target/i386: kvm: initialize feature MSRs very early

target/i386: kvm: initialize feature MSRs very early

Some read-only MSRs affect the behavior of ioctls such as
KVM_SET_NESTED_STATE.  We can initialize them once and for all
right after the CPU is realized, since they will never be modified
by the guest.

Reported-by: Qingua Cheng <qcheng@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1579544504-3616-2-git-send-email-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 420ae1fc51c99abfd03b1c590f55617edd2a2bed)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>