From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.11]) (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 347BF10FD; Sat, 16 Mar 2024 00:49:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710550192; cv=none; b=kdkk5CSCIh7MA6d0bRDjbyej+jJouDYeNj6E1M74cNPCbca7PfLAb4CXy48v8HhmC2YO5c6r8Dd67OEcKgPeJmJjLjkqut5Q6XSI20tLS7WkgB5fBVbz2AejNA1waPu11F7PzsSZoTK93PndSHxBmqgQ4Jhe3RI3vg1O1VI7RF8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710550192; c=relaxed/simple; bh=sQQiicBhSeNqbbamPsWA7WiPkkdzlPRuFofio/wpKFk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=mZa3MnVCffYvg2WIk/zkeCzYb3gAUbmBv/ZXiqSoVM4hRAZZ5ct72xVzRyO8Q4IGYP4eqA7e2aT29Xjlsbdr1WI9mOwI5Y0bVXOuFHcs/LcflNjZX7fxvHU8FFHFYuYBzTHIs4GoBq00Ophr1cqbAmtyFY4BoIFMVNC9Jcn+57g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=IjM5n/xp; arc=none smtp.client-ip=192.198.163.11 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="IjM5n/xp" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1710550189; x=1742086189; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=sQQiicBhSeNqbbamPsWA7WiPkkdzlPRuFofio/wpKFk=; b=IjM5n/xpi5ksKwq6ZZe/oOHvCxyqAXKGHJ+e71KlAHyzCUOH+D/pvliM Ve6uK1FNd0guTJd+gQP/Zv5T4lLDNlaTOOG0udgn7YhlfnJxYf6JadKl+ jdoqodAxmxysswEk2zvR5Tr7CjfhOjVJg+lIgfTD09Pu6gXN4iyU1JMDe j/MZLfUPJZXJjXIksmdT+S7lXFwkoOwrd+Jia5gAr3F4hR+AMx1yr6umj VkxCDyn3qJ6ErqF6+S0SUrPOoM1p0lmq3bf/pxB3hLx6+zrNjgHMCsEN2 KmbAqvNaHOdYbXm3zJgYrPI/N0c4R6ICNAIs257dISSXTJT//9FQfKf3V g==; X-IronPort-AV: E=McAfee;i="6600,9927,11014"; a="16087892" X-IronPort-AV: E=Sophos;i="6.07,129,1708416000"; d="scan'208";a="16087892" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by fmvoesa105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Mar 2024 17:49:48 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,129,1708416000"; d="scan'208";a="17449597" Received: from ls.sc.intel.com (HELO localhost) ([172.25.112.31]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Mar 2024 17:49:46 -0700 Date: Fri, 15 Mar 2024 17:49:45 -0700 From: Isaku Yamahata To: Kai Huang Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, x86@kernel.org, dave.hansen@intel.com, kirill.shutemov@linux.intel.com, peterz@infradead.org, tglx@linutronix.de, bp@alien8.de, mingo@redhat.com, hpa@zytor.com, seanjc@google.com, pbonzini@redhat.com, isaku.yamahata@intel.com, jgross@suse.com, isaku.yamahata@linux.intel.com Subject: Re: [PATCH 4/5] x86/virt/tdx: Support global metadata read for all element sizes Message-ID: <20240316004945.GL1258280@ls.amr.corp.intel.com> References: <17f1c66ae6360b14f175c45aa486f4bdcf6e0a20.1709288433.git.kai.huang@intel.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <17f1c66ae6360b14f175c45aa486f4bdcf6e0a20.1709288433.git.kai.huang@intel.com> On Sat, Mar 02, 2024 at 12:20:36AM +1300, Kai Huang wrote: > For now the kernel only reads TDMR related global metadata fields for > module initialization. All these fields are 16-bits, and the kernel > only supports reading 16-bits fields. > > KVM will need to read a bunch of non-TDMR related metadata to create and > run TDX guests. It's essential to provide a generic metadata read > infrastructure which supports reading all 8/16/32/64 bits element sizes. > > Extend the metadata read to support reading all these element sizes. > > Signed-off-by: Kai Huang > Reviewed-by: Kirill A. Shutemov > --- > arch/x86/virt/vmx/tdx/tdx.c | 59 +++++++++++++++++++++++++------------ > arch/x86/virt/vmx/tdx/tdx.h | 2 -- > 2 files changed, 40 insertions(+), 21 deletions(-) > > diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c > index eb208da4ff63..4ee4b8cf377c 100644 > --- a/arch/x86/virt/vmx/tdx/tdx.c > +++ b/arch/x86/virt/vmx/tdx/tdx.c > @@ -271,23 +271,35 @@ static int read_sys_metadata_field(u64 field_id, u64 *data) > return 0; > } > > -static int read_sys_metadata_field16(u64 field_id, > - int offset, > - void *stbuf) > +/* Return the metadata field element size in bytes */ > +static int get_metadata_field_bytes(u64 field_id) > { > - u16 *st_member = stbuf + offset; > + /* > + * TDX supports 8/16/32/64 bits metadata field element sizes. > + * TDX module determines the metadata element size based on the > + * "element size code" encoded in the field ID (see the comment > + * of MD_FIELD_ID_ELE_SIZE_CODE macro for specific encodings). > + */ > + return 1 << MD_FIELD_ID_ELE_SIZE_CODE(field_id); > +} > + > +static int stbuf_read_sys_metadata_field(u64 field_id, > + int offset, > + int bytes, > + void *stbuf) > +{ > + void *st_member = stbuf + offset; > u64 tmp; > int ret; > > - if (WARN_ON_ONCE(MD_FIELD_ID_ELE_SIZE_CODE(field_id) != > - MD_FIELD_ID_ELE_SIZE_16BIT)) > + if (WARN_ON_ONCE(get_metadata_field_bytes(field_id) != bytes)) > return -EINVAL; > > ret = read_sys_metadata_field(field_id, &tmp); > if (ret) > return ret; > > - *st_member = tmp; > + memcpy(st_member, &tmp, bytes); > > return 0; > } > @@ -295,11 +307,30 @@ static int read_sys_metadata_field16(u64 field_id, > struct field_mapping { > u64 field_id; > int offset; > + int size; > }; > > #define TD_SYSINFO_MAP(_field_id, _struct, _member) \ > { .field_id = MD_FIELD_ID_##_field_id, \ > - .offset = offsetof(_struct, _member) } > + .offset = offsetof(_struct, _member), \ > + .size = sizeof(typeof(((_struct *)0)->_member)) } Because we use compile time constant for _field_id mostly, can we add build time check? Something like this. static inline metadata_size_check(u64 field_id, size_t size) { BUILD_BUG_ON(get_metadata_field_bytes(field_id) != size); } #define TD_SYSINFO_MAP(_field_id, _struct, _member) \ { .field_id = MD_FIELD_ID_##_field_id, \ .offset = offsetof(_struct, _member), \ .size = \ ({ size_t s = sizeof(typeof(((_struct *)0)->_member)); \ metadata_size_check(MD_FIELD_ID_##_field_id, s); \ s; }) } -- Isaku Yamahata