/arch/x86/xen/setup.c
C | 540 lines | 365 code | 81 blank | 94 comment | 72 complexity | e05247d05ce83ce7b7811fd29c3503c0 MD5 | raw file
Possible License(s): GPL-2.0
- /*
- * Machine specific setup for xen
- *
- * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
- */
- #include <linux/module.h>
- #include <linux/sched.h>
- #include <linux/mm.h>
- #include <linux/pm.h>
- #include <linux/memblock.h>
- #include <linux/cpuidle.h>
- #include <linux/cpufreq.h>
- #include <asm/elf.h>
- #include <asm/vdso.h>
- #include <asm/e820.h>
- #include <asm/setup.h>
- #include <asm/acpi.h>
- #include <asm/xen/hypervisor.h>
- #include <asm/xen/hypercall.h>
- #include <xen/xen.h>
- #include <xen/page.h>
- #include <xen/interface/callback.h>
- #include <xen/interface/memory.h>
- #include <xen/interface/physdev.h>
- #include <xen/features.h>
- #include "xen-ops.h"
- #include "vdso.h"
- /* These are code, but not functions. Defined in entry.S */
- extern const char xen_hypervisor_callback[];
- extern const char xen_failsafe_callback[];
- extern void xen_sysenter_target(void);
- extern void xen_syscall_target(void);
- extern void xen_syscall32_target(void);
- /* 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;
- /*
- * 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 void __init xen_add_extra_mem(u64 start, u64 size)
- {
- unsigned long pfn;
- int i;
- for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
- /* Add new region. */
- if (xen_extra_mem[i].size == 0) {
- xen_extra_mem[i].start = start;
- xen_extra_mem[i].size = size;
- break;
- }
- /* Append to existing region. */
- if (xen_extra_mem[i].start + xen_extra_mem[i].size == start) {
- xen_extra_mem[i].size += size;
- break;
- }
- }
- if (i == XEN_EXTRA_MEM_MAX_REGIONS)
- printk(KERN_WARNING "Warning: not enough extra memory regions\n");
- memblock_reserve(start, size);
- xen_max_p2m_pfn = PFN_DOWN(start + size);
- for (pfn = PFN_DOWN(start); pfn <= xen_max_p2m_pfn; pfn++)
- __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
- }
- static unsigned long __init xen_do_chunk(unsigned long start,
- unsigned long end, bool release)
- {
- struct xen_memory_reservation reservation = {
- .address_bits = 0,
- .extent_order = 0,
- .domid = DOMID_SELF
- };
- unsigned long len = 0;
- unsigned long pfn;
- int ret;
- for (pfn = start; pfn < end; pfn++) {
- unsigned long frame;
- unsigned long mfn = pfn_to_mfn(pfn);
- if (release) {
- /* Make sure pfn exists to start with */
- if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn)
- continue;
- frame = mfn;
- } else {
- if (mfn != INVALID_P2M_ENTRY)
- continue;
- frame = pfn;
- }
- set_xen_guest_handle(reservation.extent_start, &frame);
- reservation.nr_extents = 1;
- ret = HYPERVISOR_memory_op(release ? XENMEM_decrease_reservation : XENMEM_populate_physmap,
- &reservation);
- WARN(ret != 1, "Failed to %s pfn %lx err=%d\n",
- release ? "release" : "populate", pfn, ret);
- if (ret == 1) {
- if (!early_set_phys_to_machine(pfn, release ? INVALID_P2M_ENTRY : frame)) {
- if (release)
- break;
- set_xen_guest_handle(reservation.extent_start, &frame);
- reservation.nr_extents = 1;
- ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation,
- &reservation);
- break;
- }
- len++;
- } else
- break;
- }
- if (len)
- printk(KERN_INFO "%s %lx-%lx pfn range: %lu pages %s\n",
- release ? "Freeing" : "Populating",
- start, end, len,
- release ? "freed" : "added");
- return len;
- }
- static unsigned long __init xen_release_chunk(unsigned long start,
- unsigned long end)
- {
- return xen_do_chunk(start, end, true);
- }
- static unsigned long __init xen_populate_chunk(
- const struct e820entry *list, size_t map_size,
- unsigned long max_pfn, unsigned long *last_pfn,
- unsigned long credits_left)
- {
- const struct e820entry *entry;
- unsigned int i;
- unsigned long done = 0;
- unsigned long dest_pfn;
- for (i = 0, entry = list; i < map_size; i++, entry++) {
- unsigned long s_pfn;
- unsigned long e_pfn;
- unsigned long pfns;
- long capacity;
- if (credits_left <= 0)
- break;
- if (entry->type != E820_RAM)
- continue;
- e_pfn = PFN_DOWN(entry->addr + entry->size);
- /* We only care about E820 after the xen_start_info->nr_pages */
- if (e_pfn <= max_pfn)
- continue;
- s_pfn = PFN_UP(entry->addr);
- /* If the E820 falls within the nr_pages, we want to start
- * at the nr_pages PFN.
