From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f171.google.com (mail-oi1-f171.google.com [209.85.167.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 503877C for ; Fri, 24 Jun 2022 17:19:19 +0000 (UTC) Received: by mail-oi1-f171.google.com with SMTP id w83so4429273oiw.1 for ; Fri, 24 Jun 2022 10:19:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=oNiiFv53teFu3CRex5rCry8QLqLkd97P3Hj9fAhbeYc=; b=kFAUNKf1rEgkt+OYkPh8tB9E+HPlRDJ57kjd7aaOhWKcIYCN/ZjVerEUwL1D4UqEy6 jNB2akz9JlmI2z3ciS9Jkc2XEeGMl3dvnEZrG1QqRu/ya7j4cL/8FovPHxIwC5EW6es7 Ghq27j3amQkzIckOMXvVOxDa7HU8mwaHoI3RREC2uB5mU26z2mV8kUwNG56nJSMHMRqc 7XxJo0dYVvBtJQS7ebwKtCv1V87zEy9YAPcRV8rTLCfAJuZvL7bdAFhpoy8DPcdAukCV I/VMctopfL4nnKopG199aqN6z+kRpGu+YbvvSx5/icPAGuQh+9wvM0ZMI9vQVocoE5BI 2jZg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=oNiiFv53teFu3CRex5rCry8QLqLkd97P3Hj9fAhbeYc=; b=DY0eJPCq85fv/AdzVe4adoOc3mQsqFT9dADHmNyW6h4DoiqkCQffOQbBVp0NH9p/1Q eeTevL+Q3GindaEXRIx2+EEp4PjdY7QWQR20KuU9opkbUDF9N7//cKBveNCanqcr7zPn j9LS7tBTuHVTxAw+378Vv6D5sCd8LSr/iH3MyqUyhPNLosEtifCTqHd7JSGGuq235OzH vIQbQAn4GqpUrm9T19bcOFfs6lMWNRFZu+a6/gE6PkY+hzhWDEDaMWgb5Fq5zDg81MpF VjfhJNFn16MphUOXUqThEK+7aiWzORmVmj5/t4byw0IE9t1RxQfA1RcCevaqFBExJ7NX TeAw== X-Gm-Message-State: AJIora9WKhj/1fX1otzwfvca9vX94uqOBHAsvwXcEOksauHwI0pbbLGJ 7TaEUnLOVUK/SJhstEW9adCfQPfyVkV7vAh5g5RYTw== X-Google-Smtp-Source: AGRyM1vH1Tmei+FucmqSWTWHKYA82g8W5CxsahmZ6gIJ+zkpr7Odp70Gu50EcpESE80fWGtWYk5jJ9pFsVncC/eeohY= X-Received: by 2002:a05:6808:179a:b0:32f:2b07:e733 with SMTP id bg26-20020a056808179a00b0032f2b07e733mr2572280oib.218.1656091158204; Fri, 24 Jun 2022 10:19:18 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20220614120231.48165-1-kirill.shutemov@linux.intel.com> <5af19000-4482-7eb9-f158-0a461891f087@intel.com> In-Reply-To: From: Marc Orr Date: Fri, 24 Jun 2022 10:19:07 -0700 Message-ID: Subject: Re: [PATCHv7 00/14] mm, x86/cc: Implement support for unaccepted memory To: Dave Hansen Cc: Peter Gonda , "Kirill A. Shutemov" , Borislav Petkov , Andy Lutomirski , Sean Christopherson , Andrew Morton , Joerg Roedel , Ard Biesheuvel , Andi Kleen , Kuppuswamy Sathyanarayanan , David Rientjes , Vlastimil Babka , Tom Lendacky , Thomas Gleixner , Peter Zijlstra , Paolo Bonzini , Ingo Molnar , Varad Gautam , Dario Faggioli , Mike Rapoport , David Hildenbrand , Marcelo , tim.gardner@canonical.com, Khalid ElMously , philip.cox@canonical.com, "the arch/x86 maintainers" , linux-mm@kvack.org, linux-coco@lists.linux.dev, linux-efi@vger.kernel.org, LKML Content-Type: text/plain; charset="UTF-8" On Fri, Jun 24, 2022 at 10:10 AM Dave Hansen wrote: > > On 6/24/22 10:06, Marc Orr wrote: > > I think Peter's point is a little more nuanced than that. Once lazy > > accept goes into the guest firmware -- without the feature negotiation > > that Peter is suggesting -- cloud providers now have a bookkeeping > > problem. Which images have kernels that can boot from a guest firmware > > that doesn't pre-validate all the guest memory? > > Hold on a sec though... > > Is this a matter of > > can boot from a guest firmware that doesn't pre-validate all the > guest memory? > > or > > can boot from a guest firmware that doesn't pre-validate all the > guest memory ... with access to all of that guest's RAM? > > In other words, are we talking about "fails to boot" or "can't see all > the RAM"? Ah... yeah, you're right, Dave -- I guess it's the latter. The guest won't have access to all of the memory that the customer is paying for. But that's still bad. If the customer buys a 96 GB VM and can only see 4GB because they're kernel doesn't have these patches they're going to be confused and frustrated.