From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail02.groups.io (mail02.groups.io [66.175.222.108]) by spool.mail.gandi.net (Postfix) with ESMTPS id 99362AC0A16 for ; Mon, 20 Nov 2023 04:59:47 +0000 (UTC) DKIM-Signature: a=rsa-sha256; bh=HAtm6L5oKv3EtYKN4XtTfQ6MQEN3AKB1bAMbbhqJ7A8=; c=relaxed/simple; d=groups.io; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject:To:Cc:Precedence:List-Subscribe:List-Help:Sender:List-Id:Mailing-List:Delivered-To:Reply-To:List-Unsubscribe-Post:List-Unsubscribe:Content-Type; s=20140610; t=1700456386; v=1; b=lVfA6qcx54subnFrncopzifKyaGN6JqYYw8rgHG6gqUgf6oaLJr/jowomjmY9c9ns/LdpRRU ob2bFaw4mfXN0v09WDVFEgzvZhi9o1hjiuWZsaceZ7U91GAWaWCCeLA4dZnjc3bAx0yxfdQccNS HhUKtU6NDTuvUC2hAeNW22/E= X-Received: by 127.0.0.2 with SMTP id QxAJYY7687511xSoto4P2aJM; Sun, 19 Nov 2023 20:59:46 -0800 X-Received: from mail-qk1-f182.google.com (mail-qk1-f182.google.com [209.85.222.182]) by mx.groups.io with SMTP id smtpd.web11.44400.1700456385217826798 for ; Sun, 19 Nov 2023 20:59:45 -0800 X-Received: by mail-qk1-f182.google.com with SMTP id af79cd13be357-7788f727dd7so257003485a.1 for ; Sun, 19 Nov 2023 20:59:45 -0800 (PST) X-Gm-Message-State: EBs1I1WR2XkxUqpZuLSRxPZix7686176AA= X-Google-Smtp-Source: AGHT+IEyZvfztyU4vfwMo4g73uZmUMjh0z5JlaPAD1WvYF+PixGISy2uYb8x13xRiB4QJ4PUX6CsDVawAUp98SAEj7g= X-Received: by 2002:a05:6214:400e:b0:671:c324:9f45 with SMTP id kd14-20020a056214400e00b00671c3249f45mr7578247qvb.37.1700456384193; Sun, 19 Nov 2023 20:59:44 -0800 (PST) MIME-Version: 1.0 References: <20200702205039.52400-1-oleksiyy@ami.com> <26234.1700208464926645589@groups.io> <564e680a-9373-98ab-fbd6-5b060447c17b@redhat.com> In-Reply-To: <564e680a-9373-98ab-fbd6-5b060447c17b@redhat.com> From: "Dhaval Sharma" Date: Mon, 20 Nov 2023 10:29:32 +0530 Message-ID: Subject: Re: [edk2-devel] [PATCH V3 0/4] Add New Memory Attributes To: Laszlo Ersek Cc: devel@edk2.groups.io, Oleksiy Yakovlev Precedence: Bulk List-Subscribe: List-Help: Sender: devel@edk2.groups.io List-Id: Mailing-List: list devel@edk2.groups.io; contact devel+owner@edk2.groups.io Reply-To: devel@edk2.groups.io,dhaval@rivosinc.com List-Unsubscribe-Post: List-Unsubscribe=One-Click List-Unsubscribe: Content-Type: multipart/alternative; boundary="000000000000bc7779060a8e5abb" X-GND-Status: LEGIT Authentication-Results: spool.mail.gandi.net; dkim=pass header.d=groups.io header.s=20140610 header.b=lVfA6qcx; dmarc=none; spf=pass (spool.mail.gandi.net: domain of bounce@groups.io designates 66.175.222.108 as permitted sender) smtp.mailfrom=bounce@groups.io --000000000000bc7779060a8e5abb Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Did you mean to add it as a memory type by itself like EFI_MEMORY_TYPE_INFORMATION? My interpretation of Memory Type is that it is more of SW usability construct while Memory Attr is more of HW behavioural construct. Together they define how a memory region can be used. On Fri, Nov 17, 2023 at 1:55=E2=80=AFPM Laszlo Ersek wr= ote: > On 11/17/23 09:07, Dhaval Sharma wrote: > > Hi, > > I wanted to revisit this thread and I am maintaining the context as > > there are a lot of details already mentioned here > regarding EFI_MEMORY_SP. > > Other than what has been addressed here, we also would like to have an > > option in edk2 to *avoid* using this type of memory for its own > > purposes. This seems like one of the motivations for original request > > and is being honored by OS today but not edk2 as it does not have any > > specific implementation today which takes this attribute into > consideration. > > I would like to add PCD based implementation which informs edk2 NOT to > > use this memory for its own purposes and leave it alone (as still > > available memory to OS). > > > > Specific-purpose memory (SPM). The memory is earmarked for > > specific purposes such as for specific device drivers or applications. > > The SPM attribute serves as a hint to the OS to avoid allocating this > > memory for core OS data or code that can not be relocated. > > Prolonged use of this memory for purposes other than the intended > > purpose may result in suboptimal platform performance. > > > > Some more context: > > https://lwn.net/Articles/784971/ > > Why was EFI_MEMORY_SP introduced as a memory attribute, rather than its > own memory type? > > Laszlo > > --=20 Thanks! =3DD -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#111457): https://edk2.groups.io/g/devel/message/111457 Mute This Topic: https://groups.io/mt/75267363/7686176 Group Owner: devel+owner@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [rebecca@openfw.io] -=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D-=3D- --000000000000bc7779060a8e5abb Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Did you mean to add it as a memory type by itself lik= e EFI_MEMORY_TYPE_INFORMATION?
My interpretation of Memory Type is tha= t it is more of SW usability construct while Memory Attr is more of HW beha= vioural construct. Together they define how a memory region can be used.
On = Fri, Nov 17, 2023 at 1:55=E2=80=AFPM Laszlo Ersek <lersek@redhat.com> wrote:
On 11/17/23 09:07, Dhaval Sharma wrote: > Hi,
> I wanted to revisit this thread and I am maintaining the context as > there are a lot of details already mentioned here regarding=C2=A0EFI_M= EMORY_SP.
> Other than what has been addressed here, we also would like to have an=
> option in edk2 to *avoid* using this type of memory for its own
> purposes. This seems like one of the motivations for original request<= br> > and is being honored by OS today but not edk2 as it does not have any<= br> > specific implementation today which takes this attribute into consider= ation.
> I would like to add PCD based implementation which informs edk2 NOT to=
> use this memory for its own purposes and leave it alone (as still
> available memory to OS).
>
> Specific-purpose memory (SPM). The memory is earmarked for
> specific purposes such as for specific device drivers or applications.=
> The SPM attribute serves as a hint to the OS to avoid allocating this<= br> > memory for core OS data or code that can not be relocated.
> Prolonged use of this memory for purposes other than the intended
> purpose may result in suboptimal platform performance.
>
> Some more context:
> https://lwn.net/Articles/784971/

Why was EFI_MEMORY_SP introduced as a memory attribute, rather than its
own memory type?

Laszlo



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Thanks!
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