KVM: VMX: introduce alloc_loaded_vmcs

KVM: VMX: introduce alloc_loaded_vmcs

Group together the calls to alloc_vmcs and loaded_vmcs_init.  Soon we'll also
allocate an MSR bitmap there.

Cc: stable@vger.kernel.org       # prereq for Spectre mitigation
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry-picked from f21f165ef922c2146cc5bdc620f542953c41714b)

Orabug: 28069548

Signed-off-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Brian Maly <brian.maly@oracle.com>
Conflicts:
    arch/x86/kvm/vmx.c
Contextual

Signed-off-by: Brian Maly <brian.maly@oracle.com>