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 86D042F23 for ; Sun, 6 Feb 2022 19:21:12 +0000 (UTC) Received: from zn.tnic (dslb-088-067-221-104.088.067.pools.vodafone-ip.de [88.67.221.104]) (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 98F631EC0441; Sun, 6 Feb 2022 20:21:06 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1644175266; 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=qZ+JC0pRfH6lWrzUrFpqkRDFcjI46nKdneyEJN06nQk=; b=ow+htihMgw4Pxti4RYLXi7ZysyRUArvgHjhpsNxhff27JMNO7FScwt2OQO9fzKzRUJgWyp a9pywRwMPeVHB+ZsGjFJ7ZKvh86sn2s5riv1j+ZZQXvSxDz6cXpBOFY/xpIV01KjbfMZId U4VUF69EB5x5H4KIHMBT1WoxuL/t7FM= Date: Sun, 6 Feb 2022 20:21:00 +0100 From: Borislav Petkov To: Brijesh Singh Cc: 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 , Michael Roth , Vlastimil Babka , "Kirill A . Shutemov" , Andi Kleen , "Dr . David Alan Gilbert" , brijesh.ksingh@gmail.com, tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com Subject: Re: [PATCH v9 36/43] x86/compressed/64: Add identity mapping for Confidential Computing blob Message-ID: References: <20220128171804.569796-1-brijesh.singh@amd.com> <20220128171804.569796-37-brijesh.singh@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: <20220128171804.569796-37-brijesh.singh@amd.com> On Fri, Jan 28, 2022 at 11:17:57AM -0600, Brijesh Singh wrote: > From: Michael Roth > > The run-time kernel will need to access the Confidential Computing > blob very early in boot to access the CPUID table it points to. At > that stage of boot it will be relying on the identity-mapped page table > set up by boot/compressed kernel, so make sure the blob and the CPUID > table it points to are mapped in advance. > > Signed-off-by: Michael Roth > Signed-off-by: Brijesh Singh > --- > arch/x86/boot/compressed/ident_map_64.c | 3 ++- > arch/x86/boot/compressed/misc.h | 2 ++ > arch/x86/boot/compressed/sev.c | 22 ++++++++++++++++++++++ > 3 files changed, 26 insertions(+), 1 deletion(-) Do this ontop: --- diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c index faf432684870..a5a9210d73b6 100644 --- a/arch/x86/boot/compressed/sev.c +++ b/arch/x86/boot/compressed/sev.c @@ -500,7 +500,7 @@ bool snp_init(struct boot_params *bp) void sev_prep_identity_maps(unsigned long top_level_pgt) { /* - * The ConfidentialComputing blob is used very early in uncompressed + * The Confidential Computing blob is used very early in uncompressed * kernel to find the in-memory cpuid table to handle cpuid * instructions. Make sure an identity-mapping exists so it can be * accessed after switchover. @@ -509,11 +509,10 @@ void sev_prep_identity_maps(unsigned long top_level_pgt) unsigned long cc_info_pa = boot_params->cc_blob_address; struct cc_blob_sev_info *cc_info; - kernel_add_identity_map(cc_info_pa, - cc_info_pa + sizeof(*cc_info)); + kernel_add_identity_map(cc_info_pa, cc_info_pa + sizeof(*cc_info)); + cc_info = (struct cc_blob_sev_info *)cc_info_pa; - kernel_add_identity_map((unsigned long)cc_info->cpuid_phys, - (unsigned long)cc_info->cpuid_phys + cc_info->cpuid_len); + kernel_add_identity_map(cc_info->cpuid_phys, cc_info->cpuid_phys + cc_info->cpuid_len); } sev_verify_cbit(top_level_pgt); -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette