zx/
vmar.rs

1// Copyright 2017 The Fuchsia Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5//! Type-safe bindings for Zircon vmar objects.
6
7use crate::clock::Clock;
8use crate::iob::Iob;
9use crate::{
10    object_get_info, object_get_info_single, object_get_info_vec, ok, sys, AsHandleRef, Handle,
11    HandleBased, HandleRef, Koid, Name, ObjectQuery, Status, Topic, Vmo,
12};
13use bitflags::bitflags;
14use std::mem::MaybeUninit;
15use zerocopy::{FromBytes, Immutable};
16use zx_sys::PadByte;
17
18/// An object representing a Zircon
19/// [virtual memory address region](https://fuchsia.dev/fuchsia-src/concepts/objects/vm_address_region.md).
20///
21/// As essentially a subtype of `Handle`, it can be freely interconverted.
22#[derive(Debug, Eq, PartialEq, Ord, PartialOrd, Hash)]
23#[repr(transparent)]
24pub struct Vmar(Handle);
25impl_handle_based!(Vmar);
26
27sys::zx_info_vmar_t!(VmarInfo);
28
29impl From<sys::zx_info_vmar_t> for VmarInfo {
30    fn from(sys::zx_info_vmar_t { base, len }: sys::zx_info_vmar_t) -> VmarInfo {
31        VmarInfo { base, len }
32    }
33}
34
35// VmarInfo is able to be safely replaced with a byte representation and is a PoD type.
36unsafe impl ObjectQuery for VmarInfo {
37    const TOPIC: Topic = Topic::VMAR;
38    type InfoTy = VmarInfo;
39}
40
41struct VmarMapsInfo;
42unsafe impl ObjectQuery for VmarMapsInfo {
43    const TOPIC: Topic = Topic::VMAR_MAPS;
44    type InfoTy = MapInfo;
45}
46
47static_assert_align!(
48    /// Ergonomic wrapper around `zx_info_maps_t`.
49    #[repr(C)]
50    #[derive(Copy, Clone, FromBytes, Immutable)]
51    <sys::zx_info_maps_t> pub struct MapInfo {
52        pub name <name>: Name,
53        pub base <base>: usize,
54        pub size <size>: usize,
55        pub depth <depth>: usize,
56        r#type <r#type>: sys::zx_info_maps_type_t,
57        u <u>: sys::InfoMapsTypeUnion,
58    }
59);
60
61impl MapInfo {
62    pub fn new(
63        name: Name,
64        base: usize,
65        size: usize,
66        depth: usize,
67        details: MapDetails<'_>,
68    ) -> Result<MapInfo, Status> {
69        let (map_type, map_details_union) = match details {
70            MapDetails::None => (
71                sys::ZX_INFO_MAPS_TYPE_NONE,
72                sys::InfoMapsTypeUnion { mapping: Default::default() },
73            ),
74            MapDetails::AddressSpace => (
75                sys::ZX_INFO_MAPS_TYPE_ASPACE,
76                sys::InfoMapsTypeUnion { mapping: Default::default() },
77            ),
78            MapDetails::Vmar => (
79                sys::ZX_INFO_MAPS_TYPE_VMAR,
80                sys::InfoMapsTypeUnion { mapping: Default::default() },
81            ),
82            MapDetails::Mapping(mapping_details) => (
83                sys::ZX_INFO_MAPS_TYPE_MAPPING,
84                sys::InfoMapsTypeUnion {
85                    mapping: {
86                        let mut mapping: sys::zx_info_maps_mapping_t = Default::default();
87                        mapping.mmu_flags = mapping_details.mmu_flags.bits();
88                        mapping.vmo_koid = mapping_details.vmo_koid.raw_koid();
89                        mapping.vmo_offset = mapping_details.vmo_offset;
90                        mapping.committed_bytes = mapping_details.committed_bytes;
91                        mapping.populated_bytes = mapping_details.populated_bytes;
92                        mapping.committed_private_bytes = mapping_details.committed_private_bytes;
93                        mapping.populated_private_bytes = mapping_details.populated_private_bytes;
94                        mapping.committed_scaled_bytes = mapping_details.committed_scaled_bytes;
95                        mapping.populated_scaled_bytes = mapping_details.populated_scaled_bytes;
96                        mapping.committed_fractional_scaled_bytes =
97                            mapping_details.committed_fractional_scaled_bytes;
98                        mapping.populated_fractional_scaled_bytes =
99                            mapping_details.populated_fractional_scaled_bytes;
100                        mapping
101                    },
102                },
103            ),
104            MapDetails::Unknown => {
105                return Err(Status::INVALID_ARGS);
106            }
107        };
108        Ok(MapInfo { name, base, size, depth, r#type: map_type, u: map_details_union })
109    }
110
111    pub fn details<'a>(&'a self) -> MapDetails<'a> {
112        match self.r#type {
113            sys::ZX_INFO_MAPS_TYPE_NONE => MapDetails::None,
114            sys::ZX_INFO_MAPS_TYPE_ASPACE => MapDetails::AddressSpace,
115            sys::ZX_INFO_MAPS_TYPE_VMAR => MapDetails::Vmar,
116            sys::ZX_INFO_MAPS_TYPE_MAPPING => {
117                // SAFETY: these values are produced by the kernel or `new()` which guarantees the
118                // discriminant matches the union contents.
119                let raw_mapping = unsafe { &self.u.mapping };
120                let mapping_details = zerocopy::transmute_ref!(raw_mapping);
121                MapDetails::Mapping(mapping_details)
122            }
123            _ => MapDetails::Unknown,
124        }
125    }
126}
127
128impl std::cmp::PartialEq for MapInfo {
129    fn eq(&self, other: &Self) -> bool {
130        self.name == other.name
131            && self.base == other.base
132            && self.size == other.size
133            && self.depth == other.depth
134            && self.details() == other.details()
135    }
136}
137impl std::cmp::Eq for MapInfo {}
138
139impl std::fmt::Debug for MapInfo {
140    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
141        f.debug_struct("MapInfo")
142            .field("name", &self.name)
143            .field("base", &format_args!("{:#x}", self.base))
144            .field("size", &self.size)
145            .field("depth", &self.depth)
146            .field("details", &self.details())
147            .finish()
148    }
149}
150
151#[derive(Copy, Clone, Debug, Eq, PartialEq)]
152pub enum MapDetails<'a> {
153    /// The underlying value returned by the kernel is unknown.
154    Unknown,
155    None,
156    AddressSpace,
157    Vmar,
158    // Mapping returns a reference to avoid copying data.
159    Mapping(&'a MappingDetails),
160}
161
162impl<'a> MapDetails<'a> {
163    pub fn as_mapping(&'a self) -> Option<&'a MappingDetails> {
164        match self {
165            Self::Mapping(d) => Some(*d),
166            _ => None,
167        }
168    }
169}
170
171static_assert_align!(
172    #[repr(C)]
173    #[derive(Copy, Clone, Debug, Eq, FromBytes, Immutable, PartialEq)]
174    <sys::zx_info_maps_mapping_t> pub struct MappingDetails {
175        pub mmu_flags <mmu_flags>: VmarFlagsExtended,
176        padding1: [PadByte; 4],
177        pub vmo_koid <vmo_koid>: Koid,
178        pub vmo_offset <vmo_offset>: u64,
179        pub committed_bytes <committed_bytes>: usize,
180        pub populated_bytes <populated_bytes>: usize,
181        pub committed_private_bytes <committed_private_bytes>: usize,
182        pub populated_private_bytes <populated_private_bytes>: usize,
183        pub committed_scaled_bytes <committed_scaled_bytes>: usize,
184        pub populated_scaled_bytes <populated_scaled_bytes>: usize,
185        pub committed_fractional_scaled_bytes <committed_fractional_scaled_bytes>: u64,
186        pub populated_fractional_scaled_bytes <populated_fractional_scaled_bytes>: u64,
187    }
188);
189
190impl Default for MappingDetails {
191    fn default() -> MappingDetails {
192        Self::from(sys::zx_info_maps_mapping_t::default())
193    }
194}
195
196impl From<sys::zx_info_maps_mapping_t> for MappingDetails {
197    fn from(info: sys::zx_info_maps_mapping_t) -> MappingDetails {
198        zerocopy::transmute!(info)
199    }
200}
201
202impl Vmar {
203    pub fn allocate(
204        &self,
205        offset: usize,
206        size: usize,
207        flags: VmarFlags,
208    ) -> Result<(Vmar, usize), Status> {
209        let mut mapped = 0;
210        let mut handle = 0;
211        let status = unsafe {
212            sys::zx_vmar_allocate(
213                self.raw_handle(),
214                flags.bits(),
215                offset,
216                size,
217                &mut handle,
218                &mut mapped,
219            )
220        };
221        ok(status)?;
222        unsafe { Ok((Vmar::from(Handle::from_raw(handle)), mapped)) }
223    }
224
225    pub fn map(
226        &self,
227        vmar_offset: usize,
228        vmo: &Vmo,
229        vmo_offset: u64,
230        len: usize,
231        flags: VmarFlags,
232    ) -> Result<usize, Status> {
233        let flags = VmarFlagsExtended::from_bits_truncate(flags.bits());
234        unsafe { self.map_unsafe(vmar_offset, vmo, vmo_offset, len, flags) }
235    }
236
237    /// Directly call `zx_vmar_map`.
238    ///
239    /// # Safety
240    ///
241    /// This function is unsafe because certain flags to `zx_vmar_map` may
242    /// replace an existing mapping which is referenced elsewhere.
243    pub unsafe fn map_unsafe(
244        &self,
245        vmar_offset: usize,
246        vmo: &Vmo,
247        vmo_offset: u64,
248        len: usize,
249        flags: VmarFlagsExtended,
250    ) -> Result<usize, Status> {
251        let mut mapped = 0;
252        let status = sys::zx_vmar_map(
253            self.0.raw_handle(),
254            flags.bits(),
255            vmar_offset,
256            vmo.raw_handle(),
257            vmo_offset,
258            len,
259            &mut mapped,
260        );
261        ok(status).map(|_| mapped)
262    }
263
264    /// Directly call `zx_vmar_unmap`.
265    ///
266    /// # Safety
267    ///
268    /// This function is unsafe because unmapping memory regions can arbitrarily
269    /// cause read, write, and execution errors. Among other things, the caller
270    /// must ensure that:
271    ///
272    /// - The region being unmapped will not be accessed after unmapping.
273    /// - All references to memory in the region must be dropped or forgotten
274    ///   prior to calling this method.
275    /// - If the region contained executable code, then code in the region must
276    ///   not be currently executing and may not be executed in the future.
277    ///
278    /// This is not an exhaustive list, as there are many ways to cause memory
279    /// unsafety with memory mappings.
280    pub unsafe fn unmap(&self, addr: usize, len: usize) -> Result<(), Status> {
281        // SAFETY: The caller has guaranteed that unmapping the given region
282        // will not cause undefined behavior.
283        ok(unsafe { sys::zx_vmar_unmap(self.0.raw_handle(), addr, len) })
284    }
285
286    /// Perform an operation on VMOs mapped into this VMAR.
287    ///
288    /// Wraps the
289    /// [zx_vmar_op_range](https://fuchsia.dev/fuchsia-src/reference/syscalls/vmar_op_range.md)
290    /// syscall.
291    pub fn op_range(&self, op: VmarOp, addr: usize, len: usize) -> Result<(), Status> {
292        ok(unsafe {
293            sys::zx_vmar_op_range(
294                self.0.raw_handle(),
295                op.into_raw(),
296                addr,
297                len,
298                std::ptr::null_mut(),
299                0,
300            )
301        })
302    }
303
304    /// Directly call `zx_vmar_protect`.
305    ///
306    /// # Safety
307    ///
308    /// This function is unsafe because changing the access protections for
309    /// memory regions can arbitrarily cause read, write, and execution errors.
310    /// Among other things, the caller must ensure that if a read, write, or
311    /// execute permission is removed from a memory region, it must not read,
312    /// write, or execute it respetively.
313    ///
314    /// This is not an exhaustive list, as there are many ways to cause memory
315    /// unsafety with memory mappings.
316    pub unsafe fn protect(&self, addr: usize, len: usize, flags: VmarFlags) -> Result<(), Status> {
317        // SAFETY: The caller has guaranteed that protecting the given region
318        // will not cause undefined behavior.
319        ok(unsafe { sys::zx_vmar_protect(self.raw_handle(), flags.bits(), addr, len) })
320    }
321
322    /// Directly call `zx_vmar_destroy`.
323    ///
324    /// # Safety
325    ///
326    /// This function is unsafe because destroying a region unmaps all of the
327    /// mappings within it. See [`Vmar::unmap`] for more details on how
328    /// unmapping memory regions can cause memory unsafety.
329    pub unsafe fn destroy(&self) -> Result<(), Status> {
330        // SAFETY: The caller has guaranteed that destroying the given region
331        // will not cause undefined behavior.
332        ok(unsafe { sys::zx_vmar_destroy(self.raw_handle()) })
333    }
334
335    /// Wraps the
336    /// [zx_object_get_info](https://fuchsia.dev/fuchsia-src/reference/syscalls/object_get_info.md)
337    /// syscall for the ZX_INFO_VMAR topic.
338    pub fn info(&self) -> Result<VmarInfo, Status> {
339        Ok(object_get_info_single::<VmarInfo>(self.as_handle_ref())?)
340    }
341
342    /// Wraps the
343    /// [zx_object_get_info](https://fuchsia.dev/fuchsia-src/reference/syscalls/object_get_info.md)
344    /// syscall for the ZX_INFO_VMAR_MAPS topic.
345    ///
346    /// Returns an initialized slice of `MapInfo`s, any uninitialized trailing entries, and the
347    /// total number of infos that the kernel had available.
348    pub fn info_maps<'a>(
349        &self,
350        buf: &'a mut [MaybeUninit<MapInfo>],
351    ) -> Result<(&'a mut [MapInfo], &'a mut [MaybeUninit<MapInfo>], usize), Status> {
352        object_get_info::<VmarMapsInfo>(self.as_handle_ref(), buf)
353    }
354
355    /// Wraps the
356    /// [zx_object_get_info](https://fuchsia.dev/fuchsia-src/reference/syscalls/object_get_info.md)
357    /// syscall for the ZX_INFO_VMAR_MAPS topic.
358    pub fn info_maps_vec(&self) -> Result<Vec<MapInfo>, Status> {
359        object_get_info_vec::<VmarMapsInfo>(self.as_handle_ref())
360    }
361
362    /// Wraps the [zx_vmar_map_iob](https://fuchsia.dev/fuchsia-src/reference/syscalls/zx_vmar_map_iob.md)
363    /// syscall.
364    pub fn map_iob(
365        &self,
366        options: VmarFlags,
367        vmar_offset: usize,
368        iob: &Iob,
369        region_index: u32,
370        region_offset: u64,
371        region_len: usize,
372    ) -> Result<usize, Status> {
373        let mut addr = 0;
374        let status = unsafe {
375            sys::zx_vmar_map_iob(
376                self.raw_handle(),
377                options.bits(),
378                vmar_offset,
379                iob.raw_handle(),
380                region_index,
381                region_offset,
382                region_len,
383                &mut addr,
384            )
385        };
386        ok(status)?;
387        Ok(addr)
388    }
389
390    /// Wraps the [zx_vmar_map_clock](https://fuchsia.dev/fuchsia-src/reference/syscalls/zx_vmar_map_clock.md)
391    /// syscall.
392    pub fn map_clock(
393        &self,
394        options: VmarFlags,
395        vmar_offset: usize,
396        clock: &Clock,
397        length: usize,
398    ) -> Result<usize, Status> {
399        let mut addr = 0;
400        let status = unsafe {
401            sys::zx_vmar_map_clock(
402                self.raw_handle(),
403                options.bits(),
404                vmar_offset,
405                clock.raw_handle(),
406                length,
407                &mut addr,
408            )
409        };
410        ok(status)?;
411        Ok(addr)
412    }
413}
414
415/// VM Address Range opcodes
416#[derive(Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
417#[repr(transparent)]
418pub struct VmarOp(u32);
419impl VmarOp {
420    pub fn from_raw(raw: u32) -> Self {
421        Self(raw)
422    }
423    pub fn into_raw(self) -> u32 {
424        self.0
425    }
426}
427
428assoc_values!(VmarOp, [
429    COMMIT =           sys::ZX_VMAR_OP_COMMIT;
430    DECOMMIT =         sys::ZX_VMAR_OP_DECOMMIT;
431    PREFETCH =         sys::ZX_VMAR_OP_PREFETCH;
432    MAP_RANGE =        sys::ZX_VMAR_OP_MAP_RANGE;
433    DONT_NEED =        sys::ZX_VMAR_OP_DONT_NEED;
434    ALWAYS_NEED =      sys::ZX_VMAR_OP_ALWAYS_NEED;
435]);
436
437// TODO(smklein): Ideally we would have two separate sets of bitflags,
438// and a union of both of them.
439macro_rules! vmar_flags {
440    (
441        safe: [$($safe_name:ident : $safe_sys_name:ident,)*],
442        extended: [$($ex_name:ident : $ex_sys_name:ident,)*],
443    ) => {
444        /// Flags to VMAR routines which are considered safe.
445        #[repr(transparent)]
446        #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, FromBytes, Immutable)]
447        pub struct VmarFlags(sys::zx_vm_option_t);
448
449        bitflags! {
450            impl VmarFlags: sys::zx_vm_option_t {
451                $(
452                    const $safe_name = sys::$safe_sys_name;
453                )*
454            }
455        }
456
457        impl std::fmt::Debug for VmarFlags {
458            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
459                bitflags::parser::to_writer(self, f)
460            }
461        }
462
463        /// Flags to all VMAR routines.
464        #[repr(transparent)]
465        #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, FromBytes, Immutable, Default)]
466        pub struct VmarFlagsExtended(sys::zx_vm_option_t);
467
468        bitflags! {
469            impl VmarFlagsExtended: sys::zx_vm_option_t {
470                $(
471                    const $safe_name = sys::$safe_sys_name;
472                )*
473                $(
474                    const $ex_name = sys::$ex_sys_name;
475                )*
476            }
477        }
478
479        impl std::fmt::Debug for VmarFlagsExtended {
480            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
481                bitflags::parser::to_writer(self, f)
482            }
483        }
484    };
485}
486
487vmar_flags! {
488    safe: [
489        PERM_READ: ZX_VM_PERM_READ,
490        PERM_WRITE: ZX_VM_PERM_WRITE,
491        PERM_EXECUTE: ZX_VM_PERM_EXECUTE,
492        COMPACT: ZX_VM_COMPACT,
493        SPECIFIC: ZX_VM_SPECIFIC,
494        CAN_MAP_SPECIFIC: ZX_VM_CAN_MAP_SPECIFIC,
495        CAN_MAP_READ: ZX_VM_CAN_MAP_READ,
496        CAN_MAP_WRITE: ZX_VM_CAN_MAP_WRITE,
497        CAN_MAP_EXECUTE: ZX_VM_CAN_MAP_EXECUTE,
498        MAP_RANGE: ZX_VM_MAP_RANGE,
499        REQUIRE_NON_RESIZABLE: ZX_VM_REQUIRE_NON_RESIZABLE,
500        ALLOW_FAULTS: ZX_VM_ALLOW_FAULTS,
501        OFFSET_IS_UPPER_LIMIT: ZX_VM_OFFSET_IS_UPPER_LIMIT,
502        PERM_READ_IF_XOM_UNSUPPORTED: ZX_VM_PERM_READ_IF_XOM_UNSUPPORTED,
503
504        // Alignment options
505        ALIGN_1KB: ZX_VM_ALIGN_1KB,
506        ALIGN_2KB: ZX_VM_ALIGN_2KB,
507        ALIGN_4KB: ZX_VM_ALIGN_4KB,
508        ALIGN_8KB: ZX_VM_ALIGN_8KB,
509        ALIGN_16KB: ZX_VM_ALIGN_16KB,
510        ALIGN_32KB: ZX_VM_ALIGN_32KB,
511        ALIGN_64KB: ZX_VM_ALIGN_64KB,
512        ALIGN_128KB: ZX_VM_ALIGN_128KB,
513        ALIGN_256KB: ZX_VM_ALIGN_256KB,
514        ALIGN_512KB: ZX_VM_ALIGN_512KB,
515        ALIGN_1MB: ZX_VM_ALIGN_1MB,
516        ALIGN_2MB: ZX_VM_ALIGN_2MB,
517        ALIGN_4MB: ZX_VM_ALIGN_4MB,
518        ALIGN_8MB: ZX_VM_ALIGN_8MB,
519        ALIGN_16MB: ZX_VM_ALIGN_16MB,
520        ALIGN_32MB: ZX_VM_ALIGN_32MB,
521        ALIGN_64MB: ZX_VM_ALIGN_64MB,
522        ALIGN_128MB: ZX_VM_ALIGN_128MB,
523        ALIGN_256MB: ZX_VM_ALIGN_256MB,
524        ALIGN_512MB: ZX_VM_ALIGN_512MB,
525        ALIGN_1GB: ZX_VM_ALIGN_1GB,
526        ALIGN_2GB: ZX_VM_ALIGN_2GB,
527        ALIGN_4GB: ZX_VM_ALIGN_4GB,
528    ],
529    extended: [
530        SPECIFIC_OVERWRITE: ZX_VM_SPECIFIC_OVERWRITE,
531    ],
532}
533
534#[cfg(test)]
535mod tests {
536    // The unit tests are built with a different crate name, but fuchsia_runtime returns a "real"
537    // zx::Vmar that we need to use.
538    use zx::{Status, VmarFlags};
539
540    #[test]
541    fn allocate_and_info() -> Result<(), Status> {
542        let size = usize::pow(2, 20); // 1MiB
543        let root_vmar = fuchsia_runtime::vmar_root_self();
544        let (vmar, base) = root_vmar.allocate(0, size, VmarFlags::empty())?;
545
546        let info = vmar.info()?;
547        assert!(info.base == base);
548        assert!(info.len == size);
549        Ok(())
550    }
551
552    #[test]
553    fn root_vmar_info() -> Result<(), Status> {
554        let root_vmar = fuchsia_runtime::vmar_root_self();
555        let info = root_vmar.info()?;
556        assert!(info.base > 0);
557        assert!(info.len > 0);
558        Ok(())
559    }
560
561    #[test]
562    fn root_vmar_maps() {
563        let root_vmar = fuchsia_runtime::vmar_root_self();
564        let info = root_vmar.info_maps_vec().unwrap();
565        assert!(!info.is_empty());
566    }
567}
zx/vmar.rs

zx/
vmar.rs
