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Bug 993388

Summary: devices behind an i82801b11-bridge are ignored
Product: Red Hat Enterprise Linux 7 Reporter: Laine Stump <laine>
Component: qemu-kvmAssignee: Gerd Hoffmann <kraxel>
Status: CLOSED CURRENTRELEASE QA Contact: Virtualization Bugs <virt-bugs>
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: 7.0CC: acathrow, hhuang, juli, juzhang, kraxel, rhod, shuang, sluo, virt-maint
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: qemu-kvm-1.5.3-1.el7 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2014-06-13 11:39:08 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 819968, 841379    
Attachments:
Description Flags
reproduce-bug-screenshot none

Description Laine Stump 2013-08-05 20:33:21 UTC 
When an i82801b11-bridge is added to a q35 virtual machine, and devices are placed behind it (e.g. virtio disks, but it's true for anything), those devices are not seen by the guest OS.

This was discovered as a part of testing libvirt patches to support q35, and Gerd Hoffman diagnosed the root cause and has already posted a patch to the qemu-devel mailing list:

  https://www.redhat.com/archives/libvir-list/2013-August/msg00165.html
  http://lists.nongnu.org/archive/html/qemu-devel/2013-08/msg00367.html

I am refraining from pushing the workaround patch to libvirt, anticipating that this patch will be pushed to upstream and RHEL7 qemu, so without this patch, q35 machinetypes created by libvirt will not be able to boot.
Comment 1 Gerd Hoffmann 2013-08-30 08:12:53 UTC 
Fix merged in upstream qemu 1.5.3.
Comment 4 Jun Li 2013-12-13 10:15:26 UTC 
Reproduce:
Version-Release number of selected component (if applicable):
qemu-kvm-1.5.1-2.el7.x86_64

<cli>:
# /usr/libexec/qemu-kvm -M q35 -cpu host -enable-kvm -m 4G -smp 4,sockets=2,cores=2,threads=1 -device virtio-scsi-pci,bus=pcie.0,addr=0x5,id=scsi0 -drive file=/home/juli/RHEL-7.0-20131127.1.qcow2,if=none,id=drive-scsi0-0-0,media=disk,cache=none,format=qcow2,werror=stop,rerror=stop,aio=native -device scsi-hd,drive=drive-scsi0-0-0,bus=scsi0.0,scsi-id=0,lun=0,id=juli,bootindex=1  -device ioh3420,bus=pcie.0,id=root.0 -device i82801b11-bridge,bus=root.0,id=bridge1 -device ich9-usb-uhci1,id=usb1,bus=bridge1,addr=0x1 -drive file=/home/juli/data_disk.qcow2_v3,if=none,id=drive-virtio-disk1,format=qcow2,cache=none,werror=stop,rerror=stop,aio=native -device virtio-blk-pci,scsi=on,bus=bridge1,addr=0x6,drive=drive-virtio-disk1,id=virtio-disk1  -netdev tap,id=hostnet0,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet0,mq=on,vectors=17,id=net0,mac=00:1a:4a:42:0b:38,bus=pcie.0 -spice port=5932,disable-ticketing -k en-us -vga qxl -global qxl-vga.vram_size=67108864 -monitor stdio -device virtio-balloon-pci,id=ballooning -qmp tcp:0:4445,server,nowait -global pvpanic.ioport=0x0505
----
(qemu) info status 
VM status: paused (guest-panicked)
---
Guest can not boot. The attachment is the screenshot of guest.
-----------------------------------
Verify this bug:
Version-Release number of selected component (if applicable):
qemu-kvm-1.5.3-21.el7.x86_64
---
<cli>:
# /usr/libexec/qemu-kvm -M q35 -cpu host -enable-kvm -m 4G -smp 4,sockets=2,cores=2,threads=1 -device virtio-scsi-pci,bus=pcie.0,addr=0x5,id=scsi0 -drive file=/home/juli/RHEL-7.0-20131127.1.qcow2,if=none,id=drive-scsi0-0-0,media=disk,cache=none,format=qcow2,werror=stop,rerror=stop,aio=native -device scsi-hd,drive=drive-scsi0-0-0,bus=scsi0.0,scsi-id=0,lun=0,id=juli,bootindex=1  -device ioh3420,bus=pcie.0,id=root.0 -device i82801b11-bridge,bus=root.0,id=bridge1 -device ich9-usb-uhci1,id=usb1,bus=bridge1,addr=0x1 -drive file=/home/juli/data_disk.qcow2_v3,if=none,id=drive-virtio-disk1,format=qcow2,cache=none,werror=stop,rerror=stop,aio=native -device virtio-blk-pci,scsi=on,bus=bridge1,addr=0x6,drive=drive-virtio-disk1,id=virtio-disk1  -netdev tap,id=hostnet0,vhost=on,script=/etc/qemu-ifup -device virtio-net-pci,netdev=hostnet0,mq=on,vectors=17,id=net0,mac=00:1a:4a:42:0b:38,bus=pcie.0 -spice port=5932,disable-ticketing -k en-us -vga qxl -global qxl-vga.vram_size=67108864 -monitor stdio -device virtio-balloon-pci,id=ballooning -qmp tcp:0:4445,server,nowait -global pvpanic.ioport=0x0505
---
# lspci
01:00.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 92)
02:01.0 USB controller: Intel Corporation 82801I (ICH9 Family) USB UHCI Controller #1 (rev 03)
02:06.0 SCSI storage controller: Red Hat, Inc Virtio block device
-------------------
As the above result, can find USB controller and Virtio block device in the guest. So this bug has been verified.
Comment 5 Jun Li 2013-12-13 10:16:35 UTC 
Created attachment 836273 [details]
reproduce-bug-screenshot
Comment 7 Ludek Smid 2014-06-13 11:39:08 UTC 
This request was resolved in Red Hat Enterprise Linux 7.0.

Contact your manager or support representative in case you have further questions about the request.