From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by mx.groups.io with SMTP id smtpd.web12.7724.1631196735743451061 for ; Thu, 09 Sep 2021 07:12:15 -0700 Authentication-Results: mx.groups.io; dkim=fail reason="body hash did not verify" header.i=@linux.microsoft.com header.s=default header.b=i+HgGlfO; spf=pass (domain: linux.microsoft.com, ip: 13.77.154.182, mailfrom: mikuback@linux.microsoft.com) Received: from [10.0.0.19] (c-73-27-179-174.hsd1.fl.comcast.net [73.27.179.174]) by linux.microsoft.com (Postfix) with ESMTPSA id ED1D920B713A; Thu, 9 Sep 2021 07:12:14 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com ED1D920B713A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1631196735; bh=POlQrH5SwV9U3BIaghqwuGbgStv2iPaV20L7OGi3sQo=; h=Subject:From:To:References:Date:In-Reply-To:From; b=i+HgGlfOAGTr/lrXxKa5lfEPLCfJ549RkmLfkQVgzSGU6OReE8KIt52bxHI1YPXz7 4rLai7o7hHWtjjoHbj78PTGZok5ZMgaUBx0lr6xZIp2tHGxbP6I/a6itgLWuEK9uTf 9qF3XXQBDrYUPU3OxTuVcccQHQzJbWTo/nF/n5UY= Subject: Re: [edk2-devel] [edk2-platforms][PATCH v1 1/1] IntelSiliconPkg: Add BaseSmmAccessLibNull From: "Michael Kubacki" To: "Ni, Ray" , "devel@edk2.groups.io" References: <28423.1628820964257783330@groups.io> <28669d2c-da78-d35f-4ad3-812a70d09ba2@linux.microsoft.com> Message-ID: <66f3e7cf-7593-6c40-b7c3-091db4164c81@linux.microsoft.com> Date: Thu, 9 Sep 2021 10:12:14 -0400 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: quoted-printable Ray, Do you have plans to do something here? Whether take this patch or=20 refactor SmmAccessLib to a PEIM? Thanks, Michael On 8/20/2021 3:34 PM, Michael Kubacki wrote: > Since you asked for an example that was just one that I provided. I=20 > don't think it detracts from the fact that a NULL instance makes sense=20 > if the SmmAccessLib library class exists. The fact that a NULL instance= =20 > could not be allowed to exist is also confusing. >=20 > I don't want to get too distracted with the example given, but I=20 > completely agree that a different library instance should be used for=20 > pre-memory and post-memory. I think the library interface is too broad=20 > in scope and that contributes to causing this issue so I filed this BZ=20 > to request the BoardInitLib API be refactored: > https://bugzilla.tianocore.org/show_bug.cgi?id=3D3578 >=20 > From the other email thread about SmmAccessLib, I think we are on the=20 > same page that the library would be better as a PEIM. Is that something= =20 > that could be done soon? Or could we have this until that is done? >=20 > Thanks, > Michael >=20 > On 8/20/2021 1:33 AM, Ni, Ray wrote: >> Null SmmAccessLib is confusing to me. Have you evaluated the option: >> Create two instances of BoardInitLib for pre-mem and post-mem. Pre-mem >> one doesn=E2=80=99t link to SmmAccessLib >> >>> -----Original Message----- >>> From: devel@edk2.groups.io On Behalf Of=20 >>> Michael Kubacki >>> Sent: Friday, August 20, 2021 12:53 AM >>> To: devel@edk2.groups.io; Ni, Ray >>> Subject: Re: [edk2-devel] [edk2-platforms][PATCH v1 1/1]=20 >>> IntelSiliconPkg: Add BaseSmmAccessLibNull >>> >>> I don't understand your argument. >>> >>> The library class (SmmAccessLib) that already exists is the abstraction >>> layer. This is not introducing a new layer of abstraction. It is using >>> the current layer of abstraction. >>> >>> Thanks, >>> Michael >>> >>> On 8/19/2021 5:49 AM, Ni, Ray wrote: >>>> Michael, >>>> >>>> I don=E2=80=99t think scenario #1 is a good reason for NULL instance o= f >>>> SmmAccessLib. The root cause is BoardInitLib lib class supports pre-me= m >>>> and post-mem board init. >>>> >>>> Below solution can avoid NULL SmmAccessLib: >>>> >>>> Create two instances of BoardInitLib for pre-mem and post-mem. Pre-mem >>>> one doesn=E2=80=99t link to SmmAccessLib. >>>> >>>> For scenario #2, if a particular platform doesn=E2=80=99t support S3, = why does >>>> this platform include the PEIM? >>>> >>>> Please understand that I want to avoid introducing more abstraction=20 >>>> layers. >>>> >>>> Thanks, >>>> >>>> Ray >>>> >>>> *From:* Michael Kubacki >>>> *Sent:* Friday, August 13, 2021 10:16 AM >>>> *To:* Ni; Ni, Ray ; devel@edk2.groups.io >>>> *Subject:* Re: [edk2-devel] [edk2-platforms][PATCH v1 1/1] >>>> IntelSiliconPkg: Add BaseSmmAccessLibNull >>>> >>>> Sure. >>>> >>>> Scenario #1: >>>> >>>> MinPlatformPkg/PlatformInit/PlatformInitPei/PlatformInitPreMem.inf and >>>> MinPlatormPkg/PlatformInit/PlatformInitPei/PlatformInitPostMem.inf bot= h >>>> link against an instance of BoardInitLib. >>>> >>>> Many boards link against a single BoardInitLib instance. See example - >>>> https://github.com/tianocore/edk2- >>> platforms/blob/cd4e6b716c7d1bcde94035e7dce14b53a553e103/Platform/Intel/= KabylakeOpenBoardPkg/KabylakeRvp3/OpenB=20 >>> >>> oardPkg.dsc#L203 >>>> >> platforms/blob/cd4e6b716c7d1bcde94035e7dce14b53a553e103/Platform/Intel/= KabylakeOpenBoardPkg/KabylakeRvp3/OpenB=20 >>> >>> oardPkg.dsc#L203> >>>> >>>> That BoardInitLib instance may link against SmmAccessLib. >>>> PlatformInitPreMem may wish to library class override the SmmAccessLib >>>> to the NULL instance while keeping it to non-NULL instance in >>>> PlatformInitPostMem. >>>> >>>> Scenario #2: >>>> >>>> A PEIM is built that checks whether the boot mode is S3. If so, it=20 >>>> calls >>>> PeiInstallSmmAccessPpi(). A particular platform does not support S3, >>>> therefore, it links BaseSmmAccessLibNull as its library instance for >>>> SmmAccessLib. >>>> >>>> >>> >>> >>>=20 >>> >>