Thanks Richard,
I have asked CentOS and qemu mailing list about this issue and waiting for their reply. 

 It is really strange that on CentOS 6.4 VM, atleast qemu was wokring but  in higher version "6.5" it is not working.





On Wed, Sep 17, 2014 at 8:57 PM, Richard W.M. Jones <rjones@redhat.com> wrote:
On Wed, Sep 17, 2014 at 08:52:57PM +0530, Priyanka Ranjan wrote:
> Many Thanks Richard for your reply.
>
> #  /usr/libexec/qemu-kvm -nographic -machine accel=kvm:tcg -device \?
>
> open /dev/kvm: No such file or directory
> failed to initialize KVM: Operation not permitted
> Back to tcg accelerator.
> Could not allocate dynamic translator buffer
>
> I tried executing "setsebool -P virt_use_execmem=on" also after looking at
>  "http://libguestfs.org/guestfs-faq.1.html"  but that also did not help.
> Please guide me how to fix this issue and proceed further.

That command is the way you're supposed to fix this problem.  If it
doesn't work then I don't know -- perhaps ask on a CentOS or qemu list,
or open a bug against CentOS?

Rich.

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