On Wed, 2013-07-24 at 10:04 +0200, Massimiliano Adamo wrote:
> 
> On Tue, 2013-07-23 at 15:31 -0600, Alex Williamson wrote:
> > On Tue, 2013-07-23 at 23:11 +0200, Massimiliano Adamo wrote:
> > > All, 
> > > 
> > > this is a bug with KVM, impacting (at least) all mainstream kernels that
> > > I tried so far: 3.2, 3.3, 3.4, 3.5, 3.8, 3.10 and 3.11
> > > 
> > > This is the link of the downstream bug:
> > > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1201092
> > > 
> > > - Firt of all I mention that this bug has been raised also for Fedora
> > > 18.
> > > Here is the link: https://bugzilla.redhat.com/show_bug.cgi?id=978608
> > > 
> > > - I am running Ubuntu Raring (with the kernel 3.8.0-27-generic), but
> > > I've also tried the mainstream kernel (without Ubuntu patches).
> > > 
> > > - It happens with the following CPU: AMD E-350D
> > > 
> > > - The kvm-ok executable says that the system is capable of running KVM,
> > > but it also says the it's disabled in the BIOS.
> > > 
> > > - This is the out put of kvm-ok:
> > > # kvm-ok
> > > INFO: /dev/kvm does not exist
> > > HINT: sudo modprobe kvm_amd
> > > INFO: Your CPU supports KVM extensions
> > > INFO: KVM (svm) is disabled by your BIOS
> > > HINT: Enter your BIOS setup and enable Virtualization Technology (VT),
> > >       and then hard poweroff/poweron your system
> > > KVM acceleration can NOT be used
> > > 
> > > - This is what modprobe kvm-amd says:
> > > # modprobe kvm-amd
> > > ERROR: could not insert 'kvm_amd': Operation not supported
> > > root@yasna:~# dmesg |tail -n1
> > > [ 2542.263745] kvm: disabled by bios
> > > 
> > > - AMD-V extension on Virtualbox works correctly.
> > > Therefore the extension works properly but it's not recognized by KVM.
> > 
> > What evidence do you have that Virtualbox is actually making use of
> > AMD-V?
> > 
> 
> Hi! That's a good point. 
> Right now I can only say "it was selectable from the GUI". Therefore I
> just imagined "it's recognized".  
> Now I try to see how to enable/check logs on Virtualbox and I'll get
> back to you with some feedback.
> 


Hi,

logs are enabled by default and they say that the extension might be
disabled even for Virtualbox:

00:00:01.406771 SVM - AMD VM Extensions                = 0 (1)
00:00:01.406945 HWACCM: No VT-x or AMD-V CPU extension found. Reason
VERR_SVM_DISABLED

(therefore, it let's you enable the AMD-V feature, because it's found on
the CPU but it's not able to use it). 

And I've found a suggestion to run the commands below: 
# rdmsr -f 12:12 0xc0000080 # If set (1), SVME is enabled.
0
#
# rdmsr -f 4:4 0xc0010114 # If set (1), it is disabled.
1

If I will have time, I would try installing Windows on a spare
partition, and then try running virtualbox there (and check logs). 
If you have a better advice, or any other idea, please just let me
know. 

p.s.: CC-ing the person who is facing the same issue with Fedora.

--  
Massimiliano


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