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-rw-r--r--arch/x86/xen/Kconfig11
-rw-r--r--arch/x86/xen/enlighten.c1
-rw-r--r--arch/x86/xen/mmu.c52
-rw-r--r--arch/x86/xen/p2m.c128
-rw-r--r--arch/x86/xen/setup.c284
5 files changed, 234 insertions, 242 deletions
diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index 5cc821cb2e09..26c731a106af 100644
--- a/arch/x86/xen/Kconfig
+++ b/arch/x86/xen/Kconfig
@@ -25,8 +25,7 @@ config XEN_PRIVILEGED_GUEST
config XEN_PVHVM
def_bool y
- depends on XEN
- depends on X86_LOCAL_APIC
+ depends on XEN && PCI && X86_LOCAL_APIC
config XEN_MAX_DOMAIN_MEMORY
int
@@ -49,11 +48,3 @@ config XEN_DEBUG_FS
help
Enable statistics output and various tuning options in debugfs.
Enabling this option may incur a significant performance overhead.
-
-config XEN_DEBUG
- bool "Enable Xen debug checks"
- depends on XEN
- default n
- help
- Enable various WARN_ON checks in the Xen MMU code.
- Enabling this option WILL incur a significant performance overhead.
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 2d69617950f7..da8afd576a6b 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -251,6 +251,7 @@ static void __init xen_init_cpuid_mask(void)
~((1 << X86_FEATURE_APIC) | /* disable local APIC */
(1 << X86_FEATURE_ACPI)); /* disable ACPI */
ax = 1;
+ cx = 0;
xen_cpuid(&ax, &bx, &cx, &dx);
xsave_mask =
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index 3dd53f997b11..87f6673b1207 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -495,41 +495,6 @@ static pte_t xen_make_pte(pteval_t pte)
}
PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte);
-#ifdef CONFIG_XEN_DEBUG
-pte_t xen_make_pte_debug(pteval_t pte)
-{
- phys_addr_t addr = (pte & PTE_PFN_MASK);
- phys_addr_t other_addr;
- bool io_page = false;
- pte_t _pte;
-
- if (pte & _PAGE_IOMAP)
- io_page = true;
-
- _pte = xen_make_pte(pte);
-
- if (!addr)
- return _pte;
-
- if (io_page &&
- (xen_initial_domain() || addr >= ISA_END_ADDRESS)) {
- other_addr = pfn_to_mfn(addr >> PAGE_SHIFT) << PAGE_SHIFT;
- WARN_ONCE(addr != other_addr,
- "0x%lx is using VM_IO, but it is 0x%lx!\n",
- (unsigned long)addr, (unsigned long)other_addr);
- } else {
- pteval_t iomap_set = (_pte.pte & PTE_FLAGS_MASK) & _PAGE_IOMAP;
- other_addr = (_pte.pte & PTE_PFN_MASK);
- WARN_ONCE((addr == other_addr) && (!io_page) && (!iomap_set),
- "0x%lx is missing VM_IO (and wasn't fixed)!\n",
- (unsigned long)addr);
- }
-
- return _pte;
-}
-PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte_debug);
-#endif
-
static pgd_t xen_make_pgd(pgdval_t pgd)
{
pgd = pte_pfn_to_mfn(pgd);
@@ -1992,9 +1957,6 @@ void __init xen_ident_map_ISA(void)
static void __init xen_post_allocator_init(void)
{
-#ifdef CONFIG_XEN_DEBUG
- pv_mmu_ops.make_pte = PV_CALLEE_SAVE(xen_make_pte_debug);
-#endif
pv_mmu_ops.set_pte = xen_set_pte;
pv_mmu_ops.set_pmd = xen_set_pmd;
pv_mmu_ops.set_pud = xen_set_pud;
@@ -2404,17 +2366,3 @@ out:
return err;
}
EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
-
-#ifdef CONFIG_XEN_DEBUG_FS
-static int p2m_dump_open(struct inode *inode, struct file *filp)
-{
