/*
 * GTT virtualization
 *
 * Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * Authors:
 *    Zhi Wang <zhi.a.wang@intel.com>
 *    Zhenyu Wang <zhenyuw@linux.intel.com>
 *    Xiao Zheng <xiao.zheng@intel.com>
 *
 * Contributors:
 *    Min He <min.he@intel.com>
 *    Bing Niu <bing.niu@intel.com>
 *
 */

#include <linux/vmalloc.h>

#include <drm/drm_print.h>

#include "gt/intel_gt_regs.h"

#include "gvt.h"
#include "i915_drv.h"
#include "i915_pvinfo.h"
#include "trace.h"

#if defined(VERBOSE_DEBUG)
#define gvt_vdbg_mm(fmt, args...) gvt_dbg_mm(fmt, ##args)
#else
#define gvt_vdbg_mm(fmt, args...)
#endif

static bool enable_out_of_sync = false;
static int preallocated_oos_pages = 8192;

/*
 * validate a gm address and related range size,
 * translate it to host gm address
 */
bool intel_gvt_ggtt_validate_range(struct intel_vgpu *vgpu, u64 addr, u32 size)
{
        if (size == 0)
                return vgpu_gmadr_is_valid(vgpu, addr);

        if (vgpu_gmadr_is_aperture(vgpu, addr) &&
            vgpu_gmadr_is_aperture(vgpu, addr + size - 1))
                return true;
        else if (vgpu_gmadr_is_hidden(vgpu, addr) &&
                 vgpu_gmadr_is_hidden(vgpu, addr + size - 1))
                return true;

        gvt_dbg_mm("Invalid ggtt range at 0x%llx, size: 0x%x\n",
                     addr, size);
        return false;
}

#define gtt_type_is_entry(type) \
        (type > GTT_TYPE_INVALID && type < GTT_TYPE_PPGTT_ENTRY \
         && type != GTT_TYPE_PPGTT_PTE_ENTRY \
         && type != GTT_TYPE_PPGTT_ROOT_ENTRY)

#define gtt_type_is_pt(type) \
        (type >= GTT_TYPE_PPGTT_PTE_PT && type < GTT_TYPE_MAX)

#define gtt_type_is_pte_pt(type) \
        (type == GTT_TYPE_PPGTT_PTE_PT)

#define gtt_type_is_root_pointer(type) \
        (gtt_type_is_entry(type) && type > GTT_TYPE_PPGTT_ROOT_ENTRY)

#define gtt_init_entry(e, t, p, v) do { \
        (e)->type = t; \
        (e)->pdev = p; \
        memcpy(&(e)->val64, &v, sizeof(v)); \
} while (0)

/*
 * Mappings between GTT_TYPE* enumerations.
 * Following information can be found according to the given type:
 * - type of next level page table
 * - type of entry inside this level page table
 * - type of entry with PSE set
 *
 * If the given type doesn't have such a kind of information,
 * e.g. give a l4 root entry type, then request to get its PSE type,
 * give a PTE page table type, then request to get its next level page
 * table type, as we know l4 root entry doesn't have a PSE bit,
 * and a PTE page table doesn't have a next level page table type,
 * GTT_TYPE_INVALID will be returned. This is useful when traversing a
 * page table.
 */

struct gtt_type_table_entry {
        int entry_type;
        int pt_type;
        int next_pt_type;
        int pse_entry_type;
};

#define GTT_TYPE_TABLE_ENTRY(type, e_type, cpt_type, npt_type, pse_type) \
        [type] = { \
                .entry_type = e_type, \
                .pt_type = cpt_type, \
                .next_pt_type = npt_type, \
                .pse_entry_type = pse_type, \
        }

static const struct gtt_type_table_entry gtt_type_table[] = {
        GTT_TYPE_TABLE_ENTRY(GTT_TYPE_PPGTT_ROOT_L4_ENTRY,
                        GTT_TYPE_PPGTT_ROOT_L4_ENTRY,
                        GTT_TYPE_INVALID,
                        GTT_TYPE_PPGTT_PML4_PT,
                        GTT_TYPE_INVALID),
        GTT_TYPE_TABLE_ENTRY(GTT_TYPE_PPGTT_PML4_PT,
                        GTT_TYPE_PPGTT_PML4_ENTRY,
                        GTT_TYPE_PPGTT_PML4_PT,
                        GTT_TYPE_PPGTT_PDP_PT,
                        GTT_TYPE_INVALID),
        GTT_TYPE_TABLE_ENTRY(GTT_TYPE_PPGTT_PML4_ENTRY,
                        GTT_TYPE_PPGTT_PML4_ENTRY,
                        GTT_TYPE_PPGTT_PML4_PT,
                        GTT_TYPE_PPGTT_PDP_PT,
                        GTT_TYPE_INVALID),
        GTT_TYPE_TABLE_ENTRY(GTT_TYPE_PPGTT_PDP_PT,
                        GTT_TYPE_PPGTT_PDP_ENTRY,
                        GTT_TYPE_PPGTT_PDP_PT,
                        GTT_TYPE_PPGTT_PDE_PT,
                        GTT_TYPE_PPGTT_PTE_1G_ENTRY),
        GTT_TYPE_TABLE_ENTRY(GTT_TYPE_PPGTT_ROOT_L3_ENTRY,
                        GTT_TYPE_PPGTT_ROOT_L3_ENTRY,
                        GTT_TYPE_INVALID,
                        GTT_TYPE_PPGTT_PDE_PT,
                        GTT_TYPE_PPGTT_PTE_1G_ENTRY),
        GTT_TYPE_TABLE_ENTRY(GTT_TYPE_PPGTT_PDP_ENTRY,
                        GTT_TYPE_PPGTT_PDP_ENTRY,
                        GTT_TYPE_PPGTT_PDP_PT,
                        GTT_TYPE_PPGTT_PDE_PT,
                        GTT_TYPE_PPGTT_PTE_1G_ENTRY),
        GTT_TYPE_TABLE_ENTRY(GTT_TYPE_PPGTT_PDE_PT,
                        GTT_TYPE_PPGTT_PDE_ENTRY,
                        GTT_TYPE_PPGTT_PDE_PT,
                        GTT_TYPE_PPGTT_PTE_PT,
                        GTT_TYPE_PPGTT_PTE_2M_ENTRY),
        GTT_TYPE_TABLE_ENTRY(GTT_TYPE_PPGTT_PDE_ENTRY,
                        GTT_TYPE_PPGTT_PDE_ENTRY,
                        GTT_TYPE_PPGTT_PDE_PT,
                        GTT_TYPE_PPGTT_PTE_PT,
                        GTT_TYPE_PPGTT_PTE_2M_ENTRY),
        /* We take IPS bit as 'PSE' for PTE level. */
        GTT_TYPE_TABLE_ENTRY(GTT_TYPE_PPGTT_PTE_PT,
                        GTT_TYPE_PPGTT_PTE_4K_ENTRY,
                        GTT_TYPE_PPGTT_PTE_PT,
                        GTT_TYPE_INVALID,
                        GTT_TYPE_PPGTT_PTE_64K_ENTRY),
        GTT_TYPE_TABLE_ENTRY(GTT_TYPE_PPGTT_PTE_4K_ENTRY,
                        GTT_TYPE_PPGTT_PTE_4K_ENTRY,
                        GTT_TYPE_PPGTT_PTE_PT,
                        GTT_TYPE_INVALID,
                        GTT_TYPE_PPGTT_PTE_64K_ENTRY),
        GTT_TYPE_TABLE_ENTRY(GTT_TYPE_PPGTT_PTE_64K_ENTRY,
                        GTT_TYPE_PPGTT_PTE_4K_ENTRY,
                        GTT_TYPE_PPGTT_PTE_PT,
                        GTT_TYPE_INVALID,
                        GTT_TYPE_PPGTT_PTE_64K_ENTRY),
        GTT_TYPE_TABLE_ENTRY(GTT_TYPE_PPGTT_PTE_2M_ENTRY,
                        GTT_TYPE_PPGTT_PDE_ENTRY,
                        GTT_TYPE_PPGTT_PDE_PT,
                        GTT_TYPE_INVALID,
                        GTT_TYPE_PPGTT_PTE_2M_ENTRY),
        GTT_TYPE_TABLE_ENTRY(GTT_TYPE_PPGTT_PTE_1G_ENTRY,
                        GTT_TYPE_PPGTT_PDP_ENTRY,
                        GTT_TYPE_PPGTT_PDP_PT,
                        GTT_TYPE_INVALID,
                        GTT_TYPE_PPGTT_PTE_1G_ENTRY),
        GTT_TYPE_TABLE_ENTRY(GTT_TYPE_GGTT_PTE,
                        GTT_TYPE_GGTT_PTE,
                        GTT_TYPE_INVALID,
                        GTT_TYPE_INVALID,
                        GTT_TYPE_INVALID),
};

static inline int get_next_pt_type(int type)
{
        return gtt_type_table[type].next_pt_type;
}

static inline int get_entry_type(int type)
{
        return gtt_type_table[type].entry_type;
}

static inline int get_pse_type(int type)
{
        return gtt_type_table[type].pse_entry_type;
}

static u64 read_pte64(struct i915_ggtt *ggtt, unsigned long index)
{
        void __iomem *addr = (gen8_pte_t __iomem *)ggtt->gsm + index;

        return readq(addr);
}

static void ggtt_invalidate(struct intel_gt *gt)
{
        intel_wakeref_t wakeref;

        wakeref = mmio_hw_access_pre(gt);
        intel_uncore_write(gt->uncore, GFX_FLSH_CNTL_GEN6, GFX_FLSH_CNTL_EN);
        mmio_hw_access_post(gt, wakeref);
}

static void write_pte64(struct i915_ggtt *ggtt, unsigned long index, u64 pte)
{
        void __iomem *addr = (gen8_pte_t __iomem *)ggtt->gsm + index;

        writeq(pte, addr);
}

static inline int gtt_get_entry64(void *pt,
                struct intel_gvt_gtt_entry *e,
                unsigned long index, bool hypervisor_access, unsigned long gpa,
                struct intel_vgpu *vgpu)
{
        const struct intel_gvt_device_info *info = &vgpu->gvt->device_info;
        int ret;

        if (WARN_ON(info->gtt_entry_size != 8))
                return -EINVAL;

        if (hypervisor_access) {
                ret = intel_gvt_read_gpa(vgpu, gpa +
                                (index << info->gtt_entry_size_shift),
                                &e->val64, 8);
                if (WARN_ON(ret))
                        return ret;
        } else if (!pt) {
                e->val64 = read_pte64(vgpu->gvt->gt->ggtt, index);
        } else {
                e->val64 = *((u64 *)pt + index);
        }
        return 0;
}

static inline int gtt_set_entry64(void *pt,
                struct intel_gvt_gtt_entry *e,
                unsigned long index, bool hypervisor_access, unsigned long gpa,
                struct intel_vgpu *vgpu)
{
        const struct intel_gvt_device_info *info = &vgpu->gvt->device_info;
        int ret;

        if (WARN_ON(info->gtt_entry_size != 8))
                return -EINVAL;

        if (hypervisor_access) {
                ret = intel_gvt_write_gpa(vgpu, gpa +
                                (index << info->gtt_entry_size_shift),
                                &e->val64, 8);
                if (WARN_ON(ret))
                        return ret;
        } else if (!pt) {
                write_pte64(vgpu->gvt->gt->ggtt, index, e->val64);
        } else {
                *((u64 *)pt + index) = e->val64;
        }
        return 0;
}

#define GTT_HAW 46

#define ADDR_1G_MASK    GENMASK_ULL(GTT_HAW - 1, 30)
#define ADDR_2M_MASK    GENMASK_ULL(GTT_HAW - 1, 21)
#define ADDR_64K_MASK   GENMASK_ULL(GTT_HAW - 1, 16)
#define ADDR_4K_MASK    GENMASK_ULL(GTT_HAW - 1, 12)

#define GTT_SPTE_FLAG_MASK GENMASK_ULL(62, 52)
#define GTT_SPTE_FLAG_64K_SPLITED BIT(52) /* splited 64K gtt entry */

