/** * machine_specific_memory_setup - Hook for machine specific memory setup. **/ char * __init xen_memory_setup(void) { static struct e820entry map[E820MAX] __initdata; unsigned long max_pfn = xen_start_info->nr_pages; unsigned long long mem_end; int rc; struct xen_memory_map memmap; unsigned long max_pages; unsigned long extra_pages = 0; int i; int op; max_pfn = min(MAX_DOMAIN_PAGES, max_pfn); mem_end = PFN_PHYS(max_pfn); memmap.nr_entries = E820MAX; set_xen_guest_handle(memmap.buffer, map); 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; map[0].addr = 0ULL; map[0].size = mem_end; /* 8MB slack (to balance backend allocations). */ map[0].size += 8ULL << 20; map[0].type = E820_RAM; rc = 0; } BUG_ON(rc); /* Make sure the Xen-supplied memory map is well-ordered. */ sanitize_e820_map(map, memmap.nr_entries, &memmap.nr_entries); max_pages = xen_get_max_pages(); if (max_pages > max_pfn) extra_pages += max_pages - max_pfn; /* * Set P2M for all non-RAM pages and E820 gaps to be identity * type PFNs. Any RAM pages that would be made inaccesible by * this are first released. */ xen_released_pages = xen_set_identity_and_release( map, memmap.nr_entries, max_pfn); extra_pages += xen_released_pages; /* * Clamp the amount of extra memory to a EXTRA_MEM_RATIO * factor the base size. On non-highmem systems, the base * size is the full initial memory allocation; on highmem it * is limited to the max size of lowmem, so that it doesn't * get completely filled. * * In principle there could be a problem in lowmem systems if * the initial memory is also very large with respect to * lowmem, but we won't try to deal with that here. */ extra_pages = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)), extra_pages); i = 0; while (i < memmap.nr_entries) { u64 addr = map[i].addr; u64 size = map[i].size; u32 type = map[i].type; if (type == E820_RAM) { if (addr < mem_end) { size = min(size, mem_end - addr); } else if (extra_pages) { size = min(size, (u64)extra_pages * PAGE_SIZE); extra_pages -= size / PAGE_SIZE; xen_add_extra_mem(addr, size); } else type = E820_UNUSABLE; } xen_align_and_add_e820_region(addr, size, type); map[i].addr += size; map[i].size -= size; if (map[i].size == 0) i++; } /* * In domU, the ISA region is normal, usable memory, but we * reserve ISA memory anyway because too many things poke * about in there. */ e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_RESERVED); /* * Reserve Xen bits: * - mfn_list * - xen_start_info * See comment above "struct start_info" in <xen/interface/xen.h> */ memblock_reserve(__pa(xen_start_info->mfn_list), xen_start_info->pt_base - xen_start_info->mfn_list); sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map); return "Xen"; }
/** * machine_specific_memory_setup - Hook for machine specific memory setup. **/ char * __init xen_memory_setup(void) { static struct e820entry map[E820MAX] __initdata; unsigned long max_pfn = xen_start_info->nr_pages; unsigned long long mem_end; int rc; struct xen_memory_map memmap; unsigned long extra_pages = 0; unsigned long extra_limit; int i; int op; max_pfn = min(MAX_DOMAIN_PAGES, max_pfn); mem_end = PFN_PHYS(max_pfn); memmap.nr_entries = E820MAX; set_xen_guest_handle(memmap.buffer, map); 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; map[0].addr = 0ULL; map[0].size = mem_end; /* 8MB slack (to balance backend allocations). */ map[0].size += 8ULL << 20; map[0].type = E820_RAM; rc = 0; } BUG_ON(rc); e820.nr_map = 0; xen_extra_mem_start = mem_end; for (i = 0; i < memmap.nr_entries; i++) { unsigned long long end = map[i].addr + map[i].size; if (map[i].type == E820_RAM) { if (map[i].addr < mem_end && end > mem_end) { /* Truncate region to max_mem. */ u64 delta = end - mem_end; map[i].size -= delta; extra_pages += PFN_DOWN(delta); end = mem_end; } } if (end > xen_extra_mem_start) xen_extra_mem_start = end; /* If region is non-RAM or below mem_end, add what remains */ if ((map[i].type != E820_RAM || map[i].addr < mem_end) && map[i].size > 0) e820_add_region(map[i].addr, map[i].size, map[i].type); } /* * In domU, the ISA region is normal, usable memory, but we * reserve ISA memory anyway because too many things poke * about in there. * * In Dom0, the host E820 information can leave gaps in the * ISA range, which would cause us to release those pages. To * avoid this, we unconditionally reserve them here. */ e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_RESERVED); /* * Reserve Xen bits: * - mfn_list * - xen_start_info * See