[PATCH 0/2] OvmfPkg/QemuBootOrderLib: StoreQemuBootOrder bugfix

[PATCH 0/2] OvmfPkg/QemuBootOrderLib: StoreQemuBootOrder bugfix

[Gerd Hoffmann]

Gerd Hoffmann (2):
  OvmfPkg/QemuBootOrderLib: allow slash in rom filenames
  OvmfPkg/QemuBootOrderLib: skip over unsupported entries in
    StoreQemuBootOrder

 .../QemuBootOrderLib/QemuBootOrderLib.c       | 75 ++++++++++++-------
 1 file changed, 48 insertions(+), 27 deletions(-)

-- 
2.37.3

[PATCH 1/2] OvmfPkg/QemuBootOrderLib: allow slash in rom filenames

[Gerd Hoffmann]

See comment for details.  Needed to avoid the parser abort,
so we can continue parsing the bootorder fw_cfg file.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 .../QemuBootOrderLib/QemuBootOrderLib.c       | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c b/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c
index 398de7fab4ba..374c6d8f5e91 100644
--- a/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c
+++ b/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c
@@ -432,6 +432,8 @@ ParseOfwNode (
   OUT     BOOLEAN      *IsFinal
   )
 {
+  BOOLEAN  AcceptSlash = FALSE;
+
   //
   // A leading slash is expected. End of string is tolerated.
   //
@@ -464,6 +466,21 @@ ParseOfwNode (
     return RETURN_INVALID_PARAMETER;
   }
 
+  if (SubstringEq (OfwNode->DriverName, "rom")) {
+    //
+    // bug compatibility hack
+    //
+    // qemu passes fw_cfg filenames as rom unit address.
+    // The filenames have slashes:
+    //      /rom@genroms/linuxboot_dma.bin
+    //
+    // Alow slashes in the unit address to avoid the parser trip up,
+    // so we can successfully parse the following lines (the rom
+    // entries themself are ignored).
+    //
+    AcceptSlash = TRUE;
+  }
+
   //
   // unit-address
   //
@@ -475,7 +492,7 @@ ParseOfwNode (
 
   OfwNode->UnitAddress.Ptr = *Ptr;
   OfwNode->UnitAddress.Len = 0;
-  while (IsPrintNotDelim (**Ptr)) {
+  while (IsPrintNotDelim (**Ptr) || (AcceptSlash && **Ptr == '/')) {
     ++*Ptr;
     ++OfwNode->UnitAddress.Len;
   }
-- 
2.37.3

[PATCH 2/2] OvmfPkg/QemuBootOrderLib: skip over unsupported entries in StoreQemuBootOrder

[Gerd Hoffmann]

When finding an unsupported entry just skip over and continue
with the next entry instead of stop processing altogether.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 .../QemuBootOrderLib/QemuBootOrderLib.c       | 56 ++++++++++---------
 1 file changed, 30 insertions(+), 26 deletions(-)

diff --git a/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c b/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c
index 374c6d8f5e91..18646daa67e3 100644
--- a/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c
+++ b/OvmfPkg/Library/QemuBootOrderLib/QemuBootOrderLib.c
@@ -1775,35 +1775,39 @@ StoreQemuBootOrder (
                      Translated,
                      &TranslatedSize
                      );
-  while (!RETURN_ERROR (Status)) {
-    EFI_DEVICE_PATH_PROTOCOL  *DevicePath;
+  while (Status == EFI_SUCCESS ||
+         Status == EFI_UNSUPPORTED)
+  {
+    if (Status == EFI_SUCCESS) {
+      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;
+      //
+      // 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);
     }
 
-    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.
     //
-- 
2.37.3

Re: [PATCH 0/2] OvmfPkg/QemuBootOrderLib: StoreQemuBootOrder bugfix

[Ard Biesheuvel]

On Wed, 21 Sept 2022 at 07:30, Gerd Hoffmann <kraxel@redhat.com> wrote:
>
>
>
> Gerd Hoffmann (2):
>   OvmfPkg/QemuBootOrderLib: allow slash in rom filenames
>   OvmfPkg/QemuBootOrderLib: skip over unsupported entries in
>     StoreQemuBootOrder
>

Reviewed-by: Ard Biesheuvel <ardb@kernel.org>

Merged as #3425