STRUCT AP_MATRIX_DEV(9)

💅 struct ap_matrix_dev(9)

okay bestie, so this is a page straight out of the Kernel API Manual — it's all about struct ap_matrix_dev, which (per the NAME, no cap) contains the data for the matrix device. That's the whole vibe. Let's get into it ✨

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🌸 NAME

struct ap_matrix_dev — contains the data for the matrix device. yes that's it, that's the whole assignment, and she ate 💅

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🎀 SYNOPSIS

here's the whole struct, copied exactly, do not touch, do not "clean up", do not rename anything, i'm watching you 👀

struct ap_matrix_dev {
    struct device device;
    struct ap_config_info info;
    struct list_head mdev_list;
    struct mutex mdevs_lock;
    struct ap_driver  *vfio_ap_drv;
    struct mutex guests_lock;
    struct mdev_parent parent;
    struct mdev_type mdev_type;
    struct mdev_type *mdev_types;
 };

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🦋 Members

okay so these are the members this page actually tells you about — each one gets a lil breakdown 🫶

• device — the generic device structure that's associated with the AP matrix device. the everyday, standard-device-struct bestie of the group, holdin' it down 🌈
• info — the struct containing the output from the PQAP(QCI) instruction. literally that instruction's whole output, living in here 💖
• mdev_list — the list of mediated matrix devices that have been created. it's giving roster energy 📋
• mdevs_lock — a mutex for locking the AP matrix device. and listen, it gets taken every single time we fiddle with state managed by the vfio_ap driver — whether that's through mdev_list or through writing the state of a single ap_matrix_mdev device. yes, it's quite coarse 😭 but fr fr, we don't expect much contention, so she's fine 👑
• vfio_ap_drv — the vfio_ap device driver. the driver in question, the main character 🔥
• guests_lock — a mutex for controlling access to a guest that's using AP devices passed through by the vfio_ap device driver. it gets taken when the AP devices are plugged into or unplugged from a guest 🌸, and also when an ap_matrix_mdev device is added to or removed from mdev_list, or when the list is iterated. so yeah, she's everywhere, and that's on periodt 💀

heads up bestie: the struct up top also has parent, mdev_type, and mdev_types in it — this page only documents the ones listed above, so i'm not out here making stuff up about the rest. no invented lore in this house 🙈

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🧚 SEE ALSO

• Kernel file ./drivers/s390/crypto/vfio_ap_private.h
• struct ap_matrix(9)
• struct ap_queue_table(9)
• struct ap_matrix_mdev(9)
• struct vfio_ap_queue(9)

go read those too, iykyk 📚✨

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okay that's the whole page!! 💜 this iconic lil doc lives in ./drivers/s390/crypto and it's dated October 2026, all filed under struct ap_matrix_dev(9) in your Kernel API Manual. mwah, go forth and slay your AP matrix adventures 🎀🦋⭐