libnvme(9)

🦋 NAME 🦋

okay so welcome to the libnvme(9) API Manual, bestie 💖 — this page is literally all about enum nvme_cap, and this field indicates the controller capabilities register. That's the vibe: controller capabilities decoded into shift amounts, masks, and a few iconic named values ✨.

✨ SYNOPSIS ✨

here's the enum in all its glory — every constant exactly where it belongs, no cap 👑

enum nvme_cap {
    NVME_CAP_MQES_SHIFT ,
    NVME_CAP_CQR_SHIFT ,
    NVME_CAP_AMS_SHIFT ,
    NVME_CAP_TO_SHIFT ,
    NVME_CAP_DSTRD_SHIFT ,
    NVME_CAP_NSSRS_SHIFT ,
    NVME_CAP_CSS_SHIFT ,
    NVME_CAP_BPS_SHIFT ,
    NVME_CAP_CPS_SHIFT ,
    NVME_CAP_MPSMIN_SHIFT ,
    NVME_CAP_MPSMAX_SHIFT ,
    NVME_CAP_PMRS_SHIFT ,
    NVME_CAP_CMBS_SHIFT ,
    NVME_CAP_NSSS_SHIFT ,
    NVME_CAP_CRMS_SHIFT ,
    NVME_CAP_NSSES_SHIFT ,
    NVME_CAP_MQES_MASK ,
    NVME_CAP_CQR_MASK ,
    NVME_CAP_AMS_MASK ,
    NVME_CAP_TO_MASK ,
    NVME_CAP_DSTRD_MASK ,
    NVME_CAP_NSSRS_MASK ,
    NVME_CAP_CSS_MASK ,
    NVME_CAP_BPS_MASK ,
    NVME_CAP_CPS_MASK ,
    NVME_CAP_MPSMIN_MASK ,
    NVME_CAP_MPSMAX_MASK ,
    NVME_CAP_PMRS_MASK ,
    NVME_CAP_CMBS_MASK ,
    NVME_CAP_NSSS_MASK ,
    NVME_CAP_CRMS_MASK ,
    NVME_CAP_NSSES_MASK ,
    NVME_CAP_AMS_WRR ,
    NVME_CAP_AMS_VS ,
    NVME_CAP_CSS_NVM ,
    NVME_CAP_CSS_CSI ,
    NVME_CAP_CSS_ADMIN ,
    NVME_CAP_CPS_NONE ,
    NVME_CAP_CPS_CTRL ,
    NVME_CAP_CPS_DOMAIN ,
    NVME_CAP_CPS_NVMS ,
    NVME_CAP_CRWMS ,
    NVME_CAP_CRIMS

};

🌈 Constants 🌈

okay bestie, here's the full lineup — no skips, no shortcuts, we're getting every single one 💅

• NVME_CAP_MQES_SHIFT — shift amount to get the maximum queue entries supported 🎀
• NVME_CAP_CQR_SHIFT — shift amount to get the contiguous queues required
• NVME_CAP_AMS_SHIFT — shift amount to get the arbitration mechanism supported
• NVME_CAP_TO_SHIFT — shift amount to get the timeout
• NVME_CAP_DSTRD_SHIFT — shift amount to get the doorbell stride
• NVME_CAP_NSSRS_SHIFT — shift amount to get the NVM subsystem reset supported
• NVME_CAP_CSS_SHIFT — shift amount to get the command sets supported
• NVME_CAP_BPS_SHIFT — shift amount to get the boot partition support
• NVME_CAP_CPS_SHIFT — shift amount to get the controller power scope
• NVME_CAP_MPSMIN_SHIFT — shift amount to get the memory page size minimum
• NVME_CAP_MPSMAX_SHIFT — shift amount to get the memory page size maximum
• NVME_CAP_PMRS_SHIFT — shift amount to get the persistent memory region supported
• NVME_CAP_CMBS_SHIFT — shift amount to get the controller memory buffer supported
• NVME_CAP_NSSS_SHIFT — shift amount to get the NVM subsystem shutdown supported
• NVME_CAP_CRMS_SHIFT — shift amount to get the controller ready modes supported
• NVME_CAP_NSSES_SHIFT — shift amount to get the NVM subsystem shutdown enhancements supported ✨
• NVME_CAP_MQES_MASK — mask to get the maximum queue entries supported
• NVME_CAP_CQR_MASK — mask to get the contiguous queues required
• NVME_CAP_AMS_MASK — mask to get the arbitration mechanism supported
• NVME_CAP_TO_MASK — mask to get the timeout
• NVME_CAP_DSTRD_MASK — mask to get the doorbell stride
• NVME_CAP_NSSRS_MASK — mask to get the NVM subsystem reset supported
• NVME_CAP_CSS_MASK — mask to get the command sets supported
• NVME_CAP_BPS_MASK — mask to get the boot partition support
• NVME_CAP_CPS_MASK — mask to get the controller power scope
• NVME_CAP_MPSMIN_MASK — mask to get the memory page size minimum
• NVME_CAP_MPSMAX_MASK — mask to get the memory page size maximum
• NVME_CAP_PMRS_MASK — mask to get the persistent memory region supported
• NVME_CAP_CMBS_MASK — mask to get the controller memory buffer supported
• NVME_CAP_NSSS_MASK — mask to get the NVM subsystem shutdown supported
• NVME_CAP_CRMS_MASK — mask to get the controller ready modes supported
• NVME_CAP_NSSES_MASK — mask to get the NVM subsystem shutdown enhancements supported
• NVME_CAP_AMS_WRR — weighted round robin with urgent priority class 🔥
• NVME_CAP_AMS_VS — vendor specific
• NVME_CAP_CSS_NVM — NVM command set or a discovery controller
• NVME_CAP_CSS_CSI — controller supports one or more I/O command sets
• NVME_CAP_CSS_ADMIN — no I/O command set is supported
• NVME_CAP_CPS_NONE — not reported
• NVME_CAP_CPS_CTRL — controller scope
• NVME_CAP_CPS_DOMAIN — domain scope
• NVME_CAP_CPS_NVMS — NVM subsystem scope
• NVME_CAP_CRWMS — controller ready with media support
• NVME_CAP_CRIMS — controller ready independent of media support 💜

mwah 💋 — signed, sealed, and slayed by libnvme(9), October 2026, all about enum nvme_cap 🫶