OvmfPkg: Add VirtHstiDxe driver

The driver supports qemu machine types 'pc' and 'q35'.

This patch adds some helper functions to manage the bitmasks.
The implemented features depend on both OVMF build configuration
and qemu VM configuration.

For q35 a single security feature is supported and checked: In
SMM-enabled builds the driver will verify smram is properly locked.
That test should never fail.

Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Konstantin Kostiuk <kkostiuk@redhat.com>
Initial-patch-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <Jiewen.yao@intel.com>

OvmfPkg/VirtHstiDxe/QemuQ35.c

@@ -0,0 +1,58 @@
+/** @file
+
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include <Library/BaseLib.h>
+#include <Library/DebugLib.h>
+#include <Library/HstiLib.h>
+#include <Library/PcdLib.h>
+#include <Library/PciLib.h>
+
+#include <IndustryStandard/Hsti.h>
+#include <IndustryStandard/Q35MchIch9.h>
+
+#include "VirtHstiDxe.h"
+
+STATIC VIRT_ADAPTER_INFO_PLATFORM_SECURITY  mHstiQ35 = {
+  PLATFORM_SECURITY_VERSION_VNEXTCS,
+  PLATFORM_SECURITY_ROLE_PLATFORM_REFERENCE,
+  { L"OVMF (Qemu Q35)" },
+  VIRT_HSTI_SECURITY_FEATURE_SIZE,
+};
+
+VIRT_ADAPTER_INFO_PLATFORM_SECURITY *
+VirtHstiQemuQ35Init (
+  VOID
+  )
+{
+  if (FeaturePcdGet (PcdSmmSmramRequire)) {
+    VirtHstiSetSupported (&mHstiQ35, 0, VIRT_HSTI_BYTE0_SMM_SMRAM_LOCK);
+  }
+
+  return &mHstiQ35;
+}
+
+VOID
+VirtHstiQemuQ35Verify (
+  VOID
+  )
+{
+  if (VirtHstiIsSupported (&mHstiQ35, 0, VIRT_HSTI_BYTE0_SMM_SMRAM_LOCK)) {
+    CHAR16  *ErrorMsg = NULL;
+    UINT8   SmramVal;
+    UINT8   EsmramcVal;
+
+    SmramVal   = PciRead8 (DRAMC_REGISTER_Q35 (MCH_SMRAM));
+    EsmramcVal = PciRead8 (DRAMC_REGISTER_Q35 (MCH_ESMRAMC));
+
+    if (!(EsmramcVal & MCH_ESMRAMC_T_EN)) {
+      ErrorMsg = L"q35 smram access is open";
+    } else if (!(SmramVal & MCH_SMRAM_D_LCK)) {
+      ErrorMsg = L"q35 smram config is not locked";
+    }
+
+    VirtHstiTestResult (ErrorMsg, 0, VIRT_HSTI_BYTE0_SMM_SMRAM_LOCK);
+  }
+}