SMP trouble with Solaris 10u8 as guest on Ubuntu

SMP trouble with Solaris 10u8 as guest on Ubuntu

[Kaspar Schiess]

Hi folks,

We're running Solaris 10u8 64bit on Ubuntu/KVM. The Solaris guest feels 
sluggish when I assign it more than one VCPU. With a single VCPU things 
fly and everything works fine.

By feels sluggish I mean:
- occasional ssh freezes
- slow typing
- high system (spends its time doing kernel stuff)
- Sometimes hangs while booting

These symptoms ALL go away when I limit the VM to one VCPU.

Here are the versions I can confirm this with: (from apt-show-versions | 
egrep "kvm|qemu")

Host 1:
kvm/lucid uptodate 1:84+dfsg-0ubuntu16+0.12.3+noroms+0ubuntu9
qemu-common/lucid uptodate 0.12.3+noroms-0ubuntu9
qemu-kvm/lucid uptodate 0.12.3+noroms-0ubuntu9

Host 2:
kvm/karmic-updates uptodate 1:84+dfsg-0ubuntu16+0.11.0+0ubuntu6.3
qemu-kvm/karmic-updates uptodate 0.11.0-0ubuntu6.3

Old Bug? New Feature? Should I report this? Anyone seen this? Any 
suggestions?

Thanks in advance,
kaspar