Public bug reported:

Environment:
  Distribution: Ubuntu Plucky
  Platform: SNP-enabled QEMU guest
  Kernel: 6.14.0-27-generic

Issue: 
  Guest attestation functionality is broken due to the absence of the sev-guest 
kernel module in the kernel package. This prevents proper operation of SNP 
(Secure Nested Paging) attestation features within Ubuntu Plucky guests running 
on SNP-enabled QEMU.

Impact:

 Guest attestation process fails completely
 SNP security features are non-functional
 Tools like virtee/snpguest cannot perform attestation operations on Ubuntu 
Plucky Release


Error Details:

We observe the following issue during generation of SNP guest report on
QEMU guest using virtee/snpguest tool:

root@localhost:~# snpguest report attestation-report.bin 
random-request-data.txt --random
ERROR: unable to open /dev/sev-guest
because: No such file or directory (os error 2)


When attempting to manually load the sev-guest module on QEMU guest, we see the 
following issue:
root@localhost:~# modprobe sev-guest
modprobe: FATAL: Module sev-guest not found in directory 
/lib/modules/6.14.0-27-generic

Expected Behavior: The sev-guest kernel module should be included in the
kernel package and available for loading to enable proper SNP guest
attestation functionality.

Actual Behavior: The sev-guest module is missing from the kernel/kernel
module package, preventing SNP attestation features from working.

QEMU CLI used for SNP Guest(Ubuntu Plucky version) launch:

 qemu-system-x86_64 \
  -enable-kvm \
  -cpu EPYC-v4 \
  -nographic  \
  -machine memory-encryption=sev0 \
  -object memory-backend-memfd,id=ram1,size=4096M \
  -machine memory-backend=ram1 \
  -object sev-snp-guest,id=sev0,cbitpos=51,reduced-phys-bits=1,kernel-hashes=on 
\
  -bios OVMF.amdsev.fd \
  -kernel guest-ubuntu-plucky.efi

virtee/snpguest tool link: 
  https://github.com/virtee/snpguest.git
Regular SNP Guest Attestation Process Link:
  
https://github.com/virtee/snpguest/tree/main?tab=readme-ov-file#regular-attestation-flowchart

ProblemType: Bug
DistroRelease: Ubuntu 25.04
Package: linux-modules-6.14.0-27-generic 6.14.0-27.27
ProcVersionSignature: Ubuntu 6.14.0-27.27-generic 6.14.6
Uname: Linux 6.14.0-27-generic x86_64
AlsaDevices:
 total 0
 crw-rw---- 1 root audio 116,  1 Jul 30 18:36 seq
 crw-rw---- 1 root audio 116, 33 Jul 30 18:36 timer
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.32.0-0ubuntu5.3
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
AudioDevicesInUse: Error: [Errno 2] No such file or directory: 'fuser'
CRDA: N/A
CasperMD5CheckResult: unknown
Date: Wed Jul 30 18:52:33 2025
Dependencies:
 
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: QEMU Standard PC (i440FX + PIIX, 1996)
PciMultimedia:
 
ProcEnviron:
 PATH=(custom, no user)
 SHELL=/bin/bash
 TERM=vt220
ProcFB: 0 simpledrmdrmfb
ProcKernelCmdLine: console=ttyS0
RelatedPackageVersions:
 linux-restricted-modules-6.14.0-27-generic N/A
 linux-backports-modules-6.14.0-27-generic  N/A
 linux-firmware                             N/A
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 11/17/2024
dmi.bios.release: 0.0
dmi.bios.vendor: EDK II
dmi.bios.version: edk2-20241117-5.fc41
dmi.chassis.type: 1
dmi.chassis.vendor: QEMU
dmi.chassis.version: pc-i440fx-9.1
dmi.modalias: 
dmi:bvnEDKII:bvredk2-20241117-5.fc41:bd11/17/2024:br0.0:svnQEMU:pnStandardPC(i440FX+PIIX,1996):pvrpc-i440fx-9.1:cvnQEMU:ct1:cvrpc-i440fx-9.1:sku:
dmi.product.name: Standard PC (i440FX + PIIX, 1996)
dmi.product.version: pc-i440fx-9.1
dmi.sys.vendor: QEMU

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: amd64 apport-bug plucky

** Attachment added: "sev-guest-module-issue-ubuntu-plucky.pdf"
   
https://bugs.launchpad.net/bugs/2119148/+attachment/5894900/+files/sev-guest-module-issue-ubuntu-plucky.pdf

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https://bugs.launchpad.net/bugs/2119148

Title:
  sev-guest kernel module not included in kernel package for SNP QEMU
  guests

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