OvmfPkg/QemuBootOrderLib: add StoreQemuBootOrder()

The function reads the boot order from qemu fw_cfg, translates it into
device paths and stores them in 'QemuBootOrderNNNN' variables.  In case
there is no boot ordering configured the function will do nothing.

Use case: Allow applications loaded via 'qemu -kernel bootloader.efi'
obey the boot order.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>

5 files changed, 143 insertions, 0 deletions

diff --git a/OvmfPkg/Include/Library/QemuBootOrderLib.h b/OvmfPkg/Include/Library/QemuBootOrderLib.h
index 9f06439aed..f0369298a1 100644
--- a/OvmfPkg/Include/Library/QemuBootOrderLib.h
+++ b/OvmfPkg/Include/Library/QemuBootOrderLib.h
@@ -48,6 +48,20 @@ ConnectDevicesFromQemu (
   );

 

 /**

+  Write qemu boot order to uefi variables.

+

+  Attempt to retrieve the "bootorder" fw_cfg file from QEMU. Translate

+  the OpenFirmware device paths therein to UEFI device path fragments.

+

+  On Success store the device path in QemuBootOrderNNNN variables.

+**/

+VOID

+EFIAPI

+StoreQemuBootOrder (

+  VOID

+  );

+

+/**

 

   Set the boot order based on configuration retrieved from QEMU.

 

diff --git a/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c b/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c
index 51016a5548..98f6f07341 100644
--- a/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c
+++ b/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c
@@ -1695,6 +1695,11 @@ PlatformBootManagerAfterConsole (
   PciAcpiInitialization ();

 

   //

+  // Write qemu bootorder to efi variables

+  //

+  StoreQemuBootOrder ();

+

+  //

   // Process QEMU's -kernel command line option

   //

   TryRunningQemuKernel ();

diff --git a/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c b/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c
index 67d29ac642..398de7fab4 100644
--- a/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c
+++ b/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c
@@ -1687,6 +1687,128 @@ FreeFwCfg:
 }

 

 /**

+  Write qemu boot order to uefi variables.

+

+  Attempt to retrieve the "bootorder" fw_cfg file from QEMU. Translate

+  the OpenFirmware device paths therein to UEFI device path fragments.

+

+  On Success store the device path in QemuBootOrderNNNN variables.

+**/

+VOID

+EFIAPI

+StoreQemuBootOrder (

+  VOID

+  )

+{

+  RETURN_STATUS         Status;

+  FIRMWARE_CONFIG_ITEM  FwCfgItem;

+  UINTN                 FwCfgSize;

+  CHAR8                 *FwCfg;

+  EFI_STATUS            EfiStatus;

+  EXTRA_ROOT_BUS_MAP    *ExtraPciRoots;

+  CONST CHAR8           *FwCfgPtr;

+  UINTN                 TranslatedSize;

+  CHAR16                Translated[TRANSLATION_OUTPUT_SIZE];

+  UINTN                 VariableIndex = 0;

+  CHAR16                VariableName[20];

+

+  Status = QemuFwCfgFindFile ("bootorder", &FwCfgItem, &FwCfgSize);

+  if (RETURN_ERROR (Status)) {

+    return;

+  }

+

+  if (FwCfgSize == 0) {

+    return;

+  }

+

+  FwCfg = AllocatePool (FwCfgSize);

+  if (FwCfg == NULL) {

+    return;

+  }

+

+  QemuFwCfgSelectItem (FwCfgItem);

+  QemuFwCfgReadBytes (FwCfgSize, FwCfg);

+  if (FwCfg[FwCfgSize - 1] != '\0') {

+    Status = RETURN_INVALID_PARAMETER;

+    goto FreeFwCfg;

+  }

+

+  DEBUG ((DEBUG_VERBOSE, "%a: FwCfg:\n", __FUNCTION__));

+  DEBUG ((DEBUG_VERBOSE, "%a\n", FwCfg));

+  DEBUG ((DEBUG_VERBOSE, "%a: FwCfg: <end>\n", __FUNCTION__));

+

+  if (FeaturePcdGet (PcdQemuBootOrderPciTranslation)) {

+    EfiStatus = CreateExtraRootBusMap (&ExtraPciRoots);

+    if (EFI_ERROR (EfiStatus)) {

+      Status = (RETURN_STATUS)EfiStatus;

+      goto FreeFwCfg;

+    }

+  } else {

+    ExtraPciRoots = NULL;

+  }

+

+  //

+  // Translate each OpenFirmware path to a UEFI devpath prefix.

