From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by mx.groups.io with SMTP id smtpd.web11.20673.1633405264221469310 for ; Mon, 04 Oct 2021 20:41:05 -0700 Authentication-Results: mx.groups.io; dkim=missing; spf=pass (domain: intel.com, ip: 192.55.52.115, mailfrom: min.m.xu@intel.com) X-IronPort-AV: E=McAfee;i="6200,9189,10127"; a="225958235" X-IronPort-AV: E=Sophos;i="5.85,347,1624345200"; d="scan'208";a="225958235" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Oct 2021 20:40:48 -0700 X-IronPort-AV: E=Sophos;i="5.85,347,1624345200"; d="scan'208";a="487828712" Received: from mxu9-mobl1.ccr.corp.intel.com ([10.255.29.239]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Oct 2021 20:40:46 -0700 From: "Min Xu" To: devel@edk2.groups.io Cc: Min Xu , Ard Biesheuvel , Jordan Justen , Brijesh Singh , Erdem Aktas , James Bottomley , Jiewen Yao , Tom Lendacky Subject: [PATCH V2 19/28] OvmfPkg: Check Tdx in QemuFwCfgPei to avoid DMA operation Date: Tue, 5 Oct 2021 11:39:30 +0800 Message-Id: X-Mailer: git-send-email 2.29.2.windows.2 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RFC： https://bugzilla.tianocore.org/show_bug.cgi?id=3429 If TDX is enabled then we do not support DMA operation in PEI phase. This is mainly because DMA in TDX guest requires using bounce buffer (which need to allocate dynamic memory and allocating a PAGE size'd buffer can be challenge in PEI phase). Cc: Ard Biesheuvel Cc: Jordan Justen Cc: Brijesh Singh Cc: Erdem Aktas Cc: James Bottomley Cc: Jiewen Yao Cc: Tom Lendacky Signed-off-by: Min Xu --- .../QemuFwCfgLib/QemuFwCfgLibInternal.h | 11 +++++++ OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c | 32 +++++++++++++++++++ .../Library/QemuFwCfgLib/QemuFwCfgPeiLib.inf | 2 ++ 3 files changed, 45 insertions(+) diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibInternal.h b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibInternal.h index 1fa80686e0bd..1130552bc60a 100644 --- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibInternal.h +++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLibInternal.h @@ -60,4 +60,15 @@ InternalQemuFwCfgDmaBytes ( IN UINT32 Control ); +/** + Check if it is Tdx guest + + @retval TRUE It is Tdx guest + @retval FALSE It is not Tdx guest +**/ +BOOLEAN +QemuFwCfgIsTdxGuest ( + VOID + ); + #endif diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c index ecabd88fab66..bd2e51363bc6 100644 --- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c +++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c @@ -14,12 +14,30 @@ #include #include #include +#include #include "QemuFwCfgLibInternal.h" STATIC BOOLEAN mQemuFwCfgSupported = FALSE; STATIC BOOLEAN mQemuFwCfgDmaSupported; +/** + Check if it is Tdx guest + + @retval TRUE It is Tdx guest + @retval FALSE It is not Tdx guest +**/ +BOOLEAN +QemuFwCfgIsTdxGuest ( + VOID + ) +{ + CONFIDENTIAL_COMPUTING_WORK_AREA_HEADER *CcWorkAreaHeader; + + CcWorkAreaHeader = (CONFIDENTIAL_COMPUTING_WORK_AREA_HEADER *) FixedPcdGet32 (PcdOvmfWorkAreaBase); + return (CcWorkAreaHeader != NULL && CcWorkAreaHeader->GuestType == GUEST_TYPE_INTEL_TDX); +} + /** Returns a boolean indicating if the firmware configuration interface @@ -82,6 +100,14 @@ QemuFwCfgInitialize ( // if (MemEncryptSevIsEnabled ()) { DEBUG ((DEBUG_INFO, "SEV: QemuFwCfg fallback to IO Port interface.\n")); + } else if (QemuFwCfgIsTdxGuest ()) { + // + // If TDX is enabled then we do not support DMA operations in PEI phase. + // This is mainly because DMA in TDX guest requires using bounce buffer + // (which need to allocate dynamic memory and allocating a PAGE size'd + // buffer can be challenge in PEI phase) + // + DEBUG ((DEBUG_INFO, "TDX: QemuFwCfg fallback to IO Port interface.\n")); } else { mQemuFwCfgDmaSupported = TRUE; DEBUG ((DEBUG_INFO, "QemuFwCfg interface (DMA) is supported.\n")); @@ -162,6 +188,12 @@ InternalQemuFwCfgDmaBytes ( // ASSERT (!MemEncryptSevIsEnabled ()); + // + // TDX does not support DMA operations in PEI stage, we should + // not have reached here. + // + ASSERT (!QemuFwCfgIsTdxGuest ()); + Access.Control = SwapBytes32 (Control); Access.Length = SwapBytes32 (Size); Access.Address = SwapBytes64 ((UINTN)Buffer); diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiLib.inf b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiLib.inf index 9f9af7d03201..3910511880c9 100644 --- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiLib.inf +++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPeiLib.inf @@ -43,3 +43,5 @@ MemoryAllocationLib MemEncryptSevLib +[Pcd] + gUefiOvmfPkgTokenSpaceGuid.PcdOvmfWorkAreaBase -- 2.29.2.windows.2