Bug 1752188: Move GPUBufferDescriptor validation to server. r=jgilbert

Depends on [`wgpu#2673`].

WebGPU requires `GPUBufferDescriptor` validation failure to:

1) generate an error on the Device timeline, and

2) mark the new buffer as invalid.

Satisfy 1) by moving most validation to the compositor process.

Requirement 2) is harder. `wgpu_core::Global::device_create_buffer`
already takes care of some validation for us, and marks the provided
buffer id invalid when there's a problem. However, there are certain
errors the spec requires us to detect which `device_create_buffer`
cannot even see, because they are caught by standard Rust validation
steps in the process of creating the `wgpu_types::BufferDescriptor`
that one would *pass to* that function. For example, if there are
bogus bits set in the `usage` property, we can't even construct a Rust
`BufferUsages` value from that to include in the `BufferDescriptor`
that we must pass to `device_create_buffer`.

This means that we need to do some validation ourselves, in the
process of constructing that `BufferDescriptor`, and use the
`Global::create_buffer_error` method added in [`wgpu#2673`] to mark
the new buffer as invalid.

[`wgpu#2673`]: gfx-rs/wgpu#2673

Differential Revision: https://phabricator.services.mozilla.com/D146768

dom/webgpu/ipc/PWebGPU.ipdl

@@ -10,6 +10,7 @@ using layers::CompositableHandle from "mozilla/layers/LayersTypes.h";
 using RawId from "mozilla/webgpu/WebGPUTypes.h";
 using dom::GPURequestAdapterOptions from "mozilla/dom/WebGPUBinding.h";
 using dom::GPUCommandBufferDescriptor from "mozilla/dom/WebGPUBinding.h";
+using dom::GPUBufferDescriptor from "mozilla/dom/WebGPUBinding.h";
 using webgpu::ffi::WGPUHostMap from "mozilla/webgpu/ffi/wgpu.h";
 using MaybeScopedError from "mozilla/webgpu/WebGPUTypes.h";
 
@@ -38,6 +39,8 @@ parent:
   async CommandEncoderAction(RawId selfId, RawId aDeviceId, ByteBuf buf);
   async BumpImplicitBindGroupLayout(RawId pipelineId, bool isCompute, uint32_t index, RawId assignId);
 
+  async CreateBuffer(RawId deviceId, RawId bufferId, GPUBufferDescriptor desc);
+
   async InstanceRequestAdapter(GPURequestAdapterOptions options, RawId[] ids) returns (ByteBuf byteBuf);
   async AdapterRequestDevice(RawId selfId, ByteBuf buf, RawId newId) returns (bool success);
   async AdapterDestroy(RawId selfId);

dom/webgpu/ipc/WebGPUChild.cpp

@@ -352,23 +352,11 @@ Maybe<DeviceRequest> WebGPUChild::AdapterRequestDevice(
 
 RawId WebGPUChild::DeviceCreateBuffer(RawId aSelfId,
                                       const dom::GPUBufferDescriptor& aDesc) {
-  ffi::WGPUBufferDescriptor desc = {};
-  nsCString label;
-  if (aDesc.mLabel.WasPassed()) {
-    LossyCopyUTF16toASCII(aDesc.mLabel.Value(), label);
-    desc.label = label.get();
-  }
-  desc.size = aDesc.mSize;
-  desc.usage = aDesc.mUsage;
-  desc.mapped_at_creation = aDesc.mMappedAtCreation;
-
-  ByteBuf bb;
-  RawId id =
-      ffi::wgpu_client_create_buffer(mClient.get(), aSelfId, &desc, ToFFI(&bb));
-  if (!SendDeviceAction(aSelfId, std::move(bb))) {
+  RawId bufferId = ffi::wgpu_client_make_buffer_id(mClient.get(), aSelfId);
+  if (!SendCreateBuffer(aSelfId, bufferId, aDesc)) {
     MOZ_CRASH("IPC failure");
   }
-  return id;
+  return bufferId;
 }
 
 RawId WebGPUChild::DeviceCreateTexture(RawId aSelfId,

dom/webgpu/ipc/WebGPUParent.cpp

@@ -334,6 +334,22 @@ ipc::IPCResult WebGPUParent::RecvDeviceDestroy(RawId aSelfId) {
   return IPC_OK();
 }
 
+ipc::IPCResult WebGPUParent::RecvCreateBuffer(
+    RawId aSelfId, RawId aBufferId, dom::GPUBufferDescriptor&& aDesc) {
+  nsCString label;
+  const char* labelOrNull = nullptr;
+  if (aDesc.mLabel.WasPassed()) {
+    LossyCopyUTF16toASCII(aDesc.mLabel.Value(), label);
+    labelOrNull = label.get();
+  }
+  ErrorBuffer error;
+  ffi::wgpu_server_device_create_buffer(mContext.get(), aSelfId, aBufferId,
+                                        labelOrNull, aDesc.mSize, aDesc.mUsage,
+                                        aDesc.mMappedAtCreation, error.ToFFI());
+  ForwardError(aSelfId, error);
+  return IPC_OK();
+}
+
 ipc::IPCResult WebGPUParent::RecvBufferReturnShmem(RawId aSelfId,
                                                    Shmem&& aShmem) {
   MOZ_LOG(sLogger, LogLevel::Info,
@@ -744,13 +760,11 @@ ipc::IPCResult WebGPUParent::RecvSwapChainPresent(
 
       ffi::WGPUBufferUsages usage =
           WGPUBufferUsages_COPY_DST | WGPUBufferUsages_MAP_READ;
-      ffi::WGPUBufferDescriptor desc = {};
-      desc.size = bufferSize;
-      desc.usage = usage;
 
