Files
cloud-hypervisor/vmm/src/memory_manager.rs
Sebastien Boeuf d1ce52f3a8 vmm: memory_manager: Make backing file from snapshot optional
Let's not assume that a backing file is going to be the result from
a snapshot for each memory region. These regions might be backed by
a file on the host filesystem (not a temporary file in host RAM), which
means they don't need to be copied and stored into dedicated files.

That's why this commit prepares for further changes by introducing an
optional PathBuf associated with the snapshot of each memory region.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
2020-08-25 16:43:10 +02:00

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Rust
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// Copyright © 2019 Intel Corporation
//
// SPDX-License-Identifier: Apache-2.0
//
extern crate hypervisor;
#[cfg(target_arch = "x86_64")]
use crate::config::SgxEpcConfig;
use crate::config::{HotplugMethod, MemoryConfig, MemoryZoneConfig};
use crate::MEMORY_MANAGER_SNAPSHOT_ID;
#[cfg(feature = "acpi")]
use acpi_tables::{aml, aml::Aml};
use anyhow::anyhow;
#[cfg(target_arch = "x86_64")]
use arch::x86_64::{SgxEpcRegion, SgxEpcSection};
use arch::{get_host_cpu_phys_bits, layout, RegionType};
#[cfg(target_arch = "x86_64")]
use devices::ioapic;
use devices::BusDevice;
#[cfg(target_arch = "x86_64")]
use libc::{MAP_NORESERVE, MAP_POPULATE, MAP_SHARED, PROT_READ, PROT_WRITE};
use std::convert::TryInto;
use std::ffi;
use std::fs::{File, OpenOptions};
use std::io;
#[cfg(target_arch = "x86_64")]
use std::os::unix::io::AsRawFd;
use std::os::unix::io::{FromRawFd, RawFd};
use std::path::PathBuf;
use std::result;
use std::sync::{Arc, Mutex};
use url::Url;
#[cfg(target_arch = "x86_64")]
use vm_allocator::GsiApic;
use vm_allocator::SystemAllocator;
use vm_memory::guest_memory::FileOffset;
use vm_memory::{
mmap::MmapRegionError, Address, Bytes, Error as MmapError, GuestAddress, GuestAddressSpace,
GuestMemory, GuestMemoryAtomic, GuestMemoryLoadGuard, GuestMemoryMmap, GuestMemoryRegion,
GuestRegionMmap, GuestUsize, MemoryRegionAddress, MmapRegion,
};
use vm_migration::{
Migratable, MigratableError, Pausable, Snapshot, SnapshotDataSection, Snapshottable,
Transportable,
};
#[cfg(target_arch = "x86_64")]
const X86_64_IRQ_BASE: u32 = 5;
const HOTPLUG_COUNT: usize = 8;
#[derive(Default)]
struct HotPlugState {
base: u64,
length: u64,
active: bool,
inserting: bool,
removing: bool,
}
pub struct MemoryManager {
guest_memory: GuestMemoryAtomic<GuestMemoryMmap>,
next_memory_slot: u32,
start_of_device_area: GuestAddress,
end_of_device_area: GuestAddress,
pub vm: Arc<dyn hypervisor::Vm>,
hotplug_slots: Vec<HotPlugState>,
selected_slot: usize,
backing_file: Option<PathBuf>,
mergeable: bool,
allocator: Arc<Mutex<SystemAllocator>>,
hotplug_method: HotplugMethod,
boot_ram: u64,
current_ram: u64,
next_hotplug_slot: usize,
pub virtiomem_region: Option<Arc<GuestRegionMmap>>,
pub virtiomem_resize: Option<virtio_devices::Resize>,
snapshot: Mutex<Option<GuestMemoryLoadGuard<GuestMemoryMmap>>>,
shared: bool,
hugepages: bool,
balloon: Option<Arc<Mutex<virtio_devices::Balloon>>>,
#[cfg(target_arch = "x86_64")]
sgx_epc_region: Option<SgxEpcRegion>,
use_zones: bool,
}
#[derive(Debug)]
pub enum Error {
/// Failed to create shared file.
SharedFileCreate(io::Error),
/// Failed to set shared file length.
SharedFileSetLen(io::Error),
/// Mmap backed guest memory error
GuestMemory(MmapError),
/// Failed to allocate a memory range.
MemoryRangeAllocation,
/// Failed to create map region
MmapRegion(),
/// Error from region creation
GuestMemoryRegion(MmapRegionError),
/// No ACPI slot available
NoSlotAvailable,
/// Not enough space in the hotplug RAM region
InsufficientHotplugRAM,
/// The requested hotplug memory addition is not a valid size
InvalidSize,
/// Failed to set the user memory region.
SetUserMemoryRegion(hypervisor::HypervisorVmError),
/// Failed to EventFd.
EventFdFail(io::Error),
/// Eventfd write error
EventfdError(io::Error),
/// Failed to virtio-mem resize
VirtioMemResizeFail(virtio_devices::mem::Error),
/// Cannot restore VM
Restore(MigratableError),
/// Cannot create the system allocator
CreateSystemAllocator,
/// The number of external backing files doesn't match the number of
/// memory regions.
InvalidAmountExternalBackingFiles,
/// Failed to virtio-balloon resize
VirtioBalloonResizeFail(virtio_devices::balloon::Error),
/// Invalid SGX EPC section size
#[cfg(target_arch = "x86_64")]
EpcSectionSizeInvalid,
/// Failed allocating SGX EPC region
#[cfg(target_arch = "x86_64")]
SgxEpcRangeAllocation,
/// Failed opening SGX virtual EPC device
#[cfg(target_arch = "x86_64")]
SgxVirtEpcOpen(io::Error),
/// Failed setting the SGX virtual EPC section size
#[cfg(target_arch = "x86_64")]
SgxVirtEpcFileSetLen(io::Error),
/// Failed creating a new MmapRegion instance.
#[cfg(target_arch = "x86_64")]
NewMmapRegion(vm_memory::mmap::MmapRegionError),
/// No memory zones found.
MissingMemoryZones,
/// Memory configuration is not valid.
InvalidMemoryParameters,
/// Forbidden operation. Impossible to resize guest memory if it is
/// backed by user defined memory regions.
InvalidResizeWithMemoryZones,
/// Forbidden operation. Impossible to restore guest memory if it is
/// backed by user defined memory regions.
