#ifdef _WIN32
#include <iterator>
#include <unordered_map>
#include <boost/icl/separate_interval_set.hpp>
#include <windows.h>
#include "common/dynamic_library.h"
#elif defined(__linux__) || defined(__FreeBSD__) // ^^^ Windows ^^^ vvv Linux vvv
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>
#endif // ^^^ Linux ^^^
#include <mutex>
#include "common/alignment.h"
#include "common/assert.h"
#include "common/host_memory.h"
#include "common/logging/log.h"
#include "common/scope_exit.h"
namespace Common {
constexpr size_t PageAlignment = 0x1000;
constexpr size_t HugePageSize = 0x200000;
#ifdef _WIN32
// Manually imported for MinGW compatibility
#ifndef MEM_RESERVE_PLACEHOLDER
#define MEM_RESERVE_PLACEHOLDER 0x00040000
#endif
#ifndef MEM_REPLACE_PLACEHOLDER
#define MEM_REPLACE_PLACEHOLDER 0x00004000
#endif
#ifndef MEM_COALESCE_PLACEHOLDERS
#define MEM_COALESCE_PLACEHOLDERS 0x00000001
#endif
#ifndef MEM_PRESERVE_PLACEHOLDER
#define MEM_PRESERVE_PLACEHOLDER 0x00000002
#endif
using PFN_CreateFileMapping2 = _Ret_maybenull_ HANDLE(WINAPI*)(
_In_ HANDLE File, _In_opt_ SECURITY_ATTRIBUTES* SecurityAttributes, _In_ ULONG DesiredAccess,
_In_ ULONG PageProtection, _In_ ULONG AllocationAttributes, _In_ ULONG64 MaximumSize,
_In_opt_ PCWSTR Name,
_Inout_updates_opt_(ParameterCount) MEM_EXTENDED_PARAMETER* ExtendedParameters,
_In_ ULONG ParameterCount);
using PFN_VirtualAlloc2 = _Ret_maybenull_ PVOID(WINAPI*)(
_In_opt_ HANDLE Process, _In_opt_ PVOID BaseAddress, _In_ SIZE_T Size,
_In_ ULONG AllocationType, _In_ ULONG PageProtection,
_Inout_updates_opt_(ParameterCount) MEM_EXTENDED_PARAMETER* ExtendedParameters,
_In_ ULONG ParameterCount);
using PFN_MapViewOfFile3 = _Ret_maybenull_ PVOID(WINAPI*)(
_In_ HANDLE FileMapping, _In_opt_ HANDLE Process, _In_opt_ PVOID BaseAddress,
_In_ ULONG64 Offset, _In_ SIZE_T ViewSize, _In_ ULONG AllocationType, _In_ ULONG PageProtection,
_Inout_updates_opt_(ParameterCount) MEM_EXTENDED_PARAMETER* ExtendedParameters,
_In_ ULONG ParameterCount);
using PFN_UnmapViewOfFile2 = BOOL(WINAPI*)(_In_ HANDLE Process, _In_ PVOID BaseAddress,
_In_ ULONG UnmapFlags);
template <typename T>
static void GetFuncAddress(Common::DynamicLibrary& dll, const char* name, T& pfn) {
if (!dll.GetSymbol(name, &pfn)) {
LOG_CRITICAL(HW_Memory, "Failed to load {}", name);
throw std::bad_alloc{};
}
}
class HostMemory::Impl {
public:
explicit Impl(size_t backing_size_, size_t virtual_size_)
: backing_size{backing_size_}, virtual_size{virtual_size_}, process{GetCurrentProcess()},
kernelbase_dll("Kernelbase") {
if (!kernelbase_dll.IsOpen()) {
LOG_CRITICAL(HW_Memory, "Failed to load Kernelbase.dll");
throw std::bad_alloc{};
}
GetFuncAddress(kernelbase_dll, "CreateFileMapping2", pfn_CreateFileMapping2);
GetFuncAddress(kernelbase_dll, "VirtualAlloc2", pfn_VirtualAlloc2);
GetFuncAddress(kernelbase_dll, "MapViewOfFile3", pfn_MapViewOfFile3);
GetFuncAddress(kernelbase_dll, "UnmapViewOfFile2", pfn_UnmapViewOfFile2);
// Allocate backing file map
backing_handle =
pfn_CreateFileMapping2(INVALID_HANDLE_VALUE, nullptr, FILE_MAP_WRITE | FILE_MAP_READ,
PAGE_READWRITE, SEC_COMMIT, backing_size, nullptr, nullptr, 0);
if (!backing_handle) {
LOG_CRITICAL(HW_Memory, "Failed to allocate {} MiB of backing memory",
backing_size >> 20);
throw std::bad_alloc{};
}
// Allocate a virtual memory for the backing file map as placeholder
backing_base = static_cast<u8*>(pfn_VirtualAlloc2(process, nullptr, backing_size,
MEM_RESERVE | MEM_RESERVE_PLACEHOLDER,
PAGE_NOACCESS, nullptr, 0));
if (!backing_base) {
Release();
LOG_CRITICAL(HW_Memory, "Failed to reserve {} MiB of virtual memory",
