[Qemu-devel] [Bug 1779120] [NEW] disk missing in the guest contingently when hotplug several virtio scsi disks consecutively

[Qemu-devel] [Bug 1779120] [NEW] disk missing in the guest contingently when hotplug several virtio scsi disks consecutively

[贞贵李]

Public bug reported:

Hi, I found a bug that disk missing (not all disks missing ) in the
guest contingently when hotplug several virtio scsi disks consecutively.
After rebooting the guest,the missing disks appear again.

The guest is centos7.3 running on a centos7.3 host and the scsi
controllers are configed with iothread.  The scsi controller xml is
below:

    <controller type='scsi' index='0' model='virtio-scsi'>
      <driver iothread='26'/>
      <alias name='scsi0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
    </controller>

If the scsi controllers are configed without iothread,  disks are all
can be seen in the guest when hotplug several virtio scsi disks
consecutively.

I think the biggest difference between them is that scsi controllers
with iothread call virtio_notify_irqfd to notify guest and scsi
controllers without iothread call virtio_notify instead.  What make it
difference? Will interrupts are lost when call virtio_notify_irqfd  due
to  race condition for some unknow reasons? Maybe guys more familiar
with scsi dataplane can help. Thanks for your reply!

** Affects: qemu
     Importance: Undecided
         Status: New

** Description changed:

  Hi, I found a bug that disk missing (not all disks missing ) in the
  guest contingently when hotplug several virtio scsi disks consecutively.
  After rebooting the guest,the missing disks appear again.
  
  The guest is centos7.3 running on a centos7.3 host and the scsi
  controllers are configed with iothread.  The scsi controller xml is
  below:
  
-     <controller type='scsi' index='0' model='virtio-scsi'>
-       <driver iothread='26'/>
-       <alias name='scsi0'/>
-       <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
-     </controller>
+     <controller type='scsi' index='0' model='virtio-scsi'>
+       <driver iothread='26'/>
+       <alias name='scsi0'/>
+       <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
+     </controller>
  
- 
- If the scsi controllers are configed without iothread,  disks are all can be seen in the guest when hotplug several virtio scsi disks consecutively.
+ If the scsi controllers are configed without iothread,  disks are all
+ can be seen in the guest when hotplug several virtio scsi disks
+ consecutively.
  
  I think the biggest difference between them is that scsi controllers
  with iothread call virtio_notify_irqfd to notify guest and scsi
- controllers without
- 
- iothread call virtio_notify instead.  What make it difference? Will
- interrupts are lost when call virtio_notify_irqfd  due to  race
- condition for some unknow reasons? Maybe guys more familiar with scsi
- dataplane can help. Thanks for your reply!
+ controllers without iothread call virtio_notify instead.  What make it
+ difference? Will interrupts are lost when call virtio_notify_irqfd  due
+ to  race condition for some unknow reasons? Maybe guys more familiar
+ with scsi dataplane can help. Thanks for your reply!

-- 
You received this bug notification because you are a member of qemu-
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https://bugs.launchpad.net/bugs/1779120

Title:
  disk missing in the guest contingently when hotplug several virtio
  scsi disks consecutively

Status in QEMU:
  New

Bug description:
  Hi, I found a bug that disk missing (not all disks missing ) in the
  guest contingently when hotplug several virtio scsi disks
  consecutively.  After rebooting the guest,the missing disks appear
  again.

  The guest is centos7.3 running on a centos7.3 host and the scsi
  controllers are configed with iothread.  The scsi controller xml is
  below:

      <controller type='scsi' index='0' model='virtio-scsi'>
        <driver iothread='26'/>
        <alias name='scsi0'/>
        <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
      </controller>

  If the scsi controllers are configed without iothread,  disks are all
  can be seen in the guest when hotplug several virtio scsi disks
  consecutively.

  I think the biggest difference between them is that scsi controllers
  with iothread call virtio_notify_irqfd to notify guest and scsi
  controllers without iothread call virtio_notify instead.  What make it
  difference? Will interrupts are lost when call virtio_notify_irqfd
  due to  race condition for some unknow reasons? Maybe guys more
  familiar with scsi dataplane can help. Thanks for your reply!

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1779120/+subscriptions

[Qemu-devel] [Bug 1779120] Re: disk missing in the guest contingently when hotplug several virtio scsi disks consecutively

[Stefan Hajnoczi]

Please post the following information:
(host)# rpm -qa | grep qemu-kvm
(guest)# uname -r

What are the exact steps to reproduce this issue (virsh command-lines
and XML)?