- * If that would mean going past the E820 entry, skip it
- */
- if (s_pfn <= max_pfn) {
- capacity = e_pfn - max_pfn;
- dest_pfn = max_pfn;
- } else {
- capacity = e_pfn - s_pfn;
- dest_pfn = s_pfn;
- }
- if (credits_left < capacity)
- capacity = credits_left;
- pfns = xen_do_chunk(dest_pfn, dest_pfn + capacity, false);
- done += pfns;
- *last_pfn = (dest_pfn + pfns);
- if (pfns < capacity)
- break;
- credits_left -= pfns;
- }
- return done;
- }
- static void __init xen_set_identity_and_release_chunk(
- unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages,
- unsigned long *released, unsigned long *identity)
- {
- unsigned long pfn;
- /*
- * 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);
- if (start_pfn < nr_pages)
- *released += xen_release_chunk(
- start_pfn, min(end_pfn, nr_pages));
- *identity += set_phys_range_identity(start_pfn, end_pfn);
- }
- static unsigned long __init xen_set_identity_and_release(
- const struct e820entry *list, size_t map_size, unsigned long nr_pages)
- {
- phys_addr_t start = 0;
- unsigned long released = 0;
- unsigned long identity = 0;
- const struct e820entry *entry;
- int i;
- /*
- * Combine non-RAM regions and gaps until a RAM region (or the
- * end of the map) is reached, then set the 1:1 map and
- * release the pages (if available) in those non-RAM regions.
- *
- * 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, entry = list; i < map_size; i++, entry++) {
- phys_addr_t end = entry->addr + entry->size;
- if (entry->type == E820_RAM || i == map_size - 1) {
- unsigned long start_pfn = PFN_DOWN(start);
- unsigned long end_pfn = PFN_UP(end);
- if (entry->type == E820_RAM)
- end_pfn = PFN_UP(entry->addr);
- if (start_pfn < end_pfn)
- xen_set_identity_and_release_chunk(
- start_pfn, end_pfn, nr_pages,
- &released, &identity);
- start = end;
- }
- }
- if (released)
- printk(KERN_INFO "Released %lu pages of unused memory\n", released);
- if (identity)
- printk(KERN_INFO "Set %ld page(s) to 1-1 mapping\n", identity);
- return released;
- }
- static unsigned long __init xen_get_max_pages(void)
- {
- unsigned long max_pages = MAX_DOMAIN_PAGES;
- domid_t domid = DOMID_SELF;
- int ret;
- /*
- * 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, MAX_DOMAIN_PAGES);
- }
- static void xen_align_and_add_e820_region(u64 start, u64 size, int type)
- {
- u64 end = start + size;
- /* Align RAM regions to page boundaries. */
- if (type == E820_RAM) {
- start = PAGE_ALIGN(start);
- end &= ~((u64)PAGE_SIZE - 1);
- }
- e820_add_region(start, end - start, type);
- }
- /**
- * 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++;
- }
- /*
- * 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";
- }
- /*
- * Set the bit indicating "nosegneg" library variants should be used.
- * We only need to bother in pure 32-bit mode; compat 32-bit processes
- * can have un-truncated segments, so wrapping around is allowed.
- */
- static void __init fiddle_vdso(void)
- {
- #ifdef CONFIG_X86_32
- u32 *mask;
- mask = VDSO32_SYMBOL(&vdso32_int80_start, NOTE_MASK);
- *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
- mask = VDSO32_SYMBOL(&vdso32_sysenter_start, NOTE_MASK);
- *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
- #endif
- }
- static int __cpuinit 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 __cpuinit xen_enable_sysenter(void)
- {
- int ret;
- unsigned sysenter_feature;
- #ifdef CONFIG_X86_32
- sysenter_feature = X86_FEATURE_SEP;
- #else
- sysenter_feature = X86_FEATURE_SYSENTER32;
- #endif
- if (!boot_cpu_has(sysenter_feature))
- return;
- ret = register_callback(CALLBACKTYPE_sysenter, xen_sysenter_target);
- if(ret != 0)
- setup_clear_cpu_cap(sysenter_feature);
- }
- void __cpuinit xen_enable_syscall(void)
- {
- #ifdef CONFIG_X86_64
- int ret;
- ret = register_callback(CALLBACKTYPE_syscall, xen_syscall_target);
- 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_syscall32_target);
- if (ret != 0)
- setup_clear_cpu_cap(X86_FEATURE_SYSCALL32);
- }
- #endif /* CONFIG_X86_64 */
- }
- void __init xen_arch_setup(void)
- {
- xen_panic_handler_init();
- HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments);
- HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables);
- if (!xen_feature(XENFEAT_auto_translated_physmap))
- HYPERVISOR_vm_assist(VMASST_CMD_enable,
- VMASST_TYPE_pae_extended_cr3);
- if (register_callback(CALLBACKTYPE_event, xen_hypervisor_callback) ||
- register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback))
- BUG();
- xen_enable_sysenter();
- xen_enable_syscall();
- #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 */
- #ifdef CONFIG_X86_32
- boot_cpu_data.hlt_works_ok = 1;
- #endif
- disable_cpuidle();
- disable_cpufreq();
- WARN_ON(set_pm_idle_to_default());
- fiddle_vdso();
- }