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