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Fri, 22 Jul 2022 11:45:17 +0000 (UTC) X-FDA: 79714555074.06.0382474 Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) by imf02.hostedemail.com (Postfix) with ESMTP id 454C580063 for ; Fri, 22 Jul 2022 11:45:16 +0000 (UTC) Received: from zn.tnic (p200300ea97297665329c23fffea6a903.dip0.t-ipconnect.de [IPv6:2003:ea:9729:7665:329c:23ff:fea6:a903]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id E5EF91EC04E4; Fri, 22 Jul 2022 13:35:37 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1658489738; 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:in-reply-to:in-reply-to: references:references; bh=iA4hF9kkPlWcq5B8sNQx2XUmWFJBZdfDGxazbgtSxSs=; b=Gfc3qmAZEapfyhMcE8YqM23jtcCxb3f562sZrP/kg89pc7XVy8A0voe5xVEINVUjkO8ZaW m4rhZaFIc53CaGiUZGsfxI0n7W63uo5tIJG6Ml78lhKPPuk10M76vzqvHbod4qaMEiPiSw UGND80nYqOiUPTj4DE81rtyPQKffhqE= Date: Fri, 22 Jul 2022 13:35:32 +0200 From: Borislav Petkov To: "Kalra, Ashish" Cc: Sean Christopherson , Dave Hansen , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , "kvm@vger.kernel.org" , "linux-coco@lists.linux.dev" , "linux-mm@kvack.org" , "linux-crypto@vger.kernel.org" , "tglx@linutronix.de" , "mingo@redhat.com" , "jroedel@suse.de" , "Lendacky, Thomas" , "hpa@zytor.com" , "ardb@kernel.org" , "pbonzini@redhat.com" , "vkuznets@redhat.com" , "jmattson@google.com" , "luto@kernel.org" , "dave.hansen@linux.intel.com" , "slp@redhat.com" , "pgonda@google.com" , "peterz@infradead.org" , "srinivas.pandruvada@linux.intel.com" , "rientjes@google.com" , "dovmurik@linux.ibm.com" , "tobin@ibm.com" , "Roth, Michael" , "vbabka@suse.cz" , "kirill@shutemov.name" , "ak@linux.intel.com" , "tony.luck@intel.com" , "marcorr@google.com" , "sathyanarayanan.kuppuswamy@linux.intel.com" , "alpergun@google.com" , "dgilbert@redhat.com" , "jarkko@kernel.org" Subject: Re: [PATCH Part2 v6 05/49] x86/sev: Add RMP entry lookup helpers Message-ID: References: <25be3068-be13-a451-86d4-ff4cc12ddb23@intel.com> <681e4e45-eff1-600c-9b81-1fa9bdf24232@intel.com> <99d72d58-a9bb-d75c-93af-79d497dfe176@intel.com> <5db37cc2-4fb1-7a73-c39a-3531260414d0@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1658490317; a=rsa-sha256; cv=none; b=6vxsZDXApu+EL12SO0X7blsaLKPfU+anyVnhFbqBYfbC5npnUepQfXFdFXI1SifIARld/a orJ1gIdQ+xhhtl0kpK6chTH0zOYbGadhRE+/MUwo7ggLUWPjNF+MVMzKgRuDKb6vM9m4vR 52tHc1SdvZD9v0ZqYRbv7He81Or7iOw= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=alien8.de header.s=dkim header.b=Gfc3qmAZ; dmarc=pass (policy=none) header.from=alien8.de; spf=pass (imf02.hostedemail.com: domain of bp@alien8.de designates 5.9.137.197 as permitted sender) smtp.mailfrom=bp@alien8.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1658490317; h=from:from:sender: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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=iA4hF9kkPlWcq5B8sNQx2XUmWFJBZdfDGxazbgtSxSs=; b=yRl7jTvl0V54rddLA9aXmZsKoZ4kt5dz9qcp9K8pc1KeS9MUPTqy8S34bPmjQvMciabViR BMGzQX026Z4aY5t4cu25yCUbFRkn4LnpeJwRuTpeozwNf7QTaM7D7iQ8TITpje2DwA0Ou7 sUfjDKWWHWf75oZ1n6DxMnKPesjIbKw= X-Rspamd-Queue-Id: 454C580063 Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=alien8.de header.s=dkim header.b=Gfc3qmAZ; dmarc=pass (policy=none) header.from=alien8.de; spf=pass (imf02.hostedemail.com: domain of bp@alien8.de designates 5.9.137.197 as permitted sender) smtp.mailfrom=bp@alien8.de X-Rspam-User: X-Rspamd-Server: rspam07 X-Stat-Signature: 7uhqj1qj31y7okq8xmykk4j94yb1t8rf X-HE-Tag: 1658490316-603601 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 Thu, Jun 23, 2022 at 10:43:40PM +0000, Kalra, Ashish wrote: > Yes, that's a nice way to hide it from the rest of the kernel which > does not require access to this structure anyway, in essence, it > becomes a private structure. So this whole discussion whether there should be a model check or not in case a new RMP format gets added in the future is moot - when a new model format comes along, *then* the distinction should be done and added in code - not earlier. This is nothing else but normal CPU enablement work - it should be done when it is really needed. Because the opposite can happen: you can add a model check which excludes future model X, future model X comes along but does *not* change the RMP format and then you're going to have to relax that model check again to fix SNP on the new model X. So pls add the model checks only when really needed. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette