drm/i915/gvt: vGPU graphics memory virtualization

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: Zhi Wang <zhi.a.wang@intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/gvt/hypercall.h b/drivers/gpu/drm/i915/gvt/hypercall.h
index f43614eb3b14..67d8b1a26e73 100644
--- a/drivers/gpu/drm/i915/gvt/hypercall.h
+++ b/drivers/gpu/drm/i915/gvt/hypercall.h
@@ -42,6 +42,14 @@ struct intel_gvt_mpt {
 	int (*attach_vgpu)(void *vgpu, unsigned long *handle);
 	void (*detach_vgpu)(unsigned long handle);
 	int (*inject_msi)(unsigned long handle, u32 addr, u16 data);
+	unsigned long (*from_virt_to_mfn)(void *p);
+	int (*set_wp_page)(unsigned long handle, u64 gfn);
+	int (*unset_wp_page)(unsigned long handle, u64 gfn);
+	int (*read_gpa)(unsigned long handle, unsigned long gpa, void *buf,
+			unsigned long len);
+	int (*write_gpa)(unsigned long handle, unsigned long gpa, void *buf,
+			 unsigned long len);
+	unsigned long (*gfn_to_mfn)(unsigned long handle, unsigned long gfn);
 };
 
 extern struct intel_gvt_mpt xengt_mpt;