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 X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D3AADC433E2 for ; Mon, 29 Jun 2020 19:06:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B0955206F1 for ; Mon, 29 Jun 2020 19:06:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593457615; bh=moWSrIfU+P1Yxb27qSo8YJtpW3dFfDsu52598MoiYoY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=BF1sASmFde1W3lM+QjGy8yBdH/5+tl13/dBTMDbnIR31vpDCM+vNQuJAmTjW1CTPU A+6JzXEE0gAqGUmUiCWX+/YCHKhpQJOGlL3ezmdGQFsfQgPswgJHwtE9M2j5rusLsp ChAWIvN7JiWBNIJcAHtTFCAU7iFKhrXe6U1IN02E= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730102AbgF2TGt (ORCPT ); Mon, 29 Jun 2020 15:06:49 -0400 Received: from mail-wr1-f68.google.com ([209.85.221.68]:39070 "EHLO mail-wr1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728941AbgF2TGs (ORCPT ); Mon, 29 Jun 2020 15:06:48 -0400 Received: by mail-wr1-f68.google.com with SMTP id q5so17657430wru.6; Mon, 29 Jun 2020 12:06:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=9kB1Yqxehc4mOOV+E+s8ly+87mL5I0qDl2+46tT33LU=; b=FEd80YYsVCJ6pf74frJNQnajWBRVFV0QMHP/qy3W0W9HXQvypW8nvMlgqUbUnomnHi O8YsWoOkY/0gsW1wuFENzG/2p0MVio6drckkCAWQhUX6YDslI8N05qYfTEXdmhP050ez bhhL/WcbK3Get7wdtSpsPanlCdnMclxEMNQpfZM5K1TVukzTINfUA72OwM6DkmfPxH9t /nSv3f411beyEx6DfQgAOSHjXwM11BzG+OadcwuOj4GrnqcsG3ZF6B8VfA3RAP+dKogT E1J4xLWzGLTYfhBLP5IHDZsHCJwR02k3Inzl4qa08HVYqt+obUA97UjS6qAGnkjPz7dV 9u+w== X-Gm-Message-State: AOAM532gqGscXvj6dC9M5WbWWjQSodQTDCt6C2jhKsLmH65iLW6oWn1k /XtV0uL03teTbKbOIBhaR8A= X-Google-Smtp-Source: ABdhPJzQcaoC3As2bwvXjFpEkhrTsir6J88mWLOgOu4Igyehnga3Bo7Tm9krH0O+TUUtcdYBw1n/EA== X-Received: by 2002:adf:de12:: with SMTP id b18mr19710508wrm.390.1593457606425; Mon, 29 Jun 2020 12:06:46 -0700 (PDT) Received: from liuwe-devbox-debian-v2 ([51.145.34.42]) by smtp.gmail.com with ESMTPSA id e17sm728179wrr.88.2020.06.29.12.06.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 Jun 2020 12:06:45 -0700 (PDT) Date: Mon, 29 Jun 2020 19:06:44 +0000 From: Wei Liu To: Andres Beltran Cc: Wei Liu , Andres Beltran , KY Srinivasan , Haiyang Zhang , Stephen Hemminger , "linux-hyperv@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Michael Kelley , "parri.andrea@gmail.com" Subject: Re: [PATCH 1/3] Drivers: hv: vmbus: Add vmbus_requestor data structure for VMBus hardening Message-ID: <20200629190644.hlem6jskyx26csaj@liuwe-devbox-debian-v2> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20180716 Sender: linux-hyperv-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org On Mon, Jun 29, 2020 at 06:19:46PM +0000, Andres Beltran wrote: [...] > > > EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw); > > > + > > > +/* > > > + * vmbus_next_request_id - Returns a new request id. It is also > > > + * the index at which the guest memory address is stored. > > > + * Uses a spin lock to avoid race conditions. > > > + * @rqstor: Pointer to the requestor struct > > > + * @rqst_add: Guest memory address to be stored in the array > > > + */ > > > +u64 vmbus_next_request_id(struct vmbus_requestor *rqstor, u64 rqst_addr) > > > +{ > > > + unsigned long flags; > > > + u64 current_id; > > > + > > > + spin_lock_irqsave(&rqstor->req_lock, flags); > > > > Do you really need the irqsave variant here? I.e. is there really a > > chance this code is reachable from an interrupt handler? > > Other VMBus drivers will also need to use this functionality, and > some of them will be called with interrupts disabled. So, I think > we should keep the irqsave variant here. > Okay. This makes sense. Wei.