BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=3902
Bad IO performance in SEC phase is observed after TDX features was introduced. (after commit b6b2de884864 - "MdePkg: Support mmio for Tdx guest in BaseIoLibIntrinsic"). This is because IsTdxGuest() will be called in each MMIO operation. It is trying to cache the result of the probe in the efi data segment. However, that doesn't work in SEC, because the data segment is read only (so the write seems to succeed but a read will always return the original value), leading to us calling TdIsEnabled() check for every mmio we do, which is causing the slowdown because it's very expensive. CcProbe is introduced in this patch-set. It is called in BaseIoLibIntrinsicSev instead of IsTdxGuest. There are 2 versions of the CcProbeLib. Null instance of CcProbe always returns CCGuestTypeNonEncrypted. Its OvmfPkg version checks the Ovmf work area and returns the CC guest type. In this patch-set another issue is fixed with CcProbe as well. If the working guest is SEV and in the beginning of SecMain.c TdIsEnabled() was called. At this point, exception handling is not established and a CPUID instruction will generate a #VC and cause the booting SEV guest to crash. Patch #7 is to fix this broken. Code is at: https://github.com/mxu9/edk2/tree/cc_probe.v3 v3 changes: - Fix the broken issue in SEV guest at SecMain.c. Please refer to Patch #7. v2 changes: - Rename TdProbe to CcProbe to make the lib work for Confidential Computing guests. - Rename the GUEST_TYPE to CC_GUEST_TYPE and move it from WorkArea.h@OvmfPkg to ConfidentialComputingGuestAttr.h@MdePkg. This is because CcProbeLib is designed to return the CC Guest type and the lib is located at MdePkg. - Rename the CC_GUEST_TYPE's fields name to Camel style. See the commit message in patch #1. Cc: Michael D Kinney <michael.d.kin...@intel.com> Cc: Liming Gao <gaolim...@byosoft.com.cn> Cc: Zhiguang Liu <zhiguang....@intel.com> Cc: James Bottomley <j...@linux.ibm.com> Cc: Jiewen Yao <jiewen....@intel.com> Cc: Gerd Hoffmann <kra...@redhat.com> Cc: Brijesh Singh <brijesh.si...@amd.com> Cc: Erdem Aktas <erdemak...@google.com> Cc: Tom Lendacky <thomas.lenda...@amd.com> Signed-off-by: Min Xu <min.m...@intel.com> Min Xu (7): MdePkg: Add CC_GUEST_TYPE in ConfidentialComputingGuestAttr.h OvmfPkg: Replace GUEST_TYPE with CC_GUEST_TYPE MdePkg: Add CcProbeLib OvmfPkg: Add CcProbeLib OvmfPkg: Add CcProbeLib in *.dsc MdePkg: Probe Cc guest in BaseIoLibIntrinsicSev OvmfPkg: Call CcProbe in SecMain.c instead of TsIsEnabled .../Include/ConfidentialComputingGuestAttr.h | 11 ++++++- MdePkg/Include/Library/CcProbeLib.h | 26 ++++++++++++++++ .../BaseIoLibIntrinsicSev.inf | 1 + .../BaseIoLibIntrinsic/IoLibInternalTdx.c | 13 ++------ .../Library/CcProbeLibNull/CcProbeLibNull.c | 26 ++++++++++++++++ .../Library/CcProbeLibNull/CcProbeLibNull.inf | 21 +++++++++++++ MdePkg/MdePkg.dec | 5 +++ MdePkg/MdePkg.dsc | 1 + OvmfPkg/AmdSev/AmdSevX64.dsc | 1 + OvmfPkg/Bhyve/BhyveX64.dsc | 1 + OvmfPkg/CloudHv/CloudHvX64.dsc | 1 + OvmfPkg/Include/WorkArea.h | 9 +----- OvmfPkg/IntelTdx/IntelTdxX64.dsc | 1 + OvmfPkg/IntelTdx/Sec/SecMain.c | 6 ++-- OvmfPkg/IntelTdx/Sec/SecMain.inf | 1 + .../PeiMemEncryptSevLibInternal.c | 2 +- .../SecMemEncryptSevLibInternal.c | 2 +- OvmfPkg/Library/CcProbeLib/CcProbeLib.c | 31 +++++++++++++++++++ OvmfPkg/Library/CcProbeLib/CcProbeLib.inf | 25 +++++++++++++++ OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgPei.c | 2 +- OvmfPkg/Microvm/MicrovmX64.dsc | 1 + OvmfPkg/OvmfPkgIa32.dsc | 1 + OvmfPkg/OvmfPkgIa32X64.dsc | 1 + OvmfPkg/OvmfPkgX64.dsc | 1 + OvmfPkg/OvmfXen.dsc | 1 + OvmfPkg/Sec/AmdSev.c | 2 +- OvmfPkg/Sec/SecMain.c | 5 +-- OvmfPkg/Sec/SecMain.inf | 1 + 28 files changed, 170 insertions(+), 29 deletions(-) create mode 100644 MdePkg/Include/Library/CcProbeLib.h create mode 100644 MdePkg/Library/CcProbeLibNull/CcProbeLibNull.c create mode 100644 MdePkg/Library/CcProbeLibNull/CcProbeLibNull.inf create mode 100644 OvmfPkg/Library/CcProbeLib/CcProbeLib.c create mode 100644 OvmfPkg/Library/CcProbeLib/CcProbeLib.inf -- 2.29.2.windows.2 -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#88969): https://edk2.groups.io/g/devel/message/88969 Mute This Topic: https://groups.io/mt/90516971/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
