OvmfPkg/SmmAccess: close and lock SMRAM at default SMBASE

During normal boot, when EFI_DXE_SMM_READY_TO_LOCK_PROTOCOL is installed
by platform BDS, the SMM IPL locks SMRAM (TSEG) through
EFI_SMM_ACCESS2_PROTOCOL.Lock(). See SmmIplReadyToLockEventNotify() in
"MdeModulePkg/Core/PiSmmCore/PiSmmIpl.c".

During S3 resume, S3Resume2Pei locks SMRAM (TSEG) through
PEI_SMM_ACCESS_PPI.Lock(), before executing the boot script. See
S3ResumeExecuteBootScript() in
"UefiCpuPkg/Universal/Acpi/S3Resume2Pei/S3Resume.c".

Those are precisely the places where the SMRAM at the default SMBASE
should be locked too. Add such an action to SmramAccessLock().

Notes:

- The SMRAM at the default SMBASE doesn't support the "closed and
  unlocked" state (and so it can't be closed without locking it, and it
  cannot be opened after closing it).

- The SMRAM at the default SMBASE isn't (and shouldn't) be exposed with
  another EFI_SMRAM_DESCRIPTOR in the GetCapabilities() members of
  EFI_SMM_ACCESS2_PROTOCOL / PEI_SMM_ACCESS_PPI. That's because the SMRAM
  in question is not "general purpose"; it's only QEMU's solution to
  protect the initial SMI handler from the OS, when a VCPU is hot-plugged.

  Consequently, the state of the SMRAM at the default SMBASE is not
  reflected in the "OpenState" / "LockState" fields of the protocol and
  PPI.

- An alternative to extending SmramAccessLock() would be to register an
  EFI_DXE_SMM_READY_TO_LOCK_PROTOCOL notify in SmmAccess2Dxe (for locking
  at normal boot), and an EDKII_S3_SMM_INIT_DONE_GUID PPI notify in
  SmmAccessPei (for locking at S3 resume).

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1512
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Message-Id: <20200129214412.2361-10-lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

diff --git a/OvmfPkg/SmmAccess/SmmAccess2Dxe.c b/OvmfPkg/SmmAccess/SmmAccess2Dxe.c
index e098f6f15f778e6438f9f5948213e0ba2066e4e7..3691a6cd1f10ff14cebd1ffc646adcc6df4887c4 100644 (file)
--- a/OvmfPkg/SmmAccess/SmmAccess2Dxe.c
+++ b/OvmfPkg/SmmAccess/SmmAccess2Dxe.c
@@ -145,6 +145,13 @@ SmmAccess2DxeEntryPoint (
 \r
   InitQ35TsegMbytes ();\r
   GetStates (&mAccess2.LockState, &mAccess2.OpenState);\r
+\r
+  //\r
+  // SmramAccessLock() depends on "mQ35SmramAtDefaultSmbase"; init the latter\r
+  // just before exposing the former via EFI_SMM_ACCESS2_PROTOCOL.Lock().\r
+  //\r
+  InitQ35SmramAtDefaultSmbase ();\r
+\r
   return gBS->InstallMultipleProtocolInterfaces (&ImageHandle,\r
                 &gEfiSmmAccess2ProtocolGuid, &mAccess2,\r
                 NULL);\r

diff --git a/OvmfPkg/SmmAccess/SmmAccess2Dxe.inf b/OvmfPkg/SmmAccess/SmmAccess2Dxe.inf
index 7ced6b4e7ff4a12a8526bb2ba7de665bee61bda1..d86381d0fbe2a1b58e6bcc333ec96e35718062bb 100644 (file)
--- a/OvmfPkg/SmmAccess/SmmAccess2Dxe.inf
+++ b/OvmfPkg/SmmAccess/SmmAccess2Dxe.inf
@@ -49,6 +49,7 @@
   gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire\r
 \r
 [Pcd]\r
+  gUefiOvmfPkgTokenSpaceGuid.PcdQ35SmramAtDefaultSmbase\r
   gUefiOvmfPkgTokenSpaceGuid.PcdQ35TsegMbytes\r
 \r
 [Depex]\r

diff --git a/OvmfPkg/SmmAccess/SmmAccessPei.c b/OvmfPkg/SmmAccess/SmmAccessPei.c
index d67850651c5835618e36b6cde4fabaab00128332..c8bbc17e907a11af85ac59df70f83184b92f8947 100644 (file)
--- a/OvmfPkg/SmmAccess/SmmAccessPei.c
+++ b/OvmfPkg/SmmAccess/SmmAccessPei.c
@@ -372,6 +372,12 @@ SmmAccessPeiEntryPoint (
   CopyMem (GuidHob, &SmramMap[DescIdxSmmS3ResumeState],\r
     sizeof SmramMap[DescIdxSmmS3ResumeState]);\r
 \r
+  //\r
+  // SmramAccessLock() depends on "mQ35SmramAtDefaultSmbase"; init the latter\r
+  // just before exposing the former via PEI_SMM_ACCESS_PPI.Lock().\r
+  //\r
+  InitQ35SmramAtDefaultSmbase ();\r
+\r
   //\r
   // We're done. The next step should succeed, but even if it fails, we can't\r
   // roll back the above BuildGuidHob() allocation, because PEI doesn't support\r

diff --git a/OvmfPkg/SmmAccess/SmmAccessPei.inf b/OvmfPkg/SmmAccess/SmmAccessPei.inf
index d73a029cc79085efd64e40e1579e2dda0f213588..1698c4ce6c924129a1bb6098ae6e82d766071a1d 100644 (file)
--- a/OvmfPkg/SmmAccess/SmmAccessPei.inf
+++ b/OvmfPkg/SmmAccess/SmmAccessPei.inf
@@ -54,6 +54,7 @@
   gUefiOvmfPkgTokenSpaceGuid.PcdSmmSmramRequire\r
 \r
 [Pcd]\r
+  gUefiOvmfPkgTokenSpaceGuid.PcdQ35SmramAtDefaultSmbase\r
   gUefiOvmfPkgTokenSpaceGuid.PcdQ35TsegMbytes\r
 \r
 [Ppis]\r

diff --git a/OvmfPkg/SmmAccess/SmramInternal.c b/OvmfPkg/SmmAccess/SmramInternal.c
index 09657d0f9b0fcae17f7deea1864379000e31174c..0b07dc667b3fd885f2bba999ea0c9cd7ebcf54c1 100644 (file)
--- a/OvmfPkg/SmmAccess/SmramInternal.c
+++ b/OvmfPkg/SmmAccess/SmramInternal.c
@@ -21,6 +21,12 @@
 //\r
 UINT16 mQ35TsegMbytes;\r
 \r
+//\r
+// The value of PcdQ35SmramAtDefaultSmbase is saved into this variable at\r
+// module startup.\r
+//\r
+STATIC BOOLEAN mQ35SmramAtDefaultSmbase;\r
+\r
 /**\r
   Save PcdQ35TsegMbytes into mQ35TsegMbytes.\r
 **/\r
@@ -32,6 +38,17 @@ InitQ35TsegMbytes (
   mQ35TsegMbytes = PcdGet16 (PcdQ35TsegMbytes);\r
 }\r
 \r
+/**\r
+  Save PcdQ35SmramAtDefaultSmbase into mQ35SmramAtDefaultSmbase.\r
+**/\r
+VOID\r
+InitQ35SmramAtDefaultSmbase (\r
+  VOID\r
+  )\r
+{\r
+  mQ35SmramAtDefaultSmbase = PcdGetBool (PcdQ35SmramAtDefaultSmbase);\r
+}\r
+\r
 /**\r
   Read the MCH_SMRAM and ESMRAMC registers, and update the LockState and\r
   OpenState fields in the PEI_SMM_ACCESS_PPI / EFI_SMM_ACCESS2_PROTOCOL object,\r
@@ -125,6 +142,14 @@ SmramAccessLock (
   PciOr8 (DRAMC_REGISTER_Q35 (MCH_ESMRAMC), MCH_ESMRAMC_T_EN);\r
   PciOr8 (DRAMC_REGISTER_Q35 (MCH_SMRAM),   MCH_SMRAM_D_LCK);\r
 \r
+  //\r
+  // Close & lock the SMRAM at the default SMBASE, if it exists.\r
+  //\r
+  if (mQ35SmramAtDefaultSmbase) {\r
+    PciWrite8 (DRAMC_REGISTER_Q35 (MCH_DEFAULT_SMBASE_CTL),\r
+      MCH_DEFAULT_SMBASE_LCK);\r
+  }\r
+\r
   GetStates (LockState, OpenState);\r
   if (*OpenState || !*LockState) {\r
     return EFI_DEVICE_ERROR;\r

diff --git a/OvmfPkg/SmmAccess/SmramInternal.h b/OvmfPkg/SmmAccess/SmramInternal.h
index 74d962b4ecae770af16f90c99aebff36c46cf550..a4d8827adfe4fbd25e160b5523da510c337ce153 100644 (file)
--- a/OvmfPkg/SmmAccess/SmramInternal.h
+++ b/OvmfPkg/SmmAccess/SmramInternal.h
@@ -38,6 +38,14 @@ InitQ35TsegMbytes (
   VOID\r
   );\r
 \r
+/**\r
+  Save PcdQ35SmramAtDefaultSmbase into mQ35SmramAtDefaultSmbase.\r
+**/\r
+VOID\r
+InitQ35SmramAtDefaultSmbase (\r
+  VOID\r
+  );\r
+\r
 /**\r
   Read the MCH_SMRAM and ESMRAMC registers, and update the LockState and\r
   OpenState fields in the PEI_SMM_ACCESS_PPI / EFI_SMM_ACCESS2_PROTOCOL object,\r