#define GTT_64K_PTE_STRIDE 16

static unsigned long gen8_gtt_get_pfn(struct intel_gvt_gtt_entry *e)
{
        unsigned long pfn;

        if (e->type == GTT_TYPE_PPGTT_PTE_1G_ENTRY)
                pfn = (e->val64 & ADDR_1G_MASK) >> PAGE_SHIFT;
        else if (e->type == GTT_TYPE_PPGTT_PTE_2M_ENTRY)
                pfn = (e->val64 & ADDR_2M_MASK) >> PAGE_SHIFT;
        else if (e->type == GTT_TYPE_PPGTT_PTE_64K_ENTRY)
                pfn = (e->val64 & ADDR_64K_MASK) >> PAGE_SHIFT;
        else
                pfn = (e->val64 & ADDR_4K_MASK) >> PAGE_SHIFT;
        return pfn;
}

static void gen8_gtt_set_pfn(struct intel_gvt_gtt_entry *e, unsigned long pfn)
{
        if (e->type == GTT_TYPE_PPGTT_PTE_1G_ENTRY) {
                e->val64 &= ~ADDR_1G_MASK;
                pfn &= (ADDR_1G_MASK >> PAGE_SHIFT);
        } else if (e->type == GTT_TYPE_PPGTT_PTE_2M_ENTRY) {
                e->val64 &= ~ADDR_2M_MASK;
                pfn &= (ADDR_2M_MASK >> PAGE_SHIFT);
        } else if (e->type == GTT_TYPE_PPGTT_PTE_64K_ENTRY) {
                e->val64 &= ~ADDR_64K_MASK;
                pfn &= (ADDR_64K_MASK >> PAGE_SHIFT);
        } else {
                e->val64 &= ~ADDR_4K_MASK;
                pfn &= (ADDR_4K_MASK >> PAGE_SHIFT);
        }

        e->val64 |= (pfn << PAGE_SHIFT);
}

static bool gen8_gtt_test_pse(struct intel_gvt_gtt_entry *e)
{
        return !!(e->val64 & _PAGE_PSE);
}

static void gen8_gtt_clear_pse(struct intel_gvt_gtt_entry *e)
{
        if (gen8_gtt_test_pse(e)) {
                switch (e->type) {
                case GTT_TYPE_PPGTT_PTE_2M_ENTRY:
                        e->val64 &= ~_PAGE_PSE;
                        e->type = GTT_TYPE_PPGTT_PDE_ENTRY;
                        break;
                case GTT_TYPE_PPGTT_PTE_1G_ENTRY:
                        e->type = GTT_TYPE_PPGTT_PDP_ENTRY;
                        e->val64 &= ~_PAGE_PSE;
                        break;
                default:
                        WARN_ON(1);
                }
        }
}

static bool gen8_gtt_test_ips(struct intel_gvt_gtt_entry *e)
{
        if (GEM_WARN_ON(e->type != GTT_TYPE_PPGTT_PDE_ENTRY))
                return false;

        return !!(e->val64 & GEN8_PDE_IPS_64K);
}

static void gen8_gtt_clear_ips(struct intel_gvt_gtt_entry *e)
{
        if (GEM_WARN_ON(e->type != GTT_TYPE_PPGTT_PDE_ENTRY))
                return;

        e->val64 &= ~GEN8_PDE_IPS_64K;
}

static bool gen8_gtt_test_present(struct intel_gvt_gtt_entry *e)
{
        /*
         * i915 writes PDP root pointer registers without present bit,
         * it also works, so we need to treat root pointer entry
         * specifically.
         */
        if (e->type == GTT_TYPE_PPGTT_ROOT_L3_ENTRY
                        || e->type == GTT_TYPE_PPGTT_ROOT_L4_ENTRY)
                return (e->val64 != 0);
        else
                return (e->val64 & GEN8_PAGE_PRESENT);
}

static void gtt_entry_clear_present(struct intel_gvt_gtt_entry *e)
{
        e->val64 &= ~GEN8_PAGE_PRESENT;
}

static void gtt_entry_set_present(struct intel_gvt_gtt_entry *e)
{
        e->val64 |= GEN8_PAGE_PRESENT;
}

static bool gen8_gtt_test_64k_splited(struct intel_gvt_gtt_entry *e)
{
        return !!(e->val64 & GTT_SPTE_FLAG_64K_SPLITED);
}

static void gen8_gtt_set_64k_splited(struct intel_gvt_gtt_entry *e)
{
        e->val64 |= GTT_SPTE_FLAG_64K_SPLITED;
}

static void gen8_gtt_clear_64k_splited(struct intel_gvt_gtt_entry *e)
{
        e->val64 &= ~GTT_SPTE_FLAG_64K_SPLITED;
}

/*
 * Per-platform GMA routines.
 */
static unsigned long gma_to_ggtt_pte_index(unsigned long gma)
{
        unsigned long x = (gma >> I915_GTT_PAGE_SHIFT);

        trace_gma_index(__func__, gma, x);
        return x;
}

#define DEFINE_PPGTT_GMA_TO_INDEX(prefix, ename, exp) \
static unsigned long prefix##_gma_to_##ename##_index(unsigned long gma) \
{ \
        unsigned long x = (exp); \
        trace_gma_index(__func__, gma, x); \
        return x; \
}

DEFINE_PPGTT_GMA_TO_INDEX(gen8, pte, (gma >> 12 & 0x1ff));
DEFINE_PPGTT_GMA_TO_INDEX(gen8, pde, (gma >> 21 & 0x1ff));
DEFINE_PPGTT_GMA_TO_INDEX(gen8, l3_pdp, (gma >> 30 & 0x3));
DEFINE_PPGTT_GMA_TO_INDEX(gen8, l4_pdp, (gma >> 30 & 0x1ff));
DEFINE_PPGTT_GMA_TO_INDEX(gen8, pml4, (gma >> 39 & 0x1ff));

static const struct intel_gvt_gtt_pte_ops gen8_gtt_pte_ops = {
        .get_entry = gtt_get_entry64,
        .set_entry = gtt_set_entry64,
        .clear_present = gtt_entry_clear_present,
        .set_present = gtt_entry_set_present,
        .test_present = gen8_gtt_test_present,
        .test_pse = gen8_gtt_test_pse,
        .clear_pse = gen8_gtt_clear_pse,
        .clear_ips = gen8_gtt_clear_ips,
        .test_ips = gen8_gtt_test_ips,
        .clear_64k_splited = gen8_gtt_clear_64k_splited,
        .set_64k_splited = gen8_gtt_set_64k_splited,
        .test_64k_splited = gen8_gtt_test_64k_splited,
        .get_pfn = gen8_gtt_get_pfn,
        .set_pfn = gen8_gtt_set_pfn,
};

static const struct intel_gvt_gtt_gma_ops gen8_gtt_gma_ops = {
        .gma_to_ggtt_pte_index = gma_to_ggtt_pte_index,
        .gma_to_pte_index = gen8_gma_to_pte_index,
        .gma_to_pde_index = gen8_gma_to_pde_index,
        .gma_to_l3_pdp_index = gen8_gma_to_l3_pdp_index,
        .gma_to_l4_pdp_index = gen8_gma_to_l4_pdp_index,
        .gma_to_pml4_index = gen8_gma_to_pml4_index,
};

/* Update entry type per pse and ips bit. */
static void update_entry_type_for_real(const struct intel_gvt_gtt_pte_ops *pte_ops,
        struct intel_gvt_gtt_entry *entry, bool ips)
{
        switch (entry->type) {
        case GTT_TYPE_PPGTT_PDE_ENTRY:
        case GTT_TYPE_PPGTT_PDP_ENTRY:
                if (pte_ops->test_pse(entry))
                        entry->type = get_pse_type(entry->type);
                break;
        case GTT_TYPE_PPGTT_PTE_4K_ENTRY:
                if (ips)
                        entry->type = get_pse_type(entry->type);
                break;
        default:
                GEM_BUG_ON(!gtt_type_is_entry(entry->type));
        }

        GEM_BUG_ON(entry->type == GTT_TYPE_INVALID);
}

/*
 * MM helpers.
 */
static void _ppgtt_get_root_entry(struct intel_vgpu_mm *mm,
                struct intel_gvt_gtt_entry *entry, unsigned long index,
                bool guest)
{
        const struct intel_gvt_gtt_pte_ops *pte_ops = mm->vgpu->gvt->gtt.pte_ops;

        GEM_BUG_ON(mm->type != INTEL_GVT_MM_PPGTT);

        entry->type = mm->ppgtt_mm.root_entry_type;
        pte_ops->get_entry(guest ? mm->ppgtt_mm.guest_pdps :
                           mm->ppgtt_mm.shadow_pdps,
                           entry, index, false, 0, mm->vgpu);
        update_entry_type_for_real(pte_ops, entry, false);
}

static inline void ppgtt_get_guest_root_entry(struct intel_vgpu_mm *mm,
                struct intel_gvt_gtt_entry *entry, unsigned long index)
{
        _ppgtt_get_root_entry(mm, entry, index, true);
}

static inline void ppgtt_get_shadow_root_entry(struct intel_vgpu_mm *mm,
                struct intel_gvt_gtt_entry *entry, unsigned long index)
{
        _ppgtt_get_root_entry(mm, entry, index, false);
}

static void _ppgtt_set_root_entry(struct intel_vgpu_mm *mm,
                struct intel_gvt_gtt_entry *entry, unsigned long index,
                bool guest)
{
        const struct intel_gvt_gtt_pte_ops *pte_ops = mm->vgpu->gvt->gtt.pte_ops;

        pte_ops->set_entry(guest ? mm->ppgtt_mm.guest_pdps :
                           mm->ppgtt_mm.shadow_pdps,
                           entry, index, false, 0, mm->vgpu);
}

static inline void ppgtt_set_shadow_root_entry(struct intel_vgpu_mm *mm,
                struct intel_gvt_gtt_entry *entry, unsigned long index)
{
        _ppgtt_set_root_entry(mm, entry, index, false);
}

static void ggtt_get_guest_entry(struct intel_vgpu_mm *mm,
                struct intel_gvt_gtt_entry *entry, unsigned long index)
{
        const struct intel_gvt_gtt_pte_ops *pte_ops = mm->vgpu->gvt->gtt.pte_ops;

        GEM_BUG_ON(mm->type != INTEL_GVT_MM_GGTT);

        entry->type = GTT_TYPE_GGTT_PTE;
        pte_ops->get_entry(mm->ggtt_mm.virtual_ggtt, entry, index,
                           false, 0, mm->vgpu);
}

static void ggtt_set_guest_entry(struct intel_vgpu_mm *mm,
                struct intel_gvt_gtt_entry *entry, unsigned long index)
{
        const struct intel_gvt_gtt_pte_ops *pte_ops = mm->vgpu->gvt->gtt.pte_ops;

        GEM_BUG_ON(mm->type != INTEL_GVT_MM_GGTT);

        pte_ops->set_entry(mm->ggtt_mm.virtual_ggtt, entry, index,
                           false, 0, mm->vgpu);
}

static void ggtt_get_host_entry(struct intel_vgpu_mm *mm,
                struct intel_gvt_gtt_entry *entry, unsigned long index)
{
        const struct intel_gvt_gtt_pte_ops *pte_ops = mm->vgpu->gvt->gtt.pte_ops;

        GEM_BUG_ON(mm->type != INTEL_GVT_MM_GGTT);

        pte_ops->get_entry(NULL, entry, index, false, 0, mm->vgpu);
}

static void ggtt_set_host_entry(struct intel_vgpu_mm *mm,
                struct intel_gvt_gtt_entry *entry, unsigned long index)
{
        const struct intel_gvt_gtt_pte_ops *pte_ops = mm->vgpu->gvt->gtt.pte_ops;
        unsigned long offset = index;

        GEM_BUG_ON(mm->type != INTEL_GVT_MM_GGTT);

        if (vgpu_gmadr_is_aperture(mm->vgpu, index << I915_GTT_PAGE_SHIFT)) {
                offset -= (vgpu_aperture_gmadr_base(mm->vgpu) >> PAGE_SHIFT);
                mm->ggtt_mm.host_ggtt_aperture[offset] = entry->val64;
        } else if (vgpu_gmadr_is_hidden(mm->vgpu, index << I915_GTT_PAGE_SHIFT)) {
                offset -= (vgpu_hidden_gmadr_base(mm->vgpu) >> PAGE_SHIFT);
                mm->ggtt_mm.host_ggtt_hidden[offset] = entry->val64;
        }

        pte_ops->set_entry(NULL, entry, index, false, 0, mm->vgpu);
}

/*
 * PPGTT shadow page table helpers.
 */
static inline int ppgtt_spt_get_entry(
                struct intel_vgpu_ppgtt_spt *spt,
                void *page_table, int type,
                struct intel_gvt_gtt_entry *e, unsigned long index,
                bool guest)
{
        struct intel_gvt *gvt = spt->vgpu->gvt;
        const struct intel_gvt_gtt_pte_ops *ops = gvt->gtt.pte_ops;
        int ret;

        e->type = get_entry_type(type);

        if (WARN(!gtt_type_is_entry(e->type), "invalid entry type\n"))
                return -EINVAL;

        ret = ops->get_entry(page_table, e, index, guest,
                        spt->guest_page.gfn << I915_GTT_PAGE_SHIFT,
                        spt->vgpu);
        if (ret)
                return ret;

        update_entry_type_for_real(ops, e, guest ?
                                   spt->guest_page.pde_ips : false);

        gvt_vdbg_mm("read ppgtt entry, spt type %d, entry type %d, index %lu, value %llx\n",
                    type, e->type, index, e->val64);
        return 0;
}

static inline int ppgtt_spt_set_entry(
                struct intel_vgpu_ppgtt_spt *spt,
                void *page_table, int type,
                struct intel_gvt_gtt_entry *e, unsigned long index,
                bool guest)
{
        struct intel_gvt *gvt = spt->vgpu->gvt;
        const struct intel_gvt_gtt_pte_ops *ops = gvt->gtt.pte_ops;

        if (WARN(!gtt_type_is_entry(e->type), "invalid entry type\n"))
                return -EINVAL;

        gvt_vdbg_mm("set ppgtt entry, spt type %d, entry type %d, index %lu, value %llx\n",
                    type, e->type, index, e->val64);

        return ops->set_entry(page_table, e, index, guest,
                        spt->guest_page.gfn << I915_GTT_PAGE_SHIFT,
                        spt->vgpu);
}

#define ppgtt_get_guest_entry(spt, e, index) \
        ppgtt_spt_get_entry(spt, NULL, \
                spt->guest_page.type, e, index, true)

#define ppgtt_set_guest_entry(spt, e, index) \
        ppgtt_spt_set_entry(spt, NULL, \
                spt->guest_page.type, e, index, true)

#define ppgtt_get_shadow_entry(spt, e, index) \
        ppgtt_spt_get_entry(spt, spt->shadow_page.vaddr, \
                spt->shadow_page.type, e, index, false)

#define ppgtt_set_shadow_entry(spt, e, index) \
        ppgtt_spt_set_entry(spt, spt->shadow_page.vaddr, \
                spt->shadow_page.type, e, index, false)

static void *alloc_spt(gfp_t gfp_mask)
{
        struct intel_vgpu_ppgtt_spt *spt;

        spt = kzalloc_obj(*spt, gfp_mask);
        if (!spt)
                return NULL;

        spt->shadow_page.page = alloc_page(gfp_mask);
        if (!spt->shadow_page.page) {
                kfree(spt);
                return NULL;
        }
        return spt;
}

static void free_spt(struct intel_vgpu_ppgtt_spt *spt)
{
        __free_page(spt->shadow_page.page);
        kfree(spt);
}

static int detach_oos_page(struct intel_vgpu *vgpu,
                struct intel_vgpu_oos_page *oos_page);

static void ppgtt_free_spt(struct intel_vgpu_ppgtt_spt *spt)
{
        struct device *kdev = spt->vgpu->gvt->gt->i915->drm.dev;

        trace_spt_free(spt->vgpu->id, spt, spt->guest_page.type);

        dma_unmap_page(kdev, spt->shadow_page.mfn << I915_GTT_PAGE_SHIFT, 4096,
                       DMA_BIDIRECTIONAL);

        radix_tree_delete(&spt->vgpu->gtt.spt_tree, spt->shadow_page.mfn);

        if (spt->guest_page.gfn) {
                if (spt->guest_page.oos_page)
                        detach_oos_page(spt->vgpu, spt->guest_page.oos_page);

                intel_vgpu_unregister_page_track(spt->vgpu, spt->guest_page.gfn);
        }

        list_del_init(&spt->post_shadow_list);
        free_spt(spt);
}

static void ppgtt_free_all_spt(struct intel_vgpu *vgpu)
{
        struct intel_vgpu_ppgtt_spt *spt, *spn;
        struct radix_tree_iter iter;
        LIST_HEAD(all_spt);
        void __rcu **slot;

        rcu_read_lock();
        radix_tree_for_each_slot(slot, &vgpu->gtt.spt_tree, &iter, 0) {
                spt = radix_tree_deref_slot(slot);
                list_move(&spt->post_shadow_list, &all_spt);
        }
        rcu_read_unlock();

        list_for_each_entry_safe(spt, spn, &all_spt, post_shadow_list)
                ppgtt_free_spt(spt);
}

static int ppgtt_handle_guest_write_page_table_bytes(
                struct intel_vgpu_ppgtt_spt *spt,
                u64 pa, void *p_data, int bytes);

static int ppgtt_write_protection_handler(
                struct intel_vgpu_page_track *page_track,
                u64 gpa, void *data, int bytes)
{
        struct intel_vgpu_ppgtt_spt *spt = page_track->priv_data;

        int ret;

        if (bytes != 4 && bytes != 8)
                return -EINVAL;

        ret = ppgtt_handle_guest_write_page_table_bytes(spt, gpa, data, bytes);
        if (ret)
                return ret;
        return ret;
}

/* Find a spt by guest gfn. */
static struct intel_vgpu_ppgtt_spt *intel_vgpu_find_spt_by_gfn(
                struct intel_vgpu *vgpu, unsigned long gfn)
{
        struct intel_vgpu_page_track *track;

        track = intel_vgpu_find_page_track(vgpu, gfn);
        if (track && track->handler == ppgtt_write_protection_handler)
                return track->priv_data;

        return NULL;
}

/* Find the spt by shadow page mfn. */
static inline struct intel_vgpu_ppgtt_spt *intel_vgpu_find_spt_by_mfn(
                struct intel_vgpu *vgpu, unsigned long mfn)
{
        return radix_tree_lookup(&vgpu->gtt.spt_tree, mfn);
}

static int reclaim_one_ppgtt_mm(struct intel_gvt *gvt);

/* Allocate shadow page table without guest page. */
static struct intel_vgpu_ppgtt_spt *ppgtt_alloc_spt(
                struct intel_vgpu *vgpu, enum intel_gvt_gtt_type type)
{
        struct device *kdev = vgpu->gvt->gt->i915->drm.dev;
        struct intel_vgpu_ppgtt_spt *spt = NULL;
        dma_addr_t daddr;
        int ret;

retry:
        spt = alloc_spt(GFP_KERNEL | __GFP_ZERO);
        if (!spt) {
                if (reclaim_one_ppgtt_mm(vgpu->gvt))
                        goto retry;

                gvt_vgpu_err("fail to allocate ppgtt shadow page\n");
                return ERR_PTR(-ENOMEM);
        }

        spt->vgpu = vgpu;
        atomic_set(&spt->refcount, 1);
        INIT_LIST_HEAD(&spt->post_shadow_list);

        /*
         * Init shadow_page.
         */
        spt->shadow_page.type = type;
        daddr = dma_map_page(kdev, spt->shadow_page.page,
                             0, 4096, DMA_BIDIRECTIONAL);
        if (dma_mapping_error(kdev, daddr)) {
                gvt_vgpu_err("fail to map dma addr\n");
                ret = -EINVAL;
                goto err_free_spt;
        }
        spt->shadow_page.vaddr = page_address(spt->shadow_page.page);
        spt->shadow_page.mfn = daddr >> I915_GTT_PAGE_SHIFT;

        ret = radix_tree_insert(&vgpu->gtt.spt_tree, spt->shadow_page.mfn, spt);
        if (ret)
                goto err_unmap_dma;

        return spt;

err_unmap_dma:
        dma_unmap_page(kdev, daddr, PAGE_SIZE, DMA_BIDIRECTIONAL);
err_free_spt:
        free_spt(spt);
        return ERR_PTR(ret);
}

/* Allocate shadow page table associated with specific gfn. */
static struct intel_vgpu_ppgtt_spt *ppgtt_alloc_spt_gfn(
                struct intel_vgpu *vgpu, enum intel_gvt_gtt_type type,
                unsigned long gfn, bool guest_pde_ips)
{
        struct intel_vgpu_ppgtt_spt *spt;
        int ret;

        spt = ppgtt_alloc_spt(vgpu, type);
        if (IS_ERR(spt))
                return spt;

        /*
         * Init guest_page.
         */
        ret = intel_vgpu_register_page_track(vgpu, gfn,
                        ppgtt_write_protection_handler, spt);
        if (ret) {
                ppgtt_free_spt(spt);
                return ERR_PTR(ret);
        }

        spt->guest_page.type = type;
        spt->guest_page.gfn = gfn;
        spt->guest_page.pde_ips = guest_pde_ips;

        trace_spt_alloc(vgpu->id, spt, type, spt->shadow_page.mfn, gfn);

        return spt;
}

#define pt_entry_size_shift(spt) \
        ((spt)->vgpu->gvt->device_info.gtt_entry_size_shift)

#define pt_entries(spt) \
        (I915_GTT_PAGE_SIZE >> pt_entry_size_shift(spt))

#define for_each_present_guest_entry(spt, e, i) \
        for (i = 0; i < pt_entries(spt); \
             i += spt->guest_page.pde_ips ? GTT_64K_PTE_STRIDE : 1) \
                if (!ppgtt_get_guest_entry(spt, e, i) && \
                    spt->vgpu->gvt->gtt.pte_ops->test_present(e))

#define for_each_present_shadow_entry(spt, e, i) \
        for (i = 0; i < pt_entries(spt); \
             i += spt->shadow_page.pde_ips ? GTT_64K_PTE_STRIDE : 1) \
                if (!ppgtt_get_shadow_entry(spt, e, i) && \
                    spt->vgpu->gvt->gtt.pte_ops->test_present(e))

#define for_each_shadow_entry(spt, e, i) \
        for (i = 0; i < pt_entries(spt); \
             i += (spt->shadow_page.pde_ips ? GTT_64K_PTE_STRIDE : 1)) \
                if (!ppgtt_get_shadow_entry(spt, e, i))

static inline void ppgtt_get_spt(struct intel_vgpu_ppgtt_spt *spt)
{
        int v = atomic_read(&spt->refcount);

        trace_spt_refcount(spt->vgpu->id, "inc", spt, v, (v + 1));
        atomic_inc(&spt->refcount);
}

static inline int ppgtt_put_spt(struct intel_vgpu_ppgtt_spt *spt)
{
        int v = atomic_read(&spt->refcount);

        trace_spt_refcount(spt->vgpu->id, "dec", spt, v, (v - 1));
        return atomic_dec_return(&spt->refcount);
}

static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt);

static int ppgtt_invalidate_spt_by_shadow_entry(struct intel_vgpu *vgpu,
                struct intel_gvt_gtt_entry *e)
{
        struct drm_i915_private *i915 = vgpu->gvt->gt->i915;
        const struct intel_gvt_gtt_pte_ops *ops = vgpu->gvt->gtt.pte_ops;
        struct intel_vgpu_ppgtt_spt *s;
        enum intel_gvt_gtt_type cur_pt_type;

        GEM_BUG_ON(!gtt_type_is_pt(get_next_pt_type(e->type)));

        if (e->type != GTT_TYPE_PPGTT_ROOT_L3_ENTRY
                && e->type != GTT_TYPE_PPGTT_ROOT_L4_ENTRY) {
                cur_pt_type = get_next_pt_type(e->type);

                if (!gtt_type_is_pt(cur_pt_type) ||
                                !gtt_type_is_pt(cur_pt_type + 1)) {
                        drm_WARN(&i915->drm, 1,
                                 "Invalid page table type, cur_pt_type is: %d\n",
                                 cur_pt_type);
                        return -EINVAL;
                }

                cur_pt_type += 1;

                if (ops->get_pfn(e) ==
                        vgpu->gtt.scratch_pt[cur_pt_type].page_mfn)
                        return 0;
        }
        s = intel_vgpu_find_spt_by_mfn(vgpu, ops->get_pfn(e));
        if (!s) {
                gvt_vgpu_err("fail to find shadow page: mfn: 0x%lx\n",
                                ops->get_pfn(e));
                return -ENXIO;
        }
        return ppgtt_invalidate_spt(s);
}

static inline void ppgtt_invalidate_pte(struct intel_vgpu_ppgtt_spt *spt,
                struct intel_gvt_gtt_entry *entry)
{
        struct intel_vgpu *vgpu = spt->vgpu;
        const struct intel_gvt_gtt_pte_ops *ops = vgpu->gvt->gtt.pte_ops;
        unsigned long pfn;
        int type;

        pfn = ops->get_pfn(entry);
        type = spt->shadow_page.type;

        /* Uninitialized spte or unshadowed spte. */
        if (!pfn || pfn == vgpu->gtt.scratch_pt[type].page_mfn)
                return;

        intel_gvt_dma_unmap_guest_page(vgpu, pfn << PAGE_SHIFT);
}

static int ppgtt_invalidate_spt(struct intel_vgpu_ppgtt_spt *spt)
{
        struct intel_vgpu *vgpu = spt->vgpu;
        struct intel_gvt_gtt_entry e;
        unsigned long index;
        int ret;

        trace_spt_change(spt->vgpu->id, "die", spt,
                        spt->guest_page.gfn, spt->shadow_page.type);

        if (ppgtt_put_spt(spt) > 0)
                return 0;

        for_each_present_shadow_entry(spt, &e, index) {
                switch (e.type) {
                case GTT_TYPE_PPGTT_PTE_4K_ENTRY:
                        gvt_vdbg_mm("invalidate 4K entry\n");
                        ppgtt_invalidate_pte(spt, &e);
                        break;
                case GTT_TYPE_PPGTT_PTE_64K_ENTRY:
                        /* We don't setup 64K shadow entry so far. */
                        WARN(1, "suspicious 64K gtt entry\n");
                        continue;
                case GTT_TYPE_PPGTT_PTE_2M_ENTRY:
                        gvt_vdbg_mm("invalidate 2M entry\n");
                        continue;
                case GTT_TYPE_PPGTT_PTE_1G_ENTRY:
                        WARN(1, "GVT doesn't support 1GB page\n");
                        continue;
                case GTT_TYPE_PPGTT_PML4_ENTRY:
                case GTT_TYPE_PPGTT_PDP_ENTRY:
                case GTT_TYPE_PPGTT_PDE_ENTRY:
                        gvt_vdbg_mm("invalidate PMUL4/PDP/PDE entry\n");
                        ret = ppgtt_invalidate_spt_by_shadow_entry(
                                        spt->vgpu, &e);
                        if (ret)
                                goto fail;
                        break;
                default:
                        GEM_BUG_ON(1);
                }
        }

        trace_spt_change(spt->vgpu->id, "release", spt,
                         spt->guest_page.gfn, spt->shadow_page.type);
        ppgtt_free_spt(spt);
        return 0;
fail:
        gvt_vgpu_err("fail: shadow page %p shadow entry 0x%llx type %d\n",
                        spt, e.val64, e.type);
        return ret;
}

static bool vgpu_ips_enabled(struct intel_vgpu *vgpu)
{
        struct drm_i915_private *dev_priv = vgpu->gvt->gt->i915;

        if (GRAPHICS_VER(dev_priv) == 9) {
                u32 ips = vgpu_vreg_t(vgpu, GEN8_GAMW_ECO_DEV_RW_IA) &
                        GAMW_ECO_ENABLE_64K_IPS_FIELD;

                return ips == GAMW_ECO_ENABLE_64K_IPS_FIELD;
        } else if (GRAPHICS_VER(dev_priv) >= 11) {
                /* 64K paging only controlled by IPS bit in PTE now. */
                return true;
        } else
                return false;
}

static int ppgtt_populate_spt(struct intel_vgpu_ppgtt_spt *spt);

static struct intel_vgpu_ppgtt_spt *ppgtt_populate_spt_by_guest_entry(
                struct intel_vgpu *vgpu, struct intel_gvt_gtt_entry *we)
{
        const struct intel_gvt_gtt_pte_ops *ops = vgpu->gvt->gtt.pte_ops;
        struct intel_vgpu_ppgtt_spt *spt = NULL;
        bool ips = false;
        int ret;