comment above "struct start_info" in <xen/interface/xen.h> */ memblock_x86_reserve_range(__pa(xen_start_info->mfn_list), __pa(xen_start_info->pt_base), "XEN START INFO"); sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map); extra_pages += xen_return_unused_memory(xen_start_info->nr_pages, &e820); /* * Clamp the amount of extra memory to a EXTRA_MEM_RATIO * factor the base size. On non-highmem systems, the base * size is the full initial memory allocation; on highmem it * is limited to the max size of lowmem, so that it doesn't * get completely filled. * * In principle there could be a problem in lowmem systems if * the initial memory is also very large with respect to * lowmem, but we won't try to deal with that here. */ extra_limit = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)), max_pfn + extra_pages); if (extra_limit >= max_pfn) extra_pages = extra_limit - max_pfn; else extra_pages = 0; if (!xen_initial_domain()) xen_add_extra_mem(extra_pages); return "Xen"; }
/** * machine_specific_memory_setup - Hook for machine specific memory setup. **/ char * __init xen_memory_setup(void) { static struct e820entry map[E820MAX] __initdata; unsigned long max_pfn = xen_start_info->nr_pages; unsigned long long mem_end; int rc; struct xen_memory_map memmap; unsigned long max_pages; unsigned long last_pfn = 0; unsigned long extra_pages = 0; unsigned long populated; int i; int op; max_pfn = min(MAX_DOMAIN_PAGES, max_pfn); mem_end = PFN_PHYS(max_pfn); memmap.nr_entries = E820MAX; set_xen_guest_handle(memmap.buffer, map); 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; map[0].addr = 0ULL; map[0].size = mem_end; /* 8MB slack (to balance backend allocations). */ map[0].size += 8ULL << 20; map[0].type = E820_RAM; rc = 0; } BUG_ON(rc); /* Make sure the Xen-supplied memory map is well-ordered. */ sanitize_e820_map(map, memmap.nr_entries, &memmap.nr_entries); max_pages = xen_get_max_pages(); if (max_pages > max_pfn) extra_pages += max_pages - max_pfn; /* * Set P2M for all non-RAM pages and E820 gaps to be identity * type PFNs. Any RAM pages that would be made inaccesible by * this are first released. */ xen_released_pages = xen_set_identity_and_release( map, memmap.nr_entries, max_pfn); /* * Populate back the non-RAM pages and E820 gaps that had been * released. */ populated = xen_populate_chunk(map, memmap.nr_entries, max_pfn, &last_pfn, xen_released_pages); xen_released_pages -= populated; extra_pages += xen_released_pages; if (last_pfn > max_pfn) { max_pfn = min(MAX_DOMAIN_PAGES, last_pfn); mem_end = PFN_PHYS(max_pfn); } /* * Clamp the amount of extra memory to a EXTRA_MEM_RATIO * factor the base size. On non-highmem systems, the base * size is the full initial memory allocation; on highmem it * is limited to the max size of lowmem, so that it doesn't * get completely filled. * * In principle there could be a problem in lowmem systems if * the initial memory is also very large with respect to * lowmem, but we won't try to deal with that here. */ extra_pages = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)), extra_pages); i = 0; while (i < memmap.nr_entries) { u64 addr = map[i].addr; u64 size = map[i].size; u32 type = map[i].type; if (type == E820_RAM) { if (addr < mem_end) { size = min(size, mem_end - addr); } else if (extra_pages) { size = min(size, (u64)extra_pages * PAGE_SIZE); extra_pages -= size / PAGE_SIZE; xen_add_extra_mem(addr, size); } else type = E820_UNUSABLE; } xen_align_and_add_e820_region(addr, size, type); map[i].addr += size; map[i].size -= size; if (map[i].size == 0) i++; } printk(KERN_DEBUG "*************************" "max_pages %lu, extra_pages %lu, " "max_pfn %lu, last_pfn %lu, mem_end %llu \n", max_pages, extra_pages, max_pfn, last_pfn, mem_end); /* * In domU, the ISA region is normal, usable memory, but we * reserve ISA memory anyway because too many things poke * about in there. */ e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_RESERVED); /* * Reserve Xen bits: * - mfn_list * - xen_start_info * See comment above "struct start_info" in <xen/interface/xen.h> * We tried to make the the memblock_reserve more selective so * that it would be clear what region is reserved. Sadly we ran * in the problem wherein on a 64-bit hypervisor with a 32-bit * initial domain, the pt_base has the cr3 value which is not * neccessarily where the pagetable starts! As Jan put it: " * Actually, the adjustment turns out to be correct: The page * tables for a 32-on-64 dom0 get allocated