backing_size >> 20);
throw std::bad_alloc{};
}
// Map backing placeholder
void* const ret = pfn_MapViewOfFile3(backing_handle, process, backing_base, 0, backing_size,
MEM_REPLACE_PLACEHOLDER, PAGE_READWRITE, nullptr, 0);
if (ret != backing_base) {
Release();
LOG_CRITICAL(HW_Memory, "Failed to map {} MiB of virtual memory", backing_size >> 20);
throw std::bad_alloc{};
}
// Allocate virtual address placeholder
virtual_base = static_cast<u8*>(pfn_VirtualAlloc2(process, nullptr, virtual_size,
MEM_RESERVE | MEM_RESERVE_PLACEHOLDER,
PAGE_NOACCESS, nullptr, 0));
if (!virtual_base) {
Release();
LOG_CRITICAL(HW_Memory, "Failed to reserve {} GiB of virtual memory",
virtual_size >> 30);
throw std::bad_alloc{};
}
}
~Impl() {
Release();
}
void Map(size_t virtual_offset, size_t host_offset, size_t length) {
std::unique_lock lock{placeholder_mutex};
if (!IsNiechePlaceholder(virtual_offset, length)) {
Split(virtual_offset, length);
}
ASSERT(placeholders.find({virtual_offset, virtual_offset + length}) == placeholders.end());
TrackPlaceholder(virtual_offset, host_offset, length);
MapView(virtual_offset, host_offset, length);
}
void Unmap(size_t virtual_offset, size_t length) {
std::lock_guard lock{placeholder_mutex};
// Unmap until there are no more placeholders
while (UnmapOnePlaceholder(virtual_offset, length)) {
}
}
void Protect(size_t virtual_offset, size_t length, bool read, bool write) {
DWORD new_flags{};
if (read && write) {
new_flags = PAGE_READWRITE;
} else if (read && !write) {
new_flags = PAGE_READONLY;
} else if (!read && !write) {
new_flags = PAGE_NOACCESS;
} else {
UNIMPLEMENTED_MSG("Protection flag combination read={} write={}", read, write);
}
const size_t virtual_end = virtual_offset + length;
std::lock_guard lock{placeholder_mutex};
auto [it, end] = placeholders.equal_range({virtual_offset, virtual_end});
while (it != end) {
const size_t offset = std::max(it->lower(), virtual_offset);
const size_t protect_length = std::min(it->upper(), virtual_end) - offset;
DWORD old_flags{};
if (!VirtualProtect(virtual_base + offset, protect_length, new_flags, &old_flags)) {
LOG_CRITICAL(HW_Memory, "Failed to change virtual memory protect rules");
}
++it;
}
}
const size_t backing_size; ///< Size of the backing memory in bytes
const size_t virtual_size; ///< Size of the virtual address placeholder in bytes
u8* backing_base{};
u8* virtual_base{};
private:
/// Release all resources in the object
void Release() {
if (!placeholders.empty()) {
for (const auto& placeholder : placeholders) {
if (!pfn_UnmapViewOfFile2(process, virtual_base + placeholder.lower(),
MEM_PRESERVE_PLACEHOLDER)) {
LOG_CRITICAL(HW_Memory, "Failed to unmap virtual memory placeholder");
}
}
Coalesce(0, virtual_size);
}
if (virtual_base) {
if (!VirtualFree(virtual_base, 0, MEM_RELEASE)) {
LOG_CRITICAL(HW_Memory, "Failed to free virtual memory");
}
}
if (backing_base) {
if (!pfn_UnmapViewOfFile2(process, backing_base, MEM_PRESERVE_PLACEHOLDER)) {
LOG_CRITICAL(HW_Memory, "Failed to unmap backing memory placeholder");
}
if (!VirtualFreeEx(process, backing_base, 0, MEM_RELEASE)) {
LOG_CRITICAL(HW_Memory, "Failed to free backing memory");
}
}
if (!CloseHandle(backing_handle)) {
LOG_CRITICAL(HW_Memory, "Failed to free backing memory file handle");
}
}
/// Unmap one placeholder in the given range (partial unmaps are supported)
/// Return true when there are no more placeholders to unmap
bool UnmapOnePlaceholder(size_t virtual_offset, size_t length) {
const auto it = placeholders.find({virtual_offset, virtual_offset + length});
const auto begin = placeholders.begin();