        GEM_BUG_ON(!gtt_type_is_pt(get_next_pt_type(we->type)));

        if (we->type == GTT_TYPE_PPGTT_PDE_ENTRY)
                ips = vgpu_ips_enabled(vgpu) && ops->test_ips(we);

        spt = intel_vgpu_find_spt_by_gfn(vgpu, ops->get_pfn(we));
        if (spt) {
                ppgtt_get_spt(spt);

                if (ips != spt->guest_page.pde_ips) {
                        spt->guest_page.pde_ips = ips;

                        gvt_dbg_mm("reshadow PDE since ips changed\n");
                        clear_page(spt->shadow_page.vaddr);
                        ret = ppgtt_populate_spt(spt);
                        if (ret) {
                                ppgtt_put_spt(spt);
                                goto err;
                        }
                }
        } else {
                int type = get_next_pt_type(we->type);

                if (!gtt_type_is_pt(type)) {
                        ret = -EINVAL;
                        goto err;
                }

                spt = ppgtt_alloc_spt_gfn(vgpu, type, ops->get_pfn(we), ips);
                if (IS_ERR(spt)) {
                        ret = PTR_ERR(spt);
                        goto err;
                }

                ret = intel_vgpu_enable_page_track(vgpu, spt->guest_page.gfn);
                if (ret)
                        goto err_free_spt;

                ret = ppgtt_populate_spt(spt);
                if (ret)
                        goto err_free_spt;

                trace_spt_change(vgpu->id, "new", spt, spt->guest_page.gfn,
                                 spt->shadow_page.type);
        }
        return spt;

err_free_spt:
        ppgtt_free_spt(spt);
        spt = NULL;
err:
        gvt_vgpu_err("fail: shadow page %p guest entry 0x%llx type %d\n",
                     spt, we->val64, we->type);
        return ERR_PTR(ret);
}

static inline void ppgtt_generate_shadow_entry(struct intel_gvt_gtt_entry *se,
                struct intel_vgpu_ppgtt_spt *s, struct intel_gvt_gtt_entry *ge)
{
        const struct intel_gvt_gtt_pte_ops *ops = s->vgpu->gvt->gtt.pte_ops;

        se->type = ge->type;
        se->val64 = ge->val64;

        /* Because we always split 64KB pages, so clear IPS in shadow PDE. */
        if (se->type == GTT_TYPE_PPGTT_PDE_ENTRY)
                ops->clear_ips(se);

        ops->set_pfn(se, s->shadow_page.mfn);
}

static int split_2MB_gtt_entry(struct intel_vgpu *vgpu,
        struct intel_vgpu_ppgtt_spt *spt, unsigned long index,
        struct intel_gvt_gtt_entry *se)
{
        const struct intel_gvt_gtt_pte_ops *ops = vgpu->gvt->gtt.pte_ops;
        struct intel_vgpu_ppgtt_spt *sub_spt;
        struct intel_gvt_gtt_entry sub_se;
        unsigned long start_gfn;
        dma_addr_t dma_addr;
        unsigned long sub_index;
        int ret;

        gvt_dbg_mm("Split 2M gtt entry, index %lu\n", index);

        start_gfn = ops->get_pfn(se);

        sub_spt = ppgtt_alloc_spt(vgpu, GTT_TYPE_PPGTT_PTE_PT);
        if (IS_ERR(sub_spt))
                return PTR_ERR(sub_spt);

        for_each_shadow_entry(sub_spt, &sub_se, sub_index) {
                ret = intel_gvt_dma_map_guest_page(vgpu, start_gfn + sub_index,
                                                   PAGE_SIZE, &dma_addr);
                if (ret)
                        goto err;
                sub_se.val64 = se->val64;

                /* Copy the PAT field from PDE. */
                sub_se.val64 &= ~_PAGE_PAT;
                sub_se.val64 |= (se->val64 & _PAGE_PAT_LARGE) >> 5;

                ops->set_pfn(&sub_se, dma_addr >> PAGE_SHIFT);
                ppgtt_set_shadow_entry(sub_spt, &sub_se, sub_index);
        }

        /* Clear dirty field. */
        se->val64 &= ~_PAGE_DIRTY;

        ops->clear_pse(se);
        ops->clear_ips(se);
        ops->set_pfn(se, sub_spt->shadow_page.mfn);
        ppgtt_set_shadow_entry(spt, se, index);
        return 0;
err:
        /* Cancel the existing address mappings of DMA addr. */
        for_each_present_shadow_entry(sub_spt, &sub_se, sub_index) {
                gvt_vdbg_mm("invalidate 4K entry\n");
                ppgtt_invalidate_pte(sub_spt, &sub_se);
        }
        /* Release the new allocated spt. */
        trace_spt_change(sub_spt->vgpu->id, "release", sub_spt,
                sub_spt->guest_page.gfn, sub_spt->shadow_page.type);
        ppgtt_free_spt(sub_spt);
        return ret;
}

static int split_64KB_gtt_entry(struct intel_vgpu *vgpu,
        struct intel_vgpu_ppgtt_spt *spt, unsigned long index,
        struct intel_gvt_gtt_entry *se)
{
        const struct intel_gvt_gtt_pte_ops *ops = vgpu->gvt->gtt.pte_ops;
        struct intel_gvt_gtt_entry entry = *se;
        unsigned long start_gfn;
        dma_addr_t dma_addr;
        int i, ret;

        gvt_vdbg_mm("Split 64K gtt entry, index %lu\n", index);

        GEM_BUG_ON(index % GTT_64K_PTE_STRIDE);

        start_gfn = ops->get_pfn(se);

        entry.type = GTT_TYPE_PPGTT_PTE_4K_ENTRY;
        ops->set_64k_splited(&entry);

        for (i = 0; i < GTT_64K_PTE_STRIDE; i++) {
                ret = intel_gvt_dma_map_guest_page(vgpu, start_gfn + i,
                                                   PAGE_SIZE, &dma_addr);
                if (ret)
                        return ret;

                ops->set_pfn(&entry, dma_addr >> PAGE_SHIFT);
                ppgtt_set_shadow_entry(spt, &entry, index + i);
        }
        return 0;
}

static int ppgtt_populate_shadow_entry(struct intel_vgpu *vgpu,
        struct intel_vgpu_ppgtt_spt *spt, unsigned long index,
        struct intel_gvt_gtt_entry *ge)
{
        const struct intel_gvt_gtt_pte_ops *pte_ops = vgpu->gvt->gtt.pte_ops;
        struct intel_gvt_gtt_entry se = *ge;
        unsigned long gfn;
        dma_addr_t dma_addr;
        int ret;

        if (!pte_ops->test_present(ge))
                return 0;

        gfn = pte_ops->get_pfn(ge);

        switch (ge->type) {
        case GTT_TYPE_PPGTT_PTE_4K_ENTRY:
                gvt_vdbg_mm("shadow 4K gtt entry\n");
                ret = intel_gvt_dma_map_guest_page(vgpu, gfn, PAGE_SIZE, &dma_addr);
                if (ret)
                        return -ENXIO;
                break;
        case GTT_TYPE_PPGTT_PTE_64K_ENTRY:
                gvt_vdbg_mm("shadow 64K gtt entry\n");
                /*
                 * The layout of 64K page is special, the page size is
                 * controlled by upper PDE. To be simple, we always split
                 * 64K page to smaller 4K pages in shadow PT.
                 */
                return split_64KB_gtt_entry(vgpu, spt, index, &se);
        case GTT_TYPE_PPGTT_PTE_2M_ENTRY:
                gvt_vdbg_mm("shadow 2M gtt entry\n");
                if (!HAS_PAGE_SIZES(vgpu->gvt->gt->i915, I915_GTT_PAGE_SIZE_2M) ||
                    intel_gvt_dma_map_guest_page(vgpu, gfn,
                                                 I915_GTT_PAGE_SIZE_2M, &dma_addr))
                        return split_2MB_gtt_entry(vgpu, spt, index, &se);
                break;
        case GTT_TYPE_PPGTT_PTE_1G_ENTRY:
                gvt_vgpu_err("GVT doesn't support 1GB entry\n");
                return -EINVAL;
        default:
                GEM_BUG_ON(1);
                return -EINVAL;
        }

        /* Successfully shadowed a 4K or 2M page (without splitting). */
        pte_ops->set_pfn(&se, dma_addr >> PAGE_SHIFT);
        ppgtt_set_shadow_entry(spt, &se, index);
        return 0;
}

static int ppgtt_populate_spt(struct intel_vgpu_ppgtt_spt *spt)
{
        struct intel_vgpu *vgpu = spt->vgpu;
        struct intel_vgpu_ppgtt_spt *s;
        struct intel_gvt_gtt_entry se, ge;
        unsigned long i;
        int ret;

        trace_spt_change(spt->vgpu->id, "born", spt,
                         spt->guest_page.gfn, spt->shadow_page.type);

        for_each_present_guest_entry(spt, &ge, i) {
                if (gtt_type_is_pt(get_next_pt_type(ge.type))) {
                        s = ppgtt_populate_spt_by_guest_entry(vgpu, &ge);
                        if (IS_ERR(s)) {
                                ret = PTR_ERR(s);
                                goto fail;
                        }
                        ppgtt_get_shadow_entry(spt, &se, i);
                        ppgtt_generate_shadow_entry(&se, s, &ge);
                        ppgtt_set_shadow_entry(spt, &se, i);
                } else {
                        ret = ppgtt_populate_shadow_entry(vgpu, spt, i, &ge);
                        if (ret)
                                goto fail;
                }
        }
        return 0;
fail:
        gvt_vgpu_err("fail: shadow page %p guest entry 0x%llx type %d\n",
                        spt, ge.val64, ge.type);
        return ret;
}

static int ppgtt_handle_guest_entry_removal(struct intel_vgpu_ppgtt_spt *spt,
                struct intel_gvt_gtt_entry *se, unsigned long index)
{
        struct intel_vgpu *vgpu = spt->vgpu;
        const struct intel_gvt_gtt_pte_ops *ops = vgpu->gvt->gtt.pte_ops;
        int ret;

        trace_spt_guest_change(spt->vgpu->id, "remove", spt,
                               spt->shadow_page.type, se->val64, index);

        gvt_vdbg_mm("destroy old shadow entry, type %d, index %lu, value %llx\n",
                    se->type, index, se->val64);

        if (!ops->test_present(se))
                return 0;

        if (ops->get_pfn(se) ==
            vgpu->gtt.scratch_pt[spt->shadow_page.type].page_mfn)
                return 0;

        if (gtt_type_is_pt(get_next_pt_type(se->type))) {
                struct intel_vgpu_ppgtt_spt *s =
                        intel_vgpu_find_spt_by_mfn(vgpu, ops->get_pfn(se));
                if (!s) {
                        gvt_vgpu_err("fail to find guest page\n");
                        ret = -ENXIO;
                        goto fail;
                }
                ret = ppgtt_invalidate_spt(s);
                if (ret)
                        goto fail;
        } else {
                /* We don't setup 64K shadow entry so far. */
                WARN(se->type == GTT_TYPE_PPGTT_PTE_64K_ENTRY,
                     "suspicious 64K entry\n");
                ppgtt_invalidate_pte(spt, se);
        }

        return 0;
fail:
        gvt_vgpu_err("fail: shadow page %p guest entry 0x%llx type %d\n",
                        spt, se->val64, se->type);
        return ret;
}

static int ppgtt_handle_guest_entry_add(struct intel_vgpu_ppgtt_spt *spt,
                struct intel_gvt_gtt_entry *we, unsigned long index)
{
        struct intel_vgpu *vgpu = spt->vgpu;
        struct intel_gvt_gtt_entry m;
        struct intel_vgpu_ppgtt_spt *s;
        int ret;

        trace_spt_guest_change(spt->vgpu->id, "add", spt, spt->shadow_page.type,
                               we->val64, index);

        gvt_vdbg_mm("add shadow entry: type %d, index %lu, value %llx\n",
                    we->type, index, we->val64);

        if (gtt_type_is_pt(get_next_pt_type(we->type))) {
                s = ppgtt_populate_spt_by_guest_entry(vgpu, we);
                if (IS_ERR(s)) {
                        ret = PTR_ERR(s);
                        goto fail;
                }
                ppgtt_get_shadow_entry(spt, &m, index);
                ppgtt_generate_shadow_entry(&m, s, we);
                ppgtt_set_shadow_entry(spt, &m, index);
        } else {
                ret = ppgtt_populate_shadow_entry(vgpu, spt, index, we);
                if (ret)
                        goto fail;
        }
        return 0;
fail:
        gvt_vgpu_err("fail: spt %p guest entry 0x%llx type %d\n",
                spt, we->val64, we->type);
        return ret;
}

static int sync_oos_page(struct intel_vgpu *vgpu,
                struct intel_vgpu_oos_page *oos_page)
{
        const struct intel_gvt_device_info *info = &vgpu->gvt->device_info;
        struct intel_gvt *gvt = vgpu->gvt;
        const struct intel_gvt_gtt_pte_ops *ops = gvt->gtt.pte_ops;
        struct intel_vgpu_ppgtt_spt *spt = oos_page->spt;
        struct intel_gvt_gtt_entry old, new;
        int index;
        int ret;

        trace_oos_change(vgpu->id, "sync", oos_page->id,
                         spt, spt->guest_page.type);

