OvmfPkg: use generic QEMU image loader for secure boot enabled builds

The QemuLoadImageLib implementation we currently use for all OVMF
builds copies the behavior of the QEMU loader code that precedes it,
which is to disregard UEFI secure boot policies entirely when it comes
to loading kernel images that have been specified on the QEMU command
line. This behavior deviates from ArmVirtQemu based builds, which do
take UEFI secure boot policies into account, and refuse to load images
from the command line that cannot be authenticated.

The disparity was originally due to the fact that the QEMU command line
kernel loader did not use LoadImage and StartImage at all, but this
changed recently, and now, there are only a couple of reasons left to
stick with the legacy loader:
- it permits loading images that lack a valid PE/COFF header,
- it permits loading X64 kernels on IA32 firmware running on a X64
  capable system.

Since every non-authentic PE/COFF image can trivially be converted into
an image that lacks a valid PE/COFF header, the former case can simply
not be supported in a UEFI secure boot context. The latter case is highly
theoretical, given that one could easily switch to native X64 firmware in
a VM scenario.

That leaves us with little justification to use the legacy loader at all
when UEFI secure boot policies are in effect, so let's switch to the
generic loader for UEFI secure boot enabled builds.

Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=2566
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>

diff --git a/OvmfPkg/OvmfPkgIa32.dsc b/OvmfPkg/OvmfPkgIa32.dsc
index ec21d2f3f6cbe561bfc7560a6921ceb844c74440..8916255df4dff3149be8b4bc4bfb9268e165de1d 100644 (file)
--- a/OvmfPkg/OvmfPkgIa32.dsc
+++ b/OvmfPkg/OvmfPkgIa32.dsc
@@ -363,7 +363,11 @@
   PciLib|OvmfPkg/Library/DxePciLibI440FxQ35/DxePciLibI440FxQ35.inf\r
   MpInitLib|UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf\r
   QemuFwCfgS3Lib|OvmfPkg/Library/QemuFwCfgS3Lib/DxeQemuFwCfgS3LibFwCfg.inf\r
+!if $(SECURE_BOOT_ENABLE) == TRUE\r
+  QemuLoadImageLib|OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.inf\r
+!else\r
   QemuLoadImageLib|OvmfPkg/Library/X86QemuLoadImageLib/X86QemuLoadImageLib.inf\r
+!endif\r
 !if $(TPM_ENABLE) == TRUE\r
   Tpm12DeviceLib|SecurityPkg/Library/Tpm12DeviceLibTcg/Tpm12DeviceLibTcg.inf\r
   Tpm2DeviceLib|SecurityPkg/Library/Tpm2DeviceLibTcg2/Tpm2DeviceLibTcg2.inf\r

diff --git a/OvmfPkg/OvmfPkgIa32X64.dsc b/OvmfPkg/OvmfPkgIa32X64.dsc
index 3c80a18c608628f3662e768c80fdd7848c5028e0..342ff96cc2798b36162c9f5de72019b3928de283 100644 (file)
--- a/OvmfPkg/OvmfPkgIa32X64.dsc
+++ b/OvmfPkg/OvmfPkgIa32X64.dsc
@@ -367,7 +367,11 @@
   PciLib|OvmfPkg/Library/DxePciLibI440FxQ35/DxePciLibI440FxQ35.inf\r
   MpInitLib|UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf\r
   QemuFwCfgS3Lib|OvmfPkg/Library/QemuFwCfgS3Lib/DxeQemuFwCfgS3LibFwCfg.inf\r
+!if $(SECURE_BOOT_ENABLE) == TRUE\r
+  QemuLoadImageLib|OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.inf\r
+!else\r
   QemuLoadImageLib|OvmfPkg/Library/X86QemuLoadImageLib/X86QemuLoadImageLib.inf\r
+!endif\r
 !if $(TPM_ENABLE) == TRUE\r
   Tpm12DeviceLib|SecurityPkg/Library/Tpm12DeviceLibTcg/Tpm12DeviceLibTcg.inf\r
   Tpm2DeviceLib|SecurityPkg/Library/Tpm2DeviceLibTcg2/Tpm2DeviceLibTcg2.inf\r

diff --git a/OvmfPkg/OvmfPkgX64.dsc b/OvmfPkg/OvmfPkgX64.dsc
index 63f1f935f4f3547a8bc88e486ca7308ae94cf857..1fb2de5e01213e423431e6b55b490f3f4065c962 100644 (file)
--- a/OvmfPkg/OvmfPkgX64.dsc
+++ b/OvmfPkg/OvmfPkgX64.dsc
@@ -367,7 +367,11 @@
   PciLib|OvmfPkg/Library/DxePciLibI440FxQ35/DxePciLibI440FxQ35.inf\r
   MpInitLib|UefiCpuPkg/Library/MpInitLib/DxeMpInitLib.inf\r
   QemuFwCfgS3Lib|OvmfPkg/Library/QemuFwCfgS3Lib/DxeQemuFwCfgS3LibFwCfg.inf\r
+!if $(SECURE_BOOT_ENABLE) == TRUE\r
+  QemuLoadImageLib|OvmfPkg/Library/GenericQemuLoadImageLib/GenericQemuLoadImageLib.inf\r
+!else\r
   QemuLoadImageLib|OvmfPkg/Library/X86QemuLoadImageLib/X86QemuLoadImageLib.inf\r
+!endif\r
 !if $(TPM_ENABLE) == TRUE\r
   Tpm12DeviceLib|SecurityPkg/Library/Tpm12DeviceLibTcg/Tpm12DeviceLibTcg.inf\r
   Tpm2DeviceLib|SecurityPkg/Library/Tpm2DeviceLibTcg2/Tpm2DeviceLibTcg2.inf\r