in the order "first L1", * "first L2", "first L3", so the offset to the page table base is * indeed 2. When reading xen/include/public/xen.h's comment * very strictly, this is not a violation (since there nothing is said * that the first thing in the page table space is pointed to by * pt_base; I admit that this seems to be implied though, namely * do I think that it is implied that the page table space is the * range [pt_base, pt_base + nt_pt_frames), whereas that * range here indeed is [pt_base - 2, pt_base - 2 + nt_pt_frames), * which - without a priori knowledge - the kernel would have * difficulty to figure out)." - so lets just fall back to the * easy way and reserve the whole region. */ memblock_reserve(__pa(xen_start_info->mfn_list), xen_start_info->pt_base - xen_start_info->mfn_list); sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map); return "Xen"; }
/** * machine_specific_memory_setup - Hook for machine specific memory setup. **/ char * __init xen_memory_setup(void) { static struct e820entry map[E820MAX] __initdata; static struct e820entry map_raw[E820MAX] __initdata; unsigned long max_pfn = xen_start_info->nr_pages; unsigned long long mem_end; int rc; struct xen_memory_map memmap; unsigned long extra_pages = 0; unsigned long extra_limit; unsigned long identity_pages = 0; int i; int op; max_pfn = min(MAX_DOMAIN_PAGES, max_pfn); mem_end = PFN_PHYS(max_pfn); memmap.nr_entries = E820MAX; set_xen_guest_handle(memmap.buffer, map); 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; map[0].addr = 0ULL; map[0].size = mem_end; /* 8MB slack (to balance backend allocations). */ map[0].size += 8ULL << 20; map[0].type = E820_RAM; rc = 0; } BUG_ON(rc); memcpy(map_raw, map, sizeof(map)); e820.nr_map = 0; #ifdef CONFIG_X86_32 xen_extra_mem_start = mem_end; #else xen_extra_mem_start = max((1ULL << 32), mem_end); #endif for (i = 0; i < memmap.nr_entries; i++) { unsigned long long end; /* Guard against non-page aligned E820 entries. */ if (map[i].type == E820_RAM) map[i].size -= (map[i].size + map[i].addr) % PAGE_SIZE; end = map[i].addr + map[i].size; if (map[i].type == E820_RAM && end > mem_end) { /* RAM off the end - may be partially included */ u64 delta = min(map[i].size, end - mem_end); map[i].size -= delta; end -= delta; extra_pages += PFN_DOWN(delta); /* * Set RAM below 4GB that is not for us to be unusable. * This prevents "System RAM" address space from being * used as potential resource for I/O address (happens * when 'allocate_resource' is called). */ if (delta && (xen_initial_domain() && end < 0x100000000ULL)) e820_add_region(end, delta, E820_UNUSABLE); } if (map[i].size > 0 && end > xen_extra_mem_start) xen_extra_mem_start = end; /* Add region if any remains */ if (map[i].size > 0) e820_add_region(map[i].addr, map[i].size, map[i].type); } /* * In domU, the ISA region is normal, usable memory, but we * reserve ISA memory anyway because too many things poke * about in there. * * In Dom0, the host E820 information can leave gaps in the * ISA range, which would cause us to release those pages. To * avoid this, we unconditionally reserve them here. */ e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_RESERVED); /* * Reserve Xen bits: * - mfn_list * - xen_start_info * See comment above "struct start_info" in <xen/interface/xen.h> */ memblock_x86_reserve_range(__pa(xen_start_info->mfn_list), __pa(xen_start_info->pt_base), "XEN START INFO"); sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map); extra_pages += xen_return_unused_memory(xen_start_info->nr_pages, &e820); /* * Clamp the amount of extra memory to a EXTRA_MEM_RATIO * factor the base size. On non-highmem systems, the base * size is the full initial memory allocation; on highmem it * is limited to the max size of lowmem, so that it doesn't * get completely filled. * * In principle there could be a problem in lowmem systems if * the initial memory is also very large with respect to * lowmem, but we won't try to deal with that here. */ extra_limit = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)), max_pfn + extra_pages); if (extra_limit >= max_pfn) extra_pages = extra_limit - max_pfn; else extra_pages = 0; xen_add_extra_mem(extra_pages); /* * Set P2M for all non-RAM pages and E820 gaps to be identity * type PFNs. We supply it with the non-sanitized version * of the E820. */ identity_pages = xen_set_identity(map_raw, memmap.nr_entries); printk(KERN_INFO "Set %ld page(s) to 1-1 mapping.\n", identity_pages); return "Xen"; }