** Description changed: + [ Impact ] + + * Certain configurations can crash qemu. + + * Fix is from upstream prevents a MemoryRegion from parenting itself + + [ Test Plan ] + Reproduction: 0) Install libvirtd and virt-manager 1) `sudo usermod -aG render libvirt-qemu` (not sure why that is not the default) 2) `sudo systemctl restart libvirtd` to apply ^ 3) Edit `/etc/libvirt/qemu.conf` to set `seccomp_sandbox = 0` (another packaging misconfiguration?) 4) Create Ubuntu VM using virt-manager with Virtio GPU and enable OpenGL acceleration in Spice display 5) Edit `<video>`'s model to be `<model type="virtio" heads="1" primary="yes" blob="on">` 6) Edit XML configuration like this: ``` <domain xmlns:qemu="http://libvirt.org/schemas/domain/qemu/1.0"; type="kvm"> ... <qemu:override> <qemu:device alias="video0"> <qemu:frontend> <qemu:property name="venus" type="bool" value="true"/> <qemu:property name="hostmem" type="unsigned" value="1073741824"/> </qemu:frontend> </qemu:device> </qemu:override> </domain> ``` With this not only OpenGL, but Vulkan acceleration should be working inside VM. Now boot VM (I used Ubuntu 24.04 as guest with Mesa 26.1.2 from https://launchpad.net/~kisak/+archive/ubuntu/kisak-mesa). Expectation: it works Reality: a) Black screen without steps 1, 2 and 3 above b) Once I log in into user session (with both Wayland and X11) QEMU on the host segfaults: ``` [ 8153.437312] qemu-system-x86[1913075]: segfault at 0 ip 00007f97b27aa3e2 sp 00007f97b190b448 error 4 in libc.so.6[1aa3e2,7f97b2628000+198000] likely on CPU 50 (core 18, socket 0) [ 8153.437324] Code: 1f 84 00 00 00 00 00 90 f3 0f 1e fa 89 f8 09 f0 c1 e0 14 3d 00 00 00 f8 0f 87 1a 03 00 00 62 e1 fe 28 6f 07 62 b2 7d 20 26 d0 <62> f1 7d 22 74 0e c5 fb 93 c9 ff c1 74 40 0f bc c9 0f b6 04 0f 0f ``` + + [ Where problems could occur ] + + * This is in the code for gpu in the virito/virtgl context and only + there. This is a reasonable, but rare setup. If we missed a regression + one should look for those components (virtgl and virti-gpu) in the bug + report to map it back to potentially be an issue cause by this. + + [ Other Info ] + + * n/a + + + ---- elements moved up e.g. the good test descriptions ---- + I have no idea what is going on there, but there seem to be multiple packaging and other issues with libvirt+QEMU in Ubuntu 26.04 right now. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: qemu-system-x86 1:10.2.1+ds-1ubuntu3 Uname: Linux 7.0.12-x64v3-xanmod1 x86_64 ApportVersion: 2.34.0-0ubuntu2 Architecture: amd64 CasperMD5CheckResult: unknown CurrentDesktop: Custom Date: Sun Jun 14 18:04:07 2026 MachineType: ASUS System Product Name ProcKernelCmdLine: BOOT_IMAGE=/root/boot/vmlinuz-7.0.12-x64v3-xanmod1 root=UUID=5170aca4-061a-4c6c-ab00-bd7fc8ae6030 ro rootflags=subvol=root nosplash amd_iommu=on intel_iommu=on libahci.ignore_sss=1 SourcePackage: qemu UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 07/18/2025 dmi.bios.release: 12.3 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 1203 dmi.board.asset.tag: Default string dmi.board.name: Pro WS TRX50-SAGE WIFI dmi.board.vendor: ASUSTeK COMPUTER INC. dmi.board.version: Rev 1.xx dmi.chassis.asset.tag: Default string dmi.chassis.type: 3 dmi.chassis.vendor: Default string dmi.chassis.version: Default string dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1203:bd07/18/2025:br12.3:svnASUS:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnProWSTRX50-SAGEWIFI:rvrRev1.xx:cvnDefaultstring:ct3:cvrDefaultstring:skuSKU:pfaTobefilledbyO.E.M.: dmi.product.family: To be filled by O.E.M. dmi.product.name: System Product Name dmi.product.sku: SKU dmi.product.version: System Version dmi.sys.vendor: ASUS
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2156706 Title: qemu-system-x86 crashes when `blob=true` is specified for virtio GPU To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/2156706/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
