From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id AFF18EB64D7 for ; Wed, 28 Jun 2023 13:35:57 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3391C8D0002; Wed, 28 Jun 2023 09:35:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 2E91E8D0001; Wed, 28 Jun 2023 09:35:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1B07A8D0002; Wed, 28 Jun 2023 09:35:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 079A08D0001 for ; Wed, 28 Jun 2023 09:35:57 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id CCE8D1403B6 for ; Wed, 28 Jun 2023 13:35:56 +0000 (UTC) X-FDA: 80952254712.20.722A538 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf08.hostedemail.com (Postfix) with ESMTP id 1C8E9160020 for ; Wed, 28 Jun 2023 13:35:53 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=hTq8v5SM; dmarc=none; spf=none (imf08.hostedemail.com: domain of peterz@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=peterz@infradead.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1687959354; 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=ytMNkCq5mj8QRrqKEhG7DQ+40mAfpQCegQXaR8xPOy8=; b=t+MfL50Lluuf/yYii2RdhjObTpTmygYpUstktY6l0abH/ANFJNSLlwYKQ2PmAOo7+3AimR Ps3lEJyLGCCwA87F8rwwoTERL+njX3pyikyCNxQZq5geuDnPydgx366rbUAV8oIfZIo2cW MfXTOH8Prqq+DYm5sNbKhjkZNn47Ggg= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=hTq8v5SM; dmarc=none; spf=none (imf08.hostedemail.com: domain of peterz@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=peterz@infradead.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1687959354; a=rsa-sha256; cv=none; b=lvy3F+8ky8HPDyZz+iI+pB7ma6ZjQzgJ5u9MloL4lkVT0fQRKkRNiGzaihq9kh3H9d7Jw0 ATR5aadGoZ0hX+R976Mf0z8Z0FYvFMFhtTS0IU9IfIO02R8Lg/52kwl+J8q6E5TyzHOeTc Xz4iIVf8gWNOy+JPrSHSp4d6TnUsI4Q= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=ytMNkCq5mj8QRrqKEhG7DQ+40mAfpQCegQXaR8xPOy8=; b=hTq8v5SMGqKnRYTlooA05bx+Lj HRsozeIMcbs653IAaL+XNxCu6YICEE0b0CTdaYd0qHf4tfYBxP8Z0aiOY9+6U+6YGB4y8fMoWE82a tIokfXhEns2lo+ZchXhidsFn5/peKcmJyfXQsYcmVtAKNJeCxwFXhefsLPMGw1q5srfBPR4ELKInp SlYUXTieGCmAasREoJyoRxSY8OV0FwFTkC54mkhirbu70zX66NdujVbKpR17ENFBMubV7c2wvmx+z 7ieoGmbW/EWfsBkNHW4jmHqREGUFRknwi501NHA8pzjGtbC7e5dC/ZghtE0Mw1hA+Eb1gwCDkj5bE Vq2LosxQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1qEVKg-003olR-0n; Wed, 28 Jun 2023 13:35:42 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 5432C30005E; Wed, 28 Jun 2023 15:35:41 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 3B98924810076; Wed, 28 Jun 2023 15:35:41 +0200 (CEST) Date: Wed, 28 Jun 2023 15:35:41 +0200 From: Peter Zijlstra To: "Huang, Kai" Cc: "kirill.shutemov@linux.intel.com" , "kvm@vger.kernel.org" , "Raj, Ashok" , "Huang, Ying" , "Hansen, Dave" , "david@redhat.com" , "bagasdotme@gmail.com" , "ak@linux.intel.com" , "Wysocki, Rafael J" , "linux-kernel@vger.kernel.org" , "Chatre, Reinette" , "Christopherson,, Sean" , "pbonzini@redhat.com" , "mingo@redhat.com" , "Yamahata, Isaku" , "nik.borisov@suse.com" , "tglx@linutronix.de" , "Luck, Tony" , "linux-mm@kvack.org" , "hpa@zytor.com" , "imammedo@redhat.com" , "Shahar, Sagi" , "bp@alien8.de" , "Brown, Len" , "Gao, Chao" , "sathyanarayanan.kuppuswamy@linux.intel.com" , "Williams, Dan J" , "x86@kernel.org" Subject: Re: [PATCH v12 07/22] x86/virt/tdx: Add skeleton to enable TDX on demand Message-ID: <20230628133541.GF2438817@hirez.programming.kicks-ass.net> References: <104d324cd68b12e14722ee5d85a660cccccd8892.1687784645.git.kai.huang@intel.com> <20230627095012.ln47s62pqzdrnb7x@box.shutemov.name> <20230627121853.ek5zr7sfiezfkfyj@box.shutemov.name> <9361abfa9bf22c2a1a4b25e5495bcccc5b8dcd43.camel@intel.com> <7b61715ad35d7b9916f55df72378e02e62c5cc4e.camel@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7b61715ad35d7b9916f55df72378e02e62c5cc4e.camel@intel.com> X-Rspam-User: X-Stat-Signature: pzc9rgeuqmdis1bk6tgq4dbeh4k4e51x X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 1C8E9160020 X-HE-Tag: 1687959353-826254 X-HE-Meta: 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 C89czfeR Y/tnZ5nh3RqIQiabC8CH8E5LFmCvyieFTFtyyzYqOJRTnXTyA36I0EFFVgm4yXNMf1ioq0isDTlrN9xdPI2fYNM6K5xoLqwwhS3M12AhAAwKxnJALSzhsoKa+NYyRRc5i0xLFZaN1oeNYyQ8GkG2bsCNmyP6Z5sxPK6dpLc3P8C6ifblzZYAlM8UX9g== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Jun 28, 2023 at 12:28:12AM +0000, Huang, Kai wrote: > On Tue, 2023-06-27 at 22:37 +0000, Huang, Kai wrote: > > > > > > > > +/* > > > > + * Do the module global initialization if not done yet. > > > > + * It's always called with interrupts and preemption disabled. > > > > + */ > > > > > > If interrupts are always disabled why do you need _irqsave()? > > > > > > > I'll remove the _irqsave(). > > > > AFAICT Isaku preferred this for additional security, but this is not > > necessary. > > > > > > Damn. I think we can change the comment to say this function is called with > preemption being disabled, but _can_ be called with interrupt disabled. And we > keep using the _irqsave() version. > > /* > * Do the module global initialization if not done yet. It's always > * called with preemption disabled and can be called with interrupts > * disabled. > */ That's still not explaining *why*, what you want to say is: Can be called locally or through an IPI function call.