resources+pci: allocator rework (allocation tags)

AddressAllocator now maintains a HashMap<Alloc, (u64, u64, u64)>,
which uniquely maps a Allocation enum (e.g: PciBar(bus, dev, bar),
GpuRenderNode, etc...) to it's address, size, and human-readable tag
/ description.

The interface has also been modified to use Error instead of Option.

Aside from improving debugging, tracking allocations will have
numerous uses in the future. For example, when allocating guest memory
over VmControl sockets, it will be possible to restrict allocations to
pre-allocated slices of memory owned by the requesting device.

To plumb through PCI information to PCI devices, this CL necessitated
the addition of a PciDevice method called `assign_bus_dev`, which
notifies PCI devices of their uniquely assigned Bus and Device numbers.

BUG=chromium:936567
TEST=cargo test -p resources && cargo build --features="gpu gpu-forward"

Change-Id: I8b4b0e32c6f3168138739249ede53d03143ee5c3
Reviewed-on: https://chromium-review.googlesource.com/1536207
Commit-Ready: Daniel Prilik <prilik@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Zach Reizner <zachr@chromium.org>

1 files changed, 60 insertions, 3 deletions

diff --git a/resources/src/lib.rs b/resources/src/lib.rs
index b16b2da..a49f998 100644
--- a/resources/src/lib.rs
+++ b/resources/src/lib.rs
@@ -4,10 +4,67 @@
 
 //! Manages system resources that can be allocated to VMs and their devices.
 
+#[cfg(feature = "wl-dmabuf")]
+extern crate gpu_buffer;
+extern crate libc;
+extern crate msg_socket;
+extern crate sys_util;
+
+use std::fmt::Display;
+
+pub use crate::address_allocator::AddressAllocator;
+pub use crate::gpu_allocator::{
+    GpuAllocatorError, GpuMemoryAllocator, GpuMemoryDesc, GpuMemoryPlaneDesc,
+};
+pub use crate::system_allocator::SystemAllocator;
+
 mod address_allocator;
 mod gpu_allocator;
 mod system_allocator;
 
-pub use crate::address_allocator::AddressAllocator;
-pub use crate::gpu_allocator::{GpuMemoryAllocator, GpuMemoryDesc, GpuMemoryPlaneDesc};
-pub use crate::system_allocator::SystemAllocator;
+/// Used to tag SystemAllocator allocations.
+#[derive(Debug, Eq, PartialEq, Hash)]
+pub enum Alloc {
+    /// An anonymous resource allocation.
+    /// Should only be instantiated through `SystemAllocator::get_anon_alloc()`.
+    /// Avoid using these. Instead, use / create a more descriptive Alloc variant.
+    Anon(usize),
+    /// A PCI BAR region with associated bus, device, and bar numbers.
+    PciBar { bus: u8, dev: u8, bar: u8 },
+    /// GPU render node region.
+    GpuRenderNode,
+}
+
+#[derive(Debug, Eq, PartialEq)]
+pub enum Error {
+    AllocSizeZero,
+    BadAlignment,
+    CreateGpuAllocator(GpuAllocatorError),
+    ExistingAlloc(Alloc),
+    MissingDeviceAddresses,
+    MissingMMIOAddresses,
+    NoIoAllocator,
+    OutOfSpace,
+    PoolOverflow { base: u64, size: u64 },
+    PoolSizeZero,
+}
+
+pub type Result<T> = std::result::Result<T, Error>;
+
+impl Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        use self::Error::*;
+        match self {
+            AllocSizeZero => write!(f, "Allocation cannot have size of 0"),
+            BadAlignment => write!(f, "Pool alignment must be a power of 2"),
+            CreateGpuAllocator(e) => write!(f, "Failed to create GPU allocator: {:?}", e),
+            ExistingAlloc(tag) => write!(f, "Alloc already exists: {:?}", tag),
+            MissingDeviceAddresses => write!(f, "Device address range not specified"),
+            MissingMMIOAddresses => write!(f, "MMIO address range not specified"),
+            NoIoAllocator => write!(f, "No IO address range specified"),
+            OutOfSpace => write!(f, "Out of space"),
+            PoolOverflow { base, size } => write!(f, "base={} + size={} overflows", base, size),
+            PoolSizeZero => write!(f, "Pool cannot have size of 0"),
+        }
+    }
+}