// SPDX-License-Identifier: GPL-2.0 /* * Machine specific setup for xen * * Jeremy Fitzhardinge , XenSource Inc, 2007 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "xen-ops.h" #include "mmu.h" #define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024) /* Amount of extra memory space we add to the e820 ranges */ struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata; /* Number of pages released from the initial allocation. */ unsigned long xen_released_pages; /* E820 map used during setting up memory. */ static struct e820_table xen_e820_table __initdata; /* * Buffer used to remap identity mapped pages. We only need the virtual space. * The physical page behind this address is remapped as needed to different * buffer pages. */ #define REMAP_SIZE (P2M_PER_PAGE - 3) static struct { unsigned long next_area_mfn; unsigned long target_pfn; unsigned long size; unsigned long mfns[REMAP_SIZE]; } xen_remap_buf __initdata __aligned(PAGE_SIZE); static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY; /* * The maximum amount of extra memory compared to the base size. The * main scaling factor is the size of struct page. At extreme ratios * of base:extra, all the base memory can be filled with page * structures for the extra memory, leaving no space for anything * else. * * 10x seems like a reasonable balance between scaling flexibility and * leaving a practically usable system. */ #define EXTRA_MEM_RATIO (10) static bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB); static void __init xen_parse_512gb(void) { bool val = false; char *arg; arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit"); if (!arg) return; arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit="); if (!arg) val = true; else if (strtobool(arg + strlen("xen_512gb_limit="), &val)) return; xen_512gb_limit = val; } static void __init xen_add_extra_mem(unsigned long start_pfn, unsigned long n_pfns) { int i; /* * No need to check for zero size, should happen rarely and will only * write a new entry regarded to be unused due to zero size. */ for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { /* Add new region. */ if (xen_extra_mem[i].n_pfns == 0) { xen_extra_mem[i].start_pfn = start_pfn; xen_extra_mem[i].n_pfns = n_pfns; break; } /* Append to existing region. */ if (xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns == start_pfn) { xen_extra_mem[i].n_pfns += n_pfns; break; } } if (i == XEN_EXTRA_MEM_MAX_REGIONS) printk(KERN_WARNING "Warning: not enough extra memory regions\n"); memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns)); } static void __init xen_del_extra_mem(unsigned long start_pfn, unsigned long n_pfns) { int i; unsigned long start_r, size_r; for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { start_r = xen_extra_mem[i].start_pfn; size_r = xen_extra_mem[i].n_pfns; /* Start of region. */ if (start_r == start_pfn) { BUG_ON(n_pfns > size_r); xen_extra_mem[i].start_pfn += n_pfns; xen_extra_mem[i].n_pfns -= n_pfns; break; } /* End of region. */ if (start_r + size_r == start_pfn + n_pfns) { BUG_ON(n_pfns > size_r); xen_extra_mem[i].n_pfns -= n_pfns; break; } /* Mid of region. */ if (start_pfn > start_r && start_pfn < start_r + size_r) { BUG_ON(start_pfn + n_pfns > start_r + size_r); xen_extra_mem[i].n_pfns = start_pfn - start_r; /* Calling memblock_reserve() again is okay. */ xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r - (start_pfn + n_pfns)); break; } } memblock_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns)); } /* * Called during boot before the p2m list can take entries beyond the * hypervisor supplied p2m list. Entries in extra mem are to be regarded as * invalid. */ unsigned long __ref xen_chk_extra_mem(unsigned long pfn) { int i; for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { if (pfn >= xen_extra_mem[i].start_pfn && pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns) return INVALID_P2M_ENTRY; } return IDENTITY_FRAME(pfn); } /* * Mark all pfns of extra mem as invalid in p2m list. */ void __init xen_inv_extra_mem(void) { unsigned long pfn, pfn_s, pfn_e; int