[edk2-devel] [PATCH v3 3/4] OvmfPkg: Don't build in QemuVideoDxe when we have CSM

[David Woodhouse]

QemuVideoDxe installs its own legacy INT 10h handler for the benefit of
systems like Windows 2008r2 which attempt to use INT 10h even when booted
via EFI.

This interacts extremely badly with a CSM actually attempting to install
a real video BIOS.

The last thing done before invoking a legacy OpROM is to call INT 10h to
set a plain text mode. In the case where it's the video BIOS OpROM being
loaded, INT 10h will normally point to an iret stub in the CSM itself.

Unless QemuVideoDxe has changed INT10h to point to a location in the
0xC0000 segment that it didn't allocate properly, so the real OpROM has
been shadowed over them top of it, and the INT 10h vector now points to
some random place in the middle of the newly-shadowed OpROM.

Don't Do That Then. QemuVideoDxe doesn't do any acceleration and just
sets up a linear framebuffer, so we don't lose much by just
unconditionally using BiosVideoDxe instead when CSM is present.

Signed-off-by: David Woodhouse <dwmw2 at infradead.org>
Reviewed-by: Laszlo Ersek <lersek at redhat.com>
---
 OvmfPkg/OvmfPkgIa32.dsc    | 2 ++
 OvmfPkg/OvmfPkgIa32.fdf    | 5 +++--
 OvmfPkg/OvmfPkgIa32X64.dsc | 2 ++
 OvmfPkg/OvmfPkgIa32X64.fdf | 5 +++--
 OvmfPkg/OvmfPkgX64.dsc     | 2 ++
 OvmfPkg/OvmfPkgX64.fdf     | 5 +++--
 6 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
index 473eaba24613..87716123997a 100644
--- a/OvmfPkg/OvmfPkgIa32.dsc
+++ b/OvmfPkg/OvmfPkgIa32.dsc
@@ -738,7 +738,9 @@ [Components]
   MdeModulePkg/Universal/DisplayEngineDxe/DisplayEngineDxe.inf
   MdeModulePkg/Universal/MemoryTest/NullMemoryTestDxe/NullMemoryTestDxe.inf
 
+!ifndef $(CSM_ENABLE)
   OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
+!endif
   OvmfPkg/QemuRamfbDxe/QemuRamfbDxe.inf
   OvmfPkg/VirtioGpuDxe/VirtioGpu.inf
 
diff --git a/OvmfPkg/OvmfPkgIa32.fdf b/OvmfPkg/OvmfPkgIa32.fdf
index 14100356b4f6..785affeb90c8 100644
--- a/OvmfPkg/OvmfPkgIa32.fdf
+++ b/OvmfPkg/OvmfPkgIa32.fdf
@@ -305,9 +305,10 @@ [FV.DXEFV]
 INF  OvmfPkg/Csm/BiosThunk/VideoDxe/VideoDxe.inf
 INF  OvmfPkg/Csm/LegacyBiosDxe/LegacyBiosDxe.inf
 INF  RuleOverride=CSM OvmfPkg/Csm/Csm16/Csm16.inf
-!endif
-
+!else
 INF  OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
+!endif
+
 INF  OvmfPkg/QemuRamfbDxe/QemuRamfbDxe.inf
 INF  OvmfPkg/VirtioGpuDxe/VirtioGpu.inf
 INF  OvmfPkg/PlatformDxe/Platform.inf
diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
index 73f33b721832..639e33cb285f 100644
--- a/OvmfPkg/OvmfPkgIa32X64.dsc
+++ b/OvmfPkg/OvmfPkgIa32X64.dsc
@@ -747,7 +747,9 @@ [Components.X64]
   MdeModulePkg/Universal/DisplayEngineDxe/DisplayEngineDxe.inf
   MdeModulePkg/Universal/MemoryTest/NullMemoryTestDxe/NullMemoryTestDxe.inf
 
+!ifndef $(CSM_ENABLE)
   OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
+!endif
   OvmfPkg/QemuRamfbDxe/QemuRamfbDxe.inf
   OvmfPkg/VirtioGpuDxe/VirtioGpu.inf
 
diff --git a/OvmfPkg/OvmfPkgIa32X64.fdf b/OvmfPkg/OvmfPkgIa32X64.fdf
index 5af3cdc93d20..74407072563b 100644
--- a/OvmfPkg/OvmfPkgIa32X64.fdf
+++ b/OvmfPkg/OvmfPkgIa32X64.fdf
@@ -311,9 +311,10 @@ [FV.DXEFV]
 INF  OvmfPkg/Csm/BiosThunk/VideoDxe/VideoDxe.inf
 INF  OvmfPkg/Csm/LegacyBiosDxe/LegacyBiosDxe.inf
 INF  RuleOverride=CSM OvmfPkg/Csm/Csm16/Csm16.inf
-!endif
-
+!else
 INF  OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
+!endif
+
 INF  OvmfPkg/QemuRamfbDxe/QemuRamfbDxe.inf
 INF  OvmfPkg/VirtioGpuDxe/VirtioGpu.inf
 INF  OvmfPkg/PlatformDxe/Platform.inf
diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
index 39ac79156529..69a3497c2c9e 100644
--- a/OvmfPkg/OvmfPkgX64.dsc
+++ b/OvmfPkg/OvmfPkgX64.dsc
@@ -745,7 +745,9 @@ [Components]
   MdeModulePkg/Universal/DisplayEngineDxe/DisplayEngineDxe.inf
   MdeModulePkg/Universal/MemoryTest/NullMemoryTestDxe/NullMemoryTestDxe.inf
 
+!ifndef $(CSM_ENABLE)
   OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
+!endif
   OvmfPkg/QemuRamfbDxe/QemuRamfbDxe.inf
   OvmfPkg/VirtioGpuDxe/VirtioGpu.inf
 
diff --git a/OvmfPkg/OvmfPkgX64.fdf b/OvmfPkg/OvmfPkgX64.fdf
index 5af3cdc93d20..74407072563b 100644
--- a/OvmfPkg/OvmfPkgX64.fdf
+++ b/OvmfPkg/OvmfPkgX64.fdf
@@ -311,9 +311,10 @@ [FV.DXEFV]
 INF  OvmfPkg/Csm/BiosThunk/VideoDxe/VideoDxe.inf
 INF  OvmfPkg/Csm/LegacyBiosDxe/LegacyBiosDxe.inf
 INF  RuleOverride=CSM OvmfPkg/Csm/Csm16/Csm16.inf
-!endif
-
+!else
 INF  OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
+!endif
+
 INF  OvmfPkg/QemuRamfbDxe/QemuRamfbDxe.inf
 INF  OvmfPkg/VirtioGpuDxe/VirtioGpu.inf
 INF  OvmfPkg/PlatformDxe/Platform.inf
-- 
2.21.0


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