kvm: nVMX: Enforce cpl=0 for VMX instructions

VMX instructions executed inside a L1 VM will always trigger a VM exit
even when executed with cpl 3. This means we must perform the
privilege check in software.

Fixes: 70f3aac964ae("kvm: nVMX: Remove superfluous VMX instruction fault checks")
Cc: stable@vger.kernel.org
Signed-off-by: Felix Wilhelm <fwilhelm@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
static __always_inline unsigned long vmcs_readl(unsigned long field)
{
	vmcs_checkl(field);
	if (static_branch_unlikely(&enable_evmcs))
		return evmcs_read64(field);
	return __vmcs_readl(field);
}

static __always_inline unsigned long vmcs_readl(unsigned long field)
{
	vmcs_checkl(field);
	if (static_branch_unlikely(&enable_evmcs))
		return evmcs_read64(field);
	return __vmcs_readl(field);
}