       ErrorBuffer error;
       ffi::wgpu_server_device_create_buffer(mContext.get(), data->mDeviceId,
-                                            &desc, bufferId, error.ToFFI());
+                                            bufferId, nullptr, bufferSize,
+                                            usage, false, error.ToFFI());
       if (ForwardError(data->mDeviceId, error)) {
         return IPC_OK();
       }

dom/webgpu/ipc/WebGPUParent.h

@@ -34,6 +34,8 @@ class WebGPUParent final : public PWebGPUParent {
       AdapterRequestDeviceResolver&& resolver);
   ipc::IPCResult RecvAdapterDestroy(RawId aSelfId);
   ipc::IPCResult RecvDeviceDestroy(RawId aSelfId);
+  ipc::IPCResult RecvCreateBuffer(RawId aSelfId, RawId aBufferId,
+                                  dom::GPUBufferDescriptor&& aDesc);
   ipc::IPCResult RecvBufferReturnShmem(RawId aSelfId, Shmem&& aShmem);
   ipc::IPCResult RecvBufferMap(RawId aSelfId, ffi::WGPUHostMap aHostMap,
                                uint64_t aOffset, uint64_t size,

dom/webgpu/ipc/WebGPUSerialize.h

@@ -33,6 +33,9 @@ DEFINE_IPC_SERIALIZER_WITHOUT_FIELDS(mozilla::dom::GPUCommandBufferDescriptor);
 DEFINE_IPC_SERIALIZER_WITH_FIELDS(mozilla::dom::GPURequestAdapterOptions,
                                   mPowerPreference, mForceFallbackAdapter);
 
+DEFINE_IPC_SERIALIZER_WITH_FIELDS(mozilla::dom::GPUBufferDescriptor, mSize,
+                                  mUsage, mMappedAtCreation);
+
 DEFINE_IPC_SERIALIZER_WITH_FIELDS(mozilla::webgpu::ScopedError, operationError,
                                   validationMessage);
 

gfx/wgpu_bindings/cbindgen.toml

@@ -43,6 +43,7 @@ exclude = [
 	"Option_BufferSize", "Option_NonZeroU32", "Option_NonZeroU8",
 	"ANativeWindow_setBuffersGeometry",
 ]
+include = ["BufferUsages"]
 
 [export.rename]
 "BufferDescriptor_RawString" = "BufferDescriptor"

gfx/wgpu_bindings/src/client.rs

@@ -475,26 +475,6 @@ pub extern "C" fn wgpu_client_make_buffer_id(
         .alloc(backend)
 }
 
-#[no_mangle]
-pub extern "C" fn wgpu_client_create_buffer(
-    client: &Client,
-    device_id: id::DeviceId,
-    desc: &wgt::BufferDescriptor<RawString>,
-    bb: &mut ByteBuf,
-) -> id::BufferId {
-    let backend = device_id.backend();
-    let id = client
-        .identities
-        .lock()
-        .select(backend)
-        .buffers
-        .alloc(backend);
-
-    let action = DeviceAction::CreateBuffer(id, desc.map_label(cow_label));
-    *bb = make_byte_buf(&action);
-    id
-}
-
 #[no_mangle]
 pub extern "C" fn wgpu_client_create_texture(
     client: &Client,

gfx/wgpu_bindings/src/lib.rs

@@ -75,7 +75,6 @@ struct ImplicitLayout<'a> {
 
 #[derive(serde::Serialize, serde::Deserialize)]
 enum DeviceAction<'a> {
-    CreateBuffer(id::BufferId, wgc::resource::BufferDescriptor<'a>),
     CreateTexture(id::TextureId, wgc::resource::TextureDescriptor<'a>),
     CreateSampler(id::SamplerId, wgc::resource::SamplerDescriptor<'a>),
     CreateBindGroupLayout(

gfx/wgpu_bindings/src/server.rs

@@ -211,12 +211,30 @@ pub extern "C" fn wgpu_server_device_drop(global: &Global, self_id: id::DeviceId
 pub extern "C" fn wgpu_server_device_create_buffer(
     global: &Global,
     self_id: id::DeviceId,
-    desc: &wgt::BufferDescriptor<RawString>,
-    new_id: id::BufferId,
+    buffer_id: id::BufferId,
+    label_or_null: RawString,
+    size: wgt::BufferAddress,
+    usage: u32,
+    mapped_at_creation: bool,
     mut error_buf: ErrorBuffer,
 ) {
-    let desc = desc.map_label(cow_label);
-    let (_, error) = gfx_select!(self_id => global.device_create_buffer(self_id, &desc, new_id));
+    let label = cow_label(&label_or_null);
+    let usage = match wgt::BufferUsages::from_bits(usage) {
+        Some(usage) => usage,
+        None => {
+            error_buf.init_str("GPUBufferDescriptor's 'usage' includes invalid unimplemented bits \
+                                or unimplemented usages");
+            gfx_select!(self_id => global.create_buffer_error(buffer_id, label));
+            return;
+        }
+    };
+    let desc = wgc::resource::BufferDescriptor {
+        label,
+        size,
+        usage,
+        mapped_at_creation,
+    };
+    let (_, error) = gfx_select!(self_id => global.device_create_buffer(self_id, &desc, buffer_id));
     if let Some(err) = error {
         error_buf.init(err);
     }
@@ -285,12 +303,6 @@ impl Global {
         mut error_buf: ErrorBuffer,
     ) {
         match action {
-            DeviceAction::CreateBuffer(id, desc) => {
-                let (_, error) = self.device_create_buffer::<A>(self_id, &desc, id);
-                if let Some(err) = error {
-                    error_buf.init(err);
-                }
-            }
             DeviceAction::CreateTexture(id, desc) => {
                 let (_, error) = self.device_create_texture::<A>(self_id, &desc, id);
                 if let Some(err) = error {