- return single_open(filp, p2m_dump_show, NULL);
-}
-
-static const struct file_operations p2m_dump_fops = {
- .open = p2m_dump_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
-};
-#endif /* CONFIG_XEN_DEBUG_FS */
diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 58efeb9d5440..1b267e75158d 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -161,7 +161,9 @@
#include <asm/xen/page.h>
#include <asm/xen/hypercall.h>
#include <asm/xen/hypervisor.h>
+#include <xen/grant_table.h>
+#include "multicalls.h"
#include "xen-ops.h"
static void __init m2p_override_init(void);
@@ -676,7 +678,8 @@ static unsigned long mfn_hash(unsigned long mfn)
}
/* Add an MFN override for a particular page */
-int m2p_add_override(unsigned long mfn, struct page *page, bool clear_pte)
+int m2p_add_override(unsigned long mfn, struct page *page,
+ struct gnttab_map_grant_ref *kmap_op)
{
unsigned long flags;
unsigned long pfn;
@@ -692,16 +695,28 @@ int m2p_add_override(unsigned long mfn, struct page *page, bool clear_pte)
"m2p_add_override: pfn %lx not mapped", pfn))
return -EINVAL;
}
-
- page->private = mfn;
+ WARN_ON(PagePrivate(page));
+ SetPagePrivate(page);
+ set_page_private(page, mfn);
page->index = pfn_to_mfn(pfn);
if (unlikely(!set_phys_to_machine(pfn, FOREIGN_FRAME(mfn))))
return -ENOMEM;
- if (clear_pte && !PageHighMem(page))
- /* Just zap old mapping for now */
- pte_clear(&init_mm, address, ptep);
+ if (kmap_op != NULL) {
+ if (!PageHighMem(page)) {
+ struct multicall_space mcs =
+ xen_mc_entry(sizeof(*kmap_op));
+
+ MULTI_grant_table_op(mcs.mc,
+ GNTTABOP_map_grant_ref, kmap_op, 1);
+
+ xen_mc_issue(PARAVIRT_LAZY_MMU);
+ }
+ /* let's use dev_bus_addr to record the old mfn instead */
+ kmap_op->dev_bus_addr = page->index;
+ page->index = (unsigned long) kmap_op;
+ }
spin_lock_irqsave(&m2p_override_lock, flags);
list_add(&page->lru, &m2p_overrides[mfn_hash(mfn)]);
spin_unlock_irqrestore(&m2p_override_lock, flags);
@@ -735,13 +750,56 @@ int m2p_remove_override(struct page *page, bool clear_pte)
spin_lock_irqsave(&m2p_override_lock, flags);
list_del(&page->lru);
spin_unlock_irqrestore(&m2p_override_lock, flags);
- set_phys_to_machine(pfn, page->index);
+ WARN_ON(!PagePrivate(page));
+ ClearPagePrivate(page);
- if (clear_pte && !PageHighMem(page))
- set_pte_at(&init_mm, address, ptep,
- pfn_pte(pfn, PAGE_KERNEL));
- /* No tlb flush necessary because the caller already
- * left the pte unmapped. */
+ if (clear_pte) {
+ struct gnttab_map_grant_ref *map_op =
+ (struct gnttab_map_grant_ref *) page->index;
+ set_phys_to_machine(pfn, map_op->dev_bus_addr);
+ if (!PageHighMem(page)) {
+ struct multicall_space mcs;
+ struct gnttab_unmap_grant_ref *unmap_op;
+
+ /*
+ * It might be that we queued all the m2p grant table
+ * hypercalls in a multicall, then m2p_remove_override
+ * get called before the multicall has actually been
+ * issued. In this case handle is going to -1 because
+ * it hasn't been modified yet.
+ */
+ if (map_op->handle == -1)
+ xen_mc_flush();
+ /*
+ * Now if map_op->handle is negative it means that the
+ * hypercall actually returned an error.
