OvmfPkg: SmbiosPlatformDxe: eliminate duplicate entry point validation

At this point all platforms that use OvmfPkg/SmbiosPlatformDxe in edk2,
namely ArmVirtQemu.dsc and OvmfPkg*.dsc, have been migrated to
SmbiosVersionLib. Therefore SmbiosPlatformDxe itself can forego verifying
QEMU's SMBIOS entry point; if SmbiosVersionLib's validation was
successful, it should just rely on that.

(Note that SmbiosPlatformDxe has a depex on EFI_SMBIOS_PROTOCOL, installed
by SmbiosDxe, containing SmbiosVersionLib, therefore the set/get order of
PcdQemuSmbiosValidated is ensured.)

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Wei Huang <wei@redhat.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Gabriel L. Somlo <somlo@cmu.edu>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18180 6f19259b-4bc3-4df7-8a09-765794883524

4 files changed, 28 insertions, 21 deletions

diff --git a/OvmfPkg/Library/SmbiosVersionLib/DetectSmbiosVersionLib.c b/OvmfPkg/Library/SmbiosVersionLib/DetectSmbiosVersionLib.c
index 0efe020eea..9d5e337e1a 100644
--- a/OvmfPkg/Library/SmbiosVersionLib/DetectSmbiosVersionLib.c
+++ b/OvmfPkg/Library/SmbiosVersionLib/DetectSmbiosVersionLib.c
@@ -40,6 +40,15 @@ DetectSmbiosVersion (
   QEMU_SMBIOS_ANCHOR   QemuAnchor;

   UINT16               SmbiosVersion;

 

+  if (PcdGetBool (PcdQemuSmbiosValidated)) {

+    //

+    // Some other module, linked against this library, has already performed

+    // the task at hand. This should never happen, but it's easy to handle;

+    // just exit early.

+    //

+    return RETURN_SUCCESS;

+  }

+

   if (RETURN_ERROR (QemuFwCfgFindFile (

                       "etc/smbios/smbios-anchor", &Anchor, &AnchorSize)) ||

       RETURN_ERROR (QemuFwCfgFindFile (

@@ -72,5 +81,10 @@ DetectSmbiosVersion (
     SmbiosVersion));

   PcdSet16 (PcdSmbiosVersion, SmbiosVersion);

 

+  //

+  // SMBIOS platform drivers can now fetch and install

+  // "etc/smbios/smbios-tables" from QEMU.

+  //

+  PcdSetBool (PcdQemuSmbiosValidated, TRUE);

   return RETURN_SUCCESS;

 }

diff --git a/OvmfPkg/Library/SmbiosVersionLib/DetectSmbiosVersionLib.inf b/OvmfPkg/Library/SmbiosVersionLib/DetectSmbiosVersionLib.inf
index 14c25c924e..8487e73e46 100644
--- a/OvmfPkg/Library/SmbiosVersionLib/DetectSmbiosVersionLib.inf
+++ b/OvmfPkg/Library/SmbiosVersionLib/DetectSmbiosVersionLib.inf
@@ -49,3 +49,4 @@
 

 [Pcd]

   gEfiMdeModulePkgTokenSpaceGuid.PcdSmbiosVersion

+  gUefiOvmfPkgTokenSpaceGuid.PcdQemuSmbiosValidated

diff --git a/OvmfPkg/SmbiosPlatformDxe/Qemu.c b/OvmfPkg/SmbiosPlatformDxe/Qemu.c
index f7ace4f1de..9466b950fc 100644
--- a/OvmfPkg/SmbiosPlatformDxe/Qemu.c
+++ b/OvmfPkg/SmbiosPlatformDxe/Qemu.c
@@ -15,6 +15,7 @@
 #include "SmbiosPlatformDxe.h"

 #include <Library/QemuFwCfgLib.h>

 #include <Library/MemoryAllocationLib.h>

+#include <Library/PcdLib.h>

 

 /**

   Locates and extracts the QEMU SMBIOS data if present in fw_cfg

@@ -27,32 +28,19 @@ GetQemuSmbiosTables (
   VOID

   )

 {

-  SMBIOS_TABLE_ENTRY_POINT QemuAnchor;

-  FIRMWARE_CONFIG_ITEM     Anchor, Tables;

-  UINTN                    AnchorSize, TablesSize;

+  EFI_STATUS               Status;

+  FIRMWARE_CONFIG_ITEM     Tables;

+  UINTN                    TablesSize;

   UINT8                    *QemuTables;

 

-  if (EFI_ERROR (QemuFwCfgFindFile (

-                   "etc/smbios/smbios-anchor", &Anchor, &AnchorSize)) ||

-      EFI_ERROR (QemuFwCfgFindFile (

-                   "etc/smbios/smbios-tables", &Tables, &TablesSize)) ||

-      AnchorSize != sizeof (QemuAnchor) ||

-      TablesSize == 0) {

+  if (!PcdGetBool (PcdQemuSmbiosValidated)) {

     return NULL;

   }

 

-  //

-  // We copy the entry point structure to perform some additional checks,

-  // but discard it upon return.

-  //

-  QemuFwCfgSelectItem (Anchor);

-  QemuFwCfgReadBytes (AnchorSize, &QemuAnchor);

-

-  if (AsciiStrnCmp ((CHAR8 *)QemuAnchor.AnchorString, "_SM_", 4) ||

-      AsciiStrnCmp ((CHAR8 *)QemuAnchor.IntermediateAnchorString, "_DMI_", 5) ||

-      TablesSize != QemuAnchor.TableLength) {

-    return NULL;

-  }

+  Status = QemuFwCfgFindFile ("etc/smbios/smbios-tables", &Tables,

+             &TablesSize);

+  ASSERT_EFI_ERROR (Status);

+  ASSERT (TablesSize > 0);

 

   QemuTables = AllocatePool (TablesSize);

   if (QemuTables == NULL) {

diff --git a/OvmfPkg/SmbiosPlatformDxe/SmbiosPlatformDxe.inf b/OvmfPkg/SmbiosPlatformDxe/SmbiosPlatformDxe.inf
index 3b90aac438..91815ecd6f 100644
--- a/OvmfPkg/SmbiosPlatformDxe/SmbiosPlatformDxe.inf
+++ b/OvmfPkg/SmbiosPlatformDxe/SmbiosPlatformDxe.inf
@@ -53,6 +53,10 @@
   HobLib

   QemuFwCfgLib

   MemoryAllocationLib

+  PcdLib

+

+[Pcd]

+  gUefiOvmfPkgTokenSpaceGuid.PcdQemuSmbiosValidated

 

 [Protocols]

   gEfiSmbiosProtocolGuid                      # PROTOCOL ALWAYS_CONSUMED