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1779120

Title:
  disk missing in the guest contingently when hotplug several virtio
  scsi disks consecutively

Status in QEMU:
  New

Bug description:
  Hi, I found a bug that disk missing (not all disks missing ) in the
  guest contingently when hotplug several virtio scsi disks
  consecutively.  After rebooting the guest,the missing disks appear
  again.

  The guest is centos7.3 running on a centos7.3 host and the scsi
  controllers are configed with iothread.  The scsi controller xml is
  below:

      <controller type='scsi' index='0' model='virtio-scsi'>
        <driver iothread='26'/>
        <alias name='scsi0'/>
        <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
      </controller>

  If the scsi controllers are configed without iothread,  disks are all
  can be seen in the guest when hotplug several virtio scsi disks
  consecutively.

  I think the biggest difference between them is that scsi controllers
  with iothread call virtio_notify_irqfd to notify guest and scsi
  controllers without iothread call virtio_notify instead.  What make it
  difference? Will interrupts are lost when call virtio_notify_irqfd
  due to  race condition for some unknow reasons? Maybe guys more
  familiar with scsi dataplane can help. Thanks for your reply!

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1779120/+subscriptions

[Qemu-devel] [Bug 1779120] Re: disk missing in the guest contingently when hotplug several virtio scsi disks consecutively

[Jie Wang]

I also met this bug

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devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1779120

Title:
  disk missing in the guest contingently when hotplug several virtio
  scsi disks consecutively

Status in QEMU:
  New

Bug description:
  Hi, I found a bug that disk missing (not all disks missing ) in the
  guest contingently when hotplug several virtio scsi disks
  consecutively.  After rebooting the guest,the missing disks appear
  again.

  The guest is centos7.3 running on a centos7.3 host and the scsi
  controllers are configed with iothread.  The scsi controller xml is
  below:

      <controller type='scsi' index='0' model='virtio-scsi'>
        <driver iothread='26'/>
        <alias name='scsi0'/>
        <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
      </controller>

  If the scsi controllers are configed without iothread,  disks are all
  can be seen in the guest when hotplug several virtio scsi disks
  consecutively.

  I think the biggest difference between them is that scsi controllers
  with iothread call virtio_notify_irqfd to notify guest and scsi
  controllers without iothread call virtio_notify instead.  What make it
  difference? Will interrupts are lost when call virtio_notify_irqfd
  due to  race condition for some unknow reasons? Maybe guys more
  familiar with scsi dataplane can help. Thanks for your reply!

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1779120/+subscriptions

Re: [Qemu-devel] [Bug 1779120] Re: disk missing in the guest contingently when hotplug several virtio scsi disks consecutively

[贞贵李]

Hi, Stefan.
(host)# rpm -qa | grep qemu-kvm
qemu-kvm-2.8.1-25.142.x86_64
(guest)# uname -r
3.10.0-514.el7.x86_64

I also tried the newest version of qemu-kvm, but it also met this issue.
The steps to reproduce this issue are below:

1)attach four virtio-scsi controller with dataplane to vm.
     <controller type='scsi' index='0' model='virtio-scsi'>
       <driver iothread='1'/>
       <alias name='scsi0'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x07' 
function='0x0'/>
     </controller>
     <controller type='scsi' index='1' model='virtio-scsi'>
       <driver iothread='2'/>
       <alias name='scsi1'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x0a' 
function='0x0'/>
     </controller>
     <controller type='scsi' index='2' model='virtio-scsi'>
       <driver iothread='3'/>
       <alias name='scsi2'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x0b' 
function='0x0'/>
     </controller>
     <controller type='scsi' index='3' model='virtio-scsi'>
       <driver iothread='4'/>
       <alias name='scsi3'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x0c' 
function='0x0'/>
     </controller>

2)attach 35 virtio-scsi disks(sda - sdai) to vm consecutively. One 
controller has 15 scsi disks.
A example of disk xml is below:
     <disk type='block' device='lun' rawio='yes'>
       <driver name='qemu' type='raw' cache='none' io='native'/>
       <source dev='/dev/mapper/360022a11000c1e0a0787bb2500000139'/>
       <backingStore/>
       <target dev='sda' bus='scsi'/>
       <shareable/>
       <alias name='scsi0-0-0-0'/>
       <address type='drive' controller='0' bus='0' target='0' unit='0'/>
     </disk>

    You can write a shell script like this:
        for((i=1;i++;i<=35))
        do
             virsh attach-device centos7.3_64_server scsi_disk_$i.xml 
--config --live
        done

This issue is a probabilistic event. If it does not appear, repeat the 
above steps several more times.
Thank you!