+ */
+ if (map_op->handle == GNTST_general_error) {
+ printk(KERN_WARNING "m2p_remove_override: "
+ "pfn %lx mfn %lx, failed to modify kernel mappings",
+ pfn, mfn);
+ return -1;
+ }
+
+ mcs = xen_mc_entry(
+ sizeof(struct gnttab_unmap_grant_ref));
+ unmap_op = mcs.args;
+ unmap_op->host_addr = map_op->host_addr;
+ unmap_op->handle = map_op->handle;
+ unmap_op->dev_bus_addr = 0;
+
+ MULTI_grant_table_op(mcs.mc,
+ GNTTABOP_unmap_grant_ref, unmap_op, 1);
+
+ xen_mc_issue(PARAVIRT_LAZY_MMU);
+
+ set_pte_at(&init_mm, address, ptep,
+ pfn_pte(pfn, PAGE_KERNEL));
+ __flush_tlb_single(address);
+ map_op->host_addr = 0;
+ }
+ } else
+ set_phys_to_machine(pfn, page->index);
return 0;
}
@@ -758,7 +816,7 @@ struct page *m2p_find_override(unsigned long mfn)
spin_lock_irqsave(&m2p_override_lock, flags);
list_for_each_entry(p, bucket, lru) {
- if (p->private == mfn) {
+ if (page_private(p) == mfn) {
ret = p;
break;
}
@@ -782,17 +840,21 @@ unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn)
EXPORT_SYMBOL_GPL(m2p_find_override_pfn);
#ifdef CONFIG_XEN_DEBUG_FS
-
-int p2m_dump_show(struct seq_file *m, void *v)
+#include <linux/debugfs.h>
+#include "debugfs.h"
+static int p2m_dump_show(struct seq_file *m, void *v)
{
static const char * const level_name[] = { "top", "middle",
- "entry", "abnormal" };
- static const char * const type_name[] = { "identity", "missing",
- "pfn", "abnormal"};
+ "entry", "abnormal", "error"};
#define TYPE_IDENTITY 0
#define TYPE_MISSING 1
#define TYPE_PFN 2
#define TYPE_UNKNOWN 3
+ static const char * const type_name[] = {
+ [TYPE_IDENTITY] = "identity",
+ [TYPE_MISSING] = "missing",
+ [TYPE_PFN] = "pfn",
+ [TYPE_UNKNOWN] = "abnormal"};
unsigned long pfn, prev_pfn_type = 0, prev_pfn_level = 0;
unsigned int uninitialized_var(prev_level);
unsigned int uninitialized_var(prev_type);
@@ -856,4 +918,32 @@ int p2m_dump_show(struct seq_file *m, void *v)
#undef TYPE_PFN
#undef TYPE_UNKNOWN
}
-#endif
+
+static int p2m_dump_open(struct inode *inode, struct file *filp)
+{
+ return single_open(filp, p2m_dump_show, NULL);
+}
+
+static const struct file_operations p2m_dump_fops = {
+ .open = p2m_dump_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static struct dentry *d_mmu_debug;
+
+static int __init xen_p2m_debugfs(void)
+{
+ struct dentry *d_xen = xen_init_debugfs();
+
+ if (d_xen == NULL)
+ return -ENOMEM;
+
+ d_mmu_debug = debugfs_create_dir("mmu", d_xen);
+
+ debugfs_create_file("p2m", 0600, d_mmu_debug, NULL, &p2m_dump_fops);
+ return 0;
+}
+fs_initcall(xen_p2m_debugfs);
+#endif /* CONFIG_XEN_DEBUG_FS */
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 46d6d21dbdbe..38d0af4fefec 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -37,7 +37,10 @@ extern void xen_syscall_target(void);
extern void xen_syscall32_target(void);
/* Amount of extra memory space we add to the e820 ranges */
-phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
+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
@@ -51,48 +54,47 @@ phys_addr_t xen_extra_mem_start, xen_extra_mem_size;
*/
#define EXTRA_MEM_RATIO (10)
-static void __init xen_add_extra_mem(unsigned long pages)
+static void __init xen_add_extra_mem(u64 start, u64 size)
{
unsigned long pfn;
+ int i;
- u64 size = (u64)pages * PAGE_SIZE;
- u64 extra_start = xen_extra_mem_start + xen_extra_mem_size;
-
- if (!pages)
- return;
-
- e820_add_region(extra_start, size, E820_RAM);
- sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
-
- memblock_x86_reserve_range(extra_start, extra_start + size, "XEN EXTRA");
+ 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");
- xen_extra_mem_size += size;
+ memblock_x86_reserve_range(start, start + size, "XEN EXTRA");
- xen_max_p2m_pfn = PFN_DOWN(extra_start + size);
+ xen_max_p2m_pfn = PFN_DOWN(start + size);
- for (pfn = PFN_DOWN(extra_start); pfn <= xen_max_p2m_pfn; pfn++)
+ for (pfn = PFN_DOWN(start); pfn <= xen_max_p2m_pfn; pfn++)
__set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
}
-static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
- phys_addr_t end_addr)
+static unsigned long __init xen_release_chunk(unsigned long start,
+ unsigned long end)
{
struct xen_memory_reservation reservation = {
.address_bits = 0,
.extent_order = 0,
.domid = DOMID_SELF
};
- unsigned long start, end;
unsigned long len = 0;
unsigned long pfn;
int ret;
- start = PFN_UP(start_addr);
- end = PFN_DOWN(end_addr);
-
- if (end <= start)
- return 0;
-
for(pfn = start; pfn < end; pfn++) {
unsigned long mfn = pfn_to_mfn(pfn);
@@ -117,72 +119,52 @@ static unsigned long __init xen_release_chunk(phys_addr_t start_addr,
return len;
}
-static unsigned long __init xen_return_unused_memory(unsigned long max_pfn,
- const struct e820map *e820)
+static unsigned long __init xen_set_identity_and_release(
+ const struct e820entry *list, size_t map_size, unsigned long nr_pages)
{
- phys_addr_t max_addr = PFN_PHYS(max_pfn);
- phys_addr_t last_end = ISA_END_ADDRESS;
+ phys_addr_t start = 0;
unsigned long released = 0;
- int i;
-
- /* Free any unused memory above the low 1Mbyte. */
- for (i = 0; i < e820->nr_map && last_end < max_addr; i++) {
- phys_addr_t end = e820->map[i].addr;
- end = min(max_addr, end);
-
- if (last_end < end)
- released += xen_release_chunk(last_end, end);
- last_end = max(last_end, e820->map[i].addr + e820->map[i].size);
- }
-
- if (last_end < max_addr)
- released += xen_release_chunk(last_end, max_addr);
-
- printk(KERN_INFO "released %lu pages of unused memory\n", released);
- return released;
-}
-
-static unsigned long __init xen_set_identity(const struct e820entry *list,
- ssize_t map_size)
-{
- phys_addr_t last = xen_initial_domain() ? 0 : ISA_END_ADDRESS;
- phys_addr_t start_pci = last;
- const struct e820entry *entry;
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 start = entry->addr;
- phys_addr_t end = start + entry->size;
+ phys_addr_t end = entry->addr + entry->size;
- if (start < last)
- start = last;
+ if (entry->type == E820_RAM || i == map_size - 1) {
+ unsigned long start_pfn = PFN_DOWN(start);
+ unsigned long end_pfn = PFN_UP(end);
- if (end <= start)
- continue;
+ if (entry->type == E820_RAM)
+ end_pfn = PFN_UP(entry->addr);
- /* Skip over the 1MB region. */
- if (last > end)
- continue;
+ if (start_pfn < end_pfn) {
+ if (start_pfn < nr_pages)
+ released += xen_release_chunk(
+ start_pfn, min(end_pfn, nr_pages));
- if ((entry->type == E820_RAM) || (entry->type == E820_UNUSABLE)) {
- if (start > start_pci)
identity += set_phys_range_identity(
- PFN_UP(start_pci), PFN_DOWN(start));
-
- /* Without saving 'last' we would gooble RAM too
- * at the end of the loop. */
- last = end;
- start_pci = end;
- continue;
+ start_pfn, end_pfn);
+ }
+ start = end;
}
- start_pci = min(start, start_pci);
- last = end;
}
- if (last > start_pci)
- identity += set_phys_range_identity(
- PFN_UP(start_pci), PFN_DOWN(last));
- return identity;
+
+ printk(KERN_INFO "Released %lu pages of unused memory\n", released);
+ printk(KERN_INFO "Set %ld page(s) to 1-1 mapping\n", identity);
+
+ return released;
}
static unsigned long __init xen_get_max_pages(void)
@@ -197,21 +179,32 @@ static unsigned long __init xen_get_max_pages(void)
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;
- 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 max_pages;
unsigned long extra_pages = 0;
- unsigned long extra_limit;
- unsigned long identity_pages = 0;
int i;
int op;
@@ -237,58 +230,65 @@ char * __init xen_memory_setup(void)
}
BUG_ON(rc);
- memcpy(map_raw, map, sizeof(map));
- e820.nr_map = 0;
- xen_extra_mem_start = mem_end;
- 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);
+ /* 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;
}
- if (map[i].size > 0 && end > xen_extra_mem_start)
- xen_extra_mem_start = end;
+ xen_align_and_add_e820_region(addr, size, type);
- /* Add region if any remains */
- if (map[i].size > 0)
- e820_add_region(map[i].addr, map[i].size, map[i].type);
+ map[i].addr += size;
+ map[i].size -= size;
+ if (map[i].size == 0)
+ i++;
}
- /* Align the balloon area so that max_low_pfn does not get set
- * to be at the _end_ of the PCI gap at the far end (fee01000).
- * Note that xen_extra_mem_start gets set in the loop above to be
- * past the last E820 region. */
- if (xen_initial_domain() && (xen_extra_mem_start < (1ULL<<32)))
- xen_extra_mem_start = (1ULL<<32);
/*
* 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);
@@ -305,44 +305,6 @@ char * __init xen_memory_setup(void)
sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
- extra_limit = xen_get_max_pages();
- if (max_pfn + extra_pages > extra_limit) {
- if (extra_limit > max_pfn)
- extra_pages = extra_limit - max_pfn;
- else
- extra_pages = 0;
- }
-
- 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";
}