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* [PATCH 0/4] Introduce TdProbe in MdePkg
@ 2022-04-13  9:08 Min Xu
  2022-04-13  9:08 ` [PATCH 1/4] MdePkg: Add TdProbeLib Min Xu
                   ` (4 more replies)
  0 siblings, 5 replies; 8+ messages in thread
From: Min Xu @ 2022-04-13  9:08 UTC (permalink / raw)
  To: devel
  Cc: Min Xu, Michael D Kinney, Liming Gao, Zhiguang Liu,
	James Bottomley, James Bottomley, Jiewen Yao, Gerd Hoffmann,
	Brijesh Singh, Erdem Aktas, Tom Lendacky

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.

TdProbe is introduced in this patch-set. It is called in
BaseIoLibIntrinsicSev instead of IsTdxGuest. There are 2 versions of the
TdProbeLib. Null instance of TdProbe always returns TD_PROBE_NON. Its
OvmfPkg version checks the Ovmf work area to determine the Td guest type.

Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Zhiguang Liu <zhiguang.liu@intel.com>
Cc: James Bottomley <jejb@linux.ibm.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Erdem Aktas <erdemaktas@google.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Min Xu <min.m.xu@intel.com>

Min Xu (4):
  MdePkg: Add TdProbeLib
  OvmfPkg/IntelTdx: Add TdProbeLib
  MdePkg: Probe Td guest in BaseIoLibIntrinsicSev
  OvmfPkg: Add TdProbeLib in *.dsc

 MdePkg/Include/Library/TdProbeLib.h           | 26 +++++++++++++
 .../BaseIoLibIntrinsicSev.inf                 |  1 +
 .../BaseIoLibIntrinsic/IoLibInternalTdx.c     | 13 +------
 .../Library/TdProbeLibNull/TdProbeLibNull.c   | 25 ++++++++++++
 .../Library/TdProbeLibNull/TdProbeLibNull.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/IntelTdx/IntelTdxX64.dsc              |  1 +
 OvmfPkg/IntelTdx/TdProbeLib/TdProbeLib.c      | 38 +++++++++++++++++++
 OvmfPkg/IntelTdx/TdProbeLib/TdProbeLib.inf    | 25 ++++++++++++
 OvmfPkg/Microvm/MicrovmX64.dsc                |  1 +
 OvmfPkg/OvmfPkgIa32.dsc                       |  1 +
 OvmfPkg/OvmfPkgIa32X64.dsc                    |  1 +
 OvmfPkg/OvmfPkgX64.dsc                        |  1 +
 OvmfPkg/OvmfXen.dsc                           |  1 +
 18 files changed, 153 insertions(+), 11 deletions(-)
 create mode 100644 MdePkg/Include/Library/TdProbeLib.h
 create mode 100644 MdePkg/Library/TdProbeLibNull/TdProbeLibNull.c
 create mode 100644 MdePkg/Library/TdProbeLibNull/TdProbeLibNull.inf
 create mode 100644 OvmfPkg/IntelTdx/TdProbeLib/TdProbeLib.c
 create mode 100644 OvmfPkg/IntelTdx/TdProbeLib/TdProbeLib.inf

-- 
2.29.2.windows.2


^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2022-04-13 13:28 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2022-04-13  9:08 [PATCH 0/4] Introduce TdProbe in MdePkg Min Xu
2022-04-13  9:08 ` [PATCH 1/4] MdePkg: Add TdProbeLib Min Xu
2022-04-13  9:08 ` [PATCH 2/4] OvmfPkg/IntelTdx: " Min Xu
2022-04-13  9:08 ` [PATCH 3/4] MdePkg: Probe Td guest in BaseIoLibIntrinsicSev Min Xu
2022-04-13  9:08 ` [PATCH 4/4] OvmfPkg: Add TdProbeLib in *.dsc Min Xu
2022-04-13 12:55 ` [PATCH 0/4] Introduce TdProbe in MdePkg James Bottomley
2022-04-13 13:12   ` [edk2-devel] " Yao, Jiewen
2022-04-13 13:27     ` Min Xu

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