Crate nvme 

NVMe controller emulator (NVMe 2.0, NVM command set).

This crate emulates an NVMe controller as a PCI device with MMIO BAR0, MSI-X, and admin + I/O queue pairs. It targets the NVMe Base 2.0 specification (version register reports 0x00020000) with vendor ID 0x1414 (Microsoft).

Architecture

• PCI layer (NvmeController) — MMIO BAR0 register handling, PCI config space, MSI-X interrupt routing, doorbell writes.
• Coordinator — manages enable/reset sequencing, namespace add/remove.
• Admin worker — processes admin commands: Identify Controller/Namespace, Create/Delete I/O Queue, Get/Set Features, Async Event Request.
• I/O workers — pool of tasks (one per completion queue) processing NVM commands: READ, WRITE, FLUSH, Dataset Management (TRIM), and persistent reservation commands.

What it doesn’t implement

Firmware update, admin-level namespace management (create/delete), multi-path I/O, end-to-end data protection (PI), and save/restore (SaveRestore returns not-supported).

Namespace management

Namespaces can be added and removed at runtime via NvmeControllerClient. Each namespace wraps a Disk and a background task monitors capacity changes via wait_resize, completing Async Event Requests with CHANGED_NAMESPACE_LIST when the disk size changes.

Key constants

• MAX_DATA_TRANSFER_SIZE: 256 KB
• MAX_QES: 256 queue entries
• BAR0_LEN: 64 KB

Modules

resolver

Resource resolver for the nvme controller.

Structs

NvmeController

An NVMe controller.

NvmeControllerCaps

The NVMe controller’s capabilities.

NvmeControllerClient

Client for modifying the NVMe controller state at runtime.

Enums

AddNamespaceError

Error returned when a namespace cannot be added.