summaryrefslogtreecommitdiffstats
path: root/kernel/arch/x86/xen/setup.c
diff options
context:
space:
mode:
authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/arch/x86/xen/setup.c
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/arch/x86/xen/setup.c')
-rw-r--r--kernel/arch/x86/xen/setup.c864
1 files changed, 864 insertions, 0 deletions
diff --git a/kernel/arch/x86/xen/setup.c b/kernel/arch/x86/xen/setup.c
new file mode 100644
index 000000000..55f388ef4
--- /dev/null
+++ b/kernel/arch/x86/xen/setup.c
@@ -0,0 +1,864 @@
+/*
+ * 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/numa.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"
+#include "p2m.h"
+#include "mmu.h"
+
+/* 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;
+
+/*
+ * 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 void __init xen_add_extra_mem(phys_addr_t start, phys_addr_t size)
+{
+ 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);
+}
+
+static void __init xen_del_extra_mem(phys_addr_t start, phys_addr_t size)
+{
+ int i;
+ phys_addr_t start_r, size_r;
+
+ for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
+ start_r = xen_extra_mem[i].start;
+ size_r = xen_extra_mem[i].size;
+
+ /* Start of region. */
+ if (start_r == start) {
+ BUG_ON(size > size_r);
+ xen_extra_mem[i].start += size;
+ xen_extra_mem[i].size -= size;
+ break;
+ }
+ /* End of region. */
+ if (start_r + size_r == start + size) {
+ BUG_ON(size > size_r);
+ xen_extra_mem[i].size -= size;
+ break;
+ }
+ /* Mid of region. */
+ if (start > start_r && start < start_r + size_r) {
+ BUG_ON(start + size > start_r + size_r);
+ xen_extra_mem[i].size = start - start_r;
+ /* Calling memblock_reserve() again is okay. */
+ xen_add_extra_mem(start + size, start_r + size_r -
+ (start + size));
+ break;
+ }
+ }
+ memblock_free(start, size);
+}
+
+/*
+ * 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;
+ phys_addr_t addr = PFN_PHYS(pfn);
+
+ for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) {
+ if (addr >= xen_extra_mem[i].start &&
+ addr < xen_extra_mem[i].start + xen_extra_mem[i].size)
+ 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].size)
+ continue;
+ pfn_s = PFN_DOWN(xen_extra_mem[i].start);
+ pfn_e = PFN_UP(xen_extra_mem[i].start + xen_extra_mem[i].size);
+ 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(
+ const struct e820entry *list, size_t map_size,
+ unsigned long *min_pfn)
+{
+ const struct e820entry *entry;
+ unsigned int i;
+ unsigned long done = 0;
+
+ for (i = 0, entry = list; i < map_size; i++, entry++) {
+ unsigned long s_pfn;
+ unsigned long e_pfn;
+
+ if (entry->type != E820_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 *released)
+{
+ 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) {
+ (*released)++;
+ 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);
+
+ BUG_ON(xen_feature(XENFEAT_auto_translated_physmap));
+
+ 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(
+ const struct e820entry *list, size_t map_size, unsigned long start_pfn,
+ unsigned long end_pfn, unsigned long nr_pages, unsigned long remap_pfn,
+ unsigned long *released, unsigned long *remapped)
+{
+ unsigned long pfn;
+ unsigned long i = 0;
+ unsigned long n = end_pfn - start_pfn;
+
+ 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(list, map_size,
+ &remap_pfn);
+ if (!remap_range_size) {
+ pr_warning("Unable to find available pfn range, not remapping identity pages\n");
+ xen_set_identity_and_release_chunk(cur_pfn,
+ cur_pfn + left, nr_pages, released);
+ 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;
+ *remapped += 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 void __init xen_set_identity_and_remap(
+ const struct e820entry *list, size_t map_size, unsigned long nr_pages,
+ unsigned long *released, unsigned long *remapped)
+{
+ phys_addr_t start = 0;
+ unsigned long last_pfn = nr_pages;
+ const struct e820entry *entry;
+ unsigned long num_released = 0;
+ unsigned long num_remapped = 0;
+ 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
+ * remap the memory 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)
+ last_pfn = xen_set_identity_and_remap_chunk(
+ list, map_size, start_pfn,
+ end_pfn, nr_pages, last_pfn,
+ &num_released, &num_remapped);
+ start = end;
+ }
+ }
+
+ *released = num_released;
+ *remapped = num_remapped;
+
+ pr_info("Released %ld page(s)\n", num_released);
+}
+
+/*
+ * 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 independant from the order.
