[kernel] Begin replacing page_manager with vm_space
This is the first commit of several reworking the VM system. The main focus is replacing page_manager's global functionality with objects representing individual VM spaces. The main changes in this commit were: - Adding the (as yet unused) vm_area object, which will be the main point of control for programs to allocate or share memory. - Replace the old vm_space with a new one based on state in its page tables. They will also be containers for vm_areas. - vm_space takes over from page_manager as the page fault handler - Commented out the page walking in memory_bootstrap; I'll probably need to recreate this functionality, but it was broken as it was. - Split out the page_table.h implementations from page_manager.cpp into the new page_table.cpp, updated it, and added page_table::iterator as well.
This commit is contained in:
@@ -1,256 +1,125 @@
|
||||
#include <algorithm>
|
||||
#include "kutil/vector.h"
|
||||
#include "log.h"
|
||||
#include "objects/process.h"
|
||||
#include "objects/vm_area.h"
|
||||
#include "page_manager.h"
|
||||
#include "vm_space.h"
|
||||
|
||||
using node_type = kutil::avl_node<vm_range>;
|
||||
using node_vec = kutil::vector<node_type*>;
|
||||
|
||||
DEFINE_SLAB_ALLOCATOR(node_type, 1);
|
||||
|
||||
vm_space::vm_space(uintptr_t start, size_t size)
|
||||
int
|
||||
vm_space::area::compare(const vm_space::area &o) const
|
||||
{
|
||||
node_type *node = new node_type;
|
||||
node->address = start;
|
||||
node->size = size;
|
||||
node->state = vm_state::none;
|
||||
m_ranges.insert(node);
|
||||
|
||||
log::info(logs::vmem, "Creating address space from %016llx-%016llx",
|
||||
start, start+size);
|
||||
if (base > o.base) return 1;
|
||||
else if (base < o.base) return -1;
|
||||
else return 0;
|
||||
}
|
||||
|
||||
vm_space::vm_space()
|
||||
bool
|
||||
vm_space::area::operator==(const vm_space::area &o) const
|
||||
{
|
||||
return o.base == base && o.area == area;
|
||||
}
|
||||
|
||||
|
||||
vm_space::vm_space(page_table *p, bool kernel) :
|
||||
m_kernel(kernel),
|
||||
m_pml4(p)
|
||||
{
|
||||
}
|
||||
|
||||
inline static bool
|
||||
contains(node_type *node, uintptr_t start, size_t size)
|
||||
vm_space::~vm_space()
|
||||
{
|
||||
return start >= node->address &&
|
||||
size <= node->size;
|
||||
for (auto &a : m_areas)
|
||||
a.area->remove_from(this);
|
||||
}
|
||||
|
||||
inline static bool
|
||||
overlaps(node_type *node, uintptr_t start, size_t size)
|
||||
vm_space &
|
||||
vm_space::kernel_space()
|
||||
{
|
||||
return start < node->end() &&
|
||||
(start + size) > node->address;
|
||||
extern vm_space &g_kernel_space;
|
||||
return g_kernel_space;
|
||||
}
|
||||
|
||||
static node_type *
|
||||
find_overlapping(node_type *from, uintptr_t start, size_t size)
|
||||
bool
|
||||
vm_space::add(uintptr_t base, vm_area *area)
|
||||
{
|
||||
while (from) {
|
||||
if (overlaps(from, start, size))
|
||||
return from;
|
||||
|
||||
from = start < from->address ?
