Comment 0 for bug 2019108

On an openstack KVM guest VM the following kernel message is displayed: "XSAVE consistency problem: size 2560 != kernel_size 0" (see further traces collected through "ubuntu-bug linux" command)

As a result, the avx feature isn't enabled in the kernel, failing some programs that require it (e.g mongodb requires avx instruction set).

This problem reproduces on 23.04 Lua kernel (6.2.0-20), 22.04 Jammy HWE kernel (5.19.0-35) but not on Jammy GA kernel (5.15.0-71.78).

I'm suspecting a kernel regression since v>5.15 that would be more strict with possibly QEMU emulated XSAVE CPUID features.

Related yet unanswered support question: https://askubuntu.com/questions/1467238/xsave-consistency-problem-preventing-avx-on-kvm-guests-running-jammy-hwe

This looks similar to the following kernel thread https://<email address hidden>/T/

Although I don't yet have access to the KVM hypervisor host, I'd like to know if there is a possible workaround by fixing KVM/QEMU configuration possibly enabling XSAVEC in addition to XSAVES feature in the KVM guest, for upgrading KVM/QEMU version.

Full diagnostics performed so far at https://github.com/orange-cloudfoundry/paas-templates/issues/1960#issuecomment-1534484042

ProblemType: Bug
DistroRelease: Ubuntu 23.04
Package: linux-image-6.2.0-20-generic 6.2.0-20.20
ProcVersionSignature: Ubuntu 6.2.0-20.20-generic 6.2.6
Uname: Linux 6.2.0-20-generic x86_64
AlsaDevices:
 total 0
 crw-rw---- 1 root audio 116, 1 May 10 09:35 seq
 crw-rw---- 1 root audio 116, 33 May 10 09:35 timer
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.26.1-0ubuntu2
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
Date: Wed May 10 12:31:18 2023
IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
Lspci: Error: [Errno 2] No such file or directory: 'lspci'
Lspci-vt: Error: [Errno 2] No such file or directory: 'lspci'
Lsusb: Error: [Errno 2] No such file or directory: 'lsusb'
Lsusb-t: Error: [Errno 2] No such file or directory: 'lsusb'
Lsusb-v: Error: [Errno 2] No such file or directory: 'lsusb'
MachineType: OpenStack Foundation OpenStack Nova
PciMultimedia:

ProcFB: 0 cirrusdrmfb
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-6.2.0-20-generic root=UUID=03a4e7a1-715a-4ceb-8fa6-d86a817a7092 ro vconsole.keymap=us net.ifnames=0 biosdevname=0 crashkernel=auto selinux=0 plymouth.enable=0 console=ttyS0,115200n8 earlyprintk=ttyS0 rootdelay=300 ipv6.disable=1 audit=1 cgroup_enable=memory swapaccount=1 systemd.unified_cgroup_hierarchy=false quiet splash vt.handoff=7
RelatedPackageVersions:
 linux-restricted-modules-6.2.0-20-generic N/A
 linux-backports-modules-6.2.0-20-generic N/A
 linux-firmware 20230323.gitbcdcfbcf-0ubuntu1
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 04/01/2014
dmi.bios.release: 0.0
dmi.bios.vendor: SeaBIOS
dmi.bios.version: rel-1.10.2-0-g5f4c7b1-20181220_000000-szxrtosci10000
dmi.chassis.type: 1
dmi.chassis.vendor: QEMU
dmi.chassis.version: pc-i440fx-2.8
dmi.modalias: dmi:bvnSeaBIOS:bvrrel-1.10.2-0-g5f4c7b1-20181220_000000-szxrtosci10000:bd04/01/2014:br0.0:svnOpenStackFoundation:pnOpenStackNova:pvr13.2.1-20220808115737_bd245dd:cvnQEMU:ct1:cvrpc-i440fx-2.8:sku:
dmi.product.family: Virtual Machine
dmi.product.name: OpenStack Nova
dmi.product.version: 13.2.1-20220808115737_bd245dd
dmi.sys.vendor: OpenStack Foundation