InvalidRestoreWithMemoryZones,
}
const ENABLE_FLAG: usize = 0;
const INSERTING_FLAG: usize = 1;
const REMOVING_FLAG: usize = 2;
const EJECT_FLAG: usize = 3;
const BASE_OFFSET_LOW: u64 = 0;
const BASE_OFFSET_HIGH: u64 = 0x4;
const LENGTH_OFFSET_LOW: u64 = 0x8;
const LENGTH_OFFSET_HIGH: u64 = 0xC;
const STATUS_OFFSET: u64 = 0x14;
const SELECTION_OFFSET: u64 = 0;
// The MMIO address space size is substracted with the size of a 4k page. This
// is done on purpose to workaround a Linux bug when the VMM allocates devices
// at the end of the addressable space.
fn mmio_address_space_size() -> u64 {
(1 << get_host_cpu_phys_bits()) - 0x1000
}
impl BusDevice for MemoryManager {
fn read(&mut self, _base: u64, offset: u64, data: &mut [u8]) {
if self.selected_slot < self.hotplug_slots.len() {
let state = &self.hotplug_slots[self.selected_slot];
match offset {
BASE_OFFSET_LOW => {
data.copy_from_slice(&state.base.to_le_bytes()[..4]);
}
BASE_OFFSET_HIGH => {
data.copy_from_slice(&state.base.to_le_bytes()[4..]);
}
LENGTH_OFFSET_LOW => {
data.copy_from_slice(&state.length.to_le_bytes()[..4]);
}
LENGTH_OFFSET_HIGH => {
data.copy_from_slice(&state.length.to_le_bytes()[4..]);
}
STATUS_OFFSET => {
if state.active {
data[0] |= 1 << ENABLE_FLAG;
}
if state.inserting {
data[0] |= 1 << INSERTING_FLAG;
}
if state.removing {
data[0] |= 1 << REMOVING_FLAG;
}
}
_ => {
warn!(
"Unexpected offset for accessing memory manager device: {:#}",
offset
);
}
}
}
}
fn write(&mut self, _base: u64, offset: u64, data: &[u8]) {
match offset {
SELECTION_OFFSET => {
self.selected_slot = usize::from(data[0]);
}
STATUS_OFFSET => {
let state = &mut self.hotplug_slots[self.selected_slot];
// The ACPI code writes back a 1 to acknowledge the insertion
if (data[0] & (1 << INSERTING_FLAG) == 1 << INSERTING_FLAG) && state.inserting {
state.inserting = false;
}
// Ditto for removal
if (data[0] & (1 << REMOVING_FLAG) == 1 << REMOVING_FLAG) && state.removing {
state.removing = false;
}
// Trigger removal of "DIMM"
if data[0] & (1 << EJECT_FLAG) == 1 << EJECT_FLAG {
warn!("Ejection of memory not currently supported");
}
}
_ => {
warn!(
"Unexpected offset for accessing memory manager device: {:#}",
offset
);
}
}
}
}
impl MemoryManager {
/// Creates all memory regions based on the available RAM ranges defined
/// by `ram_regions`, and based on the description of the memory zones.
/// In practice, this function can perform multiple memory mappings of the
/// same backing file if there's a hole in the address space between two
/// RAM ranges.
/// One example might be ram_regions containing 2 regions (0-3G and 4G-6G)
/// and zones containing two zones (size 1G and size 4G).
/// This function will create 3 resulting memory regions:
/// - First one mapping entirely the first memory zone on 0-1G range
/// - Second one mapping partially the second memory zone on 1G-3G range
/// - Third one mapping partially the second memory zone on 4G-6G range
fn create_memory_regions_from_zones(
ram_regions: &[(GuestAddress, usize)],
zones: &[MemoryZoneConfig],
prefault: bool,
) -> Result<Vec<Arc<GuestRegionMmap>>, Error> {
let mut zones = zones.to_owned();
let mut mem_regions = Vec::new();
let mut zone = zones.remove(0);
let mut zone_offset = 0;
for ram_region in ram_regions.iter() {
let mut ram_region_offset = 0;
let mut exit = false;
loop {
let mut ram_region_consumed = false;
let mut pull_next_zone = false;
let ram_region_sub_size = ram_region.1 - ram_region_offset;
let zone_sub_size = zone.size as usize - zone_offset;
let file_offset = zone_offset as u64;
let region_start = ram_region.0.unchecked_add(ram_region_offset as u64);
let region_size = if zone_sub_size <= ram_region_sub_size {
if zone_sub_size == ram_region_sub_size {
ram_region_consumed = true;
}
ram_region_offset += zone_sub_size;
pull_next_zone = true;
zone_sub_size
} else {
zone_offset += ram_region_sub_size;
ram_region_consumed = true;
ram_region_sub_size
};
mem_regions.push(MemoryManager::create_ram_region(
&zone.file,
file_offset,
region_start,
region_size,
false,
prefault,
zone.shared,
zone.hugepages,
)?);
if pull_next_zone {
// Get the next zone and reset the offset.
zone_offset = 0;
if zones.is_empty() {
exit = true;
break;
}
zone = zones.remove(0);
}
if ram_region_consumed {
break;
}
}
if exit {
break;
}
}
Ok(mem_regions)
}
pub fn new(
vm: Arc<dyn hypervisor::Vm>,
config: &MemoryConfig,
ext_regions: Option<Vec<MemoryRegion>>,
prefault: bool,
) -> Result<Arc<Mutex<MemoryManager>>, Error> {
let mut mem_regions = Vec::new();
let arch_mem_regions: Vec<(GuestAddress, usize, RegionType)>;
let use_zones = config.size == 0;
if !use_zones {
if config.zones.is_some() {
error!(
"User defined memory regions can't be provided if the \
memory size is not 0"
);
return Err(Error::InvalidMemoryParameters);
}
// Init guest memory
arch_mem_regions = arch::arch_memory_regions(config.size);
let ram_regions: Vec<(GuestAddress, usize)> = arch_mem_regions
.iter()
.filter(|r| r.2 == RegionType::Ram)
.map(|r| (r.0, r.1))
.collect();
if let Some(ext_regions) = &ext_regions {
if ram_regions.len() > ext_regions.len() {
return Err(Error::InvalidAmountExternalBackingFiles);
}
for region in ext_regions.iter() {
mem_regions.push(MemoryManager::create_ram_region(
&region.backing_file,
0,
region.start_addr,
region.size as usize,
true,
prefault,
false,
false,
)?);
}
} else {
for region in ram_regions.iter() {
mem_regions.push(MemoryManager::create_ram_region(
&config.file,
0,
region.0,
region.1,
false,
prefault,
config.shared,
config.hugepages,
)?);
}
}
} else {
if config.zones.is_none() {
error!(
"User defined memory regions must be provided if the \
memory size is 0"
);
return Err(Error::MissingMemoryZones);
}
// Safe to unwrap as we checked right above there were some
// regions.
