1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287
// Copyright 2022 The ChromiumOS Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#[cfg(feature = "gpu")]
pub(crate) mod gpu;
use std::path::Path;
use std::time::Duration;
use base::error;
use base::AsRawDescriptor;
use base::Descriptor;
use base::Error as SysError;
use base::MemoryMappingArena;
use base::MmapError;
use base::Protection;
use base::SafeDescriptor;
use base::Tube;
use base::UnixSeqpacket;
use hypervisor::MemCacheType;
use hypervisor::MemSlot;
use hypervisor::Vm;
use libc::EINVAL;
use libc::ERANGE;
use once_cell::sync::Lazy;
use resources::Alloc;
use resources::SystemAllocator;
use serde::Deserialize;
use serde::Serialize;
use vm_memory::GuestAddress;
use crate::client::HandleRequestResult;
use crate::VmMappedMemoryRegion;
use crate::VmRequest;
use crate::VmResponse;
pub fn handle_request<T: AsRef<Path> + std::fmt::Debug>(
request: &VmRequest,
socket_path: T,
) -> HandleRequestResult {
handle_request_with_timeout(request, socket_path, None)
}
pub fn handle_request_with_timeout<T: AsRef<Path> + std::fmt::Debug>(
request: &VmRequest,
socket_path: T,
timeout: Option<Duration>,
) -> HandleRequestResult {
match UnixSeqpacket::connect(&socket_path) {
Ok(s) => {
let socket = Tube::new_from_unix_seqpacket(s).map_err(|_| ())?;
if timeout.is_some() {
if let Err(e) = socket.set_recv_timeout(timeout) {
error!(
"failed to set recv timeout on socket at '{:?}': {}",
socket_path, e
);
return Err(());
}
}
if let Err(e) = socket.send(request) {
error!(
"failed to send request to socket at '{:?}': {}",
socket_path, e
);
return Err(());
}
match socket.recv() {
Ok(response) => Ok(response),
Err(e) => {
error!(
"failed to recv response from socket at '{:?}': {}",
socket_path, e
);
Err(())
}
}
}
Err(e) => {
error!("failed to connect to socket at '{:?}': {}", socket_path, e);
Err(())
}
}
}
#[derive(Serialize, Deserialize, Debug)]
pub enum VmMemoryMappingRequest {
/// Flush the content of a memory mapping to its backing file.
/// `slot` selects the arena (as returned by `Vm::add_mmap_arena`).
/// `offset` is the offset of the mapping to sync within the arena.
/// `size` is the size of the mapping to sync within the arena.
MsyncArena {
slot: MemSlot,
offset: usize,
size: usize,
},
/// Gives a MADV_PAGEOUT advice to the memory region mapped at `slot`, with the address range
/// starting at `offset` from the start of the region, and with size `size`.
MadvisePageout {
slot: MemSlot,
offset: usize,
size: usize,
},
/// Gives a MADV_REMOVE advice to the memory region mapped at `slot`, with the address range
/// starting at `offset` from the start of the region, and with size `size`.
MadviseRemove {
slot: MemSlot,
offset: usize,
size: usize,
},
}
#[derive(Serialize, Deserialize, Debug)]
pub enum VmMemoryMappingResponse {
Ok,
Err(SysError),
}
impl VmMemoryMappingRequest {
/// Executes this request on the given Vm.
///
/// # Arguments
/// * `vm` - The `Vm` to perform the request on.
///
/// This does not return a result, instead encapsulating the success or failure in a
/// `VmMsyncResponse` with the intended purpose of sending the response back over the socket
/// that received this `VmMsyncResponse`.
pub fn execute(&self, vm: &mut impl Vm) -> VmMemoryMappingResponse {
use self::VmMemoryMappingRequest::*;
match *self {
MsyncArena { slot, offset, size } => match vm.msync_memory_region(slot, offset, size) {
Ok(()) => VmMemoryMappingResponse::Ok,
Err(e) => VmMemoryMappingResponse::Err(e),
},
MadvisePageout { slot, offset, size } => {
match vm.madvise_pageout_memory_region(slot, offset, size) {
Ok(()) => VmMemoryMappingResponse::Ok,
Err(e) => VmMemoryMappingResponse::Err(e),
}
}
MadviseRemove { slot, offset, size } => {
match vm.madvise_remove_memory_region(slot, offset, size) {
Ok(()) => VmMemoryMappingResponse::Ok,
Err(e) => VmMemoryMappingResponse::Err(e),
}
}
}
}
}
#[derive(Serialize, Deserialize, Debug)]
pub enum FsMappingRequest {
/// Create an anonymous memory mapping that spans the entire region described by `Alloc`.
