64 bit host on 32 bit guest.

[harisund]

Here are the relevant details -

Laptop: Lenovo Ideapad Y510
Processor: Intel Pentium Dual CPU T2330 @ 1.6 (As reported by BIOS)
Bios: AMIBIOS 06CN29WW
Host: Windows XP 32 bit
VBox version: 2.1.4
By default, the "Enable VT-x / AMD-v" option is grayed out.

I know I can run 64 bit operating systems on this laptop. I tried F10-x86_64-Live.iso and it worked.

If I am understanding the manual correctly, I need to be able to check the above option (hardware virtualization?) before I can run a 64 bit guest on a 32 bit host with this processor, and that by default it is disabled in the BIOS. My BIOS shows me no option to enable hardware virtualization or anything like that.

Does that mean the only way I can run 64 bit guests on my laptop is to install a 64 bit host in the first place? Is there no work around?

Anyone with similar experience?

[TerryE]

Read the Forum FAQ or the manual on this. It is a tediously common Q. You need H/W virtualisation support to run 64bit OSs under VBox. I was reading a recent PC review of Intel 64 bit chips ad only about half of them support VT-x. The wiki article will tell you if yours does, but the low end ones like yours tend not to. There is no workaround that I know of.

[galitz]

You should also check the Lenovo forums. Some notebook vendors, Lenovo and HP among them, do support VT-x/AMD-V but don't supply BIOS options. Other folks in the Lenovo forums can tell you if they have actually run 64bit guests on 32bit hosts. There is no substituion for asking to see if people with the same hardware have actually done it. I'm inclined to think that you can do it so long as you have a VT-x capable processor configuration.

[CaptainFlint]

Unfortunately, T2330 does not have VT-x:
http://ark.intel.com/cpu.aspx?groupId=32432
So, it is impossible to run 64-bit guests on this laptop.

[Sasquatch]

Unfortunately, T2330 does not have VT-x:
http://ark.intel.com/cpu.aspx?groupId=32432
So, it is impossible to run 64-bit guests on this laptop.

That CPU isn't even 64 bit. You need a 64 bit CPU at least before you can run 64 bit Guests. It's not required to actually run a 64 bit Host now.

[CaptainFlint]

That CPU isn't even 64 bit.

What do you mean? The link I gave tells:
Intel® 64 Architecture
Besides, harisund wrote in the first post that he was able to boot 64-bit OS as a host. So, the CPU is 64-bit, but just without hardware virtualization.

[TerryE]

I think that Sasquatch was referring to the

• Intel® Virtualization Technology - X

and that it isn't a full 64-bit architecture. Apart from a few low end Semperons, the rest of the AMD64 CPUs support H/W virtualisation. This isn't the case with Intel where about half of the models don't.

[Sasquatch]

That CPU isn't even 64 bit.

What do you mean? The link I gave tells:
Intel® 64 Architecture
Besides, harisund wrote in the first post that he was able to boot 64-bit OS as a host. So, the CPU is 64-bit, but just without hardware virtualization.

My bad. I have the T2300, and that has VT-x, but no 64-bit extension. The T2330 is just the other way around, 64 bit capable, just no VT-x. I thought that only Core2 was 64 bit enabled. Intel kinda sucks with their names. If it would be AMD, you would know for certain that it's 64 bit capable, just not if it's AMD-V enabled.

[harisund]

Thanks for your replies guys

You have clarified every question I had.

[Sasquatch]

Just use grep.
grep * /proc/cpuinfo
Anything particular to 64bit word length?

Why ask for this? We already concluded that the CPU has 64 bit options, but no VT-x that is needed for 64 bit guests. See http://processorfinder.intel.com/detail ... Spec=SLA4K for the CPU info.

[TerryE]

Mr Biscuit, truly amazing. We never knew about /proc/cpuinfo — or the fact that on an Intel architecture it doesn't tell you whether your CPU is VT-x enabled. But the Wiki articles and the Intel datasheet that Sasquatch reference do.

[Sasquatch]

Mr-Biscuit, in addition to TerryE, here is the info of my laptop processor. Note that it is a T2300, not the E version. So I should have VT-x, right? Well, think again.

Code: Select all

processor	: 0
vendor_id	: GenuineIntel
cpu family	: 6
model		: 14
model name	: Genuine Intel(R) CPU           T2300  @ 1.66GHz
stepping	: 8
cpu MHz		: 1000.000
cache size	: 2048 KB
physical id	: 0
siblings	: 2
core id		: 0
cpu cores	: 2
apicid		: 0
initial apicid	: 0
fdiv_bug	: no
hlt_bug		: no
f00f_bug	: no
coma_bug	: no
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 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc arch_perfmon bts pni monitor est tm2 xtpr pdcm
bogomips	: 3324.67
clflush size	: 64
power management:

processor	: 1
vendor_id	: GenuineIntel
cpu family	: 6
model		: 14
model name	: Genuine Intel(R) CPU           T2300  @ 1.66GHz
stepping	: 8
cpu MHz		: 1000.000
cache size	: 2048 KB
physical id	: 0
siblings	: 2
core id		: 1
cpu cores	: 2
apicid		: 1
initial apicid	: 1
fdiv_bug	: no
hlt_bug		: no
f00f_bug	: no
coma_bug	: no
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 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx constant_tsc arch_perfmon bts pni monitor est tm2 xtpr pdcm
bogomips	: 3324.82
clflush size	: 64
power management:

[Sasquatch]

egrep '(vmx|svm)' /proc/cpuinfo


Always look for the flags.

Always simplify the process for the user instead of making them search.

If you use these tools, you don't need wikipedia.

You don't get it. If the system doesn't show these flags, while the processor is actually capable of it, it usually means that it's disabled in the BIOS. Instead of saying "you can't use hardware virtualization with your CPU", a better reply like "check your BIOS for an option, the CPU is capable but not detected by the OS".

[TerryE]

Always simplify the process for the user instead of making them search.

+1 but in this case the tool that you recommend doesn't give the answer that you suggest. //Terry

[rewolff]

May I try to suggest an enhancement for VirtualBox here?

It took me over an hour to figure this out. I google for "64 bit guest on 32 bit host" (it's among the suggestions once you start typing "virtualbox 64") and get lots of: "Now 64 bit guests supported on 32 bit hosts". Next, I try to boot, and it gives me: "your CPU is not 64-bit capable".

So... I search some more, and I have to enable a certain configuration thingy... OK. try and find the configuration thingy, which turns out not to be named: "Intel Virutalization technology" in the menu but VT-x.

But the menu item is grayed out.

Google some more, and I find you can turn this on and off in the bios. Now I reboot about two or three days a year, and I keep my desktop the way I like it, with lots of window ready-to-use. So I go into the bios, but I can't find it...

So I boot my Linux, and google some more.... So I find this thread where "the wiki" says which processors have VT-x. Which page of which wiki???? Anyway, I found the Intel page for my processor, and I don't have VT-X.

It would be VERY useful if VirtualBox would detect that it can't use VT-X (it already does: it grays out the option) and then has a little piece of code that would look through /proc/cpuinfo and search for the flag it needs. If present: print: "You CPU seems to support VT-x, but I can't enable it. Maybe you disabled this in the BIOS?" If not present: "Your CPU doesn't support virtualization required for 64-bit guests".