[PATCH v3] OvmfPkg: simply use the Bochs interface for vmsvga

[yuchenlin@synology.com]

From: yuchenlin <yuchenlin@synology.com>

BAR  |    std vga     |  vmsvga
---------------------------------
0    |   Framebuffer  | I/O space
1    |   Reserved     | Framebuffer
2    |   MMIO         | FIFO

- We cannot recognize VMW SVGA as BOCHS because that would confuse the
  IsQxl setting in QemuVideoControllerDriverStart(),

- We cannot recognize VMW SVGA as BOCHS_MMIO because BAR2 on VMW SVGA is
  not the BOCHS MMIO BAR (we can only use port IO).

Therefore the list of reasons for which we should introduce
QEMU_VIDEO_VMWARE_SVGA should name three reasons:

 (1) Get framebuffer from correct PCI BAR
 (2) Prevent using BAR2 for MMIO
 (3) Prevent mis-recognizing VMW SVGA as QXL

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: yuchenlin <yuchenlin@synology.com>
---
Changelog:

v1 -> v2
* use 'else' clause (Thanks Philippe).
* add more comment in revert patches (Thanks Philippe).
* reorder the revert patches, we should revert the last commit first.
* use correct framebuffer to ClearScreen.
* revert VMWare svga definitions.

v2 -> v3
* Update commit message (Thanks Laszlo)
* Treat QEMU_VIDEO_VMWARE_SVGA as QEMU_VIDEO_BOCHS (Thanks Laszlo)

---
 OvmfPkg/QemuVideoDxe/Driver.c | 16 +++++++++++++++-
 OvmfPkg/QemuVideoDxe/Gop.c    |  2 +-
 OvmfPkg/QemuVideoDxe/Qemu.h   |  2 ++
 3 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/OvmfPkg/QemuVideoDxe/Driver.c b/OvmfPkg/QemuVideoDxe/Driver.c
index 2304afd1e6..8e02700d39 100644
--- a/OvmfPkg/QemuVideoDxe/Driver.c
+++ b/OvmfPkg/QemuVideoDxe/Driver.c
@@ -69,6 +69,12 @@ QEMU_VIDEO_CARD gQemuVideoCardList[] = {
         0x1050,
         QEMU_VIDEO_BOCHS_MMIO,
         L"QEMU VirtIO VGA"
+    },{
+        PCI_CLASS_DISPLAY_VGA,
+        0x15ad,
+        0x0405,
+        QEMU_VIDEO_VMWARE_SVGA,
+        L"QEMU VMWare SVGA"
     },{
         0 /* end of list */
     }
@@ -316,6 +322,14 @@ QemuVideoControllerDriverStart (
     }
   }
 
+  //
+  // VMWare SVGA is handled like Bochs (with port IO only).
+  //
+  if (Private->Variant == QEMU_VIDEO_VMWARE_SVGA) {
+    Private->Variant = QEMU_VIDEO_BOCHS;
+    Private->FrameBufferVramBarIndex = PCI_BAR_IDX1;
+  }
+
   //
   // Check if accessing the bochs interface works.
   //
@@ -764,7 +778,7 @@ ClearScreen (
   Private->PciIo->Mem.Write (
                         Private->PciIo,
                         EfiPciIoWidthFillUint32,
-                        0,
+                        Private->FrameBufferVramBarIndex,
                         0,
                         0x400000 >> 2,
                         &Color
diff --git a/OvmfPkg/QemuVideoDxe/Gop.c b/OvmfPkg/QemuVideoDxe/Gop.c
index d490fa7a2e..6f542d9eac 100644
--- a/OvmfPkg/QemuVideoDxe/Gop.c
+++ b/OvmfPkg/QemuVideoDxe/Gop.c
@@ -60,7 +60,7 @@ QemuVideoCompleteModeData (
 
   Private->PciIo->GetBarAttributes (
                         Private->PciIo,
-                        0,
+                        Private->FrameBufferVramBarIndex,
                         NULL,
                         (VOID**) &FrameBufDesc
                         );
diff --git a/OvmfPkg/QemuVideoDxe/Qemu.h b/OvmfPkg/QemuVideoDxe/Qemu.h
index d7da761705..3aac9eeca6 100644
--- a/OvmfPkg/QemuVideoDxe/Qemu.h
+++ b/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 {
@@ -120,6 +121,7 @@ typedef struct {
   QEMU_VIDEO_VARIANT                    Variant;
   FRAME_BUFFER_CONFIGURE                *FrameBufferBltConfigure;
   UINTN                                 FrameBufferBltConfigureSize;
+  UINT8                                 FrameBufferVramBarIndex;
 } QEMU_VIDEO_PRIVATE_DATA;
 
 ///
-- 
2.18.0