+ */
+void __init xen_remap_memory(void)
+{
+ unsigned long buf = (unsigned long)&xen_remap_buf;
+ unsigned long mfn_save, mfn, 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++) {
+ mfn = xen_remap_buf.mfns[i];
+ xen_update_mem_tables(pfn, mfn);
+ 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_PHYS(pfn_s), PFN_PHYS(len));
+ pfn_s = xen_remap_buf.target_pfn;
+ len = xen_remap_buf.size;
+ }
+
+ mfn = xen_remap_mfn;
+ xen_remap_mfn = xen_remap_buf.next_area_mfn;
+ }
+
+ if (pfn_s != ~0UL && len)
+ xen_del_extra_mem(PFN_PHYS(pfn_s), PFN_PHYS(len));
+
+ set_pte_mfn(buf, mfn_save, PAGE_KERNEL);
+
+ pr_info("Remapped %ld page(s)\n", remapped);
+}
+
+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 __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_RAM) {
+ start = PAGE_ALIGN(start);
+ end &= ~((phys_addr_t)PAGE_SIZE - 1);
+ }
+
+ e820_add_region(start, end - start, type);
+}
+
+static void __init xen_ignore_unusable(struct e820entry *list, size_t map_size)
+{
+ struct e820entry *entry;
+ unsigned int i;
+
+ for (i = 0, entry = list; i < map_size; i++, entry++) {
+ if (entry->type == E820_UNUSABLE)
+ entry->type = E820_RAM;
+ }
+}
+
+/**
+ * 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;
+ phys_addr_t mem_end;
+ int rc;
+ struct xen_memory_map memmap;
+ unsigned long max_pages;
+ unsigned long extra_pages = 0;
+ unsigned long remapped_pages;
+ 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);
+ BUG_ON(memmap.nr_entries == 0);
+
+ /*
+ * 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(map, memmap.nr_entries);
+
+ /* 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 identity map on non-RAM pages and prepare remapping the
+ * underlying RAM.
+ */
+ xen_set_identity_and_remap(map, memmap.nr_entries, max_pfn,
+ &xen_released_pages, &remapped_pages);
+
+ extra_pages += xen_released_pages;
+ extra_pages += remapped_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) {
+ phys_addr_t addr = map[i].addr;
+ phys_addr_t 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, PFN_PHYS(extra_pages));
+ extra_pages -= PFN_DOWN(size);
+ xen_add_extra_mem(addr, size);
+ xen_max_p2m_pfn = PFN_DOWN(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++;
+ }
+
+ /*
+ * Set the rest as identity mapped, in case PCI BARs are
+ * located here.
+ *
+ * PFNs above MAX_P2M_PFN are considered identity mapped as
+ * well.
+ */
+ set_phys_range_identity(map[i-1].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_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 for auto-translated guests.
+ */
+char * __init xen_auto_xlated_memory_setup(void)
+{
+ static struct e820entry map[E820MAX] __initdata;
+
+ struct xen_memory_map memmap;
+ int i;
+ int rc;
+
+ memmap.nr_entries = E820MAX;
+ set_xen_guest_handle(memmap.buffer, map);
+
+ rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
+ if (rc < 0)
+ panic("No memory map (%d)\n", rc);
+
+ sanitize_e820_map(map, ARRAY_SIZE(map), &memmap.nr_entries);
+
+ for (i = 0; i < memmap.nr_entries; i++)
+ e820_add_region(map[i].addr, map[i].size, map[i].type);
+
+ memblock_reserve(__pa(xen_start_info->mfn_list),
+ xen_start_info->pt_base - xen_start_info->mfn_list);
+
+ 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
+ /*
+ * This could be called before selected_vdso32 is initialized, so
+ * just fiddle with both possible images. vdso_image_32_syscall
+ * can't be selected, since it only exists on 64-bit systems.
+ */
+ u32 *mask;
+ mask = vdso_image_32_int80.data +
+ vdso_image_32_int80.sym_VDSO32_NOTE_MASK;
+ *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
+ mask = vdso_image_32_sysenter.data +
+ vdso_image_32_sysenter.sym_VDSO32_NOTE_MASK;
+ *mask |= 1 << VDSO_NOTE_NONEGSEG_BIT;
+#endif
+}
+
+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;
+
+#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 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_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_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();
+ if (!xen_feature(XENFEAT_auto_translated_physmap))
+ 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());
+ fiddle_vdso();
+#ifdef CONFIG_NUMA
+ numa_off = 1;
+#endif
+}