On 2018/6/28 21:01, Stefan Hajnoczi wrote:
> Please post the following information:
> (host)# rpm -qa | grep qemu-kvm
> (guest)# uname -r
>
> What are the exact steps to reproduce this issue (virsh command-lines
> and XML)?
>

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1779120

Title:
  disk missing in the guest contingently when hotplug several virtio
  scsi disks consecutively

Status in QEMU:
  New

Bug description:
  Hi, I found a bug that disk missing (not all disks missing ) in the
  guest contingently when hotplug several virtio scsi disks
  consecutively.  After rebooting the guest,the missing disks appear
  again.

  The guest is centos7.3 running on a centos7.3 host and the scsi
  controllers are configed with iothread.  The scsi controller xml is
  below:

      <controller type='scsi' index='0' model='virtio-scsi'>
        <driver iothread='26'/>
        <alias name='scsi0'/>
        <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
      </controller>

  If the scsi controllers are configed without iothread,  disks are all
  can be seen in the guest when hotplug several virtio scsi disks
  consecutively.

  I think the biggest difference between them is that scsi controllers
  with iothread call virtio_notify_irqfd to notify guest and scsi
  controllers without iothread call virtio_notify instead.  What make it
  difference? Will interrupts are lost when call virtio_notify_irqfd
  due to  race condition for some unknow reasons? Maybe guys more
  familiar with scsi dataplane can help. Thanks for your reply!

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1779120/+subscriptions

[Bug 1779120] Re: disk missing in the guest contingently when hotplug several virtio scsi disks consecutively

[Thomas Huth]

The QEMU project is currently considering to move its bug tracking to another system. For this we need to know which bugs are still valid and which could be closed already. Thus we are setting older bugs to "Incomplete" now.
If you still think this bug report here is valid, then please switch the state back to "New" within the next 60 days, otherwise this report will be marked as "Expired". Or mark it as "Fix Released" if the problem has been solved with a newer version of QEMU already. Thank you and sorry for the inconvenience.

** Changed in: qemu
       Status: New => Incomplete

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1779120

Title:
  disk missing in the guest contingently when hotplug several virtio
  scsi disks consecutively

Status in QEMU:
  Incomplete

Bug description:
  Hi, I found a bug that disk missing (not all disks missing ) in the
  guest contingently when hotplug several virtio scsi disks
  consecutively.  After rebooting the guest,the missing disks appear
  again.

  The guest is centos7.3 running on a centos7.3 host and the scsi
  controllers are configed with iothread.  The scsi controller xml is
  below:

      <controller type='scsi' index='0' model='virtio-scsi'>
        <driver iothread='26'/>
        <alias name='scsi0'/>
        <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
      </controller>

  If the scsi controllers are configed without iothread,  disks are all
  can be seen in the guest when hotplug several virtio scsi disks
  consecutively.

  I think the biggest difference between them is that scsi controllers
  with iothread call virtio_notify_irqfd to notify guest and scsi
  controllers without iothread call virtio_notify instead.  What make it
  difference? Will interrupts are lost when call virtio_notify_irqfd
  due to  race condition for some unknow reasons? Maybe guys more
  familiar with scsi dataplane can help. Thanks for your reply!

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1779120/+subscriptions

[Bug 1779120] Re: disk missing in the guest contingently when hotplug several virtio scsi disks consecutively

[Launchpad Bug Tracker]

[Expired for QEMU because there has been no activity for 60 days.]

** Changed in: qemu
       Status: Incomplete => Expired

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1779120

Title:
  disk missing in the guest contingently when hotplug several virtio
  scsi disks consecutively

Status in QEMU:
  Expired

Bug description:
  Hi, I found a bug that disk missing (not all disks missing ) in the
  guest contingently when hotplug several virtio scsi disks
  consecutively.  After rebooting the guest,the missing disks appear
  again.

  The guest is centos7.3 running on a centos7.3 host and the scsi
  controllers are configed with iothread.  The scsi controller xml is
  below:

      <controller type='scsi' index='0' model='virtio-scsi'>
        <driver iothread='26'/>
        <alias name='scsi0'/>
        <address type='pci' domain='0x0000' bus='0x00' slot='0x07' function='0x0'/>
      </controller>

  If the scsi controllers are configed without iothread,  disks are all
  can be seen in the guest when hotplug several virtio scsi disks
  consecutively.

  I think the biggest difference between them is that scsi controllers
  with iothread call virtio_notify_irqfd to notify guest and scsi
  controllers without iothread call virtio_notify instead.  What make it
  difference? Will interrupts are lost when call virtio_notify_irqfd
  due to  race condition for some unknow reasons? Maybe guys more
  familiar with scsi dataplane can help. Thanks for your reply!

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1779120/+subscriptions