64-bit Ubuntu guest won't start - hardware acceleration "not operational"

[Andrew Schulman]

Host is 64-bit Ubuntu Maverick, guest is 64-bit Ubuntu Precise. The guest won't start, coming up with the dreaded error dialog:

VT-x/AMD-V hardware acceleration has been enabled, but is not operational.
Your 64-bit guest will fail to detect a 64-bit CPU and will not be able to boot.

Please ensure that you have enabled VT-x/AMD-V properly in the BIOS of your
host computer.

AMD-V is available in the CPU:

$ grep -c ' svm ' /proc/cpuinfo
3

and I've checked that it's enabled in the BIOS. Motherboard is a Gigabyte GA-MA790XT-UD4P, CPU is AMD Phenom II X3 720.

I'm attaching VBox.log. Note the following excerpts:

00:00:00.846 Mnemonic - Description                 = guest (host)
00:00:00.846 SVM - AMD VM Extensions                = 0 (1)

This seems to show that SVM is available in the host, but not the guest.

Virtualbox seems to claim that the error is because SVM is already in use:

00:00:00.962 HWACCM: No VT-x or AMD-V CPU extension found. Reason VERR_SVM_IN_USE

But AFAICT that's not the case. No KVM is installed, and lsmod confirms that none is loaded. I don't see any virtualization modules loaded apart from vboxdrv, vboxnet, etc.

[Klaus Espenlaub]

There must be something else marking SVM as in use. In the worst case it could be a buggy BIOS.

[Andrew Schulman]

The list of loaded modules is below. I don't believe there's anything there that would use SVM, except for vbox*. Is there any sure way to tell?

# lsmod | awk '{ print $1; }' | sort
Module
ac97_bus
aes_generic
aes_x86_64
ahci
binfmt_misc
crc_itu_t
cryptd
dm_crypt
edac_core
edac_mce_amd
firewire_core
firewire_ohci
gameport
hid
hwmon_vid
i2c_piix4
ip_tables
iptable_filter
it87
joydev
k10temp
libahci
lp
mii
nvidia
parport
parport_pc
pata_atiixp
pata_jmicron
pci_stub
ppdev
psmouse
r8169
reiserfs
serio_raw
sha256_generic
sky2
snd
snd_ac97_codec
snd_cs46xx
snd_hda_codec
snd_hda_codec_nvhdmi
snd_hda_intel
snd_hwdep
snd_page_alloc
snd_pcm
snd_rawmidi
snd_seq
snd_seq_device
snd_seq_midi
snd_seq_midi_event
snd_timer
soundcore
usb_storage
usbhid
usblp
uvesafb
vboxdrv
vboxnetadp
vboxnetflt
vboxpci
x_tables
xt_multiport

[Frank Mehnert]

Actually I have no idea. For some reason, bit 12 of MSR_EFER (0xc0000080) is set which is supposed to be clear. You could try a bad hack, doing

export VBOX_HWVIRTEX_IGNORE_SVM_IN_USE=1

before you start a VM would VirtualBox make ignore this bit and always enabled AMD-V but this could crash your host and this shouldn't be necessary.

I really think you should try to upgrade your BIOS, especially Gigabyte BIOSes are known for bugs like this.