Function pmap_init

freebsd/amd64/amd64/pmap.c:2303–2452

* Initialize the pmap module. * Called by vm_init, to initialize any structures that the pmap * system needs to map virtual memory. */

 *	system needs to map virtual memory.
 */
void
pmap_init(void)
{
	struct pmap_preinit_mapping *ppim;
	vm_page_t m, mpte;
	int error, i, ret, skz63;

	/* L1TF, reserve page @0 unconditionally */
	vm_page_blacklist_add(0, bootverbose);

	/* Detect bare-metal Skylake Server and Skylake-X. */
	if (vm_guest == VM_GUEST_NO && cpu_vendor_id == CPU_VENDOR_INTEL &&
	    CPUID_TO_FAMILY(cpu_id) == 0x6 && CPUID_TO_MODEL(cpu_id) == 0x55) {
		/*
		 * Skylake-X errata SKZ63. Processor May Hang When
		 * Executing Code In an HLE Transaction Region between
		 * 40000000H and 403FFFFFH.
		 *
		 * Mark the pages in the range as preallocated.  It
		 * seems to be impossible to distinguish between
		 * Skylake Server and Skylake X.
		 */
		skz63 = 1;
		TUNABLE_INT_FETCH("hw.skz63_enable", &skz63);
		if (skz63 != 0) {
			if (bootverbose)
				printf("SKZ63: skipping 4M RAM starting "
				    "at physical 1G\n");
			for (i = 0; i < atop(0x400000); i++) {
				ret = vm_page_blacklist_add(0x40000000 +
				    ptoa(i), FALSE);
				if (!ret && bootverbose)
					printf("page at %#lx already used\n",
					    0x40000000 + ptoa(i));
			}
		}
	}

	/* IFU */
	pmap_allow_2m_x_ept_recalculate();

	/*
	 * Initialize the vm page array entries for the kernel pmap's
	 * page table pages.
	 */ 
	PMAP_LOCK(kernel_pmap);
	for (i = 0; i < nkpt; i++) {
		mpte = PHYS_TO_VM_PAGE(KPTphys + (i << PAGE_SHIFT));
		KASSERT(mpte >= vm_page_array &&
		    mpte < &vm_page_array[vm_page_array_size],
		    ("pmap_init: page table page is out of range"));
		mpte->pindex = pmap_pde_pindex(KERNBASE) + i;
		mpte->phys_addr = KPTphys + (i << PAGE_SHIFT);
		mpte->ref_count = 1;

		/*
		 * Collect the page table pages that were replaced by a 2MB
		 * page in create_pagetables().  They are zero filled.