libnvme(2)

💖 libnvme — it's the enum nvme_id_ctrl_oacs page, bestie 💖

okay so you found yourself in the libnvme(2) manual and it's giving "controller vibe check" energy, and honestly? obsessed. this whole page is about one enum, and that enum is a little bitmask baddie that tells you which optional Admin commands and features your NVMe controller actually supports — you know, the stuff hanging out in &struct nvme_id_ctrl.oacs. no cap, that's the entire plot. 🦋

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✨ NAME ✨

enum nvme_id_ctrl_oacs — Flags indicating the optional Admin commands and features supported by the controller, see &struct nvme_id_ctrl.oacs.

like, it's the receipts for what your controller can and can't do. main character energy for a bitfield, fr fr. 👑

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🌸 SYNOPSIS 🌸

enum nvme_id_ctrl_oacs {
    NVME_CTRL_OACS_SSRS_SHIFT ,
    NVME_CTRL_OACS_FNVMS_SHIFT ,
    NVME_CTRL_OACS_FWDS_SHIFT ,
    NVME_CTRL_OACS_NMS_SHIFT ,
    NVME_CTRL_OACS_DSTS_SHIFT ,
    NVME_CTRL_OACS_DIRS_SHIFT ,
    NVME_CTRL_OACS_NSRS_SHIFT ,
    NVME_CTRL_OACS_VMS_SHIFT ,
    NVME_CTRL_OACS_DBCS_SHIFT ,
    NVME_CTRL_OACS_GLSS_SHIFT ,
    NVME_CTRL_OACS_CFLS_SHIFT ,
    NVME_CTRL_OACS_HMLMS_SHIFT ,
    NVME_CTRL_OACS_SSRS_MASK ,
    NVME_CTRL_OACS_FNVMS_MASK ,
    NVME_CTRL_OACS_FWDS_MASK ,
    NVME_CTRL_OACS_NMS_MASK ,
    NVME_CTRL_OACS_DSTS_MASK ,
    NVME_CTRL_OACS_DIRS_MASK ,
    NVME_CTRL_OACS_NSRS_MASK ,
    NVME_CTRL_OACS_VMS_MASK ,
    NVME_CTRL_OACS_DBCS_MASK ,
    NVME_CTRL_OACS_GLSS_MASK ,
    NVME_CTRL_OACS_CFLS_MASK ,
    NVME_CTRL_OACS_HMLMS_MASK ,
    NVME_CTRL_OACS_SECURITY ,
    NVME_CTRL_OACS_FORMAT ,
    NVME_CTRL_OACS_FW ,
    NVME_CTRL_OACS_NS_MGMT ,
    NVME_CTRL_OACS_SELF_TEST ,
    NVME_CTRL_OACS_DIRECTIVES ,
    NVME_CTRL_OACS_NVME_MI ,
    NVME_CTRL_OACS_VIRT_MGMT ,
    NVME_CTRL_OACS_DBBUF_CFG ,
    NVME_CTRL_OACS_LBA_STATUS ,
    NVME_CTRL_OACS_CMD_FEAT_LD ,
    NVME_CTRL_OACS_HMLM

};

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🎀 Constants 🎀

bestie, there's three flavours of constant here and they're literally a team: SHIFT ones tell you how far to shift to grab a bit, MASK ones give you the mask to grab it, and the plain-named ones are the actual bits — if set, that thing is supported. periodt. 💅

🔥 the SHIFT girlies (how many places to slide over) 🔥

• NVME_CTRL_OACS_SSRS_SHIFT — Shift amount to get the Security Send Receive supported
• NVME_CTRL_OACS_FNVMS_SHIFT — Shift amount to get the Format NVM supported
• NVME_CTRL_OACS_FWDS_SHIFT — Shift amount to get the Firmware Download supported
• NVME_CTRL_OACS_NMS_SHIFT — Shift amount to get the Namespace Management supported
• NVME_CTRL_OACS_DSTS_SHIFT — Shift amount to get the Device Self-test supported
• NVME_CTRL_OACS_DIRS_SHIFT — Shift amount to get the Directives supported
• NVME_CTRL_OACS_NSRS_SHIFT — Shift amount to get the NVMe-MI Send Receive supported
• NVME_CTRL_OACS_VMS_SHIFT — Shift amount to get the Virtualization Management supported
• NVME_CTRL_OACS_DBCS_SHIFT — Shift amount to get the Doorbell Buffer Config supported
• NVME_CTRL_OACS_GLSS_SHIFT — Shift amount to get the Get LBA Status supported
• NVME_CTRL_OACS_CFLS_SHIFT — Shift amount to get the Command and Feature Lockdown supported
• NVME_CTRL_OACS_HMLMS_SHIFT — Shift amount to get the Host Managed Live Migration support

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🦋 the MASK besties (the actual mask value) 🦋

• NVME_CTRL_OACS_SSRS_MASK — Mask to get the Security Send Receive supported
• NVME_CTRL_OACS_FNVMS_MASK — Mask to get the Format NVM supported
• NVME_CTRL_OACS_FWDS_MASK — Mask to get the Firmware Download supported
• NVME_CTRL_OACS_NMS_MASK — Mask to get the Namespace Management supported
• NVME_CTRL_OACS_DSTS_MASK — Mask to get the Device Self-test supported
• NVME_CTRL_OACS_DIRS_MASK — Mask to get the Directives supported
• NVME_CTRL_OACS_NSRS_MASK — Mask to get the NVMe-MI Send Receive supported
• NVME_CTRL_OACS_VMS_MASK — Mask to get the Virtualization Management supported
• NVME_CTRL_OACS_DBCS_MASK — Mask to get the Doorbell Buffer Config supported
• NVME_CTRL_OACS_GLSS_MASK — Mask to get the Get LBA Status supported
• NVME_CTRL_OACS_CFLS_MASK — Mask to get the Command and Feature Lockdown supported
• NVME_CTRL_OACS_HMLMS_MASK — Mask to get the Host Managed Live Migration support

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👑 the actual bits (if set, she's supported) 👑

• NVME_CTRL_OACS_SECURITY — If set, then the controller supports the Security Send and Security Receive commands.
• NVME_CTRL_OACS_FORMAT — If set then the controller supports the Format NVM command.
• NVME_CTRL_OACS_FW — If set, then the controller supports the Firmware Commit and Firmware Image Download commands.
• NVME_CTRL_OACS_NS_MGMT — If set, then the controller supports the Namespace Management capability
• NVME_CTRL_OACS_SELF_TEST — If set, then the controller supports the Device Self-test command.
• NVME_CTRL_OACS_DIRECTIVES — If set, then the controller supports Directives and the Directive Send and Directive Receive commands.
• NVME_CTRL_OACS_NVME_MI — If set, then the controller supports the NVMe-MI Send and NVMe-MI Receive commands.
• NVME_CTRL_OACS_VIRT_MGMT — If set, then the controller supports the Virtualization Management command.
• NVME_CTRL_OACS_DBBUF_CFG — If set, then the controller supports the Doorbell Buffer Config command.
• NVME_CTRL_OACS_LBA_STATUS — If set, then the controller supports the Get LBA Status capability.
• NVME_CTRL_OACS_CMD_FEAT_LD — If set, then the controller supports the command and feature lockdown capability.
• NVME_CTRL_OACS_HMLM — If set, then the controller supports the command and Host Managed Live Migration capability.

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💀 reminder bestie: SHIFT gets you the position, MASK gets you the bit, and the plain constant is the value you compare against. don't mix them up, that's a vibe check you will fail. 🫶

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and that's the whole page, babe — no SEE ALSO, no options, just the oacs enum living her best life. this libnvme(2) bop dropped in July 2026 (enum nvme_id_ctrl_oacs, part of the libnvme API manual) and honestly? she ate. ✨🌈 go check &struct nvme_id_ctrl.oacs and slay. 🎀💜