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

NsidConflict

Error returned when adding a namespace with a conflicting ID.

NvmeController

An NVMe controller.

NvmeControllerCaps

The NVMe controller’s capabilities.

NvmeControllerClient

Client for modifying the NVMe controller state at runtime.