// SPDX-License-Identifier: GPL-2.0
/*
* Machine specific setup for xen
*
* Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
*/
#include <linux/init.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 <linux/memory_hotplug.h>
#include <asm/elf.h>
#include <asm/vdso.h>
#include <asm/e820/api.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/hvc-console.h>
#include "xen-ops.h"
#include "vdso.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([31mCONFIG_XEN_512GB[0m);
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_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);
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;
#ifdef [31mCONFIG_X86_32[0m
limit = GB(64) / PAGE_SIZE;
#else
limit = MAXMEM / PAGE_SIZE;
if (!xen_initial_domain() && xen_512gb_limit)
limit = GB(512) / PAGE_SIZE;
#endif
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 [31mCONFIG_MEMORY_HOTPLUG[0m
/*
* 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;
#ifdef [31mCONFIG_X86_32[0m
/*
* Relocating the p2m on 32 bit system to an arbitrary virtual address
* is not supported, so just give up.
*/
xen_raw_console_write("Xen hypervisor allocated p2m list conflicts with E820 map\n");
BUG();
#else
xen_relocate_p2m();
memblock_free(start, size);
#endif
}
/**
* 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([31mCONFIG_MEMORY_HOTPLUG[0m) && defined([31mCONFIG_XEN_BALLOON[0m)
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. 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.
*
* Make sure we have no memory above max_pages, as this area
* isn't handled by the p2m management.
*
* 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 = 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";
}
/*
* 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 [31mCONFIG_X86_32[0m
u32 *mask = vdso_image_32.data +
vdso_image_32.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 [31mCONFIG_X86_32[0m
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 [31mCONFIG_X86_64[0m
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();
xen_pvmmu_arch_setup();
#ifdef [31mCONFIG_ACPI[0m
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 [31mCONFIG_NUMA[0m
numa_off = 1;
#endif
}