• Ping Gao's avatar
    drm/i915/gvt: implement scratch page table tree for shadow PPGTT · 3b6411c2
    Ping Gao authored
    All the unused entries in the page table tree(PML4E->PDPE->PDE->PTE)
    should point to scratch page table/scratch page to avoid page walk error
    due to the page prefetching.
    When removing an entry in shadow PPGTT,  it need map to scratch page
    also, the older implementation use single scratch page to assign to all
    level entries, it doesn't align the page walk behavior when removed
    entry is in PML, PDP, PD.  To avoid potential page walk error this patch
    implement a scratch page tree to replace the single scratch page.
    
    v2: more details in commit message address Kevin's comments.
    Signed-off-by: default avatarPing Gao <ping.a.gao@intel.com>
    Signed-off-by: default avatarZhenyu Wang <zhenyuw@linux.intel.com>
    3b6411c2
gtt.c 57.4 KB