+  //

+  FwCfgPtr       = FwCfg;

+  TranslatedSize = ARRAY_SIZE (Translated);

+  Status         = TranslateOfwPath (

+                     &FwCfgPtr,

+                     ExtraPciRoots,

+                     Translated,

+                     &TranslatedSize

+                     );

+  while (!RETURN_ERROR (Status)) {

+    EFI_DEVICE_PATH_PROTOCOL  *DevicePath;

+

+    //

+    // Convert the UEFI devpath prefix to binary representation.

+    //

+    ASSERT (Translated[TranslatedSize] == L'\0');

+    DevicePath = ConvertTextToDevicePath (Translated);

+    if (DevicePath == NULL) {

+      Status = RETURN_OUT_OF_RESOURCES;

+      goto FreeExtraPciRoots;

+    }

+

+    UnicodeSPrint (

+      VariableName,

+      sizeof (VariableName),

+      L"QemuBootOrder%04d",

+      VariableIndex++

+      );

+    DEBUG ((DEBUG_INFO, "%a: %s = %s\n", __FUNCTION__, VariableName, Translated));

+    gRT->SetVariable (

+           VariableName,

+           &gQemuBootOrderGuid,

+           EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,

+           GetDevicePathSize (DevicePath),

+           DevicePath

+           );

+    FreePool (DevicePath);

+

+    //

+    // Move to the next OFW devpath.

+    //

+    TranslatedSize = ARRAY_SIZE (Translated);

+    Status         = TranslateOfwPath (

+                       &FwCfgPtr,

+                       ExtraPciRoots,

+                       Translated,

+                       &TranslatedSize

+                       );

+  }

+

+FreeExtraPciRoots:

+  if (ExtraPciRoots != NULL) {

+    DestroyExtraRootBusMap (ExtraPciRoots);

+  }

+

+FreeFwCfg:

+  FreePool (FwCfg);

+}

+

+/**

 

   Convert the UEFI DevicePath to full text representation with DevPathToText,

   then match the UEFI device path fragment in Translated against it.

diff --git a/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.inf b/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.inf
index 7c02f04e70..211344fb0b 100644
--- a/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.inf
+++ b/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.inf
@@ -49,6 +49,7 @@
 [Guids]

   gEfiGlobalVariableGuid

   gVirtioMmioTransportGuid

+  gQemuBootOrderGuid

 

 [FeaturePcd]

   gUefiOvmfPkgTokenSpaceGuid.PcdQemuBootOrderPciTranslation

diff --git a/OvmfPkg/OvmfPkg.dec b/OvmfPkg/OvmfPkg.dec
index 5af76a5405..6b1296b15a 100644
--- a/OvmfPkg/OvmfPkg.dec
+++ b/OvmfPkg/OvmfPkg.dec
@@ -146,6 +146,7 @@
   gConfidentialComputingSecretGuid      = {0xadf956ad, 0xe98c, 0x484c, {0xae, 0x11, 0xb5, 0x1c, 0x7d, 0x33, 0x64, 0x47}}

   gConfidentialComputingSevSnpBlobGuid  = {0x067b1f5f, 0xcf26, 0x44c5, {0x85, 0x54, 0x93, 0xd7, 0x77, 0x91, 0x2d, 0x42}}

   gUefiOvmfPkgPlatformInfoGuid          = {0xdec9b486, 0x1f16, 0x47c7, {0x8f, 0x68, 0xdf, 0x1a, 0x41, 0x88, 0x8b, 0xa5}}

+  gQemuBootOrderGuid                    = {0x668f4529, 0x63d0, 0x4bb5, {0xb6, 0x5d, 0x6f, 0xbb, 0x9d, 0x36, 0xa4, 0x4a}}

 

 [Ppis]

   # PPI whose presence in the PPI database signals that the TPM base address