1 // SPDX-License-Identifier: GPL-2.0
9  * For accesses by Xen a three-level tree linked via mfns only is set up to
22  * The p2m_top_mfn level is limited to 1 page, so the maximum representable
23  * pseudo-physical address space is:
27  * unsigned long (8 bytes on 64-bit, 4 bytes on 32), leading to
33  * leaf entries, or for the top  root, or middle one, for which there is a void
40  * We also have the possibility of setting 1-1 mappings on certain regions, so
44  * The benefit of this is, that we can assume for non-RAM regions (think
60  * non-identity pfn. To protect ourselves against we elect to set (and get) the
85 #include "xen-ops.h"
120  * Used to set HYPERVISOR_shared_info->arch.max_pfn so the toolstack
142 static void p2m_top_mfn_init(unsigned long *top)  in p2m_top_mfn_init()  argument
147 		top[i] = virt_to_mfn(p2m_mid_missing_mfn);  in p2m_top_mfn_init()
150 static void p2m_top_mfn_p_init(unsigned long **top)  in p2m_top_mfn_p_init()  argument
155 		top[i] = p2m_mid_missing_mfn;  in p2m_top_mfn_p_init()
211  * - At boot time we're called rather early, and must use alloc_bootmem*()
214  * - After resume we're called from within stop_machine, but the mfn
221 	unsigned int level, topidx, mididx;  in xen_build_mfn_list_list()  local
224 	if (xen_start_info->flags & SIF_VIRT_P2M_4TOOLS)  in xen_build_mfn_list_list()
227 	/* Pre-initialize p2m_top_mfn to be completely missing */  in xen_build_mfn_list_list()
249 				      &level);  in xen_build_mfn_list_list()
250 		BUG_ON(!ptep || level != PG_LEVEL_4K);  in xen_build_mfn_list_list()
252 		ptep = (pte_t *)((unsigned long)ptep & ~(PAGE_SIZE - 1));  in xen_build_mfn_list_list()
262 			pfn += (P2M_MID_PER_PAGE - 1) * P2M_PER_PAGE;  in xen_build_mfn_list_list()
282 	if (xen_start_info->flags & SIF_VIRT_P2M_4TOOLS)  in xen_setup_mfn_list_list()
283 		HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list = ~0UL;  in xen_setup_mfn_list_list()
285 		HYPERVISOR_shared_info->arch.pfn_to_mfn_frame_list_list =  in xen_setup_mfn_list_list()
287 	HYPERVISOR_shared_info->arch.max_pfn = xen_p2m_last_pfn;  in xen_setup_mfn_list_list()
288 	HYPERVISOR_shared_info->arch.p2m_generation = 0;  in xen_setup_mfn_list_list()
289 	HYPERVISOR_shared_info->arch.p2m_vaddr = (unsigned long)xen_p2m_addr;  in xen_setup_mfn_list_list()
290 	HYPERVISOR_shared_info->arch.p2m_cr3 =  in xen_setup_mfn_list_list()
294 /* Set up p2m_top to point to the domain-builder provided p2m pages */
299 	xen_p2m_addr = (unsigned long *)xen_start_info->mfn_list;  in xen_build_dynamic_phys_to_machine()
300 	xen_p2m_size = ALIGN(xen_start_info->nr_pages, P2M_PER_PAGE);  in xen_build_dynamic_phys_to_machine()
302 	for (pfn = xen_start_info->nr_pages; pfn < xen_p2m_size; pfn++)  in xen_build_dynamic_phys_to_machine()
358 		 * Try to map missing/identity PMDs or p2m-pages if possible.  in xen_rebuild_p2m_list()
367 		chunk = (pfn & (P2M_PER_PAGE * P2M_MID_PER_PAGE - 1)) ?  in xen_rebuild_p2m_list()
391 			/* Map complete missing or identity p2m-page. */  in xen_rebuild_p2m_list()
438 	unsigned int level;  in get_phys_to_machine()  local
447 	ptep = lookup_address((unsigned long)(xen_p2m_addr + pfn), &level);  in get_phys_to_machine()
448 	BUG_ON(!ptep || level != PG_LEVEL_4K);  in get_phys_to_machine()
473 	unsigned int level;  in alloc_p2m_pmd()  local
482 			for (i--; i >= 0; i--)  in alloc_p2m_pmd()
489 	vaddr = addr & ~(PMD_SIZE * PMDS_PER_MID_PAGE - 1);  in alloc_p2m_pmd()
500 		ptechk = lookup_address(vaddr, &level);  in alloc_p2m_pmd()
502 			HYPERVISOR_shared_info->arch.p2m_generation++;  in alloc_p2m_pmd()
507 			HYPERVISOR_shared_info->arch.p2m_generation++;  in alloc_p2m_pmd()
521 	return lookup_address(addr, &level);  in alloc_p2m_pmd()
526  * that both the top and mid levels are allocated, and make sure the
536 	unsigned int level;  in xen_alloc_p2m_entry()  local
541 	ptep = lookup_address(addr, &level);  in xen_alloc_p2m_entry()
542 	BUG_ON(!ptep || level != PG_LEVEL_4K);  in xen_alloc_p2m_entry()
543 	pte_pg = (pte_t *)((unsigned long)ptep & ~(PAGE_SIZE - 1));  in xen_alloc_p2m_entry()
546 		/* PMD level is missing, allocate a new one */  in xen_alloc_p2m_entry()
549 			return -ENOMEM;  in xen_alloc_p2m_entry()
560 			/* Separately check the mid mfn level */  in xen_alloc_p2m_entry()
567 				return -ENOMEM;  in xen_alloc_p2m_entry()
593 			return -ENOMEM;  in xen_alloc_p2m_entry()
598 			p2m_init_identity(p2m, pfn & ~(P2M_PER_PAGE - 1));  in xen_alloc_p2m_entry()
603 			HYPERVISOR_shared_info->arch.p2m_generation++;  in xen_alloc_p2m_entry()
608 			HYPERVISOR_shared_info->arch.p2m_generation++;  in xen_alloc_p2m_entry()
623 		HYPERVISOR_shared_info->arch.max_pfn = xen_p2m_last_pfn;  in xen_alloc_p2m_entry()
647 	return pfn - pfn_s;  in set_phys_range_identity()
653 	unsigned int level;  in __set_phys_to_machine()  local
667 	ptep = lookup_address((unsigned long)(xen_p2m_addr + pfn), &level);  in __set_phys_to_machine()
668 	BUG_ON(!ptep || level != PG_LEVEL_4K);  in __set_phys_to_machine()
730 			ret = -ENOMEM;  in set_foreign_p2m_mapping()
754 			ret = -EINVAL;  in clear_foreign_p2m_mapping()
787 			seq_printf(m, " [0x%lx->0x%lx] %s\n", first_pfn, pfn,  in p2m_dump_show()
793 	seq_printf(m, " [0x%lx->0x%lx] %s\n", first_pfn, pfn,  in p2m_dump_show()