|
||||
from->left() :
|
||||
from->right();
|
||||
}
|
||||
|
||||
return nullptr;
|
||||
//TODO: check for collisions
|
||||
m_areas.sorted_insert({base, area});
|
||||
return true;
|
||||
}
|
||||
|
||||
node_type *
|
||||
vm_space::split_out(node_type *node, uintptr_t start, size_t size, vm_state state)
|
||||
bool
|
||||
vm_space::remove(vm_area *area)
|
||||
{
|
||||
// No cross-boundary splits allowed for now
|
||||
const bool contained = contains(node, start, size);
|
||||
kassert(contained, "Tried to split an address range across existing boundaries");
|
||||
if (!contained)
|
||||
return nullptr;
|
||||
|
||||
vm_state old_state = node->state;
|
||||
if (state == old_state)
|
||||
return node;
|
||||
|
||||
node->state = state;
|
||||
|
||||
log::debug(logs::vmem, "Splitting out region %016llx-%016llx[%d] from %016llx-%016llx[%d]",
|
||||
start, start+size, state, node->address, node->end(), old_state);
|
||||
|
||||
bool do_consolidate = false;
|
||||
if (node->address < start) {
|
||||
// Split off rest into new node
|
||||
size_t leading = start - node->address;
|
||||
|
||||
node_type *next = new node_type;
|
||||
next->address = start;
|
||||
next->size = node->size - leading;
|
||||
next->state = state;
|
||||
|
||||
node->size = leading;
|
||||
node->state = old_state;
|
||||
|
||||
log::debug(logs::vmem,
|
||||
" leading region %016llx-%016llx[%d]",
|
||||
node->address, node->address + node->size, node->state);
|
||||
|
||||
m_ranges.insert(next);
|
||||
node = next;
|
||||
} else {
|
||||
do_consolidate = true;
|
||||
}
|
||||
|
||||
if (node->end() > start + size) {
|
||||
// Split off remaining into new node
|
||||
size_t trailing = node->size - size;
|
||||
node->size -= trailing;
|
||||
|
||||
node_type *next = new node_type;
|
||||
next->state = old_state;
|
||||
next->address = node->end();
|
||||
next->size = trailing;
|
||||
|
||||
log::debug(logs::vmem,
|
||||
" tailing region %016llx-%016llx[%d]",
|
||||
next->address, next->address + next->size, next->state);
|
||||
|
||||
m_ranges.insert(next);
|
||||
} else {
|
||||
do_consolidate = true;
|
||||
}
|
||||
|
||||
if (do_consolidate)
|
||||
node = consolidate(node);
|
||||
|
||||
return node;
|
||||
}
|
||||
|
||||
node_type *
|
||||
vm_space::find_empty(node_type *node, size_t size, vm_state state)
|
||||
{
|
||||
if (node->state == vm_state::none && node->size >= size)
|
||||
return split_out(node, node->address, size, state);
|
||||
|
||||
if (node->left()) {
|
||||
node_type *found = find_empty(node->left(), size, state);
|
||||
if (found)
|
||||
return found;
|
||||
}
|
||||
|
||||
if (node->right()) {
|
||||
node_type *found = find_empty(node->right(), size, state);
|
||||
if (found)
|
||||
return found;
|
||||
}
|
||||
|
||||
return nullptr;
|
||||
}
|
||||
|
||||
inline void gather(node_type *node, node_vec &vec)
|
||||
{
|
||||
if (node) {
|
||||
gather(node->left(), vec);
|
||||
vec.append(node);
|
||||
gather(node->right(), vec);
|
||||
}
|
||||
}
|
||||
|
||||
node_type *
|
||||
vm_space::consolidate(node_type *needle)
|
||||
{
|
||||
node_vec nodes(m_ranges.count());
|
||||
gather(m_ranges.root(), nodes);
|
||||
|
||||
node_type *prev = nullptr;
|
||||
for (auto *node : nodes) {
|
||||
log::debug(logs::vmem,
|
||||
"* Existing region %016llx-%016llx[%d]",
|
||||
node->address, node->address + node->size, node->state);
|
||||
|
||||
if (prev && node->address == prev->end() && node->state == prev->state) {
|
||||
log::debug(logs::vmem,
|
||||
"Joining regions %016llx-%016llx[%d] %016llx-%016llx[%d]",
|
||||
prev->address, prev->address + prev->size, prev->state,
|
||||
node->address, node->address + node->size, node->state);
|
||||
|
||||
prev->size += node->size;
|
||||
if (needle == node)
|
||||
needle = prev;
|
||||
m_ranges.remove(node);
|
||||
} else {
|
||||
prev = node;
|
||||
for (auto &a : m_areas) {
|
||||
if (a.area == area) {
|
||||
m_areas.remove(a);
|
||||
return true;
|
||||
}
|
||||
}
|
||||
|
||||