        old.type = new.type = get_entry_type(spt->guest_page.type);
        old.val64 = new.val64 = 0;

        for (index = 0; index < (I915_GTT_PAGE_SIZE >>
                                info->gtt_entry_size_shift); index++) {
                ops->get_entry(oos_page->mem, &old, index, false, 0, vgpu);
                ops->get_entry(NULL, &new, index, true,
                               spt->guest_page.gfn << PAGE_SHIFT, vgpu);

                if (old.val64 == new.val64
                        && !test_and_clear_bit(index, spt->post_shadow_bitmap))
                        continue;

                trace_oos_sync(vgpu->id, oos_page->id,
                                spt, spt->guest_page.type,
                                new.val64, index);

                ret = ppgtt_populate_shadow_entry(vgpu, spt, index, &new);
                if (ret)
                        return ret;

                ops->set_entry(oos_page->mem, &new, index, false, 0, vgpu);
        }

        spt->guest_page.write_cnt = 0;
        list_del_init(&spt->post_shadow_list);
        return 0;
}

static int detach_oos_page(struct intel_vgpu *vgpu,
                struct intel_vgpu_oos_page *oos_page)
{
        struct intel_gvt *gvt = vgpu->gvt;
        struct intel_vgpu_ppgtt_spt *spt = oos_page->spt;

        trace_oos_change(vgpu->id, "detach", oos_page->id,
                         spt, spt->guest_page.type);

        spt->guest_page.write_cnt = 0;
        spt->guest_page.oos_page = NULL;
        oos_page->spt = NULL;

        list_del_init(&oos_page->vm_list);
        list_move_tail(&oos_page->list, &gvt->gtt.oos_page_free_list_head);

        return 0;
}

static int attach_oos_page(struct intel_vgpu_oos_page *oos_page,
                struct intel_vgpu_ppgtt_spt *spt)
{
        struct intel_gvt *gvt = spt->vgpu->gvt;
        int ret;

        ret = intel_gvt_read_gpa(spt->vgpu,
                        spt->guest_page.gfn << I915_GTT_PAGE_SHIFT,
                        oos_page->mem, I915_GTT_PAGE_SIZE);
        if (ret)
                return ret;

        oos_page->spt = spt;
        spt->guest_page.oos_page = oos_page;

        list_move_tail(&oos_page->list, &gvt->gtt.oos_page_use_list_head);

        trace_oos_change(spt->vgpu->id, "attach", oos_page->id,
                         spt, spt->guest_page.type);
        return 0;
}

static int ppgtt_set_guest_page_sync(struct intel_vgpu_ppgtt_spt *spt)
{
        struct intel_vgpu_oos_page *oos_page = spt->guest_page.oos_page;
        int ret;

        ret = intel_vgpu_enable_page_track(spt->vgpu, spt->guest_page.gfn);
        if (ret)
                return ret;

        trace_oos_change(spt->vgpu->id, "set page sync", oos_page->id,
                         spt, spt->guest_page.type);

        list_del_init(&oos_page->vm_list);
        return sync_oos_page(spt->vgpu, oos_page);
}

static int ppgtt_allocate_oos_page(struct intel_vgpu_ppgtt_spt *spt)
{
        struct intel_gvt *gvt = spt->vgpu->gvt;
        struct intel_gvt_gtt *gtt = &gvt->gtt;
        struct intel_vgpu_oos_page *oos_page = spt->guest_page.oos_page;
        int ret;

        WARN(oos_page, "shadow PPGTT page has already has a oos page\n");

        if (list_empty(&gtt->oos_page_free_list_head)) {
                oos_page = container_of(gtt->oos_page_use_list_head.next,
                        struct intel_vgpu_oos_page, list);
                ret = ppgtt_set_guest_page_sync(oos_page->spt);
                if (ret)
                        return ret;
                ret = detach_oos_page(spt->vgpu, oos_page);
                if (ret)
                        return ret;
        } else
                oos_page = container_of(gtt->oos_page_free_list_head.next,
                        struct intel_vgpu_oos_page, list);
        return attach_oos_page(oos_page, spt);
}

static int ppgtt_set_guest_page_oos(struct intel_vgpu_ppgtt_spt *spt)
{
        struct intel_vgpu_oos_page *oos_page = spt->guest_page.oos_page;

        if (WARN(!oos_page, "shadow PPGTT page should have a oos page\n"))
                return -EINVAL;

        trace_oos_change(spt->vgpu->id, "set page out of sync", oos_page->id,
                         spt, spt->guest_page.type);

        list_add_tail(&oos_page->vm_list, &spt->vgpu->gtt.oos_page_list_head);
        return intel_vgpu_disable_page_track(spt->vgpu, spt->guest_page.gfn);
}

/**
 * intel_vgpu_sync_oos_pages - sync all the out-of-synced shadow for vGPU
 * @vgpu: a vGPU
 *
 * This function is called before submitting a guest workload to host,
 * to sync all the out-of-synced shadow for vGPU
 *
 * Returns:
 * Zero on success, negative error code if failed.
 */
int intel_vgpu_sync_oos_pages(struct intel_vgpu *vgpu)
{
        struct list_head *pos, *n;
        struct intel_vgpu_oos_page *oos_page;
        int ret;

        if (!enable_out_of_sync)
                return 0;

        list_for_each_safe(pos, n, &vgpu->gtt.oos_page_list_head) {
                oos_page = container_of(pos,
                                struct intel_vgpu_oos_page, vm_list);
                ret = ppgtt_set_guest_page_sync(oos_page->spt);
                if (ret)
                        return ret;
        }
        return 0;
}

/*
 * The heart of PPGTT shadow page table.
 */
static int ppgtt_handle_guest_write_page_table(
                struct intel_vgpu_ppgtt_spt *spt,
                struct intel_gvt_gtt_entry *we, unsigned long index)
{
        struct intel_vgpu *vgpu = spt->vgpu;
        int type = spt->shadow_page.type;
        const struct intel_gvt_gtt_pte_ops *ops = vgpu->gvt->gtt.pte_ops;
        struct intel_gvt_gtt_entry old_se;
        int new_present;
        int i, ret;

        new_present = ops->test_present(we);

        /*
         * Adding the new entry first and then removing the old one, that can
         * guarantee the ppgtt table is validated during the window between
         * adding and removal.
         */
        ppgtt_get_shadow_entry(spt, &old_se, index);

        if (new_present) {
                ret = ppgtt_handle_guest_entry_add(spt, we, index);
                if (ret)
                        goto fail;
        }

        ret = ppgtt_handle_guest_entry_removal(spt, &old_se, index);
        if (ret)
                goto fail;

        if (!new_present) {
                /* For 64KB splited entries, we need clear them all. */
                if (ops->test_64k_splited(&old_se) &&
                    !(index % GTT_64K_PTE_STRIDE)) {
                        gvt_vdbg_mm("remove splited 64K shadow entries\n");
                        for (i = 0; i < GTT_64K_PTE_STRIDE; i++) {
                                ops->clear_64k_splited(&old_se);
                                ops->set_pfn(&old_se,
                                        vgpu->gtt.scratch_pt[type].page_mfn);
                                ppgtt_set_shadow_entry(spt, &old_se, index + i);
                        }
                } else if (old_se.type == GTT_TYPE_PPGTT_PTE_2M_ENTRY ||
                           old_se.type == GTT_TYPE_PPGTT_PTE_1G_ENTRY) {
                        ops->clear_pse(&old_se);
                        ops->set_pfn(&old_se,
                                     vgpu->gtt.scratch_pt[type].page_mfn);
                        ppgtt_set_shadow_entry(spt, &old_se, index);
                } else {
                        ops->set_pfn(&old_se,
                                     vgpu->gtt.scratch_pt[type].page_mfn);
                        ppgtt_set_shadow_entry(spt, &old_se, index);
                }
        }

        return 0;
fail:
        gvt_vgpu_err("fail: shadow page %p guest entry 0x%llx type %d.\n",
                        spt, we->val64, we->type);
        return ret;
}



static inline bool can_do_out_of_sync(struct intel_vgpu_ppgtt_spt *spt)
{
        return enable_out_of_sync
                && gtt_type_is_pte_pt(spt->guest_page.type)
                && spt->guest_page.write_cnt >= 2;
}

static void ppgtt_set_post_shadow(struct intel_vgpu_ppgtt_spt *spt,
                unsigned long index)
{
        set_bit(index, spt->post_shadow_bitmap);
        if (!list_empty(&spt->post_shadow_list))
                return;

        list_add_tail(&spt->post_shadow_list,
                        &spt->vgpu->gtt.post_shadow_list_head);
}

/**
 * intel_vgpu_flush_post_shadow - flush the post shadow transactions
 * @vgpu: a vGPU
 *
 * This function is called before submitting a guest workload to host,
 * to flush all the post shadows for a vGPU.
 *
 * Returns:
 * Zero on success, negative error code if failed.
 */
int intel_vgpu_flush_post_shadow(struct intel_vgpu *vgpu)
{
        struct list_head *pos, *n;
        struct intel_vgpu_ppgtt_spt *spt;
        struct intel_gvt_gtt_entry ge;
        unsigned long index;
        int ret;

        list_for_each_safe(pos, n, &vgpu->gtt.post_shadow_list_head) {
                spt = container_of(pos, struct intel_vgpu_ppgtt_spt,
                                post_shadow_list);

                for_each_set_bit(index, spt->post_shadow_bitmap,
                                GTT_ENTRY_NUM_IN_ONE_PAGE) {
                        ppgtt_get_guest_entry(spt, &ge, index);

                        ret = ppgtt_handle_guest_write_page_table(spt,
                                                        &ge, index);
                        if (ret)
                                return ret;
                        clear_bit(index, spt->post_shadow_bitmap);
                }
                list_del_init(&spt->post_shadow_list);
        }
        return 0;
}

static int ppgtt_handle_guest_write_page_table_bytes(
                struct intel_vgpu_ppgtt_spt *spt,
                u64 pa, void *p_data, int bytes)
{
        struct intel_vgpu *vgpu = spt->vgpu;
        const struct intel_gvt_gtt_pte_ops *ops = vgpu->gvt->gtt.pte_ops;
        const struct intel_gvt_device_info *info = &vgpu->gvt->device_info;
        struct intel_gvt_gtt_entry we, se;
        unsigned long index;
        int ret;

        index = (pa & (PAGE_SIZE - 1)) >> info->gtt_entry_size_shift;

        ppgtt_get_guest_entry(spt, &we, index);

        /*
         * For page table which has 64K gtt entry, only PTE#0, PTE#16,
         * PTE#32, ... PTE#496 are used. Unused PTEs update should be
         * ignored.
         */
        if (we.type == GTT_TYPE_PPGTT_PTE_64K_ENTRY &&
            (index % GTT_64K_PTE_STRIDE)) {
                gvt_vdbg_mm("Ignore write to unused PTE entry, index %lu\n",
                            index);
                return 0;
        }

        if (bytes == info->gtt_entry_size) {
                ret = ppgtt_handle_guest_write_page_table(spt, &we, index);
                if (ret)
                        return ret;
        } else {
                if (!test_bit(index, spt->post_shadow_bitmap)) {
                        int type = spt->shadow_page.type;

                        ppgtt_get_shadow_entry(spt, &se, index);
                        ret = ppgtt_handle_guest_entry_removal(spt, &se, index);
                        if (ret)
                                return ret;
                        ops->set_pfn(&se, vgpu->gtt.scratch_pt[type].page_mfn);
                        ppgtt_set_shadow_entry(spt, &se, index);
                }
                ppgtt_set_post_shadow(spt, index);
        }

        if (!enable_out_of_sync)
                return 0;

        spt->guest_page.write_cnt++;

        if (spt->guest_page.oos_page)
                ops->set_entry(spt->guest_page.oos_page->mem, &we, index,
                                false, 0, vgpu);

        if (can_do_out_of_sync(spt)) {
                if (!spt->guest_page.oos_page)
                        ppgtt_allocate_oos_page(spt);

                ret = ppgtt_set_guest_page_oos(spt);
                if (ret < 0)
                        return ret;
        }
        return 0;
}

static void invalidate_ppgtt_mm(struct intel_vgpu_mm *mm)
{
        struct intel_vgpu *vgpu = mm->vgpu;
        struct intel_gvt *gvt = vgpu->gvt;
        struct intel_gvt_gtt *gtt = &gvt->gtt;
        const struct intel_gvt_gtt_pte_ops *ops = gtt->pte_ops;
        struct intel_gvt_gtt_entry se;
        int index;

        if (!mm->ppgtt_mm.shadowed)
                return;

        for (index = 0; index < ARRAY_SIZE(mm->ppgtt_mm.shadow_pdps); index++) {
                ppgtt_get_shadow_root_entry(mm, &se, index);

                if (!ops->test_present(&se))
                        continue;

                ppgtt_invalidate_spt_by_shadow_entry(vgpu, &se);
                se.val64 = 0;
                ppgtt_set_shadow_root_entry(mm, &se, index);

                trace_spt_guest_change(vgpu->id, "destroy root pointer",
                                       NULL, se.type, se.val64, index);
        }

        mm->ppgtt_mm.shadowed = false;
}


static int shadow_ppgtt_mm(struct intel_vgpu_mm *mm)
{
        struct intel_vgpu *vgpu = mm->vgpu;
        struct intel_gvt *gvt = vgpu->gvt;
        struct intel_gvt_gtt *gtt = &gvt->gtt;
        const struct intel_gvt_gtt_pte_ops *ops = gtt->pte_ops;
        struct intel_vgpu_ppgtt_spt *spt;
        struct intel_gvt_gtt_entry ge, se;
        int index, ret;

