From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 00BA02C81 for ; Thu, 21 Oct 2021 14:28:09 +0000 (UTC) Received: from zn.tnic (p200300ec2f1912003b8abe7004197216.dip0.t-ipconnect.de [IPv6:2003:ec:2f19:1200:3b8a:be70:419:7216]) (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 CD0101EC0554; Thu, 21 Oct 2021 16:28:07 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1634826487; 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=rcU9vPUUzI5swHp7U/1X5pUaXTmEfV+1ihJzmOdAcOM=; b=qMTa8TKwojdJWcWHU4iWnSB3q3yU5q61pMpG8GDVfyoMftwa8AJp8ju65Ond55BqBrHHZr FaxndF/cbJqIyuqXkmPXxt8wD/vwcy/4fnPFK5VBwgfOiZMy6w8afPcPqpDhCVTNOfExBW fnUfImp1INRySM74yPeOVphMoiw8cy0= Date: Thu, 21 Oct 2021 16:28:07 +0200 From: Borislav Petkov To: Michael Roth Cc: 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, 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 , Vlastimil Babka , "Kirill A . Shutemov" , Andi Kleen , "Dr . David Alan Gilbert" , tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com Subject: Re: [PATCH v6 08/42] x86/sev-es: initialize sev_status/features within #VC handler Message-ID: References: <20211008180453.462291-1-brijesh.singh@amd.com> <20211008180453.462291-9-brijesh.singh@amd.com> <20211018184003.3ob2uxcpd2rpee3s@amd.com> <20211020161023.hzbj53ehmzjrt4xd@amd.com> <20211021003535.ic35p6nnxdmavw35@amd.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20211021003535.ic35p6nnxdmavw35@amd.com> On Wed, Oct 20, 2021 at 07:35:35PM -0500, Michael Roth wrote: > Fortunately, all the code makes use of sev_status to get at the SEV MSR > bits, so breaking the appropriate bits out of sme_enable() into an earlier > sev_init() routine that's the exclusive writer of sev_status sounds like a > promising approach. Ack. > It makes sense to do it immediately after the first #VC handler is set > up, so CPUID is available, and since that's where SNP CPUID table > initialization would need to happen if it's to be made available in > #VC handler. Right, and you can do all your init/CPUID prep there. > It may even be similar enough between boot/compressed and run-time kernel > that it could be a shared routine in sev-shared.c. Uuh, bonus points! :-) > But then again it also sounds like the appropriate place to move the > snp_cpuid_init*() calls, and locating the cc_blob, and since there's > differences there it might make sense to keep the boot/compressed and > kernel proper sev_init() routines separate to avoid #ifdeffery). > > Not to get ahead of myself though. Just seems like a good starting point > for how to consolidate the various users. I like how you're thinking. :) > Got it, and my apologies if I've given you that impression as it's > certainly not my intent. (though I'm sure you've heard that before.) Nothing to apologize - all good. > Agreed, if we need to check SEV MSR early for the purposes of SNP it makes > sense to move the overall SEV feature detection code earlier as well. I > should have looked into that aspect more closely before introducing the > changes. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette