Commit graph

32 commits

Author SHA1 Message Date
Daniel Verkamp
793b4703cf io_uring: convert to ThisError and sort
BUG=b:197143586
TEST=cargo check

Cq-Depend: chromium:3105310
Change-Id: I661c65e095d0a8274a68ff44d70a65bce21970f5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3105080
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>
2021-09-02 21:00:22 +00:00
Allen Webb
c6fa73d76f Fix clippy warnings and Cargo.lock
This fixes:
* version mismatches in Cargo.lock
* style issues
* implementations of Into that should be From
* deprecated protobuf APIs

It also adds RUST_BACKTRACE=1 to the kokoro tests.

BUG=None
TEST=./bin/preupload-clippy

Change-Id: I8e9157c903f2080a5fdcc4d3e4ed72fbad41c64f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3024427
Auto-Submit: Allen Webb <allenwebb@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Commit-Queue: Allen Webb <allenwebb@google.com>
2021-07-15 03:33:17 +00:00
Chirantan Ekbote
eff60328c1 Add a From impl for async errors to io::Error
Sometimes users of cros_async need to return an io::Error.  Provide a
conversion function to convert the various async errors into an
io::Error.  This allows callers to access the underlying error without
forcing us to expose these internal implementation details.

BUG=none
TEST=unit tests

Change-Id: Ie0ab00cb80ea58f628a38c173e28babf30b8d5b4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3006308
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Keiichi Watanabe <keiichiw@chromium.org>
Commit-Queue: Chirantan Ekbote <chirantan@chromium.org>
2021-07-06 11:35:26 +00:00
Zach Reizner
6d6efb20c0 remove dependencies on syscall_defines
The syscall_defines crate is redundant with an up to date libc. This
change removes any dependency on syscall_defines. A new libc is required
to bring in some new syscall numbers like the ones for io_uring.

TEST=./test_all
BUG=None

Cq-Depend: chromium:2832000
Change-Id: I6df7fb992bacb5efd54cefca08836d52f4bfcd8c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2832001
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Allen Webb <allenwebb@google.com>
Reviewed-by: Dylan Reid <dgreid@chromium.org>
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Commit-Queue: Zach Reizner <zachr@chromium.org>
2021-04-21 21:01:38 +00:00
Chirantan Ekbote
6676bdadb2 Fixup Cargo.toml for cros_async and io_uring
Add magic comments so that we can have separate ebuilds for the io_uring
and cros_async crates.

BUG=none
TEST=`FEATURES=test emerge-$BOARD cros_async`

Change-Id: I8e4befc90d44b4b021864f4358c8f9b3ec5a87d5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2794162
Reviewed-by: Dylan Reid <dgreid@chromium.org>
Reviewed-by: Stephen Barber <smbarber@chromium.org>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Commit-Queue: Chirantan Ekbote <chirantan@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
2021-04-01 03:32:58 +00:00
Dennis Kempin
758503bcb5 io_uring: Disable multi_thread_submit_and_complete
This CL reverts previous attempts at reducing the flakiness of the test
and disables it completely.

BUG=b:183722981
TEST=./test_all

Change-Id: I36527d6404c67ff9e73792676a52f064d2f48d14
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2787246
Reviewed-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>
2021-03-30 00:05:34 +00:00
Dennis Kempin
1736adac0d io_uring: Really fix flaky test
It's still flaky, removing another check. That should take care of it.
Unfortunately it does not reproduce frequently when running locally.

BUG=None
TEST=./test_all

Change-Id: Ie60fef676f860f5ff36f7b0b57ce8582f03fe669
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2774938
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Dennis Kempin <denniskempin@google.com>
2021-03-22 21:55:09 +00:00
Dennis Kempin
ae447c4bc7 io_uring: Fix flaky test
The test has been failing every ~10 test runs. The removed check
can be racy since we cannot wait for all threads to complete.

BUG=None
TEST=./test_all passes consistently

Change-Id: I231ae0734bc1a0d0c0fc991448f6ebf63b11fc56
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2768678
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Dennis Kempin <denniskempin@google.com>
2021-03-18 22:12:59 +00:00
Dennis Kempin
84b2d93c70 Fix io_uring tests for running on Kokoro
Some of the multi-threaded tests had race conditions that show up when
running inside the Kokoro Test VMs.

To wake up and complete all running threads, no-ops are inserted into
the uring. However, each thread can grab a list of results. On the
test VMs, all no-ops are read by one thread, leaving the others running,
blocking the test from completing.

Since this is just a test.. let's just leave the threads hanging and
let the OS take care of them.

BUG=b:181673923
TEST=./test_all

Change-Id: I504b6db9cf934e2454d27c1155667b4b0f7fbc77
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2750783
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Commit-Queue: Dennis Kempin <denniskempin@google.com>
2021-03-12 23:36:14 +00:00
Chirantan Ekbote
1fcc8a8f3c io_uring: Make UringContext Sync
Rather than requiring callers to wrap the entire UringContext in a big
lock, make UringContext Sync by internally using fine-grained locks:

* The submit queue is wrapped with a Mutex so that threads may still add
  operations to the submit queue even when a thread is blocked
  inside an io_uring_enter call.
* The completion queue internally uses a Mutex around the pending op
  data and completed count so that two threads don't end up trying to
  remove the same operation from the completed queue.

With this we can enable the await_uring_from_poll test.  This test
uncovered missing wakeups in the case where a uring operation is added
from one thread while the main uring thread is blocked inside an
io_uring_enter syscall. To deal with this, we call submit() whenever the
pending operation is polled and not yet submitted.

BUG=none
TEST=unit tests

Change-Id: I4c7dec65c03b7b10014f4a84d2cd16fe8758ea72
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2643842
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Chirantan Ekbote <chirantan@chromium.org>
Reviewed-by: Dylan Reid <dgreid@chromium.org>
2021-01-26 09:15:11 +00:00
Chirantan Ekbote
5380b44aef io_uring: Use IoBufMut instead of iovec
This is ABI-compatible with iovec and comes with Send + Sync impls,
which iovec does not have.

BUG=none
TEST=unit tests

Change-Id: Ic5831f557933b1d0dc823b1f6ba991ffe57baf2c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2571149
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Noah Gold <nkgold@google.com>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-by: Dylan Reid <dgreid@chromium.org>
Commit-Queue: Chirantan Ekbote <chirantan@chromium.org>
2021-01-19 11:59:30 +00:00
Andrew Walbran
9cfdbd9cc0 Fix clippy errors and some warnings.
TEST=cargo test

Change-Id: I91afe78141c717a592eec5ec77acac2a500ba163
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2623941
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Keiichi Watanabe <keiichiw@chromium.org>
Reviewed-by: Andrew Walbran <qwandor@google.com>
Reviewed-by: Keiichi Watanabe <keiichiw@chromium.org>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Commit-Queue: Andrew Walbran <qwandor@google.com>
2021-01-18 15:50:25 +00:00
Noah Gold
b3fca20e24 Refactor cros_async interface to avoid RawFd.
Instead of creating IoSourceExt from AsRawFd implementers, we've
switched to creating from a marker trait `IntoAsync`. This lets us use
other types like RawDescriptor easily with this crate.  By using the
marker, we also provide some type safety by requiring consumers of
IoSourceExt to declare that their type is expected to work with async
operations. This way we can provide stronger guarantees that an async
IO trait object will behave in a reasonable way.

This CL also purges the cros_async -> base and io_uring -> base
references, and provides the base types needed to add new async
primitives to base.

BUG=none
TEST=builds

Change-Id: I0b0ce6ca7938b22ae8e8fb4e604439f0292678f2
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2504481
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Noah Gold <nkgold@google.com>
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
2020-11-10 11:40:50 +00:00
Michael Hoyle
3038e40a6b base: Refactor mmap to use builder pattern.
BUG=b:165423256
TEST=./build_test

Change-Id: Ia67c1a7fe29b66c9cab38476eecde8c25a55617b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2442569
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Michael Hoyle <mikehoyle@google.com>
2020-10-16 07:15:24 +00:00
Zach Reizner
ab04758814 build_test: misc options, improvements, amd bug fixes
New option, --size-only, speeds up using build_test for getting release
binary size by skipping everything else. The lto flag is also added for
release builds to get a more realistic comparison.

The list of crates to test is built up automatically instead of
hard coded. To modify what gets included, empty .build_test_* files are
checked for existance. This is better than hard coding the list of
packages because it was frequently out of date.

For certain crate tests, a dynamic library that only exists in a sysroot
is required. This change includes a fix that adds the sysroot's lib
directory to the LD_LIBRARY_PATH env variable, similar to how
PKG_CONFIG_LIBDIR is modified.

TEST=build_test
BUG=None

Change-Id: I626cbcccf40035a0d29001cef7989a091848e4c9
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2444273
Tested-by: Zach Reizner <zachr@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Auto-Submit: Zach Reizner <zachr@chromium.org>
Reviewed-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Commit-Queue: Zach Reizner <zachr@chromium.org>
2020-10-15 13:40:32 +00:00
Michael Hoyle
a7e38ab421 base: Add shared memory layer to base.
This is very largely boilerplate, but changes some interfaces
to accept different parameters, esp using Descriptor.

BUG=b:162363783
TEST=./build_test

Change-Id: I81b513c0de9448c2de505fe5d3a61a29f4eccb78
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2342591
Reviewed-by: Zach Reizner <zachr@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Michael Hoyle <mikehoyle@google.com>
2020-09-30 19:44:40 +00:00
Chirantan Ekbote
370ee0fb75 io_uring: Pin iovecs in memory
Pointers to the iovec structs are shared with the kernel for the
duration of an I/O operation and so must be pinned in memory.  Use
Pin<Box<[iovec]>> instead of Vec<iovec> to express this and also to
prevent any changes made in the future from accidentally doing something
that causes the memory location of the iovecs to change.

BUG=none
TEST=unit tests

Change-Id: I317f3a6f68d457b0b0a6c86494d506b0e978b5fb
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2387823
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Chirantan Ekbote <chirantan@chromium.org>
Reviewed-by: Dylan Reid <dgreid@chromium.org>
2020-09-12 09:42:37 +00:00
Daniel Verkamp
f4a260d3df Simplify tests with tempfile::tempfile()
Where it simplifies the code, use tempfile() rather than TempDir to
create temporary files in tests.

BUG=None
TEST=./build_test

Change-Id: I5caff512a38a3b94556b0c72693e432503d6e679
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2360459
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-by: Dylan Reid <dgreid@chromium.org>
2020-08-27 00:39:03 +00:00
Michael Hoyle
6b19695c81 Add "base" crate and transition crosvm usages to it from sys_util
For now, this crate simply re-exports all of sys_util, but it will
be updated to provide new interfaces when needed. This is the
first step to making crosvm not directly depend on sys_util, so
that we can make the interface changes we need without fear of
negatively affecting (i.e. completely breaking) other usages
within chromeos.

BUG=b:162363783
TEST=./build_test

Change-Id: I7d0aa3d8a1f66af1c7fee8fd649723ef17027150
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2325168
Tested-by: Michael Hoyle <mikehoyle@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Michael Hoyle <mikehoyle@google.com>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-by: Zach Reizner <zachr@chromium.org>
2020-08-06 18:19:44 +00:00
Dylan Reid
becca3722d io_uring: handle EBUSY from uring_enter
enter can fail if there are too many pending ops. This will return
EBUSY. The user will have to handle some completions before trying
again. Only count sqes as submitted by resetting self.added when enter
returns success.

The number of sqes must also be guarded if too many are added before the
kernel can update the head pointer.

TEST=added ebusy unit test

Change-Id: I0c20677f1332732aab09f025e110eca0c2a42500
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2296699
Tested-by: Dylan Reid <dgreid@chromium.org>
Commit-Queue: Dylan Reid <dgreid@chromium.org>
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
2020-07-17 15:06:15 +00:00
Dylan Reid
eef1c93fdc uring/async: Add fsync and fallocate
These will be needed by by block.
Note that support for uring fallocate was added in 5.6. The users will
have to handle falling back to synchronous calls if fallocate returns
EINVAL.

BUG=901139
TEST=added fallocate unit tests

Change-Id: I51d635adcf0bb4dd55c5bfe50719f2fde2b88e49
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2274996
Reviewed-by: Dylan Reid <dgreid@chromium.org>
Tested-by: Dylan Reid <dgreid@chromium.org>
Commit-Queue: Dylan Reid <dgreid@chromium.org>
2020-07-17 06:13:17 +00:00
Andrew Walbran
67448289e5 Use platform abstraction around libc::__errno_location.
It has a different name on Android.

BUG=b:158290206
TEST=cargo test

Change-Id: I424d0ddf24c008a06570c709354c7c2dd9395738
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2294865
Reviewed-by: Dylan Reid <dgreid@chromium.org>
Reviewed-by: Zach Reizner <zachr@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Dylan Reid <dgreid@chromium.org>
Commit-Queue: Andrew Walbran <qwandor@google.com>
2020-07-16 13:34:19 +00:00
Dylan Reid
0cbf9d3fb5 io_uring: initialze sqes to zero
Submission queue entries have whatever value is left from last time
stored. Clear them to zero when they are pulled out prior to being
filled. It's better to do this in a central location than making each
user responsible for setting all the fields.

Change-Id: I0436e24cd97fe4bbe808d7d0cc09fa81c1323d57
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2274995
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Dylan Reid <dgreid@chromium.org>
Commit-Queue: Dylan Reid <dgreid@chromium.org>
2020-07-04 21:59:52 +00:00
Dylan Reid
e254389b63 io_uring: Don't set the num_wait value during submit
The value is ignored if WAIT isn't indicated in the flags, but it's more
clear what is happening if left as zero as well.

Change-Id: Ib3539e37d1eaad6f5a68f6c028cdd186f12a8dd4
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2274994
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Tested-by: Dylan Reid <dgreid@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Dylan Reid <dgreid@chromium.org>
2020-07-04 21:59:49 +00:00
Daniel Verkamp
4c64fa7c6f io_uring: allow alignment-changing casts of mmap
uring.rs wraps the kernel io_uring interfaces that provide C-style raw
pointers, which requires casting a *u8 into other types with stricter
alignment requirements.  All of these casts are based on the base mmap()
pointer (which is always page aligned) or offsets within an mmap
provided by the kernel, so we can assume they are safe to cast to the
relevant more-aligned types.

Fixes clippy warnings of the form:

  casting from `*mut u8` to a more-strictly-aligned pointer (`*const
  std::sync::atomic::AtomicU32`) (1 < 4 bytes)

BUG=None
TEST=bin/clippy

Change-Id: Ibef32bb8529d34ece79f089992ad8bd880c5030b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2253068
Reviewed-by: Dylan Reid <dgreid@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Daniel Verkamp <dverkamp@chromium.org>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>
2020-06-22 21:10:14 +00:00
Daniel Verkamp
af787af9bc io_uring: drop unnecessary 'static in const
clippy warns about the redundant 'static lifetime, which is implied for
const.

BUG=None
TEST=bin/clippy

Change-Id: I1d4dca90de359857ec947e12ae47858785d8867c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2253065
Reviewed-by: Dylan Reid <dgreid@chromium.org>
Tested-by: Daniel Verkamp <dverkamp@chromium.org>
Commit-Queue: Daniel Verkamp <dverkamp@chromium.org>
2020-06-22 21:10:10 +00:00
Dylan Reid
d42d3fec7a io_uring: update for mmap api change
A recent change to sys_util moved the definition of 'as_ptr' for an mmap
to a new trait, include that trait here.

Change-Id: Ib48113738fdace50e2dc7f72a5107dd95db867f9
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2241590
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-by: Stephen Barber <smbarber@chromium.org>
Tested-by: Dylan Reid <dgreid@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Dylan Reid <dgreid@chromium.org>
2020-06-12 19:26:46 +00:00
Dylan Reid
e187df2a5e io_uring: Take Vecs or iterators of iovecs
The pointer passed to the kernel for the iovecs must remain valid until
the operation completes. This is true even if the kernel copies the sqe
containing the pointer, that isn't a deep copy. If the iovecs are freed
before the kernel actually processes the op, it will fail with a bad
address error.

Move the responsibility for maintaining the list in memory from the
caller to io_uring itself. This mean io_uring must allocate.  Taking
iterators for IoSlice/IoSliceMut, means that the caller doesn't need to
allocate as well if there isn't a Vec already allocated.

Change-Id: I63a009d8ab543c8bac4132809fb851536d4ad82c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2227082
Reviewed-by: Dylan Reid <dgreid@chromium.org>
Tested-by: Dylan Reid <dgreid@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Dylan Reid <dgreid@chromium.org>
2020-06-05 17:29:51 +00:00
Dylan Reid
03164ca9d8 io_uring: allocate iovecs based on returned count from the kernel
The kernel is allowed to not only limit the number of requested entries,
but also provide more than is requested. If a non-power-of-2 is
requested, it will be rounded up to the next power of 2.

Ensure that there are enough iovecs by allocating them based on the
number returned from io_uring_setup instead of the number of entries
requested.

TEST=cargo test read_parallel

Change-Id: If92e0a31858d1af53b99af8415002a4f26b48230
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2140915
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Dylan Reid <dgreid@chromium.org>
Commit-Queue: Dylan Reid <dgreid@chromium.org>
2020-04-10 00:13:08 +00:00
Dylan Reid
23a2b7b8a2 io_uring: add reading and writing iovecs
Let the user of the io_uring interface specify a slice of iovecs to read
from or write to when queueing an operation to the ring.

These ops can be used by block that has a Vec of iovecs from the
descriptor chain already.

Change-Id: Ia91e03e441cdae03e4fdba33bb601de006ef53ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2140914
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Dylan Reid <dgreid@chromium.org>
Commit-Queue: Dylan Reid <dgreid@chromium.org>
2020-04-10 00:13:08 +00:00
Dylan Reid
40d0e01de6 io_uring: operation results are unsigned
Switch from returning an i32 to a u32. This will make handling the
number easier for users, as they can assume it is >= 0.

Any value < 0 would not be returned as Ok(value) anyways as ret < 0 is
used for error conditions.

Change-Id: I609ce55d3c6be6e28f4d7aadf7148b2ac3b18878
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2140913
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Dylan Reid <dgreid@chromium.org>
Commit-Queue: Dylan Reid <dgreid@chromium.org>
2020-04-10 00:13:06 +00:00
Dylan Reid
a9a1d02277 Add io_uring interfaces
Provide a low-level interface to operating the new io_uring interface.

This is an unsafe interface with the basic operations of setting up the
ring, adding to it, removing from it, and polling it.

This will be followed by a safe interface layer on top of this code,
then by additions to the asynchronous executor that allow for
asynchronously doing multiple operations to files from one context.

Change-Id: I71f7ffb04ce8cb4da470deda9aee768ab95d3d98
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2124009
Reviewed-by: Dylan Reid <dgreid@chromium.org>
Reviewed-by: Zach Reizner <zachr@chromium.org>
Tested-by: Dylan Reid <dgreid@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Dylan Reid <dgreid@chromium.org>
2020-04-05 21:32:20 +00:00