        if (mm->ppgtt_mm.shadowed)
                return 0;

        if (!test_bit(INTEL_VGPU_STATUS_ATTACHED, vgpu->status))
                return -EINVAL;

        mm->ppgtt_mm.shadowed = true;

        for (index = 0; index < ARRAY_SIZE(mm->ppgtt_mm.guest_pdps); index++) {
                ppgtt_get_guest_root_entry(mm, &ge, index);

                if (!ops->test_present(&ge))
                        continue;

                trace_spt_guest_change(vgpu->id, __func__, NULL,
                                       ge.type, ge.val64, index);

                spt = ppgtt_populate_spt_by_guest_entry(vgpu, &ge);
                if (IS_ERR(spt)) {
                        gvt_vgpu_err("fail to populate guest root pointer\n");
                        ret = PTR_ERR(spt);
                        goto fail;
                }
                ppgtt_generate_shadow_entry(&se, spt, &ge);
                ppgtt_set_shadow_root_entry(mm, &se, index);

                trace_spt_guest_change(vgpu->id, "populate root pointer",
                                       NULL, se.type, se.val64, index);
        }

        return 0;
fail:
        invalidate_ppgtt_mm(mm);
        return ret;
}

static struct intel_vgpu_mm *vgpu_alloc_mm(struct intel_vgpu *vgpu)
{
        struct intel_vgpu_mm *mm;

        mm = kzalloc_obj(*mm);
        if (!mm)
                return NULL;

        mm->vgpu = vgpu;
        kref_init(&mm->ref);
        atomic_set(&mm->pincount, 0);

        return mm;
}

static void vgpu_free_mm(struct intel_vgpu_mm *mm)
{
        kfree(mm);
}

/**
 * intel_vgpu_create_ppgtt_mm - create a ppgtt mm object for a vGPU
 * @vgpu: a vGPU
 * @root_entry_type: ppgtt root entry type
 * @pdps: guest pdps.
 *
 * This function is used to create a ppgtt mm object for a vGPU.
 *
 * Returns:
 * Zero on success, negative error code in pointer if failed.
 */
struct intel_vgpu_mm *intel_vgpu_create_ppgtt_mm(struct intel_vgpu *vgpu,
                enum intel_gvt_gtt_type root_entry_type, u64 pdps[])
{
        struct intel_gvt *gvt = vgpu->gvt;
        struct intel_vgpu_mm *mm;
        int ret;

        mm = vgpu_alloc_mm(vgpu);
        if (!mm)
                return ERR_PTR(-ENOMEM);

        mm->type = INTEL_GVT_MM_PPGTT;

        GEM_BUG_ON(root_entry_type != GTT_TYPE_PPGTT_ROOT_L3_ENTRY &&
                   root_entry_type != GTT_TYPE_PPGTT_ROOT_L4_ENTRY);
        mm->ppgtt_mm.root_entry_type = root_entry_type;

        INIT_LIST_HEAD(&mm->ppgtt_mm.list);
        INIT_LIST_HEAD(&mm->ppgtt_mm.lru_list);
        INIT_LIST_HEAD(&mm->ppgtt_mm.link);

        if (root_entry_type == GTT_TYPE_PPGTT_ROOT_L4_ENTRY)
                mm->ppgtt_mm.guest_pdps[0] = pdps[0];
        else
                memcpy(mm->ppgtt_mm.guest_pdps, pdps,
                       sizeof(mm->ppgtt_mm.guest_pdps));

        ret = shadow_ppgtt_mm(mm);
        if (ret) {
                gvt_vgpu_err("failed to shadow ppgtt mm\n");
                vgpu_free_mm(mm);
                return ERR_PTR(ret);
        }

        list_add_tail(&mm->ppgtt_mm.list, &vgpu->gtt.ppgtt_mm_list_head);

        mutex_lock(&gvt->gtt.ppgtt_mm_lock);
        list_add_tail(&mm->ppgtt_mm.lru_list, &gvt->gtt.ppgtt_mm_lru_list_head);
        mutex_unlock(&gvt->gtt.ppgtt_mm_lock);

        return mm;
}

static struct intel_vgpu_mm *intel_vgpu_create_ggtt_mm(struct intel_vgpu *vgpu)
{
        struct intel_vgpu_mm *mm;
        unsigned long nr_entries;

        mm = vgpu_alloc_mm(vgpu);
        if (!mm)
                return ERR_PTR(-ENOMEM);

        mm->type = INTEL_GVT_MM_GGTT;

        nr_entries = gvt_ggtt_gm_sz(vgpu->gvt) >> I915_GTT_PAGE_SHIFT;
        mm->ggtt_mm.virtual_ggtt =
                vzalloc(array_size(nr_entries,
                                   vgpu->gvt->device_info.gtt_entry_size));
        if (!mm->ggtt_mm.virtual_ggtt) {
                vgpu_free_mm(mm);
                return ERR_PTR(-ENOMEM);
        }

        mm->ggtt_mm.host_ggtt_aperture = vzalloc((vgpu_aperture_sz(vgpu) >> PAGE_SHIFT) * sizeof(u64));
        if (!mm->ggtt_mm.host_ggtt_aperture) {
                vfree(mm->ggtt_mm.virtual_ggtt);
                vgpu_free_mm(mm);
                return ERR_PTR(-ENOMEM);
        }

        mm->ggtt_mm.host_ggtt_hidden = vzalloc((vgpu_hidden_sz(vgpu) >> PAGE_SHIFT) * sizeof(u64));
        if (!mm->ggtt_mm.host_ggtt_hidden) {
                vfree(mm->ggtt_mm.host_ggtt_aperture);
                vfree(mm->ggtt_mm.virtual_ggtt);
                vgpu_free_mm(mm);
                return ERR_PTR(-ENOMEM);
        }

        return mm;
}

/**
 * _intel_vgpu_mm_release - destroy a mm object
 * @mm_ref: a kref object
 *
 * This function is used to destroy a mm object for vGPU
 *
 */
void _intel_vgpu_mm_release(struct kref *mm_ref)
{
        struct intel_vgpu_mm *mm = container_of(mm_ref, typeof(*mm), ref);

        if (GEM_WARN_ON(atomic_read(&mm->pincount)))
                gvt_err("vgpu mm pin count bug detected\n");

        if (mm->type == INTEL_GVT_MM_PPGTT) {
                list_del(&mm->ppgtt_mm.list);

                mutex_lock(&mm->vgpu->gvt->gtt.ppgtt_mm_lock);
                list_del(&mm->ppgtt_mm.lru_list);
                mutex_unlock(&mm->vgpu->gvt->gtt.ppgtt_mm_lock);

                invalidate_ppgtt_mm(mm);
        } else {
                vfree(mm->ggtt_mm.virtual_ggtt);
                vfree(mm->ggtt_mm.host_ggtt_aperture);
                vfree(mm->ggtt_mm.host_ggtt_hidden);
        }

        vgpu_free_mm(mm);
}

/**
 * intel_vgpu_unpin_mm - decrease the pin count of a vGPU mm object
 * @mm: a vGPU mm object
 *
 * This function is called when user doesn't want to use a vGPU mm object
 */
void intel_vgpu_unpin_mm(struct intel_vgpu_mm *mm)
{
        atomic_dec_if_positive(&mm->pincount);
}

/**
 * intel_vgpu_pin_mm - increase the pin count of a vGPU mm object
 * @mm: target vgpu mm
 *
 * This function is called when user wants to use a vGPU mm object. If this
 * mm object hasn't been shadowed yet, the shadow will be populated at this
 * time.
 *
 * Returns:
 * Zero on success, negative error code if failed.
 */
int intel_vgpu_pin_mm(struct intel_vgpu_mm *mm)
{
        int ret;

        atomic_inc(&mm->pincount);

        if (mm->type == INTEL_GVT_MM_PPGTT) {
                ret = shadow_ppgtt_mm(mm);
                if (ret)
                        return ret;

                mutex_lock(&mm->vgpu->gvt->gtt.ppgtt_mm_lock);
                list_move_tail(&mm->ppgtt_mm.lru_list,
                               &mm->vgpu->gvt->gtt.ppgtt_mm_lru_list_head);
                mutex_unlock(&mm->vgpu->gvt->gtt.ppgtt_mm_lock);
        }

        return 0;
}

static int reclaim_one_ppgtt_mm(struct intel_gvt *gvt)
{
        struct intel_vgpu_mm *mm;
        struct list_head *pos, *n;

        mutex_lock(&gvt->gtt.ppgtt_mm_lock);

        list_for_each_safe(pos, n, &gvt->gtt.ppgtt_mm_lru_list_head) {
                mm = container_of(pos, struct intel_vgpu_mm, ppgtt_mm.lru_list);

                if (atomic_read(&mm->pincount))
                        continue;

                list_del_init(&mm->ppgtt_mm.lru_list);
                mutex_unlock(&gvt->gtt.ppgtt_mm_lock);
                invalidate_ppgtt_mm(mm);
                return 1;
        }
        mutex_unlock(&gvt->gtt.ppgtt_mm_lock);
        return 0;
}

/*
 * GMA translation APIs.
 */
static inline int ppgtt_get_next_level_entry(struct intel_vgpu_mm *mm,
                struct intel_gvt_gtt_entry *e, unsigned long index, bool guest)
{
        struct intel_vgpu *vgpu = mm->vgpu;
        const struct intel_gvt_gtt_pte_ops *ops = vgpu->gvt->gtt.pte_ops;
        struct intel_vgpu_ppgtt_spt *s;

        s = intel_vgpu_find_spt_by_mfn(vgpu, ops->get_pfn(e));
        if (!s)
                return -ENXIO;

        if (!guest)
                ppgtt_get_shadow_entry(s, e, index);
        else
                ppgtt_get_guest_entry(s, e, index);
        return 0;
}

/**
 * intel_vgpu_gma_to_gpa - translate a gma to GPA
 * @mm: mm object. could be a PPGTT or GGTT mm object
 * @gma: graphics memory address in this mm object
 *
 * This function is used to translate a graphics memory address in specific
 * graphics memory space to guest physical address.
 *
 * Returns:
 * Guest physical address on success, INTEL_GVT_INVALID_ADDR if failed.
 */
unsigned long intel_vgpu_gma_to_gpa(struct intel_vgpu_mm *mm, unsigned long gma)
{
        struct intel_vgpu *vgpu = mm->vgpu;
        struct intel_gvt *gvt = vgpu->gvt;
        const struct intel_gvt_gtt_pte_ops *pte_ops = gvt->gtt.pte_ops;
        const struct intel_gvt_gtt_gma_ops *gma_ops = gvt->gtt.gma_ops;
        unsigned long gpa = INTEL_GVT_INVALID_ADDR;
        unsigned long gma_index[4];
        struct intel_gvt_gtt_entry e;
        int i, levels = 0;
        int ret;

        GEM_BUG_ON(mm->type != INTEL_GVT_MM_GGTT &&
                   mm->type != INTEL_GVT_MM_PPGTT);

        if (mm->type == INTEL_GVT_MM_GGTT) {
                if (!vgpu_gmadr_is_valid(vgpu, gma))
                        goto err;

                ggtt_get_guest_entry(mm, &e,
                        gma_ops->gma_to_ggtt_pte_index(gma));

                gpa = (pte_ops->get_pfn(&e) << I915_GTT_PAGE_SHIFT)
                        + (gma & ~I915_GTT_PAGE_MASK);

                trace_gma_translate(vgpu->id, "ggtt", 0, 0, gma, gpa);
        } else {
                switch (mm->ppgtt_mm.root_entry_type) {
                case GTT_TYPE_PPGTT_ROOT_L4_ENTRY:
                        ppgtt_get_shadow_root_entry(mm, &e, 0);

                        gma_index[0] = gma_ops->gma_to_pml4_index(gma);
                        gma_index[1] = gma_ops->gma_to_l4_pdp_index(gma);
                        gma_index[2] = gma_ops->gma_to_pde_index(gma);
                        gma_index[3] = gma_ops->gma_to_pte_index(gma);
                        levels = 4;
                        break;
                case GTT_TYPE_PPGTT_ROOT_L3_ENTRY:
                        ppgtt_get_shadow_root_entry(mm, &e,
                                        gma_ops->gma_to_l3_pdp_index(gma));

                        gma_index[0] = gma_ops->gma_to_pde_index(gma);
                        gma_index[1] = gma_ops->gma_to_pte_index(gma);
                        levels = 2;
                        break;
                default:
                        GEM_BUG_ON(1);
                }

                /* walk the shadow page table and get gpa from guest entry */
                for (i = 0; i < levels; i++) {
                        ret = ppgtt_get_next_level_entry(mm, &e, gma_index[i],
                                (i == levels - 1));
                        if (ret)
                                goto err;

