On Tue, Sep 6, 2011 at 3:15 PM, Nadav Har'El <n...@math.technion.ac.il>wrote:
> On Tue, Sep 06, 2011, Kfir Lavi wrote about "Nested VMX support in qemu and > kvm": > > Hi, > > Wow, I didn't expect to see a discussion about nested VMX in linux-il? > Any particular reason why you bring this up here, and not in the KVM > mailing list? > > > I'm trying to use a nested vm, but whatever I do, no vmx flag is in > > /proc/cpuinfo ? > > qemu-kvm -cpu host > > qemu-kvm -cpu host,+vmx > > qemu-kvm -cpu qemu64,+vmx > > As you can see in my original announcement, and also in > Documentation/virtual/kvm/nested-vmx.txt, nested VMX is still considered > experimental, and therefore must be enabled explictly not just in qemu > (which you did correctly) but also in the kernel module: you must load > the kvm-intel module as: > > insmod kvm-intel.ko nested=1 > > Since you didn't mention doing this, is it possible you forgot? > > If you get an error with the above insmod, it means you are using an old > version of KVM which didn't yet support nested VMX. Nested VMX was only > recently integrated with the main tree. > > > I'm running Gentoo with kernel 3.0.4 and > > I'm not sure what exactly 3.0.4 contains, but it might be too old to > contain nested VMX. Linux 3.0's cutoff date was already several months > ago, so I believe nested VMX only made it to Linux 3.1, not 3.0. > > Like I said, if insmod with "nested=1" fails, then you have too old > a module. You can get a newer kernel directly from the KVM repository. > > Yes you right, kernel linux-3.1-rc4 has this patch, and using the nested=1 parameter I'm able to use nested vmx. It is a really useful feature. (more info is in Documentation/virtual/kvm/nested-vmx.txt) Send my regards to the ppl in your team at IBM Hifa, Kfir > > I did saw some emails and patches on the net from Orit, Avi and Nadav > about > > nested vmx support, > > but it doesn't seems to work for me. > > After 11 (!) rounds of discussions spanning more than a year, Avi accepted > these patches and nested VMX is now part of the main KVM tree. So please > use the main KVM tree, not any of the old patches you find on the net, if > you can. > > Good luck, > Nadav. > > > -- > Nadav Har'El | Tuesday, Sep 6 2011, 7 Elul > 5771 > n...@math.technion.ac.il > |----------------------------------------- > Phone +972-523-790466, ICQ 13349191 |An egotist is a person of low taste, > more > http://nadav.harel.org.il |interested in himself than in me. >