return needle;
|
||||
return false;
|
||||
}
|
||||
|
||||
uintptr_t
|
||||
vm_space::reserve(uintptr_t start, size_t size)
|
||||
vm_area *
|
||||
vm_space::get(uintptr_t addr, uintptr_t *base)
|
||||
{
|
||||
|
||||
if (start == 0) {
|
||||
log::debug(logs::vmem, "Reserving any region of size %llx", size);
|
||||
node_type *node = find_empty(m_ranges.root(), size, vm_state::reserved);
|
||||
if (!node) {
|
||||
log::debug(logs::vmem, " found no large enough region");
|
||||
return 0;
|
||||
for (auto &a : m_areas) {
|
||||
uintptr_t end = a.base + a.area->size();
|
||||
if (addr >= a.base && addr < end) {
|
||||
if (base) *base = a.base;
|
||||
return a.area;
|
||||
}
|
||||
|
||||
return node->address;
|
||||
}
|
||||
|
||||
log::debug(logs::vmem, "Reserving region %016llx-%016llx",
|
||||
start, start+size);
|
||||
node_type *node = find_overlapping(m_ranges.root(), start, size);
|
||||
|
||||
if (!node) {
|
||||
log::debug(logs::vmem, " found no match");
|
||||
return 0;
|
||||
}
|
||||
|
||||
node = split_out(node, start, size, vm_state::reserved);
|
||||
return node ? start : 0;
|
||||
return nullptr;
|
||||
}
|
||||
|
||||
void
|
||||
vm_space::unreserve(uintptr_t start, size_t size)
|
||||
vm_space::page_in(uintptr_t addr, size_t count, uintptr_t phys)
|
||||
{
|
||||
log::debug(logs::vmem, "Unreserving region %016llx-%016llx", start, start+size);
|
||||
node_type *node = find_overlapping(m_ranges.root(), start, size);
|
||||
|
||||
if (!node || !contains(node, start, size)) {
|
||||
log::debug(logs::vmem, " found no match");
|
||||
return;
|
||||
}
|
||||
|
||||
split_out(node, start, size, vm_state::none);
|
||||
page_manager *pm = page_manager::get();
|
||||
pm->page_in(m_pml4, phys, addr, count, is_kernel());
|
||||
}
|
||||
|
||||
uintptr_t
|
||||
vm_space::commit(uintptr_t start, size_t size)
|
||||
void
|
||||
vm_space::page_out(uintptr_t addr, size_t count)
|
||||
{
|
||||
if (start == 0) {
|
||||
log::debug(logs::vmem, "Committing any region of size %llx", size);
|
||||
node_type *node = find_empty(m_ranges.root(), size, vm_state::committed);
|
||||
if (!node) {
|
||||
log::debug(logs::vmem, " found no large enough region");
|
||||
return 0;
|
||||
}
|
||||
|
||||
return node->address;
|
||||
}
|
||||
|
||||
log::debug(logs::vmem, "Committing region %016llx-%016llx",
|
||||
start, start+size);
|
||||
|
||||
node_type *node = find_overlapping(m_ranges.root(), start, size);
|
||||
if (!node) {
|
||||
log::debug(logs::vmem, " found no match");
|
||||
return 0;
|
||||
}
|
||||
|
||||
node = split_out(node, start, size, vm_state::committed);
|
||||
return node ? start : 0;
|
||||
page_manager *pm = page_manager::get();
|
||||
pm->page_out(m_pml4, addr, count, false);
|
||||
}
|
||||
|
||||
vm_state
|
||||
vm_space::get(uintptr_t addr)
|
||||
void
|
||||
vm_space::allow(uintptr_t start, size_t length, bool allow)
|
||||
{
|
||||
node_type *node = find_overlapping(m_ranges.root(), addr, 1);
|
||||
return node ? node->state : vm_state::unknown;
|
||||
using level = page_table::level;
|
||||
kassert((start & 0xfff) == 0, "non-page-aligned address");
|
||||
kassert((length & 0xfff) == 0, "non-page-aligned length");
|
||||
|
||||
const uintptr_t end = start + length;
|
||||
page_table::iterator it {start, m_pml4};
|
||||
|
||||
while (it.vaddress() < end) {
|
||||
level d = it.align();
|
||||
while (it.end(d) > end) ++d;
|
||||
it.allow(d-1, allow);
|
||||
it.next(d);
|
||||
}
|
||||
}
|
||||
|
||||
bool
|
||||
vm_space::handle_fault(uintptr_t addr, fault_type fault)
|
||||
{
|
||||
uintptr_t page = addr & ~0xfffull;
|
||||
|
||||
page_table::iterator it {addr, m_pml4};
|
||||
|
||||
if (!it.allowed())
|
||||
return false;
|
||||
|
||||
// TODO: pull this out of PM
|
||||
page_manager::get()->map_pages(page, 1, m_pml4);
|
||||
|
||||
/* TODO: Tell the VMA if there is one
|
||||
uintptr_t base = 0;
|
||||
vm_area *area = get(addr, &base);
|
||||
*/
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user