common/host_memory: Add Linux implementation

This commit is contained in:
Markus Wick 2021-06-05 10:07:26 +02:00
parent a7837a3791
commit 5105318bbc

View File

@ -1,11 +1,5 @@
#ifdef __linux__
#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif
#include <fcntl.h>
#include <sys/mman.h>
#include <unistd.h>
#elif defined(_WIN32) // ^^^ Linux ^^^ vvv Windows vvv
#ifdef _WIN32
#ifdef _WIN32_WINNT
#undef _WIN32_WINNT
#endif
@ -20,13 +14,23 @@
#pragma comment(lib, "mincore.lib")
#endif // ^^^ Windows ^^^
#elif defined(__linux__) // ^^^ 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/assert.h"
#include "common/host_memory.h"
#include "common/logging/log.h"
#include "common/scope_exit.h"
namespace Common {
@ -269,7 +273,113 @@ private:
std::unordered_map<size_t, size_t> placeholder_host_pointers; ///< Placeholder backing offset
};
#else
#elif defined(__linux__) // ^^^ 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
fd = memfd_create("HostMemory", 0);
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 ^^^
#error Please implement the host memory for your platform