let zones = config.zones.clone().unwrap();
if zones.is_empty() {
return Err(Error::MissingMemoryZones);
}
let mut total_ram_size: u64 = 0;
for zone in zones.iter() {
total_ram_size += zone.size;
}
arch_mem_regions = arch::arch_memory_regions(total_ram_size as GuestUsize);
let ram_regions: Vec<(GuestAddress, usize)> = arch_mem_regions
.iter()
.filter(|r| r.2 == RegionType::Ram)
.map(|r| (r.0, r.1))
.collect();
mem_regions = Self::create_memory_regions_from_zones(&ram_regions, &zones, prefault)?;
}
let guest_memory =
GuestMemoryMmap::from_arc_regions(mem_regions).map_err(Error::GuestMemory)?;
let end_of_device_area = GuestAddress(mmio_address_space_size() - 1);
let mut start_of_device_area = MemoryManager::start_addr(guest_memory.last_addr(), false);
let mut virtiomem_region = None;
let mut virtiomem_resize = None;
if let Some(size) = config.hotplug_size {
if config.hotplug_method == HotplugMethod::VirtioMem {
// Alignment must be "natural" i.e. same as size of block
let start_addr = GuestAddress(
(start_of_device_area.0 + virtio_devices::VIRTIO_MEM_DEFAULT_BLOCK_SIZE - 1)
/ virtio_devices::VIRTIO_MEM_DEFAULT_BLOCK_SIZE
* virtio_devices::VIRTIO_MEM_DEFAULT_BLOCK_SIZE,
);
if !use_zones {
virtiomem_region = Some(MemoryManager::create_ram_region(
&config.file,
0,
start_addr,
size as usize,
false,
false,
config.shared,
config.hugepages,
)?);
}
virtiomem_resize = Some(virtio_devices::Resize::new().map_err(Error::EventFdFail)?);
start_of_device_area = start_addr.unchecked_add(size);
} else {
start_of_device_area = start_of_device_area.unchecked_add(size);
}
}
let guest_memory = GuestMemoryAtomic::new(guest_memory);
let mut hotplug_slots = Vec::with_capacity(HOTPLUG_COUNT);
hotplug_slots.resize_with(HOTPLUG_COUNT, HotPlugState::default);
// Both MMIO and PIO address spaces start at address 0.
let allocator = Arc::new(Mutex::new(
SystemAllocator::new(
#[cfg(target_arch = "x86_64")]
GuestAddress(0),
#[cfg(target_arch = "x86_64")]
(1 << 16 as GuestUsize),
GuestAddress(0),
mmio_address_space_size(),
layout::MEM_32BIT_DEVICES_START,
layout::MEM_32BIT_DEVICES_SIZE,
#[cfg(target_arch = "x86_64")]
vec![GsiApic::new(
X86_64_IRQ_BASE,
ioapic::NUM_IOAPIC_PINS as u32 - X86_64_IRQ_BASE,
)],
)
.ok_or(Error::CreateSystemAllocator)?,
));
let memory_manager = Arc::new(Mutex::new(MemoryManager {
guest_memory: guest_memory.clone(),
next_memory_slot: 0,
start_of_device_area,
end_of_device_area,
vm,
hotplug_slots,
selected_slot: 0,
backing_file: config.file.clone(),
mergeable: config.mergeable,
allocator: allocator.clone(),
hotplug_method: config.hotplug_method.clone(),
boot_ram: config.size,
current_ram: config.size,
next_hotplug_slot: 0,
virtiomem_region: virtiomem_region.clone(),
virtiomem_resize,
snapshot: Mutex::new(None),
shared: config.shared,
hugepages: config.hugepages,
balloon: None,
#[cfg(target_arch = "x86_64")]
sgx_epc_region: None,
use_zones,
}));
guest_memory.memory().with_regions(|_, region| {
let _ = memory_manager.lock().unwrap().create_userspace_mapping(
region.start_addr().raw_value(),
region.len() as u64,
region.as_ptr() as u64,
config.mergeable,
false,
)?;
Ok(())
})?;
if let Some(region) = virtiomem_region {
memory_manager.lock().unwrap().create_userspace_mapping(
region.start_addr().raw_value(),
region.len() as u64,
region.as_ptr() as u64,
config.mergeable,
false,
)?;
allocator
.lock()
.unwrap()
.allocate_mmio_addresses(Some(region.start_addr()), region.len(), None)
.ok_or(Error::MemoryRangeAllocation)?;
}
// Allocate RAM and Reserved address ranges.
for region in arch_mem_regions.iter() {
allocator
.lock()
.unwrap()
.allocate_mmio_addresses(Some(region.0), region.1 as GuestUsize, None)
.ok_or(Error::MemoryRangeAllocation)?;
}
Ok(memory_manager)
}
pub fn new_from_snapshot(
snapshot: &Snapshot,
vm: Arc<dyn hypervisor::Vm>,
config: &MemoryConfig,
source_url: &str,
prefault: bool,
) -> Result<Arc<Mutex<MemoryManager>>, Error> {
if config.size == 0 {
error!(
"Not allowed to restore guest memory when backed with user \
defined memory regions."
