[Qemu-devel] [qemu-devel] Bug Report: VM crashed for some kinds of vCPU in nested virtualization

[李春奇]

Hi all,

In a nested virtualization environment of qemu+KVM, some emulated CPU (such as core2duo) may cause L2 guest crash after booting for a while. Here's my configuration:

Host:

Linux 3.5.7

Qemu is the latest version from git repository.

Emulated CPU : core2duo

L1 guest:

Linux 3.5.7

Qemu is the latest version from git

Emulated CPU : core2duo

L2 guest:

Crash at some specific point after running for sometime.

Here's the callback trace:

qemu-system-x86_64 -net nic,vlan=0,macaddr=00:26:b9:fa:fe:31 -net tap,vlan=0 -vnc :1 -hda vm1.1.img -m 512 -machine pc,accel=kvm -cpu core2duo -cdrom ubuntu-12.04.2-server-amd64.iso

TUNSETIFF: Device or resource busy

qemu-system-x86_64: pci_add_option_rom: failed to find romfile "efi-e1000.rom"

KVM: entry failed, hardware error 0x7

RAX=000000000000000f RBX=ffff88001f60c740 RCX=000000000000038f RDX=0000000000000007

RSI=000000000000000f RDI=000000000000038f RBP=ffff88001e6ffaf0 RSP=ffff88001e6ffaf0

R8 =000000070000000f R9 =0000000000000000 R10=0000000000000000 R11=0000000000000000

R12=0000000000000001 R13=0000000000000001 R14=0000000000000000 R15=ffff88001f617384

RIP=ffffffff8103fe1a RFL=00000002 [-------] CPL=0 II=0 A20=1 SMM=0 HLT=0

ES =0000 0000000000000000 000fffff 00000000

CS =0010 0000000000000000 ffffffff 00a09b00 DPL=0 CS64 [-RA]

SS =0018 0000000000000000 ffffffff 00c09300 DPL=0 DS   [-WA]

DS =0000 0000000000000000 000fffff 00000000

FS =0000 0000000000000000 000fffff 00000000

GS =0000 ffff88001f600000 000fffff 00000000

LDT=0000 0000000000000000 000fffff 00000000

TR =0040 ffff88001f611580 00002087 00008b00 DPL=0 TSS64-busy

GDT=     ffff88001f604000 0000007f

IDT=     ffffffff81dd6000 00000fff

CR0=8005003b CR2=00000000ffffffff CR3=0000000001c0b000 CR4=000007f0

DR0=0000000000000000 DR1=0000000000000000 DR2=0000000000000000 DR3=0000000000000000 

DR6=00000000ffff0ff0 DR7=0000000000000400

EFER=0000000000000d01

Code=20 89 f9 48 09 c8 5d c3 66 90 55 89 f0 89 f9 48 89 e5 0f 30 <31> c0 5d c3 66 90 55 89 f9 48 89 e5 0f 33 89 c7 48 89 d0 48 c1 e0 20 89 f9 48 09 c8 5d c3

This bug also appears in Westmere, SandyBridge and Haswell. But Nehalem, Penryn and Conroe runs OK.

Is this problem really a bug or some mistakes in configuration?

Thanks,

Arthur

--
Arthur Chunqi Li
Department of Computer Science
School of EECS
Peking University
Beijing, China