const auto end = placeholders.end();
if (it == end) {
return false;
}
const size_t placeholder_begin = it->lower();
const size_t placeholder_end = it->upper();
const size_t unmap_begin = std::max(virtual_offset, placeholder_begin);
const size_t unmap_end = std::min(virtual_offset + length, placeholder_end);
ASSERT(unmap_begin >= placeholder_begin && unmap_begin < placeholder_end);
ASSERT(unmap_end <= placeholder_end && unmap_end > placeholder_begin);
const auto host_pointer_it = placeholder_host_pointers.find(placeholder_begin);
ASSERT(host_pointer_it != placeholder_host_pointers.end());
const size_t host_offset = host_pointer_it->second;
const bool split_left = unmap_begin > placeholder_begin;
const bool split_right = unmap_end < placeholder_end;
if (!pfn_UnmapViewOfFile2(process, virtual_base + placeholder_begin,
MEM_PRESERVE_PLACEHOLDER)) {
LOG_CRITICAL(HW_Memory, "Failed to unmap placeholder");
}
// If we have to remap memory regions due to partial unmaps, we are in a data race as
// Windows doesn't support remapping memory without unmapping first. Avoid adding any extra
// logic within the panic region described below.
// Panic region, we are in a data race right now
if (split_left || split_right) {
Split(unmap_begin, unmap_end - unmap_begin);
}
if (split_left) {
MapView(placeholder_begin, host_offset, unmap_begin - placeholder_begin);
}
if (split_right) {
MapView(unmap_end, host_offset + unmap_end - placeholder_begin,
placeholder_end - unmap_end);
}
// End panic region
size_t coalesce_begin = unmap_begin;
if (!split_left) {
// Try to coalesce pages to the left
coalesce_begin = it == begin ? 0 : std::prev(it)->upper();
if (coalesce_begin != placeholder_begin) {
Coalesce(coalesce_begin, unmap_end - coalesce_begin);
}
}
if (!split_right) {
// Try to coalesce pages to the right
const auto next = std::next(it);
const size_t next_begin = next == end ? virtual_size : next->lower();
if (placeholder_end != next_begin) {
// We can coalesce to the right
Coalesce(coalesce_begin, next_begin - coalesce_begin);
}
}
// Remove and reinsert placeholder trackers
UntrackPlaceholder(it);
if (split_left) {
TrackPlaceholder(placeholder_begin, host_offset, unmap_begin - placeholder_begin);
}
if (split_right) {
TrackPlaceholder(unmap_end, host_offset + unmap_end - placeholder_begin,
placeholder_end - unmap_end);
}
return true;
}
void MapView(size_t virtual_offset, size_t host_offset, size_t length) {
if (!pfn_MapViewOfFile3(backing_handle, process, virtual_base + virtual_offset, host_offset,
length, MEM_REPLACE_PLACEHOLDER, PAGE_READWRITE, nullptr, 0)) {
LOG_CRITICAL(HW_Memory, "Failed to map placeholder");
}
}
void Split(size_t virtual_offset, size_t length) {
if (!VirtualFreeEx(process, reinterpret_cast<LPVOID>(virtual_base + virtual_offset), length,
MEM_RELEASE | MEM_PRESERVE_PLACEHOLDER)) {
LOG_CRITICAL(HW_Memory, "Failed to split placeholder");
}
}
void Coalesce(size_t virtual_offset, size_t length) {
if (!VirtualFreeEx(process, reinterpret_cast<LPVOID>(virtual_base + virtual_offset), length,
MEM_RELEASE | MEM_COALESCE_PLACEHOLDERS)) {
LOG_CRITICAL(HW_Memory, "Failed to coalesce placeholders");
}
}
void TrackPlaceholder(size_t virtual_offset, size_t host_offset, size_t length) {
placeholders.insert({virtual_offset, virtual_offset + length});
placeholder_host_pointers.emplace(virtual_offset, host_offset);
}
void UntrackPlaceholder(boost::icl::separate_interval_set<size_t>::iterator it) {
placeholder_host_pointers.erase(it->lower());
placeholders.erase(it);
}
/// Return true when a given memory region is a "nieche" and the placeholders don't have to be
/// splitted.