);
return Err(Error::InvalidRestoreWithMemoryZones);
}
let url = Url::parse(source_url).unwrap();
/* url must be valid dir which is verified in recv_vm_snapshot() */
let vm_snapshot_path = url.to_file_path().unwrap();
if let Some(mem_section) = snapshot
.snapshot_data
.get(&format!("{}-section", MEMORY_MANAGER_SNAPSHOT_ID))
{
let mem_snapshot: MemoryManagerSnapshotData =
match serde_json::from_slice(&mem_section.snapshot) {
Ok(snapshot) => snapshot,
Err(error) => {
return Err(Error::Restore(MigratableError::Restore(anyhow!(
"Could not deserialize MemoryManager {}",
error
))))
}
};
let mut ext_regions = mem_snapshot.memory_regions;
for region in ext_regions.iter_mut() {
if let Some(backing_file) = &mut region.backing_file {
let mut memory_region_path = vm_snapshot_path.clone();
memory_region_path.push(backing_file.clone());
*backing_file = memory_region_path;
}
}
// In case there was no backing file, we can safely use CoW by
// mapping the source files provided for restoring. This case
// allows for a faster VM restoration and does not require us to
// fill the memory content, hence we can return right away.
if config.file.is_none() {
return MemoryManager::new(vm, config, Some(ext_regions), prefault);
};
let memory_manager = MemoryManager::new(vm, config, None, false)?;
let guest_memory = memory_manager.lock().unwrap().guest_memory();
// In case the previous config was using a backing file, this means
// it was MAP_SHARED, therefore we must copy the content into the
// new regions so that we can still use MAP_SHARED when restoring
// the VM.
guest_memory.memory().with_regions(|index, region| {
if let Some(backing_file) = &ext_regions[index].backing_file {
// Open (read only) the snapshot file for the given region.
let mut memory_region_file = OpenOptions::new()
.read(true)
.open(backing_file)
.map_err(|e| {
Error::Restore(MigratableError::MigrateReceive(e.into()))
})?;
// Fill the region with the file content.
region
.read_from(
MemoryRegionAddress(0),
&mut memory_region_file,
region.len().try_into().unwrap(),
)
.map_err(|e| Error::Restore(MigratableError::MigrateReceive(e.into())))?;
}
Ok(())
})?;
Ok(memory_manager)
} else {
Err(Error::Restore(MigratableError::Restore(anyhow!(
"Could not find {}-section from snapshot",
MEMORY_MANAGER_SNAPSHOT_ID
))))
}
}
fn memfd_create(name: &ffi::CStr, flags: u32) -> Result<RawFd, io::Error> {
let res = unsafe { libc::syscall(libc::SYS_memfd_create, name.as_ptr(), flags) };
if res < 0 {
Err(io::Error::last_os_error())
} else {
Ok(res as RawFd)
}
}
#[allow(clippy::too_many_arguments)]
fn create_ram_region(
backing_file: &Option<PathBuf>,
mut file_offset: u64,
start_addr: GuestAddress,
size: usize,
copy_on_write: bool,
prefault: bool,
shared: bool,
hugepages: bool,
) -> Result<Arc<GuestRegionMmap>, Error> {
Ok(Arc::new(match backing_file {
Some(ref file) => {
let f = if file.is_dir() {
// Override file offset as it does not apply in this case.
info!(
"Ignoring file offset since the backing file is a \
temporary file created from the specified directory."
);
file_offset = 0;
let fs_str = format!("{}{}", file.display(), "/tmpfile_XXXXXX");
let fs = ffi::CString::new(fs_str).unwrap();
let mut path = fs.as_bytes_with_nul().to_owned();
let path_ptr = path.as_mut_ptr() as *mut _;
let fd = unsafe { libc::mkstemp(path_ptr) };
unsafe { libc::unlink(path_ptr) };
let f = unsafe { File::from_raw_fd(fd) };
f.set_len(size as u64).map_err(Error::SharedFileSetLen)?;
f
} else {
OpenOptions::new()
.read(true)
.write(true)
.open(file)
.map_err(Error::SharedFileCreate)?
};
let mut mmap_flags = if copy_on_write {
libc::MAP_NORESERVE | libc::MAP_PRIVATE
} else {
libc::MAP_NORESERVE | libc::MAP_SHARED
};
if prefault {
mmap_flags |= libc::MAP_POPULATE;
}
GuestRegionMmap::new(
MmapRegion::build(
Some(FileOffset::new(f, file_offset)),
size,
libc::PROT_READ | libc::PROT_WRITE,
mmap_flags,
)
.map_err(Error::GuestMemoryRegion)?,
start_addr,
)
.map_err(Error::GuestMemory)?
}
None => {
let fd = Self::memfd_create(
&ffi::CString::new("ch_ram").unwrap(),
if hugepages {
libc::MFD_HUGETLB | libc::MAP_HUGE_2MB as u32
} else {
0
},
)
.map_err(Error::SharedFileCreate)?;
let f = unsafe { File::from_raw_fd(fd) };
f.set_len(size as u64).map_err(Error::SharedFileSetLen)?;
let mmap_flags = libc::MAP_NORESERVE
| if shared {
libc::MAP_SHARED
} else {
libc::MAP_PRIVATE
};
GuestRegionMmap::new(
MmapRegion::build(
Some(FileOffset::new(f, 0)),
size,
libc::PROT_READ | libc::PROT_WRITE,
mmap_flags,
)
.map_err(Error::GuestMemoryRegion)?,
start_addr,
)
.map_err(Error::GuestMemory)?
}
}))
}
// Update the GuestMemoryMmap with the new range
fn add_region(&mut self, region: Arc<GuestRegionMmap>) -> Result<(), Error> {
let guest_memory = self
.guest_memory
.memory()
.insert_region(region)
.map_err(Error::GuestMemory)?;
self.guest_memory.lock().unwrap().replace(guest_memory);
Ok(())
}
//
// Calculate the start address of an area next to RAM.
//
// If the next area is device space, there is no gap.
// If the next area is hotplugged RAM, the start address needs to be aligned
// to 128MiB boundary, and a gap of 256MiB need to be set before it.
// On x86_64, it must also start at the 64bit start.
