From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.zytor.com (terminus.zytor.com [198.137.202.136]) (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 4338134D3B9 for ; Tue, 24 Mar 2026 01:33:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.137.202.136 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774315996; cv=none; b=r87Lk7GGrJUVXS8mtfsAUA+y1dkW4tlq+V6Mi8X0tvq79auMyhoReah47joePP6xBWnWXUfdERgFLo6M+rTd/IdNEq20Pb0DDDyApbcFDkLYF4N9HYnM4+4zud0XbdUkJnhwvOZ0r2EQfkYjHpdRiTtmdewl+CryvC0EDUf5Yso= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774315996; c=relaxed/simple; bh=eD5b9lXOFluspbVmHiNq/Lh7/+2PXjtvG9oRYnOjuXc=; h=Date:From:To:CC:Subject:In-Reply-To:References:Message-ID: MIME-Version:Content-Type; b=bT+hUgP/Reh03HzkKcDAsRF5kOIuXH8NJwsGn79WqRMlxfVz72w7UpvUrdS3NkI3SW/MRN8tWXoB+CVznMkTaIwqAeHCQSzH3UTH7y9q+Ls2/mRfNybRxf2ov5uhtC8v1m47xTczbwrJ8BVfg6w26vrF032K0YwfiNv+3fWRewA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com; spf=pass smtp.mailfrom=zytor.com; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b=Jq54q3bQ; arc=none smtp.client-ip=198.137.202.136 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=zytor.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=zytor.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=zytor.com header.i=@zytor.com header.b="Jq54q3bQ" Received: from ehlo.thunderbird.net (c-76-133-66-138.hsd1.ca.comcast.net [76.133.66.138]) (authenticated bits=0) by mail.zytor.com (8.18.1/8.17.1) with ESMTPSA id 62O1GTaE3605346 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NO); Mon, 23 Mar 2026 18:16:29 -0700 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 62O1GTaE3605346 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2026022301; t=1774314991; bh=eD5b9lXOFluspbVmHiNq/Lh7/+2PXjtvG9oRYnOjuXc=; h=Date:From:To:CC:Subject:In-Reply-To:References:From; b=Jq54q3bQVPnFC94gU5wIYfpM1IWtwbI5BEvdrX8Ruf1L1xlD/2Y7W0eftxEZ3nWJT 6415f/wO6ceY79svUWa3TaM8WsTGO19c8Al8jj+H70SKTascTfPA2VXnyFJ0/uf04l CL5wIJrrHNX+CUeUv1vHEIAJ2WDOgeNmck5OYmgXqC+vVcl90hYOEiENn1uXQFYcKi +BfHLknpEKfccZco1R5ptMCH7HmqGSRTDN54oLlrFddfS1sp5Cd8WCXBUNCLXYJBIg t75fTzByhBtPc2y9FenRqKfCsnAZiT/xV1e6SzoC4kmsmV7cNLOOViUGqRlOdaj0UU jxqVwcZ7x1bZg== Date: Mon, 23 Mar 2026 18:16:23 -0700 From: "H. Peter Anvin" To: Borislav Petkov CC: Maciej Wieczor-Retman , tglx@kernel.org, peterz@infradead.org, xin@zytor.com, maciej.wieczor-retman@intel.com, babu.moger@amd.com, chang.seok.bae@intel.com, sohil.mehta@intel.com, dave.hansen@linux.intel.com, jpoimboe@kernel.org, elena.reshetova@intel.com, pawan.kumar.gupta@linux.intel.com, ak@linux.intel.com, darwi@linutronix.de, mingo@redhat.com, x86@kernel.org, linux-kernel@vger.kernel.org Subject: =?US-ASCII?Q?Re=3A_=5BPATCH_v11_3/4=5D_x86/cpu=3A_Do_a_s?= =?US-ASCII?Q?anity_check_on_required_feature_bits?= User-Agent: K-9 Mail for Android In-Reply-To: <20260323220955.GIacG6M2bxw5u8Agff@fat_crate.local> References: <7312c9f2feab8aea4612ed9a1841e8c22f5f69b1.1774008873.git.m.wieczorretman@pm.me> <20260323163145.GGacFq8WW0t2uqZm91@fat_crate.local> <207ba0a6-5ebc-465a-8d54-6e5a99622a72@zytor.com> <20260323191905.GDacGSKaG4rEU8O4NA@fat_crate.local> <20260323205841.GFacGpgZDBOCCG9Y5u@fat_crate.local> <20260323215049.GGacG1uc-PQLp9DqWo@fat_crate.local> <20260323220955.GIacG6M2bxw5u8Agff@fat_crate.local> Message-ID: <0F1F6273-3E37-4CE6-8239-B2AD285B2875@zytor.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On March 23, 2026 3:09:55 PM PDT, Borislav Petkov wrote: >On Mon, Mar 23, 2026 at 03:03:34PM -0700, H=2E Peter Anvin wrote: >> Yes, hence the tainting=2E >>=20 >> The PAE case is historic, but it was a concrete example I had in my hea= d >> where this issue You also of course mention BIOS settings and there are= VMs >> =2E=2E=2E > >I'm still not convinced=2E But it is just one function so whateva=2E > >I'll buy you a beer the first time we hit this in conjunction with a real= use >case! > >(No, silly VMs don't count=2E) > >:-) > Heh :)