SWIOTLB buffer adjustment has been introduced in kernel 5.11. We can make SEV enabled resources available for testing if needed. ...Louis + --- + ProblemType: Bug + AlsaDevices: + total 0 + crw-rw---- 1 root audio 116, 1 Dec 23 13:32 seq + crw-rw---- 1 root audio 116, 33 Dec 23 13:32 timer + AplayDevices: Error: [Errno 2] No such file or directory: 'aplay' + ApportVersion: 2.20.11-0ubuntu74 + Architecture: amd64 + ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord' + AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: + CRDA: N/A + CasperMD5CheckResult: unknown + DistroRelease: Ubuntu 22.04 + IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig' + Lsusb: Error: command ['lsusb'] failed with exit code 1: + Lsusb-t: + + Lsusb-v: Error: command ['lsusb', '-v'] failed with exit code 1: + MachineType: Scaleway SCW-ENT1-S + Package: linux (not installed) + PciMultimedia: + + ProcEnviron: + TERM=screen + PATH=(custom, no user) + XDG_RUNTIME_DIR=<set> + LANG=C.UTF-8 + SHELL=/bin/bash + ProcFB: + + ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.13.0-23-generic root=UUID=1f577236-6bf2-48ef-998a-ba45f71aca7f ro console=tty1 console=ttyS0 swiotlb=262144 + ProcVersionSignature: Ubuntu 5.13.0-23.23-generic 5.13.19 + RelatedPackageVersions: + linux-restricted-modules-5.13.0-23-generic N/A + linux-backports-modules-5.13.0-23-generic N/A + linux-firmware N/A + RfKill: Error: [Errno 2] No such file or directory: 'rfkill' + Tags: jammy uec-images + Uname: Linux 5.13.0-23-generic x86_64 + UpgradeStatus: No upgrade log present (probably fresh install) + UserGroups: N/A + _MarkForUpload: True + dmi.bios.date: 02/06/2015 + dmi.bios.release: 0.0 + dmi.bios.vendor: EFI Development Kit II / OVMF + dmi.bios.version: 0.0.0 + dmi.chassis.type: 1 + dmi.chassis.vendor: QEMU + dmi.chassis.version: pc-q35-3.0 + dmi.modalias: dmi:bvnEFIDevelopmentKitII/OVMF:bvr0.0.0:bd02/06/2015:br0.0:svnScaleway:pnSCW-ENT1-S:pvrpc-q35-3.0:cvnQEMU:ct1:cvrpc-q35-3.0:sku: + dmi.product.name: SCW-ENT1-S + dmi.product.version: pc-q35-3.0 + dmi.sys.vendor: Scaleway -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1955655 Title: kernel-5.13.0-23-generic : Unable to boot when Secure Encrypted Virtualization( SEV) is enabled without setting swiotlb boot param To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1955655/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
