Reapply "OvmfPkg/QemuVideoDxe: VMWare SVGA device support"

This reverts commit 98856a724c, reapplying
c137d95081.

Note that the commit now being reverted is technically correct; the only
reason we're reverting it is because it should not have been pushed past
the Soft Feature Freeze for the edk2-stable201811 tag.

Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Julien Grall <julien.grall@linaro.org>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Cc: yuchenlin <yuchenlin@synology.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1319
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: yuchenlin <yuchenlin@synology.com>

OvmfPkg/QemuVideoDxe/Qemu.h

@@ -92,6 +92,7 @@ typedef enum {
   QEMU_VIDEO_CIRRUS_5446,
   QEMU_VIDEO_BOCHS,
   QEMU_VIDEO_BOCHS_MMIO,
+  QEMU_VIDEO_VMWARE_SVGA,
 } QEMU_VIDEO_VARIANT;
 
 typedef struct {
@@ -116,10 +117,13 @@ typedef struct {
   //
   UINTN                                 MaxMode;
   QEMU_VIDEO_MODE_DATA                  *ModeData;
+  EFI_GRAPHICS_OUTPUT_MODE_INFORMATION  *VmwareSvgaModeInfo;
 
   QEMU_VIDEO_VARIANT                    Variant;
   FRAME_BUFFER_CONFIGURE                *FrameBufferBltConfigure;
   UINTN                                 FrameBufferBltConfigureSize;
+  UINT8                                 FrameBufferVramBarIndex;
+  UINT16                                VmwareSvgaBasePort;
 } QEMU_VIDEO_PRIVATE_DATA;
 
 ///
@@ -503,9 +507,34 @@ QemuVideoBochsModeSetup (
   BOOLEAN                  IsQxl
   );
 
+EFI_STATUS
+QemuVideoVmwareSvgaModeSetup (
+  QEMU_VIDEO_PRIVATE_DATA *Private
+  );
+
 VOID
 InstallVbeShim (
   IN CONST CHAR16         *CardName,
   IN EFI_PHYSICAL_ADDRESS FrameBufferBase
   );
+
+VOID
+VmwareSvgaWrite (
+  QEMU_VIDEO_PRIVATE_DATA *Private,
+  UINT16                  Register,
+  UINT32                  Value
+  );
+
+UINT32
+VmwareSvgaRead (
+  QEMU_VIDEO_PRIVATE_DATA *Private,
+  UINT16                  Register
+  );
+
+VOID
+InitializeVmwareSvgaGraphicsMode (
+  QEMU_VIDEO_PRIVATE_DATA  *Private,
+  QEMU_VIDEO_BOCHS_MODES   *ModeData
+  );
+
 #endif