Acked-by: Brian J. Johnson <brian.john...@hpe.com>
-----Original Message-----
From: edk2-devel [mailto:edk2-devel-boun...@lists.01.org] On Behalf Of Wang,
Jian J
Sent: Wednesday, September 13, 2017 4:25 AM
To: edk2-devel@lists.01.org
Cc: jus...@ml01.01.org; Eric Dong <eric.d...@intel.com>; kin...@ml01.01.org;
Jordan L <jordan.l.jus...@intel.com>; wol...@ml01.01.org; Jiewen Yao
<jiewen....@intel.com>; Ayellet <ayellet.wol...@intel.com>; Michael D
<michael.d.kin...@intel.com>; Laszlo Ersek <ler...@redhat.com>; Star Zeng
<star.z...@intel.com>
Subject: [edk2] [PATCH 4/4] OvmfPkg/QemuVideoDxe: Update QemuVideoDxe driver to
bypass NULL pointer detection if enabled.
QemuVideoDxe driver will install VBE SHIM into page 0. If NULL pointer
detection is enabled, page 0 must be enabled temporarily before installing and
disabled again afterwards. For Windows 7 boot, BIT7 of
PcdNullPointerDetectionPropertyMask must still be set to avoid hang.
Cc: Jiewen Yao <jiewen....@intel.com>
Cc: Eric Dong <eric.d...@intel.com>
Cc: Star Zeng <star.z...@intel.com>
Cc: Laszlo Ersek <ler...@redhat.com>
Cc: Justen, Jordan L <jordan.l.jus...@intel.com>
Cc: Kinney, Michael D <michael.d.kin...@intel.com>
Cc: Wolman, Ayellet <ayellet.wol...@intel.com>
Suggested-by: Wolman, Ayellet <ayellet.wol...@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Wang, Jian J <jian.j.w...@intel.com>
---
OvmfPkg/QemuVideoDxe/Driver.c | 15 ++++++++++++++-
OvmfPkg/QemuVideoDxe/Qemu.h | 16 ++++++++++++++++
OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf | 2 ++
3 files changed, 32 insertions(+), 1 deletion(-)
diff --git a/OvmfPkg/QemuVideoDxe/Driver.c b/OvmfPkg/QemuVideoDxe/Driver.c
index 0dce80e59b..ee0eed7214 100644
--- a/OvmfPkg/QemuVideoDxe/Driver.c
+++ b/OvmfPkg/QemuVideoDxe/Driver.c
@@ -194,6 +194,7 @@ QemuVideoControllerDriverStart (
PCI_TYPE00 Pci;
QEMU_VIDEO_CARD *Card;
EFI_PCI_IO_PROTOCOL *ChildPciIo;
+ EFI_CPU_ARCH_PROTOCOL *Cpu;
OldTpl = gBS->RaiseTPL (TPL_CALLBACK);
@@ -479,7 +480,19 @@ QemuVideoControllerDriverStart (
#if defined MDE_CPU_IA32 || defined MDE_CPU_X64
if (Private->Variant == QEMU_VIDEO_BOCHS_MMIO ||
Private->Variant == QEMU_VIDEO_BOCHS) {
- InstallVbeShim (Card->Name, Private->GraphicsOutput.Mode->FrameBufferBase);
+ //
+ // Prepare CPU arch protocol for NULL pointer detection
+ //
+ Status = gBS->LocateProtocol (
+ &gEfiCpuArchProtocolGuid,
+ NULL,
+ (VOID **) &Cpu
+ );
+ ASSERT_EFI_ERROR (Status);
+
+ DISABLE_NULL_DETECTION(Cpu);
+ InstallVbeShim (Card->Name,
Private->GraphicsOutput.Mode->FrameBufferBase);
+ ENABLE_NULL_DETECTION(Cpu);
}
#endif
diff --git a/OvmfPkg/QemuVideoDxe/Qemu.h b/OvmfPkg/QemuVideoDxe/Qemu.h
index 7fbb25b3ef..bb3bc6eb0f 100644
--- a/OvmfPkg/QemuVideoDxe/Qemu.h
+++ b/OvmfPkg/QemuVideoDxe/Qemu.h
@@ -25,6 +25,7 @@
#include <Protocol/PciIo.h>
#include <Protocol/DriverSupportedEfiVersion.h>
#include <Protocol/DevicePath.h>
+#include <Protocol/Cpu.h>
#include <Library/DebugLib.h>
#include <Library/UefiDriverEntryPoint.h>
@@ -82,6 +83,21 @@ typedef struct {
#define GRAPHICS_OUTPUT_INVALIDE_MODE_NUMBER 0xffff
+//
+// VBE code will access memory between 0-4095 which will cause page fault
exception
+// if NULL pointer detection mechanism is enabled. Following macros can be
used to
+// disable/enable NULL pointer detection before/after accessing those memory.
+//
+#define NULL_DETECTION_ENABLED ((PcdGet8(PcdNullPointerDetectionPropertyMask)
& (BIT0|BIT7)) == BIT0)
+#define DISABLE_NULL_DETECTION(Cpu)
\
+ if (NULL_DETECTION_ENABLED) {
\
+ (Cpu)->SetMemoryAttributes((Cpu), 0, EFI_PAGE_SIZE, 0);
\
+ }
+#define ENABLE_NULL_DETECTION(Cpu)
\
+ if (NULL_DETECTION_ENABLED) {
\
+ (Cpu)->SetMemoryAttributes((Cpu), 0, EFI_PAGE_SIZE, EFI_MEMORY_RP);
\
+ }
+
//
// QEMU Video Private Data Structure
//
diff --git a/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
b/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
index 7c7d429bca..5d166eb99c 100644
--- a/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
+++ b/OvmfPkg/QemuVideoDxe/QemuVideoDxe.inf
@@ -72,7 +72,9 @@
gEfiGraphicsOutputProtocolGuid # PROTOCOL BY_START
gEfiDevicePathProtocolGuid # PROTOCOL BY_START
gEfiPciIoProtocolGuid # PROTOCOL TO_START
+ gEfiCpuArchProtocolGuid
[Pcd]
gOptionRomPkgTokenSpaceGuid.PcdDriverSupportedEfiVersion
+ gEfiMdeModulePkgTokenSpaceGuid.PcdNullPointerDetectionPropertyMask
--
2.14.1.windows.1
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