                        if (!pte_ops->test_present(&e)) {
                                gvt_dbg_core("GMA 0x%lx is not present\n", gma);
                                goto err;
                        }
                }

                gpa = (pte_ops->get_pfn(&e) << I915_GTT_PAGE_SHIFT) +
                                        (gma & ~I915_GTT_PAGE_MASK);
                trace_gma_translate(vgpu->id, "ppgtt", 0,
                                    mm->ppgtt_mm.root_entry_type, gma, gpa);
        }

        return gpa;
err:
        gvt_vgpu_err("invalid mm type: %d gma %lx\n", mm->type, gma);
        return INTEL_GVT_INVALID_ADDR;
}

static int emulate_ggtt_mmio_read(struct intel_vgpu *vgpu,
        unsigned int off, void *p_data, unsigned int bytes)
{
        struct intel_vgpu_mm *ggtt_mm = vgpu->gtt.ggtt_mm;
        const struct intel_gvt_device_info *info = &vgpu->gvt->device_info;
        unsigned long index = off >> info->gtt_entry_size_shift;
        unsigned long gma;
        struct intel_gvt_gtt_entry e;

        if (bytes != 4 && bytes != 8)
                return -EINVAL;

        gma = index << I915_GTT_PAGE_SHIFT;
        if (!intel_gvt_ggtt_validate_range(vgpu,
                                           gma, 1 << I915_GTT_PAGE_SHIFT)) {
                gvt_dbg_mm("read invalid ggtt at 0x%lx\n", gma);
                memset(p_data, 0, bytes);
                return 0;
        }

        ggtt_get_guest_entry(ggtt_mm, &e, index);
        memcpy(p_data, (void *)&e.val64 + (off & (info->gtt_entry_size - 1)),
                        bytes);
        return 0;
}

/**
 * intel_vgpu_emulate_ggtt_mmio_read - emulate GTT MMIO register read
 * @vgpu: a vGPU
 * @off: register offset
 * @p_data: data will be returned to guest
 * @bytes: data length
 *
 * This function is used to emulate the GTT MMIO register read
 *
 * Returns:
 * Zero on success, error code if failed.
 */
int intel_vgpu_emulate_ggtt_mmio_read(struct intel_vgpu *vgpu, unsigned int off,
        void *p_data, unsigned int bytes)
{
        const struct intel_gvt_device_info *info = &vgpu->gvt->device_info;
        int ret;

        if (bytes != 4 && bytes != 8)
                return -EINVAL;

        off -= info->gtt_start_offset;
        ret = emulate_ggtt_mmio_read(vgpu, off, p_data, bytes);
        return ret;
}

static void ggtt_invalidate_pte(struct intel_vgpu *vgpu,
                struct intel_gvt_gtt_entry *entry)
{
        const struct intel_gvt_gtt_pte_ops *pte_ops = vgpu->gvt->gtt.pte_ops;
        unsigned long pfn;

        pfn = pte_ops->get_pfn(entry);
        if (pfn != vgpu->gvt->gtt.scratch_mfn)
                intel_gvt_dma_unmap_guest_page(vgpu, pfn << PAGE_SHIFT);
}

static int emulate_ggtt_mmio_write(struct intel_vgpu *vgpu, unsigned int off,
        void *p_data, unsigned int bytes)
{
        struct intel_gvt *gvt = vgpu->gvt;
        const struct intel_gvt_device_info *info = &gvt->device_info;
        struct intel_vgpu_mm *ggtt_mm = vgpu->gtt.ggtt_mm;
        const struct intel_gvt_gtt_pte_ops *ops = gvt->gtt.pte_ops;
        unsigned long g_gtt_index = off >> info->gtt_entry_size_shift;
        unsigned long gma, gfn;
        struct intel_gvt_gtt_entry e = {.val64 = 0, .type = GTT_TYPE_GGTT_PTE};
        struct intel_gvt_gtt_entry m = {.val64 = 0, .type = GTT_TYPE_GGTT_PTE};
        dma_addr_t dma_addr;
        int ret;
        struct intel_gvt_partial_pte *partial_pte, *pos, *n;
        bool partial_update = false;

        if (bytes != 4 && bytes != 8)
                return -EINVAL;

        gma = g_gtt_index << I915_GTT_PAGE_SHIFT;

        /* the VM may configure the whole GM space when ballooning is used */
        if (!vgpu_gmadr_is_valid(vgpu, gma))
                return 0;

        e.type = GTT_TYPE_GGTT_PTE;
        memcpy((void *)&e.val64 + (off & (info->gtt_entry_size - 1)), p_data,
                        bytes);

        /* If ggtt entry size is 8 bytes, and it's split into two 4 bytes
         * write, save the first 4 bytes in a list and update virtual
         * PTE. Only update shadow PTE when the second 4 bytes comes.
         */
        if (bytes < info->gtt_entry_size) {
                bool found = false;

                list_for_each_entry_safe(pos, n,
                                &ggtt_mm->ggtt_mm.partial_pte_list, list) {
                        if (g_gtt_index == pos->offset >>
                                        info->gtt_entry_size_shift) {
                                if (off != pos->offset) {
                                        /* the second partial part*/
                                        int last_off = pos->offset &
                                                (info->gtt_entry_size - 1);

                                        memcpy((void *)&e.val64 + last_off,
                                                (void *)&pos->data + last_off,
                                                bytes);

                                        list_del(&pos->list);
                                        kfree(pos);
                                        found = true;
                                        break;
                                }

                                /* update of the first partial part */
                                pos->data = e.val64;
                                ggtt_set_guest_entry(ggtt_mm, &e, g_gtt_index);
                                return 0;
                        }
                }

                if (!found) {
                        /* the first partial part */
                        partial_pte = kzalloc_obj(*partial_pte);
                        if (!partial_pte)
                                return -ENOMEM;
                        partial_pte->offset = off;
                        partial_pte->data = e.val64;
                        list_add_tail(&partial_pte->list,
                                &ggtt_mm->ggtt_mm.partial_pte_list);
                        partial_update = true;
                }
        }

        if (!partial_update && (ops->test_present(&e))) {
                gfn = ops->get_pfn(&e);
                m.val64 = e.val64;
                m.type = e.type;

                ret = intel_gvt_dma_map_guest_page(vgpu, gfn, PAGE_SIZE,
                                                   &dma_addr);
                if (ret) {
                        gvt_vgpu_err("fail to populate guest ggtt entry\n");
                        /* guest driver may read/write the entry when partial
                         * update the entry in this situation p2m will fail
                         * setting the shadow entry to point to a scratch page
                         */
                        ops->set_pfn(&m, gvt->gtt.scratch_mfn);
                } else
                        ops->set_pfn(&m, dma_addr >> PAGE_SHIFT);
        } else {
                ops->set_pfn(&m, gvt->gtt.scratch_mfn);
                ops->clear_present(&m);
        }

        ggtt_set_guest_entry(ggtt_mm, &e, g_gtt_index);

        ggtt_get_host_entry(ggtt_mm, &e, g_gtt_index);
        ggtt_invalidate_pte(vgpu, &e);

        ggtt_set_host_entry(ggtt_mm, &m, g_gtt_index);
        ggtt_invalidate(gvt->gt);
        return 0;
}

/*
 * intel_vgpu_emulate_ggtt_mmio_write - emulate GTT MMIO register write
 * @vgpu: a vGPU
 * @off: register offset
 * @p_data: data from guest write
 * @bytes: data length
 *
 * This function is used to emulate the GTT MMIO register write
 *
 * Returns:
 * Zero on success, error code if failed.
 */
int intel_vgpu_emulate_ggtt_mmio_write(struct intel_vgpu *vgpu,
                unsigned int off, void *p_data, unsigned int bytes)
{
        const struct intel_gvt_device_info *info = &vgpu->gvt->device_info;
        int ret;
        struct intel_vgpu_submission *s = &vgpu->submission;
        struct intel_engine_cs *engine;
        int i;

        if (bytes != 4 && bytes != 8)
                return -EINVAL;

        off -= info->gtt_start_offset;
        ret = emulate_ggtt_mmio_write(vgpu, off, p_data, bytes);

        /* if ggtt of last submitted context is written,
         * that context is probably got unpinned.
         * Set last shadowed ctx to invalid.
         */
        for_each_engine(engine, vgpu->gvt->gt, i) {
                if (!s->last_ctx[i].valid)
                        continue;

                if (s->last_ctx[i].lrca == (off >> info->gtt_entry_size_shift))
                        s->last_ctx[i].valid = false;
        }
        return ret;
}

static int alloc_scratch_pages(struct intel_vgpu *vgpu,
                enum intel_gvt_gtt_type type)
{
        struct drm_i915_private *i915 = vgpu->gvt->gt->i915;
        struct intel_vgpu_gtt *gtt = &vgpu->gtt;
        const struct intel_gvt_gtt_pte_ops *ops = vgpu->gvt->gtt.pte_ops;
        int page_entry_num = I915_GTT_PAGE_SIZE >>
                                vgpu->gvt->device_info.gtt_entry_size_shift;
        void *scratch_pt;
        int i;
        struct device *dev = vgpu->gvt->gt->i915->drm.dev;
        dma_addr_t daddr;

        if (drm_WARN_ON(&i915->drm,
                        type < GTT_TYPE_PPGTT_PTE_PT || type >= GTT_TYPE_MAX))
                return -EINVAL;

        scratch_pt = (void *)get_zeroed_page(GFP_KERNEL);
        if (!scratch_pt) {
                gvt_vgpu_err("fail to allocate scratch page\n");
                return -ENOMEM;
        }

        daddr = dma_map_page(dev, virt_to_page(scratch_pt), 0, 4096, DMA_BIDIRECTIONAL);
        if (dma_mapping_error(dev, daddr)) {
                gvt_vgpu_err("fail to dmamap scratch_pt\n");
                __free_page(virt_to_page(scratch_pt));
                return -ENOMEM;
        }
        gtt->scratch_pt[type].page_mfn =
                (unsigned long)(daddr >> I915_GTT_PAGE_SHIFT);
        gtt->scratch_pt[type].page = virt_to_page(scratch_pt);
        gvt_dbg_mm("vgpu%d create scratch_pt: type %d mfn=0x%lx\n",
                        vgpu->id, type, gtt->scratch_pt[type].page_mfn);

        /* Build the tree by full filled the scratch pt with the entries which
         * point to the next level scratch pt or scratch page. The
         * scratch_pt[type] indicate the scratch pt/scratch page used by the
         * 'type' pt.
         * e.g. scratch_pt[GTT_TYPE_PPGTT_PDE_PT] is used by
         * GTT_TYPE_PPGTT_PDE_PT level pt, that means this scratch_pt it self
         * is GTT_TYPE_PPGTT_PTE_PT, and full filled by scratch page mfn.
         */
        if (type > GTT_TYPE_PPGTT_PTE_PT) {
                struct intel_gvt_gtt_entry se;

                memset(&se, 0, sizeof(struct intel_gvt_gtt_entry));
                se.type = get_entry_type(type - 1);
                ops->set_pfn(&se, gtt->scratch_pt[type - 1].page_mfn);

                /* The entry parameters like present/writeable/cache type
                 * set to the same as i915's scratch page tree.
                 */
                se.val64 |= GEN8_PAGE_PRESENT | GEN8_PAGE_RW;
                if (type == GTT_TYPE_PPGTT_PDE_PT)
                        se.val64 |= PPAT_CACHED;

                for (i = 0; i < page_entry_num; i++)
                        ops->set_entry(scratch_pt, &se, i, false, 0, vgpu);
        }

        return 0;
}

static int release_scratch_page_tree(struct intel_vgpu *vgpu)
{
        int i;
        struct device *dev = vgpu->gvt->gt->i915->drm.dev;
        dma_addr_t daddr;

        for (i = GTT_TYPE_PPGTT_PTE_PT; i < GTT_TYPE_MAX; i++) {
                if (vgpu->gtt.scratch_pt[i].page != NULL) {
                        daddr = (dma_addr_t)(vgpu->gtt.scratch_pt[i].page_mfn <<
                                        I915_GTT_PAGE_SHIFT);
                        dma_unmap_page(dev, daddr, 4096, DMA_BIDIRECTIONAL);
                        __free_page(vgpu->gtt.scratch_pt[i].page);
                        vgpu->gtt.scratch_pt[i].page = NULL;
                        vgpu->gtt.scratch_pt[i].page_mfn = 0;
                }
        }

        return 0;
}

static int create_scratch_page_tree(struct intel_vgpu *vgpu)
{
        int i, ret;

        for (i = GTT_TYPE_PPGTT_PTE_PT; i < GTT_TYPE_MAX; i++) {
                ret = alloc_scratch_pages(vgpu, i);
                if (ret)
                        goto err;
        }

        return 0;

err:
        release_scratch_page_tree(vgpu);
        return ret;
}

/**
 * intel_vgpu_init_gtt - initialize per-vGPU graphics memory virulization
 * @vgpu: a vGPU
 *
 * This function is used to initialize per-vGPU graphics memory virtualization
 * components.
 *
 * Returns:
 * Zero on success, error code if failed.
 */
int intel_vgpu_init_gtt(struct intel_vgpu *vgpu)
{
        struct intel_vgpu_gtt *gtt = &vgpu->gtt;

        INIT_RADIX_TREE(&gtt->spt_tree, GFP_KERNEL);

        INIT_LIST_HEAD(&gtt->ppgtt_mm_list_head);
        INIT_LIST_HEAD(&gtt->oos_page_list_head);
        INIT_LIST_HEAD(&gtt->post_shadow_list_head);

        gtt->ggtt_mm = intel_vgpu_create_ggtt_mm(vgpu);
        if (IS_ERR(gtt->ggtt_mm)) {
                gvt_vgpu_err("fail to create mm for ggtt.\n");
                return PTR_ERR(gtt->ggtt_mm);
        }

        intel_vgpu_reset_ggtt(vgpu, false);