AllocateSharedMemoryRegion(Alloc),
/// Create a memory mapping.
CreateMemoryMapping {
/// The slot for a MemoryMappingArena, previously returned by a response to an
/// `AllocateSharedMemoryRegion` request.
slot: u32,
/// The file descriptor that should be mapped.
fd: SafeDescriptor,
/// The size of the mapping.
size: usize,
/// The offset into the file from where the mapping should start.
file_offset: u64,
/// The memory protection to be used for the mapping. Protections other than readable and
/// writable will be silently dropped.
prot: Protection,
/// The offset into the shared memory region where the mapping should be placed.
mem_offset: usize,
},
/// Remove a memory mapping.
RemoveMemoryMapping {
/// The slot for a MemoryMappingArena.
slot: u32,
/// The offset into the shared memory region.
offset: usize,
/// The size of the mapping.
size: usize,
},
}
pub fn prepare_shared_memory_region(
vm: &mut dyn Vm,
allocator: &mut SystemAllocator,
alloc: Alloc,
cache: MemCacheType,
) -> Result<VmMappedMemoryRegion, SysError> {
if !matches!(alloc, Alloc::PciBar { .. }) {
return Err(SysError::new(EINVAL));
}
match allocator.mmio_allocator_any().get(&alloc) {
Some((range, _)) => {
let size: usize = match range.len().and_then(|x| x.try_into().ok()) {
Some(v) => v,
None => return Err(SysError::new(ERANGE)),
};
let arena = match MemoryMappingArena::new(size) {
Ok(a) => a,
Err(MmapError::SystemCallFailed(e)) => return Err(e),
_ => return Err(SysError::new(EINVAL)),
};
match vm.add_memory_region(
GuestAddress(range.start),
Box::new(arena),
false,
false,
cache,
) {
Ok(slot) => Ok(VmMappedMemoryRegion {
gfn: range.start >> 12,
slot,
}),
Err(e) => Err(e),
}
}
None => Err(SysError::new(EINVAL)),
}
}
static SHOULD_PREPARE_MEMORY_REGION: Lazy<bool> = Lazy::new(|| {
if cfg!(target_arch = "x86_64") {
// The legacy x86 MMU allocates an rmap and a page tracking array
// that take 2.5MiB per 1GiB of user memory region address space,
// so avoid mapping the whole shared memory region if we're not
// using the tdp mmu.
match std::fs::read("/sys/module/kvm/parameters/tdp_mmu") {
Ok(bytes) if !bytes.is_empty() => bytes[0] == b'Y',
_ => false,
}
} else if cfg!(target_pointer_width = "64") {
true
} else {
// Not enough address space on 32-bit systems
false
}
});
pub fn should_prepare_memory_region() -> bool {
*SHOULD_PREPARE_MEMORY_REGION
}
impl FsMappingRequest {
pub fn execute(&self, vm: &mut dyn Vm, allocator: &mut SystemAllocator) -> VmResponse {
use self::FsMappingRequest::*;
match *self {
AllocateSharedMemoryRegion(alloc) => {
match prepare_shared_memory_region(
vm,
allocator,
alloc,
MemCacheType::CacheCoherent,
) {
Ok(VmMappedMemoryRegion { gfn, slot }) => {
VmResponse::RegisterMemory { gfn, slot }
}
Err(e) => VmResponse::Err(e),
}
}
CreateMemoryMapping {
slot,
ref fd,
size,
file_offset,
prot,
mem_offset,
} => {
let raw_fd: Descriptor = Descriptor(fd.as_raw_descriptor());
match vm.add_fd_mapping(slot, mem_offset, size, &raw_fd, file_offset, prot) {
Ok(()) => VmResponse::Ok,
Err(e) => VmResponse::Err(e),
}
}
RemoveMemoryMapping { slot, offset, size } => {
match vm.remove_mapping(slot, offset, size) {
Ok(()) => VmResponse::Ok,
Err(e) => VmResponse::Err(e),
}
}
}
}
}