https://bugzilla.kernel.org/show_bug.cgi?id=98741 Bug ID: 98741 Summary: Cannot boot into kvm guest with kernel >= 3.18.x on el6.6 qemu-kvm host with virtio-blk-pci.x-data-plane=on and virtio-blk-pci.ioeventfd=on Product: Virtualization Version: unspecified Kernel Version: 3.18.x, 3.19.x, 4.0.x Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: kvm Assignee: virtualization_kvm@xxxxxxxxxxxxxxxxxxxx Reporter: jaroslav.pulchart@xxxxxxxxxxxx Regression: No Hello, I'm experiencing problem with latest kernel during testing of new features in virtual guests running at EL6.6 host in KVM with Virtio PV drivers and enabled datapalane (virtio-blk-pci.x-data-plane=on) feature to provide best IO performance. The issue cause that qemu-kvm process is stopped during quest boot. Host log: ---------------------------------- qemu-kvm: /builddir/build/BUILD/qemu-kvm-0.12.1.2/hw/msix.c:645: msix_set_mask_notifier: Assertion `!dev->msix_mask_notifier' failed. 2015-05-18 08:45:48.102+0000: shutting down ----------------------------------- Guest log: ----------------------------------- ... initcall virtio_pci_driver_init+0x0/0x1000 [virtio_pci] returned 0 after 82556 usecs calling ata_init+0x0/0x5d [libata] @ 204 libata version 3.00 loaded. initcall ata_init+0x0/0x5d [libata] returned 0 after 11641 usecs [drm:drm_framebuffer_reference] ffff8800da0c5ea0: FB ID: 21 (2) [drm:drm_framebuffer_unreference] ffff8800da0c5ea0: FB ID: 21 (3) calling ata_generic_pci_driver_init+0x0/0x1000 [ata_generic] @ 204 initcall ata_generic_pci_driver_init+0x0/0x1000 [ata_generic] returned 0 after 146 usecs calling init+0x0/0x1000 [virtio_blk] @ 250 virtio-pci 0000:00:04.0: irq 24 for MSI/MSI-X virtio-pci 0000:00:04.0: irq 25 for MSI/MSI-X ... <<END>> ... ----------------------------------- * Reproducible with this setup: Quest kernel versions: kernel 3.18, 3.19, 4.0 qemu-kvm: virtio-blk-pci.x-data-plane=on, virtio-blk-pci.ioeventfd=on * Not reproducible: Quest kernel versions: kernel 3.17 or older * Not reproducible: Quest kernel versions: kernel 3.18, 3.19, 4.0 qemu-kvm: virtio-blk-pci.x-data-plane=on + virtio-blk-pci.ioeventfd=off virtio-blk-pci.x-data-plane=off + virtio-blk-pci.ioeventfd=on I found this: 1/ "shutting down" is triggered by reentrancy into of qemu's "virtio_blk_data_plane_start()" function (see RedHat's bug #1222574), 2/ commits which introduced this issue are virtio_blk: enable VQs early on restore (6d62c37f1991aafc872f8d8be8ac60e57ede8605) virtio_net: enable VQs early on restore (e53fbd11e983e896adaabef2d2f1695d6e0af829) virtio_blk: enable VQs early (7a11370e5e6c26566904bb7f08281093a3002ff2) virtio_net: enable VQs early (4baf1e33d0842c9673fef4af207d4b74da8d0126) found by deep drive into git history of virtio drivers and several rebuilds with commits reverts (from 3.17->3.18) kernel 3.18.x build with reverted mentioned commits can successfully boot and run without issues. Best regards, Jaroslav -- You are receiving this mail because: You are watching the assignee of the bug. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
