#ifndef _NTPFAPI_H

/**
 * The PF_PFN_PRIO_REQUEST structure queries or updates a variable array of page-frame entries.
 * \remarks On x64, entries begin at offset 0xc0 and occupy 24 bytes each; the minimum
 * payload is 0xd8 bytes (one entry), aligned to 8 bytes. PfnCount must be nonzero and the supplied buffer
 * must cover 0xc0 + 24 * PfnCount bytes. The computed size must fit in ULONG. The declared 256-element
 * arrays are compatibility declarations, not a fixed request-size requirement or a maximum count.
 * Query class 6 copies only each input PageFrameIndex into a zeroed identity record before querying it.
 * Set classes 7 and 29 can copy the entries back on operation failure; class 22 copies relocation results back.
 */
typedef struct _PF_PFN_PRIO_REQUEST
{
    ULONG Version;                              // Request version: PF_PFN_PRIO_REQUEST_VERSION (1).
    ULONG RequestFlags;                         // Classes 6/7: bit 0 only; class 22 passes the low/high USHORTs to MmRelocatePfnList.
    SIZE_T PfnCount;                            // Nonzero; buffer size is FIELD_OFFSET(..., PageData) + PfnCount * sizeof(MMPFN_IDENTITY).
    SYSTEM_MEMORY_LIST_INFORMATION MemInfo;     // Memory-list statistics associated with the request.
    union
    {
        // Class 6: input PFNs, output identities. Class 16 uses PF_MEMORY_LIST_INFO instead.
        MMPFN_IDENTITY PageIdentities[256];     // Variable-length array with PfnCount entries.
        MMPFN_IDENTITY PageData[256];           // Compatibility name.
        // Classes 7, 22 and 29: caller-supplied entries; copy-back behavior is described above.
        PFN_TRIPLET Entries[256];               // Variable array of PfnCount update or relocation entries; 256 is the declared capacity, not a limit.
    };
} PF_PFN_PRIO_REQUEST, *PPF_PFN_PRIO_REQUEST;

#endif
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