-----Original Message-----
From: Li, Zhihao <zhihao.li@...>
Sent: Saturday, October 8, 2022 1:58 PM
To: devel@edk2.groups.io
Cc: Dong, Eric <eric.dong@...>; Ni, Ray <ray.ni@...>
Subject: [PATCH v2 1/1] UefiCpuPkg: Reset a parameter when BSP Exit in
CPU relaxed mode.

From: Zhihao Li <zhihao.li@...>

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4083

In CPU relaxed mode, it doesn't reset the value of
mSmmMpSyncData->AllApArrivedWithException when BSP exit smm mode.
So this patch will reset this variable. Modified the flow of
SmmCpuRendezvous to avoid enter SmmWaitForApArrival repeatedly.

Cc: Eric Dong <eric.dong@...>
Cc: Ray Ni <ray.ni@...>

Signed-off-by: Zhihao Li <zhihao.li@...>
---
UefiCpuPkg/PiSmmCpuDxeSmm/CpuService.c | 17 ++++++++++++-----
UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c | 5 +++--
2 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/CpuService.c
b/UefiCpuPkg/PiSmmCpuDxeSmm/CpuService.c
index 2ebf4543c3ed..368bacd29ea1 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/CpuService.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/CpuService.c
@@ -421,11 +421,18 @@ SmmCpuRendezvous (
goto ON_EXIT;

}



- //

- // There are some APs outside SMM, Wait for all avaiable APs to arrive.

- //

- SmmWaitForApArrival ();

- Status = mSmmMpSyncData->AllApArrivedWithException ? EFI_SUCCESS :
EFI_TIMEOUT;

+ if ((mSmmMpSyncData->EffectiveSyncMode !=
SmmCpuSyncModeTradition) && !SmmCpuFeaturesNeedConfigureMtrrs ())
{

+ //

+ // There are some APs outside SMM, Wait for all avaiable APs to arrive.

+ //

+ SmmWaitForApArrival ();

+ Status = mSmmMpSyncData->AllApArrivedWithException ? EFI_SUCCESS :
EFI_TIMEOUT;

+ } else {

+ //

+ // BSP has already waitted for APs to arrive SMM if SmmCpuSyncMode
selected or need config MTRR.

+ //

+ Status = EFI_TIMEOUT;

+ }



ON_EXIT:

if (!mSmmMpSyncData->AllApArrivedWithException) {

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
index 13c2cb8da4c3..c79da418e37c 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/MpService.c
@@ -696,8 +696,9 @@ BSPHandler (
//

// Allow APs to check in from this point on

//

- *mSmmMpSyncData->Counter = 0;

- *mSmmMpSyncData->AllCpusInSync = FALSE;

+ *mSmmMpSyncData->Counter = 0;

+ *mSmmMpSyncData->AllCpusInSync = FALSE;

+ mSmmMpSyncData->AllApArrivedWithException = FALSE;

}



/**

--
2.26.2.windows.1