mmu.h

/*
 *                          Shadow-Box
 *                         ------------
 *      Lightweight Hypervisor-Based Kernel Protector
 *
 *               Copyright (C) 2017 Seunghun Han
 *     at National Security Research Institute of South Korea
 */

/*
 * This software has GPL v2 license. See the GPL_LICENSE file.
 */
#ifndef __MMU_H__
#define __MMU_H__

/*
 * Macros.
 */
/* Page size macro. */
#define VAL_256TB				((u64)256 * 1024 * 1024 * 1024 * 1024)
#define VAL_1TB					((u64)1 * 1024 * 1024 * 1024 * 1024)
#define VAL_512GB				((u64)512 * 1024 * 1024 * 1024)
#define VAL_4GB					((u64)4* 1024 * 1024 * 1024)
#define VAL_1GB					((u64)1024 * 1024 * 1024)
#define VAL_2MB					((u64)2 * 1024 * 1024)
#define VAL_4KB					((u64)4 * 1024)

/* Page table flags. */
#define MASK_PAGEFLAG			((u64) 0xFF00000000000FFF)
#define MASK_PAGEFLAG_WO_DA		(((u64) 0xFF00000000000FFF) ^ (0x01 << 5) ^ (0x01 << 6))
#define MASK_INVALIDPAGEFLAG	((u64) 0x07FF000000000000)
#define MASK_PAGE_SIZE_FLAG		(0x01 << 7)
#define MASK_PAGEFLAG_WO_SIZE	(MASK_PAGEFLAG ^ MASK_PAGE_SIZE_FLAG)
#define MASK_PRESENT_FLAG		(0x01 << 0)
#define MASK_XD_FLAG			((u64)0x01 << 63)
#define MASK_PAGEADDR			((u64) 0xFFFFFFFFFFFFF000)

#define IS_PRESENT(x)			((x) & MASK_PRESENT_FLAG)
#define IS_SIZE_FLAG_SET(x)		((x) & MASK_PAGE_SIZE_FLAG)
#define GET_ADDR(x)				((x) & ~MASK_PAGEFLAG)

/* EPT page type. */
#define EPT_TYPE_PML4			0
#define EPT_TYPE_PDPTEPD		1
#define EPT_TYPE_PDEPT			2
#define EPT_TYPE_PTE			3

/* EPT flags */
#define EPT_READ				(0x01 << 0)
#define EPT_WRITE				(0x01 << 1)
#define EPT_EXECUTE				(0x01 << 2)
#define EPT_ALL_ACCESS			(EPT_READ | EPT_WRITE | EPT_EXECUTE)
#define EPT_BIT_PDE_2MB			(0x01 << 7)
#define EPT_BIT_MEM_TYPE_WB		(0x06 << 3)
#define EPT_PAGE_ENT_COUNT		512
#define EPT_PAGE_SIZE			4096

/*
 * Structures.
 */
/* Page table structure. */
struct sb_pagetable
{
    u64 entry[512];
};

/* EPT table structure. */
struct sb_ept_pagetable
{
    u64 entry[512];
};

/* EPT information structure. */
struct sb_ept_info
{
    u64 pml4_ent_count;
    u64 pdpte_pd_ent_count;
    u64 pdept_ent_count;
    u64 pte_ent_count;
    u64 pml4_page_count;
    u64 pdpte_pd_page_count;
    u64 pdept_page_count;
    u64 pte_page_count;
    u64* pml4_page_addr_array;
    u64* pdpte_pd_page_addr_array;
    u64* pdept_page_addr_array;
    u64* pte_page_addr_array;
};

/* Page table entry structure. */
struct vm_page_entry_struct
{
	u64 phy_addr[4];
};

/*
 * Variables.
 */
extern struct sb_ept_info g_ept_info;

/* The function prototype for walk_system_ram_range. */
typedef int (*my_walk_system_ram_range) (unsigned long start_pfn, unsigned long nr_pages,
	void *arg, int (*func)(unsigned long, unsigned long, void*));

/*
 * Functions.
 */
u64 sb_get_max_ram_size(void);
void sb_set_ept_hide_page(u64 phy_addr);
void sb_set_ept_lock_page(u64 phy_addr);
void sb_set_ept_read_only_page(u64 phy_addr);
void sb_set_ept_all_access_page(u64 phy_addr);
void sb_protect_ept_pages(void);
void sb_setup_ept_pagetable_4KB(void);
int sb_alloc_ept_pages(void);
void sb_free_ept_pages(void);
void * sb_get_pagetable_log_addr(int type, int index);
void * sb_get_pagetable_phy_addr(int iType, int iIndex);

#endif