#[allow(clippy::let_and_return)]
fn start_addr(mem_end: GuestAddress, with_gap: bool) -> GuestAddress {
let start_addr = if with_gap {
GuestAddress((mem_end.0 + 1 + (256 << 20)) & !((128 << 20) - 1))
} else {
mem_end.unchecked_add(1)
};
#[cfg(target_arch = "x86_64")]
if mem_end < arch::layout::MEM_32BIT_RESERVED_START {
return arch::layout::RAM_64BIT_START;
}
start_addr
}
fn hotplug_ram_region(&mut self, size: usize) -> Result<Arc<GuestRegionMmap>, Error> {
info!("Hotplugging new RAM: {}", size);
// Check that there is a free slot
if self.next_hotplug_slot >= HOTPLUG_COUNT {
return Err(Error::NoSlotAvailable);
}
// "Inserted" DIMM must have a size that is a multiple of 128MiB
if size % (128 << 20) != 0 {
return Err(Error::InvalidSize);
}
let start_addr = MemoryManager::start_addr(self.guest_memory.memory().last_addr(), true);
if start_addr.checked_add(size.try_into().unwrap()).unwrap() >= self.start_of_device_area()
{
return Err(Error::InsufficientHotplugRAM);
}
// Allocate memory for the region
let region = MemoryManager::create_ram_region(
&self.backing_file,
0,
start_addr,
size,
false,
false,
self.shared,
self.hugepages,
)?;
// Map it into the guest
self.create_userspace_mapping(
region.start_addr().0,
region.len() as u64,
region.as_ptr() as u64,
self.mergeable,
false,
)?;
// Tell the allocator
self.allocator
.lock()
.unwrap()
.allocate_mmio_addresses(Some(start_addr), size as GuestUsize, None)
.ok_or(Error::MemoryRangeAllocation)?;
// Update the slot so that it can be queried via the I/O port
let mut slot = &mut self.hotplug_slots[self.next_hotplug_slot];
slot.active = true;
slot.inserting = true;
slot.base = region.start_addr().0;
slot.length = region.len() as u64;
self.next_hotplug_slot += 1;
self.add_region(Arc::clone(&region))?;
Ok(region)
}
pub fn set_balloon(&mut self, balloon: Arc<Mutex<virtio_devices::Balloon>>) {
self.balloon = Some(balloon);
}
pub fn guest_memory(&self) -> GuestMemoryAtomic<GuestMemoryMmap> {
self.guest_memory.clone()
}
pub fn allocator(&self) -> Arc<Mutex<SystemAllocator>> {
self.allocator.clone()
}
pub fn start_of_device_area(&self) -> GuestAddress {
self.start_of_device_area
}
pub fn end_of_device_area(&self) -> GuestAddress {
self.end_of_device_area
}
pub fn allocate_memory_slot(&mut self) -> u32 {
let slot_id = self.next_memory_slot;
self.next_memory_slot += 1;
slot_id
}
pub fn create_userspace_mapping(
&mut self,
guest_phys_addr: u64,
memory_size: u64,
userspace_addr: u64,
mergeable: bool,
readonly: bool,
) -> Result<u32, Error> {
let slot = self.allocate_memory_slot();
let mem_region = self.vm.make_user_memory_region(
slot,
guest_phys_addr,
memory_size,
userspace_addr,
readonly,
);
self.vm
.set_user_memory_region(mem_region)
.map_err(Error::SetUserMemoryRegion)?;
// Mark the pages as mergeable if explicitly asked for.
if mergeable {
// Safe because the address and size are valid since the
// mmap succeeded.
let ret = unsafe {
libc::madvise(
userspace_addr as *mut libc::c_void,
memory_size as libc::size_t,
libc::MADV_MERGEABLE,
)
};
if ret != 0 {
let err = io::Error::last_os_error();
// Safe to unwrap because the error is constructed with
// last_os_error(), which ensures the output will be Some().
let errno = err.raw_os_error().unwrap();
if errno == libc::EINVAL {
warn!("kernel not configured with CONFIG_KSM");
} else {
warn!("madvise error: {}", err);
}
warn!("failed to mark pages as mergeable");
}
}
info!(
"Created userspace mapping: {:x} -> {:x} {:x}",
guest_phys_addr, userspace_addr, memory_size
);
Ok(slot)
}
pub fn remove_userspace_mapping(
&mut self,
guest_phys_addr: u64,
memory_size: u64,
userspace_addr: u64,
mergeable: bool,
slot: u32,
) -> Result<(), Error> {
let mem_region = self.vm.make_user_memory_region(
slot,
guest_phys_addr,
0, /* memory_size -- using 0 removes this slot */
userspace_addr,
false, /* readonly -- don't care */
);
self.vm
.set_user_memory_region(mem_region)
.map_err(Error::SetUserMemoryRegion)?;
// Mark the pages as unmergeable if there were previously marked as
// mergeable.
if mergeable {
// Safe because the address and size are valid as the region was
// previously advised.
let ret = unsafe {
libc::madvise(
userspace_addr as *mut libc::c_void,
memory_size as libc::size_t,
libc::MADV_UNMERGEABLE,
)
};
if ret != 0 {
let err = io::Error::last_os_error();
// Safe to unwrap because the error is constructed with
// last_os_error(), which ensures the output will be Some().
let errno = err.raw_os_error().unwrap();
if errno == libc::EINVAL {
warn!("kernel not configured with CONFIG_KSM");
} else {
warn!("madvise error: {}", err);
}
warn!("failed to mark pages as unmergeable");
}
}
info!(
"Removed userspace mapping: {:x} -> {:x} {:x}",
guest_phys_addr, userspace_addr, memory_size
);
Ok(())
}
pub fn virtiomem_resize(&mut self, size: u64) -> Result<(), Error> {
let region = self.virtiomem_region.take();
if let Some(region) = region {
self.add_region(region)?;
}
if let Some(resize) = &self.virtiomem_resize {
resize.work(size).map_err(Error::VirtioMemResizeFail)?;
} else {
panic!("should not fail here");
}
Ok(())
}
pub fn balloon_resize(&mut self, expected_ram: u64) -> Result<u64, Error> {
let mut balloon_size = 0;
if let Some(balloon) = &self.balloon {
if expected_ram < self.current_ram {
balloon_size = self.current_ram - expected_ram;
}
balloon
.lock()
.unwrap()
.resize(balloon_size)
.map_err(Error::VirtioBalloonResizeFail)?;
}
Ok(balloon_size)
}
/// In case this function resulted in adding a new memory region to the
/// guest memory, the new region is returned to the caller. The virtio-mem
/// use case never adds a new region as the whole hotpluggable memory has
/// already been allocated at boot time.
pub fn resize(&mut self, desired_ram: u64) -> Result<Option<Arc<GuestRegionMmap>>, Error> {
if self.use_zones {
error!(
"Not allowed to resize guest memory when backed with user \
defined memory regions.\n Try adding new memory regions \
instead."
