Bad interactions with kvm and vmware (CPU left in VMX root mode?)
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
kvm (Ubuntu) |
Confirmed
|
Undecided
|
Unassigned |
Bug Description
Binary package hint: kvm
This happens with the supplied Hardy kvm and the latest manually compiled kvm-66 kernel modules.
I can not boot my VMware virtual machine after the kvm and kvm_intel modules have been loaded. The system hard-crashes (Magic SysRq+B does not reboot the PC).
If I first start the VM and load the kvm and kvm_intel modules, it seems to work for a while. If I then do "kvm_intel" I get two capslock/scrolllock and SysRq+B also does not work here.
I can not get ANY logs from this using the standard procedures. They simply don't work. Nothing is written to the log.
I believe this happens because the CPU is left in VMX root mode. VirtualBox actually tells me to remove kvm and I suspect the problem is that VMware does not handle this exception, instead continuing and hard locking. But the root of the problem (no pun intended, of course!) happens to be in KVM leaving the CPU in VMX root mode.(?) http://
This is a terrible crash (upon reboot one time the 2nd port of my graphics card died until a frozen reboot). Also causes RAID reconstruction and data loss in home directory. SysRq+B does not even reboot the PC! Very difficult to debug, if not impossible with the stock kernel. Something needs to be done about this, in my opinion, because a lot of people who use VMware also want to experiment with kvm/qemu.
Oh, it also has the potential of destroying your virtual machine. The VMX file will almost certainly be wiped completely and the .vmem file has the potential of being corrupted. You'll be lucky if no data loss ensues.
Linux andy-desktop 2.6.24-16-generic #1 SMP Thu Apr 10 12:47:45 UTC 2008 x86_64 GNU/Linux
I am pretty sure I was able to reproduce this on a Hardy LiveCD as well.
From time to time I get this in dmesg, I don't know if it's related or not. Even without kvm loaded...:
[ 97.914251] VMBlock warning: DentryOpRevalidate: invalid args from kernel
[ 97.914460] VMBlock warning: DentryOpRevalidate: invalid args from kernel
[ 98.004492] VMBlock warning: DentryOpRevalidate: invalid args from kernel
[ 98.004675] VMBlock warning: DentryOpRevalidate: invalid args from kernel
[ 98.007695] VMBlock warning: DentryOpRevalidate: invalid args from kernel
[ 98.007842] VMBlock warning: DentryOpRevalidate: invalid args from kernel
description: | updated |
description: | updated |
Version Info:
Ubuntu Hardy, kernel linux-image- 2.6.24- 16-generic 2.6.24-16.30 (also happens with fresh 2.6.25 kernel I believe)
VMware Player 2.0.3 build-80004
kvm-66 (latest upstream) module, also happens with stock Hardy kvm in same fashion
$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Core(TM)2 CPU 6300 @ 1.86GHz
stepping : 6
cpu MHz : 1866.666
cache size : 2048 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr lahf_lm
bogomips : 3736.06
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management:
processor : 1
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Core(TM)2 CPU 6300 @ 1.86GHz
stepping : 6
cpu MHz : 1866.666
cache size : 2048 KB
physical id : 0
siblings : 2
core id : 1
cpu cores : 2
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr lahf_lm
bogomips : 3733.36
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management: