/*
* 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"
/* 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++) {
unsigned long mfn = pfn_to_mfn(pfn);
if (WARN(mfn == pfn, "Trying to over-write 1-1 mapping (pfn: %lx)\n", pfn))
continue;
WARN(mfn != INVALID_P2M_ENTRY, "Trying to remove %lx which has %lx mfn!\n",
pfn, mfn);
__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>
* 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";
}
/*
* 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 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_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 */
disable_cpuidle();
disable_cpufreq();
WARN_ON(xen_set_default_idle());
fiddle_vdso();
#ifdef CONFIG_NUMA
numa_off = 1;
#endif
}