        INIT_LIST_HEAD(&gtt->ggtt_mm->ggtt_mm.partial_pte_list);

        return create_scratch_page_tree(vgpu);
}

void intel_vgpu_destroy_all_ppgtt_mm(struct intel_vgpu *vgpu)
{
        struct list_head *pos, *n;
        struct intel_vgpu_mm *mm;

        list_for_each_safe(pos, n, &vgpu->gtt.ppgtt_mm_list_head) {
                mm = container_of(pos, struct intel_vgpu_mm, ppgtt_mm.list);
                intel_vgpu_destroy_mm(mm);
        }

        if (GEM_WARN_ON(!list_empty(&vgpu->gtt.ppgtt_mm_list_head)))
                gvt_err("vgpu ppgtt mm is not fully destroyed\n");

        if (GEM_WARN_ON(!radix_tree_empty(&vgpu->gtt.spt_tree))) {
                gvt_err("Why we still has spt not freed?\n");
                ppgtt_free_all_spt(vgpu);
        }
}

static void intel_vgpu_destroy_ggtt_mm(struct intel_vgpu *vgpu)
{
        struct intel_gvt_partial_pte *pos, *next;

        list_for_each_entry_safe(pos, next,
                                 &vgpu->gtt.ggtt_mm->ggtt_mm.partial_pte_list,
                                 list) {
                gvt_dbg_mm("partial PTE update on hold 0x%lx : 0x%llx\n",
                        pos->offset, pos->data);
                kfree(pos);
        }
        intel_vgpu_destroy_mm(vgpu->gtt.ggtt_mm);
        vgpu->gtt.ggtt_mm = NULL;
}

/**
 * intel_vgpu_clean_gtt - clean up per-vGPU graphics memory virulization
 * @vgpu: a vGPU
 *
 * This function is used to clean up per-vGPU graphics memory virtualization
 * components.
 *
 * Returns:
 * Zero on success, error code if failed.
 */
void intel_vgpu_clean_gtt(struct intel_vgpu *vgpu)
{
        intel_vgpu_destroy_all_ppgtt_mm(vgpu);
        intel_vgpu_destroy_ggtt_mm(vgpu);
        release_scratch_page_tree(vgpu);
}

static void clean_spt_oos(struct intel_gvt *gvt)
{
        struct intel_gvt_gtt *gtt = &gvt->gtt;
        struct list_head *pos, *n;
        struct intel_vgpu_oos_page *oos_page;

        WARN(!list_empty(&gtt->oos_page_use_list_head),
                "someone is still using oos page\n");

        list_for_each_safe(pos, n, &gtt->oos_page_free_list_head) {
                oos_page = container_of(pos, struct intel_vgpu_oos_page, list);
                list_del(&oos_page->list);
                free_page((unsigned long)oos_page->mem);
                kfree(oos_page);
        }
}

static int setup_spt_oos(struct intel_gvt *gvt)
{
        struct intel_gvt_gtt *gtt = &gvt->gtt;
        struct intel_vgpu_oos_page *oos_page;
        int i;
        int ret;

        INIT_LIST_HEAD(&gtt->oos_page_free_list_head);
        INIT_LIST_HEAD(&gtt->oos_page_use_list_head);

        for (i = 0; i < preallocated_oos_pages; i++) {
                oos_page = kzalloc_obj(*oos_page);
                if (!oos_page) {
                        ret = -ENOMEM;
                        goto fail;
                }
                oos_page->mem = (void *)__get_free_pages(GFP_KERNEL, 0);
                if (!oos_page->mem) {
                        ret = -ENOMEM;
                        kfree(oos_page);
                        goto fail;
                }

                INIT_LIST_HEAD(&oos_page->list);
                INIT_LIST_HEAD(&oos_page->vm_list);
                oos_page->id = i;
                list_add_tail(&oos_page->list, &gtt->oos_page_free_list_head);
        }

        gvt_dbg_mm("%d oos pages preallocated\n", i);

        return 0;
fail:
        clean_spt_oos(gvt);
        return ret;
}

/**
 * intel_vgpu_find_ppgtt_mm - find a PPGTT mm object
 * @vgpu: a vGPU
 * @pdps: pdp root array
 *
 * This function is used to find a PPGTT mm object from mm object pool
 *
 * Returns:
 * pointer to mm object on success, NULL if failed.
 */
struct intel_vgpu_mm *intel_vgpu_find_ppgtt_mm(struct intel_vgpu *vgpu,
                u64 pdps[])
{
        struct intel_vgpu_mm *mm;
        struct list_head *pos;

        list_for_each(pos, &vgpu->gtt.ppgtt_mm_list_head) {
                mm = container_of(pos, struct intel_vgpu_mm, ppgtt_mm.list);

                switch (mm->ppgtt_mm.root_entry_type) {
                case GTT_TYPE_PPGTT_ROOT_L4_ENTRY:
                        if (pdps[0] == mm->ppgtt_mm.guest_pdps[0])
                                return mm;
                        break;
                case GTT_TYPE_PPGTT_ROOT_L3_ENTRY:
                        if (!memcmp(pdps, mm->ppgtt_mm.guest_pdps,
                                    sizeof(mm->ppgtt_mm.guest_pdps)))
                                return mm;
                        break;
                default:
                        GEM_BUG_ON(1);
                }
        }
        return NULL;
}

/**
 * intel_vgpu_get_ppgtt_mm - get or create a PPGTT mm object.
 * @vgpu: a vGPU
 * @root_entry_type: ppgtt root entry type
 * @pdps: guest pdps
 *
 * This function is used to find or create a PPGTT mm object from a guest.
 *
 * Returns:
 * Zero on success, negative error code if failed.
 */
struct intel_vgpu_mm *intel_vgpu_get_ppgtt_mm(struct intel_vgpu *vgpu,
                enum intel_gvt_gtt_type root_entry_type, u64 pdps[])
{
        struct intel_vgpu_mm *mm;

        mm = intel_vgpu_find_ppgtt_mm(vgpu, pdps);
        if (mm) {
                intel_vgpu_mm_get(mm);
        } else {
                mm = intel_vgpu_create_ppgtt_mm(vgpu, root_entry_type, pdps);
                if (IS_ERR(mm))
                        gvt_vgpu_err("fail to create mm\n");
        }
        return mm;
}

/**
 * intel_vgpu_put_ppgtt_mm - find and put a PPGTT mm object.
 * @vgpu: a vGPU
 * @pdps: guest pdps
 *
 * This function is used to find a PPGTT mm object from a guest and destroy it.
 *
 * Returns:
 * Zero on success, negative error code if failed.
 */
int intel_vgpu_put_ppgtt_mm(struct intel_vgpu *vgpu, u64 pdps[])
{
        struct intel_vgpu_mm *mm;

        mm = intel_vgpu_find_ppgtt_mm(vgpu, pdps);
        if (!mm) {
                gvt_vgpu_err("fail to find ppgtt instance.\n");
                return -EINVAL;
        }
        intel_vgpu_mm_put(mm);
        return 0;
}

/**
 * intel_gvt_init_gtt - initialize mm components of a GVT device
 * @gvt: GVT device
 *
 * This function is called at the initialization stage, to initialize
 * the mm components of a GVT device.
 *
 * Returns:
 * zero on success, negative error code if failed.
 */
int intel_gvt_init_gtt(struct intel_gvt *gvt)
{
        int ret;
        void *page;
        struct device *dev = gvt->gt->i915->drm.dev;
        dma_addr_t daddr;

        gvt_dbg_core("init gtt\n");

        gvt->gtt.pte_ops = &gen8_gtt_pte_ops;
        gvt->gtt.gma_ops = &gen8_gtt_gma_ops;

        page = (void *)get_zeroed_page(GFP_KERNEL);
        if (!page) {
                gvt_err("fail to allocate scratch ggtt page\n");
                return -ENOMEM;
        }

        daddr = dma_map_page(dev, virt_to_page(page), 0,
                        4096, DMA_BIDIRECTIONAL);
        if (dma_mapping_error(dev, daddr)) {
                gvt_err("fail to dmamap scratch ggtt page\n");
                __free_page(virt_to_page(page));
                return -ENOMEM;
        }

        gvt->gtt.scratch_page = virt_to_page(page);
        gvt->gtt.scratch_mfn = (unsigned long)(daddr >> I915_GTT_PAGE_SHIFT);

        if (enable_out_of_sync) {
                ret = setup_spt_oos(gvt);
                if (ret) {
                        gvt_err("fail to initialize SPT oos\n");
                        dma_unmap_page(dev, daddr, 4096, DMA_BIDIRECTIONAL);
                        __free_page(gvt->gtt.scratch_page);
                        return ret;
                }
        }
        INIT_LIST_HEAD(&gvt->gtt.ppgtt_mm_lru_list_head);
        mutex_init(&gvt->gtt.ppgtt_mm_lock);
        return 0;
}

/**
 * intel_gvt_clean_gtt - clean up mm components of a GVT device
 * @gvt: GVT device
 *
 * This function is called at the driver unloading stage, to clean up
 * the mm components of a GVT device.
 *
 */
void intel_gvt_clean_gtt(struct intel_gvt *gvt)
{
        struct device *dev = gvt->gt->i915->drm.dev;
        dma_addr_t daddr = (dma_addr_t)(gvt->gtt.scratch_mfn <<
                                        I915_GTT_PAGE_SHIFT);

        dma_unmap_page(dev, daddr, 4096, DMA_BIDIRECTIONAL);

        __free_page(gvt->gtt.scratch_page);

        if (enable_out_of_sync)
                clean_spt_oos(gvt);
}

/**
 * intel_vgpu_invalidate_ppgtt - invalidate PPGTT instances
 * @vgpu: a vGPU
 *
 * This function is called when invalidate all PPGTT instances of a vGPU.
 *
 */
void intel_vgpu_invalidate_ppgtt(struct intel_vgpu *vgpu)
{
        struct list_head *pos, *n;
        struct intel_vgpu_mm *mm;

        list_for_each_safe(pos, n, &vgpu->gtt.ppgtt_mm_list_head) {
                mm = container_of(pos, struct intel_vgpu_mm, ppgtt_mm.list);
                if (mm->type == INTEL_GVT_MM_PPGTT) {
                        mutex_lock(&vgpu->gvt->gtt.ppgtt_mm_lock);
                        list_del_init(&mm->ppgtt_mm.lru_list);
                        mutex_unlock(&vgpu->gvt->gtt.ppgtt_mm_lock);
                        if (mm->ppgtt_mm.shadowed)
                                invalidate_ppgtt_mm(mm);
                }
        }
}

/**
 * intel_vgpu_reset_ggtt - reset the GGTT entry
 * @vgpu: a vGPU
 * @invalidate_old: invalidate old entries
 *
 * This function is called at the vGPU create stage
 * to reset all the GGTT entries.
 *
 */
void intel_vgpu_reset_ggtt(struct intel_vgpu *vgpu, bool invalidate_old)
{
        struct intel_gvt *gvt = vgpu->gvt;
        const struct intel_gvt_gtt_pte_ops *pte_ops = vgpu->gvt->gtt.pte_ops;
        struct intel_gvt_gtt_entry entry = {.type = GTT_TYPE_GGTT_PTE};
        struct intel_gvt_gtt_entry old_entry;
        u32 index;
        u32 num_entries;

        pte_ops->set_pfn(&entry, gvt->gtt.scratch_mfn);
        pte_ops->set_present(&entry);

        index = vgpu_aperture_gmadr_base(vgpu) >> PAGE_SHIFT;
        num_entries = vgpu_aperture_sz(vgpu) >> PAGE_SHIFT;
        while (num_entries--) {
                if (invalidate_old) {
                        ggtt_get_host_entry(vgpu->gtt.ggtt_mm, &old_entry, index);
                        ggtt_invalidate_pte(vgpu, &old_entry);
                }
                ggtt_set_host_entry(vgpu->gtt.ggtt_mm, &entry, index++);
        }

        index = vgpu_hidden_gmadr_base(vgpu) >> PAGE_SHIFT;
        num_entries = vgpu_hidden_sz(vgpu) >> PAGE_SHIFT;
        while (num_entries--) {
                if (invalidate_old) {
                        ggtt_get_host_entry(vgpu->gtt.ggtt_mm, &old_entry, index);
                        ggtt_invalidate_pte(vgpu, &old_entry);
                }
                ggtt_set_host_entry(vgpu->gtt.ggtt_mm, &entry, index++);
        }

        ggtt_invalidate(gvt->gt);
}

/**
 * intel_gvt_restore_ggtt - restore all vGPU's ggtt entries
 * @gvt: intel gvt device
 *
 * This function is called at driver resume stage to restore
 * GGTT entries of every vGPU.
 *
 */
void intel_gvt_restore_ggtt(struct intel_gvt *gvt)
{
        struct intel_vgpu *vgpu;
        struct intel_vgpu_mm *mm;
        int id;
        gen8_pte_t pte;
        u32 idx, num_low, num_hi, offset;

        /* Restore dirty host ggtt for all vGPUs */
        idr_for_each_entry(&(gvt)->vgpu_idr, vgpu, id) {
                mm = vgpu->gtt.ggtt_mm;

                num_low = vgpu_aperture_sz(vgpu) >> PAGE_SHIFT;
                offset = vgpu_aperture_gmadr_base(vgpu) >> PAGE_SHIFT;
                for (idx = 0; idx < num_low; idx++) {
                        pte = mm->ggtt_mm.host_ggtt_aperture[idx];
                        if (pte & GEN8_PAGE_PRESENT)
                                write_pte64(vgpu->gvt->gt->ggtt, offset + idx, pte);
                }

                num_hi = vgpu_hidden_sz(vgpu) >> PAGE_SHIFT;
                offset = vgpu_hidden_gmadr_base(vgpu) >> PAGE_SHIFT;
                for (idx = 0; idx < num_hi; idx++) {
                        pte = mm->ggtt_mm.host_ggtt_hidden[idx];
                        if (pte & GEN8_PAGE_PRESENT)
                                write_pte64(vgpu->gvt->gt->ggtt, offset + idx, pte);
                }
        }
}