i; for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { if (!xen_extra_mem[i].n_pfns) continue; pfn_s = xen_extra_mem[i].start_pfn; pfn_e = pfn_s + xen_extra_mem[i].n_pfns; for (pfn = pfn_s; pfn < pfn_e; pfn++) set_phys_to_machine(pfn, INVALID_P2M_ENTRY); } } /* * Finds the next RAM pfn available in the E820 map after min_pfn. * This function updates min_pfn with the pfn found and returns * the size of that range or zero if not found. */ static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn) { const struct e820_entry *entry = xen_e820_table.entries; unsigned int i; unsigned long done = 0; for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { unsigned long s_pfn; unsigned long e_pfn; if (entry->type != E820_TYPE_RAM) continue; e_pfn = PFN_DOWN(entry->addr + entry->size); /* We only care about E820 after this */ if (e_pfn <= *min_pfn) continue; s_pfn = PFN_UP(entry->addr); /* If min_pfn falls within the E820 entry, we want to start * at the min_pfn PFN. */ if (s_pfn <= *min_pfn) { done = e_pfn - *min_pfn; } else { done = e_pfn - s_pfn; *min_pfn = s_pfn; } break; } return done; } static int __init xen_free_mfn(unsigned long mfn) { struct xen_memory_reservation reservation = { .address_bits = 0, .extent_order = 0, .domid = DOMID_SELF }; set_xen_guest_handle(reservation.extent_start, &mfn); reservation.nr_extents = 1; return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation); } /* * This releases a chunk of memory and then does the identity map. It's used * as a fallback if the remapping fails. */ static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages) { unsigned long pfn, end; int ret; WARN_ON(start_pfn > end_pfn); /* Release pages first. */ end = min(end_pfn, nr_pages); for (pfn = start_pfn; pfn < end; pfn++) { unsigned long mfn = pfn_to_mfn(pfn); /* Make sure pfn exists to start with */ if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn) continue; ret = xen_free_mfn(mfn); WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret); if (ret == 1) { xen_released_pages++; if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY)) break; } else break; } set_phys_range_identity(start_pfn, end_pfn); } /* * Helper function to update the p2m and m2p tables and kernel mapping. */ static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn) { struct mmu_update update = { .ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE, .val = pfn }; /* Update p2m */ if (!set_phys_to_machine(pfn, mfn)) { WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n", pfn, mfn); BUG(); } /* Update m2p */ if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) { WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n", mfn, pfn); BUG(); } /* Update kernel mapping, but not for highmem. */ if (pfn >= PFN_UP(__pa(high_memory - 1))) return; if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT), mfn_pte(mfn, PAGE_KERNEL), 0)) { WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n", mfn, pfn); BUG(); } } /* * This function updates the p2m and m2p tables with an identity map from * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the * original allocation at remap_pfn. The information needed for remapping is * saved in the memory itself to avoid the need for allocating buffers. The * complete remap information is contained in a list of MFNs each containing * up to REMAP_SIZE MFNs and the start target PFN for doing the remap. * This enables us to preserve the original mfn sequence while doing the * remapping at a time when the memory management is capable of allocating * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and * its callers. */ static void __init xen_do_set_identity_and_remap_chunk( unsigned long start_pfn, unsigned long size, unsigned long remap_pfn) { unsigned long buf = (unsigned long)&xen_remap_buf; unsigned long mfn_save, mfn; unsigned long ident_pfn_iter, remap_pfn_iter; unsigned long ident_end_pfn = start_pfn + size; unsigned long left = size; unsigned int i, chunk; WARN_ON(size == 0); mfn_save = virt_to_mfn(buf); for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn; ident_pfn_iter < ident_end_pfn; ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) { chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE; /* Map first pfn to xen_remap_buf */ mfn = pfn_to_mfn(ident_pfn_iter); set_pte_mfn(buf, mfn, PAGE_KERNEL); /* Save mapping information in page */ xen_remap_buf.next_area_mfn = xen_remap_mfn; xen_remap_buf.target_pfn = remap_pfn_iter; xen_remap_buf.size = chunk; for (i = 0; i < chunk; i++) xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i); /* Put remap buf into list. */ xen_remap_mfn = mfn; /* Set identity map */ set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk); left -= chunk; } /* Restore old xen_remap_buf mapping */ set_pte_mfn(buf, mfn_save, PAGE_KERNEL); } /* * This function takes a contiguous pfn range that needs to be identity mapped * and: * * 1) Finds a new range of pfns to use to remap based on E820 and remap_pfn. * 2) Calls the do_ function to actually do the mapping/remapping work. * * The goal is to not allocate additional memory but to remap the existing * pages. In the case of an error the underlying memory is simply released back * to Xen and not remapped. */ static unsigned long __init xen_set_identity_and_remap_chunk( unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages, unsigned long remap_pfn) { unsigned long pfn; unsigned long i = 0; unsigned long n = end_pfn - start_pfn; if (remap_pfn == 0) remap_pfn = nr_pages; while (i < n) { unsigned long cur_pfn = start_pfn + i; unsigned long left = n - i; unsigned long size = left; unsigned long remap_range_size; /* Do not remap pages beyond the current allocation */ if (cur_pfn >= nr_pages) { /* Identity map remaining pages */ set_phys_range_identity(cur_pfn, cur_pfn + size); break; } if (cur_pfn + size > nr_pages) size = nr_pages - cur_pfn; remap_range_size = xen_find_pfn_range(&remap_pfn); if (!remap_range_size) { pr_warn("Unable to find available pfn range, not remapping identity pages\n"); xen_set_identity_and_release_chunk(cur_pfn, cur_pfn + left, nr_pages); break; } /* Adjust size to fit in current e820 RAM region */ if (size > remap_range_size) size = remap_range_size; xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn); /* Update variables to reflect new mappings. */ i += size; remap_pfn += size; } /* * If the PFNs are currently mapped, the VA mapping also needs * to be updated to be 1:1. */ for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++) (void)HYPERVISOR_update_va_mapping( (unsigned long)__va(pfn << PAGE_SHIFT), mfn_pte(pfn, PAGE_KERNEL_IO), 0); return remap_pfn; } static unsigned long __init xen_count_remap_pages( unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages, unsigned long remap_pages) { if (start_pfn >= nr_pages) return remap_pages; return remap_pages + min(end_pfn, nr_pages) - start_pfn; } static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages, unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages, unsigned long last_val)) { phys_addr_t start = 0; unsigned long ret_val = 0; const struct e820_entry *entry = xen_e820_table.entries; int i; /* * Combine non-RAM regions and gaps until a RAM region (or the * end of the map) is reached, then call the provided function * to perform its duty on the non-RAM region. * * The combined non-RAM regions are rounded to a whole number * of pages so any partial pages are accessible via the 1:1 * mapping. This is needed for some BIOSes that put (for * example) the DMI tables in a reserved region that begins on * a non-page boundary. */ for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { phys_addr_t end = entry->addr + entry->size; if (entry->type == E820_TYPE_RAM || i == xen_e820_table.nr_entries - 1) { unsigned long start_pfn = PFN_DOWN(start); unsigned long end_pfn = PFN_UP(end); if (entry->type == E820_TYPE_RAM) end_pfn = PFN_UP(entry->addr); if (start_pfn < end_pfn) ret_val = func(start_pfn, end_pfn, nr_pages, ret_val); start = end; } } return ret_val; } /* * Remap the memory prepared in xen_do_set_identity_and_remap_chunk(). * The remap information (which mfn remap to which pfn) is contained in the * to be remapped memory itself in a linked list anchored at xen_remap_mfn. * This scheme allows to remap the different chunks in arbitrary order while * the resulting mapping will be independent from the order. */ void __init xen_remap_memory(void) { unsigned long buf = (unsigned long)&xen_remap_buf; unsigned long mfn_save, pfn; unsigned long remapped = 0; unsigned int i; unsigned long pfn_s = ~0UL; unsigned long len = 0; mfn_save = virt_to_mfn(buf); while (xen_remap_mfn != INVALID_P2M_ENTRY) { /* Map the remap information */ set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL); BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]); pfn = xen_remap_buf.target_pfn; for (i = 0; i < xen_remap_buf.size; i++) { xen_update_mem_tables(pfn, xen_remap_buf.mfns[i]); remapped++; pfn++; } if (pfn_s == ~0UL || pfn == pfn_s) { pfn_s = xen_remap_buf.target_pfn; len += xen_remap_buf.size; } else if (pfn_s + len == xen_remap_buf.target_pfn) { len += xen_remap_buf.size; } else { xen_del_extra_mem(pfn_s, len); pfn_s = xen_remap_buf.target_pfn; len = xen_remap_buf.size; } xen_remap_mfn = xen_remap_buf.next_area_mfn; } if (pfn_s != ~0UL && len) xen_del_extra_mem(pfn_s, len); set_pte_mfn(buf, mfn_save, PAGE_KERNEL); pr_info("Remapped %ld page(s)\n", remapped); } static unsigned long __init xen_get_pages_limit(void) { unsigned long limit; limit = MAXMEM / PAGE_SIZE; if (!xen_initial_domain() && xen_512gb_limit) limit = GB(512) / PAGE_SIZE; return limit; } static unsigned long __init xen_get_max_pages(void) { unsigned long max_pages, limit; domid_t domid = DOMID_SELF; long ret; limit = xen_get_pages_limit(); max_pages = limit; /* * For the initial domain we use the maximum reservation as * the maximum page. * * For guest domains the current maximum reservation reflects * the current maximum rather than the static maximum. In this * case the e820 map provided to us will cover the static * maximum region. */ if (xen_initial_domain()) { ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid); if (ret > 0) max_pages = ret; } return min(max_pages, limit); } static void __init xen_align_and_add_e820_region(phys_addr_t start, phys_addr_t size, int type) { phys_addr_t end = start + size; /* Align RAM regions to page boundaries. */ if (type == E820_TYPE_RAM) { start = PAGE_ALIGN(start); end &= ~((phys_addr_t)PAGE_SIZE - 1); #ifdef CONFIG_MEMORY_HOTPLUG /* * Don't allow adding memory not in E820 map while booting the * system. Once the balloon driver is up it will remove that * restriction again. */ max_mem_size = end; #endif } e820__range_add(start, end - start, type); } static void __init xen_ignore_unusable(void) { struct e820_entry *entry = xen_e820_table.entries; unsigned int i; for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { if (entry->type == E820_TYPE_UNUSABLE) entry->type = E820_TYPE_RAM; } } bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size) { struct e820_entry *entry; unsigned mapcnt; phys_addr_t end; if (!size) return false; end = start + size; entry = xen_e820_table.entries; for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) { if (entry->type == E820_TYPE_RAM && entry->addr <= start && (entry->addr + entry->size) >= end) return false; entry++; } return true; } /* * Find a free area in physical memory not yet reserved and compliant with * E820 map. * Used to relocate pre-allocated areas like initrd or p2m list which are in * conflict with the to be used E820 map. * In case no area is found, return 0. Otherwise return the physical address * of the area which is already reserved for convenience. */ phys_addr_t __init xen_find_free_area(phys_addr_t size) { unsigned mapcnt; phys_addr_t addr, start; struct e820_entry *entry = xen_e820_table.entries; for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) { if (entry->type != E820_TYPE_RAM || entry->size < size) continue; start = entry->addr; for (addr = start; addr < start + size; addr += PAGE_SIZE) { if (!memblock_is_reserved(addr)) continue; start = addr + PAGE_SIZE; if (start + size > entry->addr + entry->size) break; } if (addr >= start + size) { memblock_reserve(start, size); return start; } } return 0; } /* * Like memcpy, but with physical addresses for dest and src. */ static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src, phys_addr_t n) { phys_addr_t dest_off, src_off, dest_len, src_len, len; void *from, *to; while (n) { dest_off = dest & ~PAGE_MASK; src_off = src & ~PAGE_MASK; dest_len = n; if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off) dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off; src_len = n; if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off) src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off; len = min(dest_len, src_len); to = early_memremap(dest - dest_off, dest_len + dest_off); from = early_memremap(src - src_off, src_len + src_off); memcpy(to, from, len); early_memunmap(to, dest_len + dest_off); early_memunmap(from, src_len + src_off); n -= len; dest += len; src += len; } } /* * Reserve Xen mfn_list. */ static void __init xen_reserve_xen_mfnlist(void) { phys_addr_t start, size; if (xen_start_info->mfn_list >= __START_KERNEL_map) { start = __pa(xen_start_info->mfn_list); size = PFN_ALIGN(xen_start_info->nr_pages * sizeof(unsigned long)); } else { start = PFN_PHYS(xen_start_info->first_p2m_pfn); size = PFN_PHYS(xen_start_info->nr_p2m_frames); } memblock_reserve(start, size); if (!xen_is_e820_reserved(start, size)) return; xen_relocate_p2m(); memblock_free(start, size); } /** * machine_specific_memory_setup - Hook for machine specific memory setup. **/ char * __init xen_memory_setup(void) { unsigned long max_pfn, pfn_s, n_pfns; phys_addr_t mem_end, addr, size, chunk_size; u32 type; int rc; struct xen_memory_map memmap; unsigned long max_pages; unsigned long extra_pages = 0; int i; int op; xen_parse_512gb(); max_pfn = xen_get_pages_limit(); max_pfn = min(max_pfn, xen_start_info->nr_pages); mem_end = PFN_PHYS(max_pfn); memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries); set_xen_guest_handle(memmap.buffer, xen_e820_table.entries); #if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON) xen_saved_max_mem_size = max_mem_size; #endif op = xen_initial_domain() ? XENMEM_machine_memory_map : XENMEM_memory_map; rc = HYPERVISOR_memory_op(op, &memmap); if (rc == -ENOSYS) { BUG_ON(xen_initial_domain()); memmap.nr_entries = 1; xen_e820_table.entries[0].addr = 0ULL; xen_e820_table.entries[0].size = mem_end; /* 8MB slack (to balance backend allocations). */ xen_e820_table.entries[0].size += 8ULL << 20; xen_e820_table.entries[0].type = E820_TYPE_RAM; rc = 0; } BUG_ON(rc); BUG_ON(memmap.nr_entries == 0); xen_e820_table.nr_entries = memmap.nr_entries; /* * Xen won't allow a 1:1 mapping to be created to UNUSABLE * regions, so if we're using the machine memory map leave the * region as RAM as it is in the pseudo-physical map. * * UNUSABLE regions in domUs are not handled and will need * a patch in the future. */ if (xen_initial_domain()) xen_ignore_unusable(); /* Make sure the Xen-supplied memory map is well-ordered. */ e820__update_table(&xen_e820_table); max_pages = xen_get_max_pages(); /* How many extra pages do we need due to remapping? */ max_pages += xen_foreach_remap_area(max_pfn, xen_count_remap_pages); if (max_pages > max_pfn) extra_pages += max_pages - max_pfn; /* * Clamp the amount of extra memory to a EXTRA_MEM_RATIO * factor the base size. * * Make sure we have no memory above max_pages, as this area * isn't handled by the p2m management. */ extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)), extra_pages, max_pages - max_pfn); i = 0; addr = xen_e820_table.entries[0].addr; size = xen_e820_table.entries[0].size; while (i < xen_e820_table.nr_entries) { bool discard = false; chunk_size = size; type = xen_e820_table.entries[i].type; if (type == E820_TYPE_RAM) { if (addr < mem_end) { chunk_size = min(size, mem_end - addr); } else if (extra_pages) { chunk_size = min(size, PFN_PHYS(extra_pages)); pfn_s = PFN_UP(addr); n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s; extra_pages -= n_pfns; xen_add_extra_mem(pfn_s, n_pfns); xen_max_p2m_pfn = pfn_s + n_pfns; } else discard = true; } if (!discard) xen_align_and_add_e820_region(addr, chunk_size, type); addr += chunk_size; size -= chunk_size; if (size == 0) { i++; if (i < xen_e820_table.nr_entries) { addr = xen_e820_table.entries[i].addr; size = xen_e820_table.entries[i].size; } } } /* * Set the rest as identity mapped, in case PCI BARs are * located here. */ set_phys_range_identity(addr / PAGE_SIZE, ~0ul); /* * In domU, the ISA region is normal, usable memory, but we * reserve ISA memory anyway because too many things poke * about in there. */ e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED); e820__update_table(e820_table); /* * Check whether the kernel itself conflicts with the target E820 map. * Failing now is better than running into weird problems later due * to relocating (and even reusing) pages with kernel text or data. */ if (xen_is_e820_reserved(__pa_symbol(_text), __pa_symbol(__bss_stop) - __pa_symbol(_text))) { xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n"); BUG(); } /* * Check for a conflict of the hypervisor supplied page tables with * the target E820 map. */ xen_pt_check_e820(); xen_reserve_xen_mfnlist(); /* Check for a conflict of the initrd with the target E820 map. */ if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image, boot_params.hdr.ramdisk_size)) { phys_addr_t new_area, start, size; new_area = xen_find_free_area(boot_params.hdr.ramdisk_size); if (!new_area) { xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n"); BUG(); } start = boot_params.hdr.ramdisk_image; size = boot_params.hdr.ramdisk_size; xen_phys_memcpy(new_area, start, size); pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n", start, start + size, new_area, new_area + size); memblock_free(start, size); boot_params.hdr.ramdisk_image = new_area; boot_params.ext_ramdisk_image = new_area >> 32; } /* * Set identity map on non-RAM pages and prepare remapping the * underlying RAM. */ xen_foreach_remap_area(max_pfn, xen_set_identity_and_remap_chunk); pr_info("Released %ld page(s)\n", xen_released_pages); return "Xen"; } static int register_callback(unsigned type, const void *func) { struct callback_register callback = { .type = type, .address = XEN_CALLBACK(__KERNEL_CS, func), .flags = CALLBACKF_mask_events, }; return HYPERVISOR_callback_op(CALLBACKOP_register, &callback); } void xen_enable_sysenter(void) { int ret; unsigned sysenter_feature; sysenter_feature = X86_FEATURE_SYSENTER32; if (!boot_cpu_has(sysenter_feature)) return; ret = register_callback(CALLBACKTYPE_sysenter, xen_entry_SYSENTER_compat); if(ret != 0) setup_clear_cpu_cap(sysenter_feature); } void xen_enable_syscall(void) { int ret; ret = register_callback(CALLBACKTYPE_syscall, xen_entry_SYSCALL_64); if (ret != 0) { printk(KERN_ERR "Failed to set syscall callback: %d\n", ret); /* Pretty fatal; 64-bit userspace has no other mechanism for syscalls. */ } if (boot_cpu_has(X86_FEATURE_SYSCALL32)) { ret = register_callback(CALLBACKTYPE_syscall32, xen_entry_SYSCALL_compat); if (ret != 0) setup_clear_cpu_cap(X86_FEATURE_SYSCALL32); } } static void __init xen_pvmmu_arch_setup(void) { HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments); HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables); HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_pae_extended_cr3); if (register_callback(CALLBACKTYPE_event, xen_asm_exc_xen_hypervisor_callback) || register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback)) BUG(); xen_enable_sysenter(); xen_enable_syscall(); } /* This function is not called for HVM domains */ void __init xen_arch_setup(void) { xen_panic_handler_init(); xen_pvmmu_arch_setup(); #ifdef CONFIG_ACPI if (!(xen_start_info->flags & SIF_INITDOMAIN)) { printk(KERN_INFO "ACPI in unprivileged domain disabled\n"); disable_acpi(); } #endif memcpy(boot_command_line, xen_start_info->cmd_line, MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ? COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE); /* Set up idle, making sure it calls safe_halt() pvop */ disable_cpuidle(); disable_cpufreq(); WARN_ON(xen_set_default_idle()); #ifdef CONFIG_NUMA numa_off = 1; #endif }