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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 401C6C433FE for ; Tue, 22 Nov 2022 09:10:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233084AbiKVJK5 (ORCPT ); Tue, 22 Nov 2022 04:10:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43660 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233148AbiKVJKe (ORCPT ); Tue, 22 Nov 2022 04:10:34 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 451F618B13; Tue, 22 Nov 2022 01:10:33 -0800 (PST) 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=04mH2hDCkvHpLAW6koCu4FNsbF6qrp83kpM2X4j6UkE=; b=k9zuYNijeiPPZQgyzXcFeWVzjf 2kRDb8PjFNnE3rml8UaKa2fpc2ojYbhduPE/0bMcz9S3UjP4c3qRlLNCJKEGJdXarG9GScWgmn7Tt vRktddCb9AdXAYCNM16jwhdF0wkK9N5B1dQl4GAufPTiQP9Qx3OSqnQ22tmQyECNSjZBVjb+fnING x7igpnSIxEqEwPu7Fc+rSWOo0FI5GGRFCJ0Kv9/qjws+Kp5WirAQriU844RUHMwkuq+EEor4RTOoO GuTlt3CeDJ7Avm1OIUXK6L7KyYMtSxQcVgK6xlZ1raqY51Db6NnBU3mPRgFvHwl8eQghb987Yb0iB 14zkWEOA==; 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 1oxPIR-00699A-NU; Tue, 22 Nov 2022 09:10:27 +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 9DD45300282; Tue, 22 Nov 2022 10:10:20 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 835852D669367; Tue, 22 Nov 2022 10:10:20 +0100 (CET) Date: Tue, 22 Nov 2022 10:10:20 +0100 From: Peter Zijlstra To: Kai Huang Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, seanjc@google.com, pbonzini@redhat.com, dave.hansen@intel.com, dan.j.williams@intel.com, rafael.j.wysocki@intel.com, kirill.shutemov@linux.intel.com, ying.huang@intel.com, reinette.chatre@intel.com, len.brown@intel.com, tony.luck@intel.com, ak@linux.intel.com, isaku.yamahata@intel.com, chao.gao@intel.com, sathyanarayanan.kuppuswamy@linux.intel.com, bagasdotme@gmail.com, sagis@google.com, imammedo@redhat.com Subject: Re: [PATCH v7 06/20] x86/virt/tdx: Shut down TDX module in case of error Message-ID: References: <48505089b645019a734d85c2c29f3c8ae2dbd6bd.1668988357.git.kai.huang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48505089b645019a734d85c2c29f3c8ae2dbd6bd.1668988357.git.kai.huang@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 21, 2022 at 01:26:28PM +1300, Kai Huang wrote: > +/* > + * Data structure to make SEAMCALL on multiple CPUs concurrently. > + * @err is set to -EFAULT when SEAMCALL fails on any cpu. > + */ > +struct seamcall_ctx { > + u64 fn; > + u64 rcx; > + u64 rdx; > + u64 r8; > + u64 r9; > + atomic_t err; > +}; > @@ -166,6 +180,25 @@ static int __always_unused seamcall(u64 fn, u64 rcx, u64 rdx, u64 r8, u64 r9, > } > } > > +static void seamcall_smp_call_function(void *data) > +{ > + struct seamcall_ctx *sc = data; > + int ret; > + > + ret = seamcall(sc->fn, sc->rcx, sc->rdx, sc->r8, sc->r9, NULL, NULL); > + if (ret) > + atomic_set(&sc->err, -EFAULT); > +} Can someone explain me this usage of atomic_t, please?