On guest writing a PPGTT entry, if it contains value and the old
entry is valid, gvt will read it and find & free the corresponding
old data for it. However, with the KVM write protection provided
by page_track, the guest entry will be written with new value
before gvt handling. To avoid that, we should use the shadow
entry instead.
Signed-off-by: NBing Niu <bing.niu@intel.com>
Signed-off-by: NJike Song <jike.song@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

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: NPing Gao <ping.a.gao@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

It is better to use %p format for void pointers instead of casting them
because a void* is not necessary a 64 bits value.
Signed-off-by: NJérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Since ioread32 returns a 32-bit value, it is impossible to left-shift
this value by 32 bits (it produces a compilation error). Casting the
return value of ioread32 fix this issue.
Signed-off-by: NJérémy Lefaure <jeremy.lefaure@lse.epita.fr>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Function create_scratch_page() may fail in some cases.
Signed-off-by: NDu, Changbin <changbin.du@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

The function return values should has type int if it return
a integer value.
Signed-off-by: NDu, Changbin <changbin.du@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Mark all local functions & variables as static.
Signed-off-by: NDu, Changbin <changbin.du@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

Add proper __iomem annotation for pointers obtained via ioremap().
Signed-off-by: NDu, Changbin <changbin.du@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

i915 core should only call functions and structures exposed through
intel_gvt.h. Remove internal gvt.h and i915_pvinfo.h.

Change for internal intel_gvt structure as private handler which
not requires to expose gvt internal structure for i915 core.

v2: Fix per Chris's comment
- carefully handle dev_priv->gvt assignment
- add necessary bracket for macro helper
- forward declartion struct intel_gvt
- keep free operation within same file handling alloc

v3: fix use after free and remove intel_gvt.initialized

v4: change to_gvt() to an inline
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>

The vGPU graphics memory emulation framework is responsible for graphics
memory table virtualization. Under virtualization environment, a VM will
populate the page table entry with guest page frame number(GPFN/GFN), while
HW needs a page table filled with MFN(Machine frame number). The
relationship between GFN and MFN(Machine frame number) is managed by
hypervisor, while GEN HW doesn't have such knowledge to translate a GFN.

To solve this gap, shadow GGTT/PPGTT page table is introdcued.

For GGTT, the GFN inside the guest GGTT page table entry will be translated
into MFN and written into physical GTT MMIO registers when guest write
virtual GTT MMIO registers.

For PPGTT, a shadow PPGTT page table will be created and write-protected
translated from guest PPGTT page table.  And the shadow page table root
pointers will be written into the shadow context after a guest workload
is shadowed.

vGPU graphics memory emulation framework consists:

- Per-GEN HW platform page table entry bits extract/de-extract routines.
- GTT MMIO register emulation handlers, which will call hypercall to do
GFN->MFN translation when guest write GTT MMIO register
- PPGTT shadow page table routines, e.g. shadow create/destroy/out-of-sync
Signed-off-by: NZhi Wang <zhi.a.wang@intel.com>
Signed-off-by: NZhenyu Wang <zhenyuw@linux.intel.com>