bool IsNiechePlaceholder(size_t virtual_offset, size_t length) const {
const auto it = placeholders.upper_bound({virtual_offset, virtual_offset + length});
if (it != placeholders.end() && it->lower() == virtual_offset + length) {
const bool is_root = it == placeholders.begin() && virtual_offset == 0;
return is_root || std::prev(it)->upper() == virtual_offset;
}
return false;
}
HANDLE process{}; ///< Current process handle
HANDLE backing_handle{}; ///< File based backing memory
DynamicLibrary kernelbase_dll;
PFN_CreateFileMapping2 pfn_CreateFileMapping2{};
PFN_VirtualAlloc2 pfn_VirtualAlloc2{};
PFN_MapViewOfFile3 pfn_MapViewOfFile3{};
PFN_UnmapViewOfFile2 pfn_UnmapViewOfFile2{};
std::mutex placeholder_mutex; ///< Mutex for placeholders
boost::icl::separate_interval_set<size_t> placeholders; ///< Mapped placeholders
std::unordered_map<size_t, size_t> placeholder_host_pointers; ///< Placeholder backing offset
};
#elif defined(__linux__) || defined(__FreeBSD__) // ^^^ Windows ^^^ vvv Linux vvv
class HostMemory::Impl {
public:
explicit Impl(size_t backing_size_, size_t virtual_size_)
: backing_size{backing_size_}, virtual_size{virtual_size_} {
bool good = false;
SCOPE_EXIT({
if (!good) {
Release();
}
});
// Backing memory initialization
#if defined(__FreeBSD__) && __FreeBSD__ < 13
// XXX Drop after FreeBSD 12.* reaches EOL on 2024-06-30
fd = shm_open(SHM_ANON, O_RDWR, 0600);
#else
fd = memfd_create("HostMemory", 0);
#endif
if (fd == -1) {
LOG_CRITICAL(HW_Memory, "memfd_create failed: {}", strerror(errno));
throw std::bad_alloc{};
}
// Defined to extend the file with zeros
int ret = ftruncate(fd, backing_size);
if (ret != 0) {
LOG_CRITICAL(HW_Memory, "ftruncate failed with {}, are you out-of-memory?",
strerror(errno));
throw std::bad_alloc{};
}
backing_base = static_cast<u8*>(
mmap(nullptr, backing_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0));
if (backing_base == MAP_FAILED) {
LOG_CRITICAL(HW_Memory, "mmap failed: {}", strerror(errno));
throw std::bad_alloc{};
}
// Virtual memory initialization
virtual_base = static_cast<u8*>(
mmap(nullptr, virtual_size, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0));
if (virtual_base == MAP_FAILED) {
LOG_CRITICAL(HW_Memory, "mmap failed: {}", strerror(errno));
throw std::bad_alloc{};
}
good = true;
}
~Impl() {
Release();
}
void Map(size_t virtual_offset, size_t host_offset, size_t length) {
void* ret = mmap(virtual_base + virtual_offset, length, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_FIXED, fd, host_offset);
ASSERT_MSG(ret != MAP_FAILED, "mmap failed: {}", strerror(errno));
}
void Unmap(size_t virtual_offset, size_t length) {
// The method name is wrong. We're still talking about the virtual range.
