MCX_CMDQ_MAILBOX_SIZE
nmb * MCX_CMDQ_MAILBOX_SIZE, MCX_CMDQ_MAILBOX_ALIGN);
dva += MCX_CMDQ_MAILBOX_SIZE;
kva += MCX_CMDQ_MAILBOX_SIZE;
kva += MCX_CMDQ_MAILBOX_SIZE;
kva += i * MCX_CMDQ_MAILBOX_SIZE;