From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by mx.groups.io with SMTP id smtpd.web08.18.1615913094317748585 for ; Tue, 16 Mar 2021 09:44:54 -0700 Authentication-Results: mx.groups.io; dkim=pass header.i=@redhat.com header.s=mimecast20190719 header.b=Sh3SQDgC; spf=pass (domain: redhat.com, ip: 216.205.24.124, mailfrom: lersek@redhat.com) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1615913093; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0SiRL2qzdtnAQ5F8BIJD7I2v26e1ZBVJKK+fBjqqomE=; b=Sh3SQDgClRW36Z7raSpjPhDD1upRQARrEcpfviPoD84t0hOrScH/CJ8Lbwlj787O0gRLbR Z+tATIbWrf2Oh/XY0bi+55CmrSNsK/jEnMW4cxTO+cwsOztky4axJKLYxw9e5oUBw5JuBQ +0oQgWTcDsmRiQb3rT55cka1cgED2hQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-437-0vPAHzWzNhunqM8PQk4L5Q-1; Tue, 16 Mar 2021 12:44:51 -0400 X-MC-Unique: 0vPAHzWzNhunqM8PQk4L5Q-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 90B9A107ACCA; Tue, 16 Mar 2021 16:44:50 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com (ovpn-114-138.ams2.redhat.com [10.36.114.138]) by smtp.corp.redhat.com (Postfix) with ESMTP id 558EB610AF; Tue, 16 Mar 2021 16:44:49 +0000 (UTC) Subject: Re: [PATCH v2] UefiCpuPkg/MpInitLib: avoid printing debug messages in AP To: Ray Ni , devel@edk2.groups.io Cc: Eric Dong , Rahul Kumar References: <20210316015203.1507-1-ray.ni@intel.com> From: "Laszlo Ersek" Message-ID: <0bcd4862-376c-9dc7-0cfe-0baed696a9e0@redhat.com> Date: Tue, 16 Mar 2021 17:44:48 +0100 MIME-Version: 1.0 In-Reply-To: <20210316015203.1507-1-ray.ni@intel.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=lersek@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 03/16/21 02:52, Ray Ni wrote: > MpInitLib contains a function MicrocodeDetect() which is called by > all threads as an AP procedure. > Today this function contains below code: > > if (CurrentRevision != LatestRevision) { > AcquireSpinLock(&CpuMpData->MpLock); > DEBUG (( > EFI_D_ERROR, > "Updated microcode signature [0x%08x] does not match \ > loaded microcode signature [0x%08x]\n", > CurrentRevision, LatestRevision > )); > ReleaseSpinLock(&CpuMpData->MpLock); > } > > When the if-check is passed, the code may call into PEI services: > 1. AcquireSpinLock > When the PcdSpinTimeout is not 0, TimerLib > GetPerformanceCounterProperties() is called. And some of the > TimerLib implementations would get the information cached in > HOB. But AP procedure cannot call PEI services to retrieve the > HOB list. > > 2. DEBUG > Certain DebugLib relies on ReportStatusCode services and the > ReportStatusCode PPI is retrieved through the PEI services. > DebugLibSerialPort should be used. > But when SerialPortLib is implemented to depend on PEI services, > even using DebugLibSerialPort can still cause AP calls PEI > services resulting hang. > > It causes a lot of debugging effort on the platform side. > > There are 2 options to fix the problem: > 1. make sure platform DSC chooses the proper DebugLib and set the > PcdSpinTimeout to 0. So that AcquireSpinLock and DEBUG don't call > PEI services. > 2. remove the AcquireSpinLock and DEBUG call from the procedure. > > Option #2 is preferred because it's not practical to ask every > platform DSC to be written properly. > > Following option #2, there are two sub-options: > 2.A. Just remove the if-check. > 2.B. Capture the CurrentRevision and ExpectedRevision in the memory > for each AP and print them together from BSP. > > The patch follows option 2.B. > > Signed-off-by: Ray Ni > Cc: Eric Dong > Cc: Laszlo Ersek > Cc: Rahul Kumar > --- > UefiCpuPkg/Library/MpInitLib/Microcode.c | 11 +---------- > UefiCpuPkg/Library/MpInitLib/MpLib.c | 25 ++++++++++++++++++++++++ > UefiCpuPkg/Library/MpInitLib/MpLib.h | 1 + > 3 files changed, 27 insertions(+), 10 deletions(-) > > diff --git a/UefiCpuPkg/Library/MpInitLib/Microcode.c b/UefiCpuPkg/Library/MpInitLib/Microcode.c > index 15629591e2..297c2abcd1 100644 > --- a/UefiCpuPkg/Library/MpInitLib/Microcode.c > +++ b/UefiCpuPkg/Library/MpInitLib/Microcode.c > @@ -315,17 +315,8 @@ Done: > MSR_IA32_BIOS_UPDT_TRIG, > (UINT64) (UINTN) MicrocodeData > ); > - // > - // Get and check new microcode signature > - // > - CurrentRevision = GetCurrentMicrocodeSignature (); > - if (CurrentRevision != LatestRevision) { > - AcquireSpinLock(&CpuMpData->MpLock); > - DEBUG ((EFI_D_ERROR, "Updated microcode signature [0x%08x] does not match \ > - loaded microcode signature [0x%08x]\n", CurrentRevision, LatestRevision)); > - ReleaseSpinLock(&CpuMpData->MpLock); > - } > } > + CpuMpData->CpuData[ProcessorNumber].MicrocodeRevision = GetCurrentMicrocodeSignature (); > } > > /** > diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.c b/UefiCpuPkg/Library/MpInitLib/MpLib.c > index 5040053dad..3d945972a0 100644 > --- a/UefiCpuPkg/Library/MpInitLib/MpLib.c > +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.c > @@ -2135,6 +2135,31 @@ MpInitLibInitialize ( > } > } > > + // > + // Dump the microcode revision for each core. > + // > + DEBUG_CODE ( > + UINT32 ThreadId; > + UINT32 ExpectedMicrocodeRevision; > + CpuInfoInHob = (CPU_INFO_IN_HOB *) (UINTN) CpuMpData->CpuInfoInHob; > + for (Index = 0; Index < CpuMpData->CpuCount; Index++) { > + GetProcessorLocationByApicId (CpuInfoInHob[Index].InitialApicId, NULL, NULL, &ThreadId); > + if (ThreadId == 0) { > + // > + // MicrocodeDetect() loads microcode in first thread of each core, so, > + // CpuMpData->CpuData[Index].MicrocodeEntryAddr is initialized only for first thread of each core. > + // > + ExpectedMicrocodeRevision = 0; > + if (CpuMpData->CpuData[Index].MicrocodeEntryAddr != 0) { > + ExpectedMicrocodeRevision = ((CPU_MICROCODE_HEADER *)(UINTN)CpuMpData->CpuData[Index].MicrocodeEntryAddr)->UpdateRevision; > + } > + DEBUG (( > + DEBUG_INFO, "CPU[%04d]: Microcode revision = %08x, expected = %08x\n", > + Index, CpuMpData->CpuData[Index].MicrocodeRevision, ExpectedMicrocodeRevision > + )); > + } > + } > + ); > // > // Initialize global data for MP support > // > diff --git a/UefiCpuPkg/Library/MpInitLib/MpLib.h b/UefiCpuPkg/Library/MpInitLib/MpLib.h > index 0bd60388b1..66f9eb2304 100644 > --- a/UefiCpuPkg/Library/MpInitLib/MpLib.h > +++ b/UefiCpuPkg/Library/MpInitLib/MpLib.h > @@ -144,6 +144,7 @@ typedef struct { > UINT32 ProcessorSignature; > UINT8 PlatformId; > UINT64 MicrocodeEntryAddr; > + UINT32 MicrocodeRevision; > } CPU_AP_DATA; > > // > Acked-by: Laszlo Ersek