From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9D531C433F5 for ; Thu, 11 Nov 2021 23:56:14 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3D54860EB6 for ; Thu, 11 Nov 2021 23:56:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 3D54860EB6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id BF43B6B008C; Thu, 11 Nov 2021 18:56:13 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BA15E6B0092; Thu, 11 Nov 2021 18:56:13 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A918B6B0093; Thu, 11 Nov 2021 18:56:13 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0099.hostedemail.com [216.40.44.99]) by kanga.kvack.org (Postfix) with ESMTP id 9D23B6B008C for ; Thu, 11 Nov 2021 18:56:13 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 6448B8248D52 for ; Thu, 11 Nov 2021 23:56:13 +0000 (UTC) X-FDA: 78798310626.23.506CEAE Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf16.hostedemail.com (Postfix) with ESMTP id 85DA3F00009F for ; Thu, 11 Nov 2021 23:56:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Content-Transfer-Encoding: Content-Type:In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To: Subject:Sender:Reply-To:Content-ID:Content-Description; bh=4VEbIBkqcGJ3l7Zgq/uZwytuUTxQjnyHYFTzYLajeFM=; b=TRKP74wrJUWYaJp4HuEvwVy7CF YTjoRR5QTzBEeBxq3PCrmmtk8OoH2yjaSangsFbsIzdeSF3SLaE56izUwg7fntdvR2wOK/SS+BBoW mlw1ocs5fd6xel1vUL09N1TKuP894s35YGVDEpjPgpVFbveFsZ22oH/jfhCfNxY8cANsFbTSLGVAx K2DBb0Cg0FcItQGhKOg0hYwZVpeswRgpzsjAb1ohwaQTwk1JI+3g3tjD+fcTGOK18WGrRiP2XgaLJ 80qxVMKle/wX4S20DP1RY6pgKSTZD0GwVGh8FXexqBMDy9+bYRS3kt0g4B2yElOISKUDDoO4fTzVX z6FuMwhQ==; Received: from [2601:1c0:6280:3f0::aa0b] by bombadil.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1mlJ17-008w1k-MP; Thu, 11 Nov 2021 22:58:01 +0000 Subject: Re: [PATCH v7 43/45] virt: Add SEV-SNP guest driver To: Brijesh Singh , x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-efi@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-coco@lists.linux.dev, linux-mm@kvack.org Cc: Thomas Gleixner , Ingo Molnar , Joerg Roedel , Tom Lendacky , "H. Peter Anvin" , Ard Biesheuvel , Paolo Bonzini , Sean Christopherson , Vitaly Kuznetsov , Jim Mattson , Andy Lutomirski , Dave Hansen , Sergio Lopez , Peter Gonda , Peter Zijlstra , Srinivas Pandruvada , David Rientjes , Dov Murik , Tobin Feldman-Fitzthum , Borislav Petkov , Michael Roth , Vlastimil Babka , "Kirill A . Shutemov" , Andi Kleen , "Dr . David Alan Gilbert" , tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com References: <20211110220731.2396491-1-brijesh.singh@amd.com> <20211110220731.2396491-44-brijesh.singh@amd.com> <38e5047c-43a9-400b-c507-337011e0e605@amd.com> From: Randy Dunlap Message-ID: Date: Thu, 11 Nov 2021 14:57:59 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <38e5047c-43a9-400b-c507-337011e0e605@amd.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 85DA3F00009F X-Stat-Signature: kcqy7t6g69gh3d3tswcqeqnexqzs65pq Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=infradead.org header.s=bombadil.20210309 header.b=TRKP74wr; dmarc=none; spf=none (imf16.hostedemail.com: domain of rdunlap@infradead.org has no SPF policy when checking 198.137.202.133) smtp.mailfrom=rdunlap@infradead.org X-HE-Tag: 1636674961-250766 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 11/11/21 11:27 AM, Brijesh Singh wrote: > Hi Randy, >=20 > On 11/10/21 4:27 PM, Randy Dunlap wrote: >> Hi, >> >> On 11/10/21 2:07 PM, Brijesh Singh wrote: >>> diff --git a/drivers/virt/coco/sevguest/Kconfig b/drivers/virt/coco/s= evguest/Kconfig >>> new file mode 100644 >>> index 000000000000..96190919cca8 >>> --- /dev/null >>> +++ b/drivers/virt/coco/sevguest/Kconfig >>> @@ -0,0 +1,9 @@ >>> +config SEV_GUEST >>> +=C2=A0=C2=A0=C2=A0 tristate "AMD SEV Guest driver" >>> +=C2=A0=C2=A0=C2=A0 default y >> >> For this to remain as "default y", you need to justify it. >> E.g., if a board cannot boot with an interrupt controller, >> the driver for the interrupt controller can be "default y". >> >> So why is this default y? >> No other drivers in drivers/virt/ are default y. >> >=20 > I choose the default "y" for two reasons: >=20 > 1.=C2=A0 The driver is built if the user enables the AMD memory encrypt= ion support. If the user has selected the AMD memory encryption support, = they will be querying an attestation report to verify that the guest is r= unning on AMD memory encryption enabled hardware. OK, I see. I'm OK with this. > 2. Typically, an attestation report is retrieved from an initial ramdis= k (before mounting the disk). IIUC, the standard initramfs build tools ma= y not include the driver by default and requires the user to go through h= oops. >=20 > However, I have no strong reason to keep it to "y" if other prefers "m"= . "m" is no better than "y" in this case. thanks. --=20 ~Randy