This patch fixes an error booting 32bit vista on VMX.

This patch fixes an error booting 32bit vista on VMX.

The shadow code uses hvm_get_guest_ctrl_reg(v, 4) to test whether
PAE is enabled or not.  But it is not always right if the hypervisor
calls hvm_get_guest_ctrl_reg(v, 4) between vmxassist_invoke and
vmxassist_restore

The patch uses the d->arch.hvm_vmx.cpu_state to test if the PAE is
enabled.

Also update SVM code to use the new 'pae_enabled' hvm func.

Signed-off-by: Xiaohui Xin <xiaohui.xin@intel.com>
Signed-off-by: Steven Hand <steven@xensource.com>