);
return Err(Error::InvalidResizeWithMemoryZones);
}
let mut region: Option<Arc<GuestRegionMmap>> = None;
match self.hotplug_method {
HotplugMethod::VirtioMem => {
if desired_ram >= self.boot_ram {
self.virtiomem_resize(desired_ram - self.boot_ram)?;
self.current_ram = desired_ram;
}
}
HotplugMethod::Acpi => {
if desired_ram >= self.current_ram {
region =
Some(self.hotplug_ram_region((desired_ram - self.current_ram) as usize)?);
self.current_ram = desired_ram;
}
}
}
Ok(region)
}
#[cfg(target_arch = "x86_64")]
pub fn setup_sgx(&mut self, sgx_epc_config: Vec<SgxEpcConfig>) -> Result<(), Error> {
// Go over each EPC section and verify its size is a 4k multiple. At
// the same time, calculate the total size needed for the contiguous
// EPC region.
let mut epc_region_size = 0;
for epc_section in sgx_epc_config.iter() {
if epc_section.size == 0 {
return Err(Error::EpcSectionSizeInvalid);
}
if epc_section.size & 0x0fff != 0 {
return Err(Error::EpcSectionSizeInvalid);
}
epc_region_size += epc_section.size;
}
// Now that we know about the total size for the EPC region, we can
// proceed with the allocation of the entire range. The EPC region
// must be 4kiB aligned.
let epc_region_start = self
.allocator
.lock()
.unwrap()
.allocate_mmio_addresses(None, epc_region_size as GuestUsize, Some(0x1000))
.ok_or(Error::SgxEpcRangeAllocation)?;
let mut sgx_epc_region = SgxEpcRegion::new(epc_region_start, epc_region_size as GuestUsize);
// Each section can be memory mapped into the allocated region.
let mut epc_section_start = epc_region_start.raw_value();
for epc_section in sgx_epc_config.iter() {
let file = OpenOptions::new()
.read(true)
.write(true)
.open("/dev/sgx/virt_epc")
.map_err(Error::SgxVirtEpcOpen)?;
let prot = PROT_READ | PROT_WRITE;
let mut flags = MAP_NORESERVE | MAP_SHARED;
if epc_section.prefault {
flags |= MAP_POPULATE;
}
// We can't use the vm-memory crate to perform the memory mapping
// here as it would try to ensure the size of the backing file is
// matching the size of the expected mapping. The /dev/sgx/virt_epc
// device does not work that way, it provides a file descriptor
// which is not matching the mapping size, as it's a just a way to
// let KVM know that an EPC section is being created for the guest.
let host_addr = unsafe {
libc::mmap(
std::ptr::null_mut(),
epc_section.size as usize,
prot,
flags,
file.as_raw_fd(),
0 as libc::off_t,
)
} as u64;
let _mem_slot = self.create_userspace_mapping(
epc_section_start,
epc_section.size,
host_addr,
false,
false,
)?;
sgx_epc_region.push(SgxEpcSection::new(
GuestAddress(epc_section_start),
epc_section.size as GuestUsize,
));
epc_section_start += epc_section.size;
}
self.sgx_epc_region = Some(sgx_epc_region);
Ok(())
}
#[cfg(target_arch = "x86_64")]
pub fn sgx_epc_region(&self) -> &Option<SgxEpcRegion> {
&self.sgx_epc_region
}
}
#[cfg(feature = "acpi")]
struct MemoryNotify {
slot_id: usize,
}
#[cfg(feature = "acpi")]
impl Aml for MemoryNotify {
fn to_aml_bytes(&self) -> Vec<u8> {
let object = aml::Path::new(&format!("M{:03}", self.slot_id));
aml::If::new(
&aml::Equal::new(&aml::Arg(0), &self.slot_id),
vec![&aml::Notify::new(&object, &aml::Arg(1))],
)
.to_aml_bytes()
}
}
#[cfg(feature = "acpi")]
struct MemorySlot {
slot_id: usize,
}
#[cfg(feature = "acpi")]
impl Aml for MemorySlot {
fn to_aml_bytes(&self) -> Vec<u8> {
aml::Device::new(
format!("M{:03}", self.slot_id).as_str().into(),
vec![
&aml::Name::new("_HID".into(), &aml::EISAName::new("PNP0C80")),
&aml::Name::new("_UID".into(), &self.slot_id),
/*
_STA return value:
Bit [0] Set if the device is present.
Bit [1] Set if the device is enabled and decoding its resources.
Bit [2] Set if the device should be shown in the UI.
Bit [3] Set if the device is functioning properly (cleared if device failed its diagnostics).
Bit [4] Set if the battery is present.
Bits [31:5] Reserved (must be cleared).
*/
&aml::Method::new(
"_STA".into(),
0,
false,
// Call into MSTA method which will interrogate device
vec![&aml::Return::new(&aml::MethodCall::new(
"MSTA".into(),
vec![&self.slot_id],
))],
),
// Get details of memory
&aml::Method::new(
"_CRS".into(),
0,
false,
// Call into MCRS which provides actual memory details
vec![&aml::Return::new(&aml::MethodCall::new(
"MCRS".into(),
vec![&self.slot_id],
))],
),
// We don't expose any NUMA characteristics so all memory is in the same "proximity domain"
&aml::Method::new(
"_PXM".into(),
0,
false,
// We aren't NUMA so associate all RAM into the same proximity region (zero)
vec![&aml::Return::new(&0u32)],
),
],
)
.to_aml_bytes()
}
}
#[cfg(feature = "acpi")]
struct MemorySlots {
slots: usize,
}
#[cfg(feature = "acpi")]
impl Aml for MemorySlots {
fn to_aml_bytes(&self) -> Vec<u8> {
let mut bytes = Vec::new();
for slot_id in 0..self.slots {
bytes.extend_from_slice(&MemorySlot { slot_id }.to_aml_bytes());
}
bytes
}
}
#[cfg(feature = "acpi")]
struct MemoryMethods {
slots: usize,
}
#[cfg(feature = "acpi")]
impl Aml for MemoryMethods {
