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=-12.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 5934CC433E0 for ; Thu, 21 Jan 2021 21:34:42 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 11E392064A for ; Thu, 21 Jan 2021 21:34:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 11E392064A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.72470.130496 (Exim 4.92) (envelope-from ) id 1l2hb4-00076R-AY; Thu, 21 Jan 2021 21:34:30 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 72470.130496; Thu, 21 Jan 2021 21:34:30 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1l2hb4-00076K-7Z; Thu, 21 Jan 2021 21:34:30 +0000 Received: by outflank-mailman (input) for mailman id 72470; Thu, 21 Jan 2021 21:34:29 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1l2hb3-00076F-9H for xen-devel@lists.xenproject.org; Thu, 21 Jan 2021 21:34:29 +0000 Received: from mail.kernel.org (unknown [198.145.29.99]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 3721b5b6-772e-48de-a5c9-5541648117ac; Thu, 21 Jan 2021 21:34:28 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id D774B2064A; Thu, 21 Jan 2021 21:34:26 +0000 (UTC) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 3721b5b6-772e-48de-a5c9-5541648117ac DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1611264867; bh=NwN1GqszfSYuIJwgLKM+mAL1gqjygo5NF8XehLPBgdc=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=DmyMFQTIDAl61bbhjorS43SRnIdPUXQTVY8Eut6wrrbc0k5I5wjHOEHDTpKLFAdeU QKKPunnKG/LFqeiNszZ13Go5KKuaUXqij6k2RFqULMvGghWC9uFF/4Fz1/N376oJj/ /QnwGrkTA1tTeBlQEtFc4wCWQBxv3ZaYKcYbE4+rTkkG1i8vmvn2HD3ntyXHaYC2my oVbyEiXivxnslIAMu0q5Iif/6EydR99tzf+/Kj1rIFtUxhasgKpN7Gg39VCKQKsfSY X3jBjYnLTGamGKgdSHqryR0374BsCEIP1sidnzsmWaXQJRwaAEi3MWRMfwAqtLU6Yh qB/ALEW3wLZ8A== Date: Thu, 21 Jan 2021 13:34:26 -0800 (PST) From: Stefano Stabellini X-X-Sender: sstabellini@sstabellini-ThinkPad-T480s To: Oleksandr cc: Stefano Stabellini , Julien Grall , xen-devel@lists.xenproject.org, Julien Grall , Volodymyr Babchuk , Oleksandr Tyshchenko Subject: Re: [PATCH V4 14/24] arm/ioreq: Introduce arch specific bits for IOREQ/DM features In-Reply-To: <4c682b4c-2deb-6d3a-fee1-588e36c89a93@gmail.com> Message-ID: References: <1610488352-18494-1-git-send-email-olekstysh@gmail.com> <1610488352-18494-15-git-send-email-olekstysh@gmail.com> <355e613a-3c9d-7978-62cd-a35df057e5cd@xen.org> <06704224-bb57-c55e-a2ee-23032095e8ea@xen.org> <9c12c1a7-81e3-20e9-7419-a625f23e4c27@xen.org> <4c682b4c-2deb-6d3a-fee1-588e36c89a93@gmail.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="8323329-462705362-1611264867=:30512" This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323329-462705362-1611264867=:30512 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT On Thu, 21 Jan 2021, Oleksandr wrote: > On 20.01.21 21:47, Stefano Stabellini wrote: > > On Wed, 20 Jan 2021, Julien Grall wrote: > > > Hi Stefano, > > > > > > On 20/01/2021 00:50, Stefano Stabellini wrote: > > > > On Tue, 19 Jan 2021, Oleksandr wrote: > > > > > diff --git a/xen/arch/arm/ioreq.c b/xen/arch/arm/ioreq.c > > > > > index 40b9e59..0508bd8 100644 > > > > > --- a/xen/arch/arm/ioreq.c > > > > > +++ b/xen/arch/arm/ioreq.c > > > > > @@ -101,12 +101,10 @@ enum io_state try_fwd_ioserv(struct > > > > > cpu_user_regs > > > > > *regs, > > > > > > > > > >  bool arch_ioreq_complete_mmio(void) > > > > >  { > > > > > -    struct vcpu *v = current; > > > > >      struct cpu_user_regs *regs = guest_cpu_user_regs(); > > > > >      const union hsr hsr = { .bits = regs->hsr }; > > > > > -    paddr_t addr = v->io.req.addr; > > > > > > > > > > -    if ( try_handle_mmio(regs, hsr, addr) == IO_HANDLED ) > > > > > +    if ( handle_ioserv(regs, current) == IO_HANDLED ) > > > > >      { > > > > >          advance_pc(regs, hsr); > > > > >          return true; > > > > Yes, but I think we want to keep the check > > > > > > > > vio->req.state == STATE_IORESP_READY > > > > > > > > So maybe (uncompiled, untested): > > > > > > > > if ( v->io.req.state != STATE_IORESP_READY ) > > > > return false; > > > Is it possible to reach this function with v->io.req.state != > > > STATE_IORESP_READY? If not, then I would suggest to add an > > > ASSERT_UNREACHABLE() before the return. > > If I am reading the state machine right it should *not* be possible to > > get here with v->io.req.state != STATE_IORESP_READY, so yes, > > ASSERT_UNREACHABLE() would work. > Agree here. If the assumption is not correct (unlikely), I think I will catch > this during testing. > In addition, we can probably drop case STATE_IORESP_READY in try_fwd_ioserv(). > > > [not tested] Yes, looks OK > diff --git a/xen/arch/arm/ioreq.c b/xen/arch/arm/ioreq.c > index 40b9e59..c7ee1a7 100644 > --- a/xen/arch/arm/ioreq.c > +++ b/xen/arch/arm/ioreq.c > @@ -71,9 +71,6 @@ enum io_state try_fwd_ioserv(struct cpu_user_regs *regs, >      case STATE_IOREQ_NONE: >          break; > > -    case STATE_IORESP_READY: > -        return IO_HANDLED; > - >      default: >          gdprintk(XENLOG_ERR, "wrong state %u\n", vio->req.state); >          return IO_ABORT; > @@ -104,9 +101,14 @@ bool arch_ioreq_complete_mmio(void) >      struct vcpu *v = current; >      struct cpu_user_regs *regs = guest_cpu_user_regs(); >      const union hsr hsr = { .bits = regs->hsr }; > -    paddr_t addr = v->io.req.addr; > > -    if ( try_handle_mmio(regs, hsr, addr) == IO_HANDLED ) > +    if ( v->io.req.state != STATE_IORESP_READY ) > +    { > +        ASSERT_UNREACHABLE(); > +        return false; > +    } > + > +    if ( handle_ioserv(regs, v) == IO_HANDLED ) >      { >          advance_pc(regs, hsr); >          return true; --8323329-462705362-1611264867=:30512--