// We don't want to unmap, we want to reserve this memory.
void* ret = mmap(virtual_base + virtual_offset, length, PROT_NONE,
MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
ASSERT_MSG(ret != MAP_FAILED, "mmap failed: {}", strerror(errno));
}
void Protect(size_t virtual_offset, size_t length, bool read, bool write) {
int flags = 0;
if (read) {
flags |= PROT_READ;
}
if (write) {
flags |= PROT_WRITE;
}
int ret = mprotect(virtual_base + virtual_offset, length, flags);
ASSERT_MSG(ret == 0, "mprotect failed: {}", strerror(errno));
}
const size_t backing_size; ///< Size of the backing memory in bytes
const size_t virtual_size; ///< Size of the virtual address placeholder in bytes
u8* backing_base{reinterpret_cast<u8*>(MAP_FAILED)};
u8* virtual_base{reinterpret_cast<u8*>(MAP_FAILED)};
private:
/// Release all resources in the object
void Release() {
if (virtual_base != MAP_FAILED) {
int ret = munmap(virtual_base, virtual_size);
ASSERT_MSG(ret == 0, "munmap failed: {}", strerror(errno));
}
if (backing_base != MAP_FAILED) {
int ret = munmap(backing_base, backing_size);
ASSERT_MSG(ret == 0, "munmap failed: {}", strerror(errno));
}
if (fd != -1) {
int ret = close(fd);
ASSERT_MSG(ret == 0, "close failed: {}", strerror(errno));
}
}
int fd{-1}; // memfd file descriptor, -1 is the error value of memfd_create
};
#else // ^^^ Linux ^^^ vvv Generic vvv
class HostMemory::Impl {
public:
explicit Impl(size_t /*backing_size */, size_t /* virtual_size */) {
// This is just a place holder.
// Please implement fastmem in a propper way on your platform.
throw std::bad_alloc{};
}
void Map(size_t virtual_offset, size_t host_offset, size_t length) {}
void Unmap(size_t virtual_offset, size_t length) {}
void Protect(size_t virtual_offset, size_t length, bool read, bool write) {}
u8* backing_base{nullptr};
u8* virtual_base{nullptr};
};
#endif // ^^^ Generic ^^^
HostMemory::HostMemory(size_t backing_size_, size_t virtual_size_)
: backing_size(backing_size_), virtual_size(virtual_size_) {
try {
// Try to allocate a fastmem arena.
// The implementation will fail with std::bad_alloc on errors.
impl = std::make_unique<HostMemory::Impl>(AlignUp(backing_size, PageAlignment),
AlignUp(virtual_size, PageAlignment) +
3 * HugePageSize);
backing_base = impl->backing_base;
virtual_base = impl->virtual_base;
if (virtual_base) {
virtual_base += 2 * HugePageSize - 1;
virtual_base -= reinterpret_cast<size_t>(virtual_base) & (HugePageSize - 1);
virtual_base_offset = virtual_base - impl->virtual_base;
}
} catch (const std::bad_alloc&) {
LOG_CRITICAL(HW_Memory,
"Fastmem unavailable, falling back to VirtualBuffer for memory allocation");
fallback_buffer = std::make_unique<Common::VirtualBuffer<u8>>(backing_size);
backing_base = fallback_buffer->data();
virtual_base = nullptr;
}
}
HostMemory::~HostMemory() = default;
HostMemory::HostMemory(HostMemory&&) noexcept = default;
HostMemory& HostMemory::operator=(HostMemory&&) noexcept = default;
void HostMemory::Map(size_t virtual_offset, size_t host_offset, size_t length) {
ASSERT(virtual_offset % PageAlignment == 0);
ASSERT(host_offset % PageAlignment == 0);
ASSERT(length % PageAlignment == 0);
ASSERT(virtual_offset + length <= virtual_size);
ASSERT(host_offset + length <= backing_size);
if (length == 0 || !virtual_base || !impl) {
return;
}
impl->Map(virtual_offset + virtual_base_offset, host_offset, length);
}
void HostMemory::Unmap(size_t virtual_offset, size_t length) {
ASSERT(virtual_offset % PageAlignment == 0);
ASSERT(length % PageAlignment == 0);
ASSERT(virtual_offset + length <= virtual_size);
if (length == 0 || !virtual_base || !impl) {
return;
}
impl->Unmap(virtual_offset + virtual_base_offset, length);
}
void HostMemory::Protect(size_t virtual_offset, size_t length, bool read, bool write) {
ASSERT(virtual_offset % PageAlignment == 0);
ASSERT(length % PageAlignment == 0);
ASSERT(virtual_offset + length <= virtual_size);
if (length == 0 || !virtual_base || !impl) {
return;
}
impl->Protect(virtual_offset + virtual_base_offset, length, read, write);
}
} // namespace Common