fn to_aml_bytes(&self) -> Vec<u8> {
let mut bytes = Vec::new();
// Add "MTFY" notification method
let mut memory_notifies = Vec::new();
for slot_id in 0..self.slots {
memory_notifies.push(MemoryNotify { slot_id });
}
let mut memory_notifies_refs: Vec<&dyn aml::Aml> = Vec::new();
for memory_notifier in memory_notifies.iter() {
memory_notifies_refs.push(memory_notifier);
}
bytes.extend_from_slice(
&aml::Method::new("MTFY".into(), 2, true, memory_notifies_refs).to_aml_bytes(),
);
// MSCN method
bytes.extend_from_slice(
&aml::Method::new(
"MSCN".into(),
0,
true,
vec![
// Take lock defined above
&aml::Acquire::new("MLCK".into(), 0xfff),
&aml::Store::new(&aml::Local(0), &aml::ZERO),
&aml::While::new(
&aml::LessThan::new(&aml::Local(0), &self.slots),
vec![
// Write slot number (in first argument) to I/O port via field
&aml::Store::new(&aml::Path::new("\\_SB_.MHPC.MSEL"), &aml::Local(0)),
// Check if MINS bit is set (inserting)
&aml::If::new(
&aml::Equal::new(&aml::Path::new("\\_SB_.MHPC.MINS"), &aml::ONE),
// Notify device if it is
vec![
&aml::MethodCall::new(
"MTFY".into(),
vec![&aml::Local(0), &aml::ONE],
),
// Reset MINS bit
&aml::Store::new(
&aml::Path::new("\\_SB_.MHPC.MINS"),
&aml::ONE,
),
],
),
// Check if MRMV bit is set
&aml::If::new(
&aml::Equal::new(&aml::Path::new("\\_SB_.MHPC.MRMV"), &aml::ONE),
// Notify device if it is (with the eject constant 0x3)
vec![
&aml::MethodCall::new(
"MTFY".into(),
vec![&aml::Local(0), &3u8],
),
// Reset MRMV bit
&aml::Store::new(
&aml::Path::new("\\_SB_.MHPC.MRMV"),
&aml::ONE,
),
],
),
&aml::Add::new(&aml::Local(0), &aml::Local(0), &aml::ONE),
],
),
// Release lock
&aml::Release::new("MLCK".into()),
],
)
.to_aml_bytes(),
);
bytes.extend_from_slice(
// Memory status method
&aml::Method::new(
"MSTA".into(),
1,
true,
vec![
// Take lock defined above
&aml::Acquire::new("MLCK".into(), 0xfff),
// Write slot number (in first argument) to I/O port via field
&aml::Store::new(&aml::Path::new("\\_SB_.MHPC.MSEL"), &aml::Arg(0)),
&aml::Store::new(&aml::Local(0), &aml::ZERO),
// Check if MEN_ bit is set, if so make the local variable 0xf (see _STA for details of meaning)
&aml::If::new(
&aml::Equal::new(&aml::Path::new("\\_SB_.MHPC.MEN_"), &aml::ONE),
vec![&aml::Store::new(&aml::Local(0), &0xfu8)],
),
// Release lock
&aml::Release::new("MLCK".into()),
// Return 0 or 0xf
&aml::Return::new(&aml::Local(0)),
],
)
.to_aml_bytes(),
);
bytes.extend_from_slice(
// Memory range method
&aml::Method::new(
"MCRS".into(),
1,
true,
vec![
// Take lock defined above
&aml::Acquire::new("MLCK".into(), 0xfff),
// Write slot number (in first argument) to I/O port via field
&aml::Store::new(&aml::Path::new("\\_SB_.MHPC.MSEL"), &aml::Arg(0)),
&aml::Name::new(
"MR64".into(),
&aml::ResourceTemplate::new(vec![&aml::AddressSpace::new_memory(
aml::AddressSpaceCachable::Cacheable,
true,
0x0000_0000_0000_0000u64,
0xFFFF_FFFF_FFFF_FFFEu64,
)]),
),
&aml::CreateField::<u32>::new(&aml::Path::new("MR64"), &14usize, "MINL".into()),
&aml::CreateField::<u32>::new(&aml::Path::new("MR64"), &18usize, "MINH".into()),
&aml::CreateField::<u32>::new(&aml::Path::new("MR64"), &22usize, "MAXL".into()),
&aml::CreateField::<u32>::new(&aml::Path::new("MR64"), &26usize, "MAXH".into()),
&aml::CreateField::<u32>::new(&aml::Path::new("MR64"), &38usize, "LENL".into()),
&aml::CreateField::<u32>::new(&aml::Path::new("MR64"), &42usize, "LENH".into()),
&aml::Store::new(&aml::Path::new("MINL"), &aml::Path::new("\\_SB_.MHPC.MHBL")),
&aml::Store::new(&aml::Path::new("MINH"), &aml::Path::new("\\_SB_.MHPC.MHBH")),
&aml::Store::new(&aml::Path::new("LENL"), &aml::Path::new("\\_SB_.MHPC.MHLL")),
&aml::Store::new(&aml::Path::new("LENH"), &aml::Path::new("\\_SB_.MHPC.MHLH")),
&aml::Add::new(
&aml::Path::new("MAXL"),
&aml::Path::new("MINL"),
&aml::Path::new("LENL"),
),
&aml::Add::new(
&aml::Path::new("MAXH"),
&aml::Path::new("MINH"),
&aml::Path::new("LENH"),
),
&aml::Subtract::new(
&aml::Path::new("MAXH"),
&aml::Path::new("MAXH"),
&aml::ONE,
),
// Release lock
&aml::Release::new("MLCK".into()),
&aml::Return::new(&aml::Path::new("MR64")),
],
)
.to_aml_bytes(),
);
bytes
}
}
#[cfg(feature = "acpi")]
impl Aml for MemoryManager {
fn to_aml_bytes(&self) -> Vec<u8> {
let mut bytes = Vec::new();
// Memory Hotplug Controller
bytes.extend_from_slice(
&aml::Device::new(
"_SB_.MHPC".into(),
vec![
&aml::Name::new("_HID".into(), &aml::EISAName::new("PNP0A06")),
&aml::Name::new("_UID".into(), &"Memory Hotplug Controller"),
// Mutex to protect concurrent access as we write to choose slot and then read back status
&aml::Mutex::new("MLCK".into(), 0),
// I/O port for memory controller
&aml::Name::new(
"_CRS".into(),
&aml::ResourceTemplate::new(vec![&aml::IO::new(
0x0a00, 0x0a00, 0x01, 0x18,
)]),
),
// OpRegion and Fields map I/O port into individual field values
&aml::OpRegion::new("MHPR".into(), aml::OpRegionSpace::SystemIO, 0xa00, 0x18),
&aml::Field::new(
"MHPR".into(),
aml::FieldAccessType::DWord,
aml::FieldUpdateRule::Preserve,
vec![
aml::FieldEntry::Named(*b"MHBL", 32), // Base (low 4 bytes)
aml::FieldEntry::Named(*b"MHBH", 32), // Base (high 4 bytes)
aml::FieldEntry::Named(*b"MHLL", 32), // Length (low 4 bytes)
aml::FieldEntry::Named(*b"MHLH", 32), // Length (high 4 bytes)
],
),
&aml::Field::new(
"MHPR".into(),
aml::FieldAccessType::DWord,
aml::FieldUpdateRule::Preserve,
vec![
aml::FieldEntry::Reserved(128),
aml::FieldEntry::Named(*b"MHPX", 32), // PXM
],
),
&aml::Field::new(
"MHPR".into(),
aml::FieldAccessType::Byte,
aml::FieldUpdateRule::WriteAsZeroes,
vec![
aml::FieldEntry::Reserved(160),
aml::FieldEntry::Named(*b"MEN_", 1), // Enabled
aml::FieldEntry::Named(*b"MINS", 1), // Inserting
aml::FieldEntry::Named(*b"MRMV", 1), // Removing
aml::FieldEntry::Named(*b"MEJ0", 1), // Ejecting
],
),
&aml::Field::new(
"MHPR".into(),
aml::FieldAccessType::DWord,
aml::FieldUpdateRule::Preserve,
vec![
aml::FieldEntry::Named(*b"MSEL", 32), // Selector
aml::FieldEntry::Named(*b"MOEV", 32), // Event
aml::FieldEntry::Named(*b"MOSC", 32), // OSC
],
),
&MemoryMethods {
slots: self.hotplug_slots.len(),
},
&MemorySlots {
slots: self.hotplug_slots.len(),
},
],
)
.to_aml_bytes(),
);
#[cfg(target_arch = "x86_64")]
{
if let Some(sgx_epc_region) = &self.sgx_epc_region {
let min = sgx_epc_region.start().raw_value() as u64;
let max = min + sgx_epc_region.size() as u64 - 1;
// SGX EPC region
bytes.extend_from_slice(
&aml::Device::new(
"_SB_.EPC_".into(),
vec![
&aml::Name::new("_HID".into(), &aml::EISAName::new("INT0E0C")),
// QWORD describing the EPC region start and size
&aml::Name::new(
"_CRS".into(),
&aml::ResourceTemplate::new(vec![&aml::AddressSpace::new_memory(
aml::AddressSpaceCachable::NotCacheable,
true,
min,
max,
)]),
),
&aml::Method::new(
"_STA".into(),
0,
false,
vec![&aml::Return::new(&0xfu8)],
),
],
)
.to_aml_bytes(),
);
}
}
bytes
}
}
impl Pausable for MemoryManager {}
#[derive(Serialize, Deserialize)]
#[serde(remote = "GuestAddress")]
pub struct GuestAddressDef(pub u64);
#[derive(Serialize, Deserialize)]
pub struct MemoryRegion {
backing_file: Option<PathBuf>,
#[serde(with = "GuestAddressDef")]
start_addr: GuestAddress,
size: GuestUsize,
}
#[derive(Serialize, Deserialize)]
pub struct MemoryManagerSnapshotData {
memory_regions: Vec<MemoryRegion>,
}
impl Snapshottable for MemoryManager {
fn id(&self) -> String {
MEMORY_MANAGER_SNAPSHOT_ID.to_string()
}
fn snapshot(&mut self) -> result::Result<Snapshot, MigratableError> {
if self.use_zones {
return Err(MigratableError::Snapshot(anyhow!(
"Not allowed to snapshot guest memory when backed with user \
defined memory regions."
)));
}
let mut memory_manager_snapshot = Snapshot::new(MEMORY_MANAGER_SNAPSHOT_ID);
let guest_memory = self.guest_memory.memory();
let mut memory_regions: Vec<MemoryRegion> = Vec::with_capacity(10);
guest_memory.with_regions_mut(|index, region| {
if region.len() == 0 {
return Err(MigratableError::Snapshot(anyhow!("Zero length region")));
}
memory_regions.push(MemoryRegion {
backing_file: Some(PathBuf::from(format!("memory-region-{}", index))),
start_addr: region.start_addr(),
size: region.len(),
});
Ok(())
})?;
let snapshot_data_section =
serde_json::to_vec(&MemoryManagerSnapshotData { memory_regions })
.map_err(|e| MigratableError::Snapshot(e.into()))?;
memory_manager_snapshot.add_data_section(SnapshotDataSection {
id: format!("{}-section", MEMORY_MANAGER_SNAPSHOT_ID),
snapshot: snapshot_data_section,
});
let mut memory_snapshot = self.snapshot.lock().unwrap();
*memory_snapshot = Some(guest_memory);
Ok(memory_manager_snapshot)
}
}
impl Transportable for MemoryManager {
fn send(
&self,
_snapshot: &Snapshot,
destination_url: &str,
) -> result::Result<(), MigratableError> {
let url = Url::parse(destination_url).map_err(|e| {
MigratableError::MigrateSend(anyhow!("Could not parse destination URL: {}", e))
})?;
match url.scheme() {
"file" => {
let vm_memory_snapshot_path = url
.to_file_path()
.map_err(|_| {
MigratableError::MigrateSend(anyhow!(
"Could not convert file URL to a file path"
))
})
.and_then(|path| {
if !path.is_dir() {
return Err(MigratableError::MigrateSend(anyhow!(
"Destination is not a directory"
)));
}
Ok(path)
})?;
if let Some(guest_memory) = &*self.snapshot.lock().unwrap() {
guest_memory.with_regions_mut(|index, region| {
let mut memory_region_path = vm_memory_snapshot_path.clone();
memory_region_path.push(format!("memory-region-{}", index));
// Create the snapshot file for the region
let mut memory_region_file = OpenOptions::new()
.read(true)
.write(true)
.create_new(true)
.open(memory_region_path)
.map_err(|e| MigratableError::MigrateSend(e.into()))?;
guest_memory
.write_to(
region.start_addr(),
&mut memory_region_file,
region.len().try_into().unwrap(),
)
.map_err(|e| MigratableError::MigrateSend(e.into()))?;
Ok(())
})?;
}
}
_ => {
return Err(MigratableError::MigrateSend(anyhow!(
"Unsupported VM transport URL scheme: {}",
url.scheme()
)))
}
}
Ok(())
}
}
impl Migratable for MemoryManager {}