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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 3913BC4338F for ; Tue, 24 Aug 2021 13:15:47 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 B502A61184 for ; Tue, 24 Aug 2021 13:15:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org B502A61184 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:56596 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mIWHJ-0008Hg-Rv for qemu-devel@archiver.kernel.org; Tue, 24 Aug 2021 09:15:45 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37204) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mIWFu-0006KW-Lq for qemu-devel@nongnu.org; Tue, 24 Aug 2021 09:14:20 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:33589) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mIWFo-0007Ve-SX for qemu-devel@nongnu.org; Tue, 24 Aug 2021 09:14:17 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1629810852; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=1QE+M34kcTP9WCNm+Yo11ot6qt4mZK3JirqZW1/f6zM=; b=IP885ca/jRebAcQL/GGLVdjMmuQ3k4yREN37l4UsTqbEBv6Rzp35EQgksbY3ABjBtD2F0W ngS1xk6QhCJz8EdejrF2WC97Y/3jEE1Pxr0NVx863Bu6zUHX0bSIUM38rydBAWdCXhWq9A 50N6OcZi9OkJBfClCx6Mgz634VCxImc= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-356-o8SuB3W8OjSAGy-EEHllzQ-1; Tue, 24 Aug 2021 09:14:08 -0400 X-MC-Unique: o8SuB3W8OjSAGy-EEHllzQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 3ADF3195D562; Tue, 24 Aug 2021 13:14:07 +0000 (UTC) Received: from localhost (unknown [10.39.195.0]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8004010190AA; Tue, 24 Aug 2021 13:13:55 +0000 (UTC) Date: Tue, 24 Aug 2021 14:13:54 +0100 From: Stefan Hajnoczi To: Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= Subject: Re: [RFC PATCH v2 4/5] softmmu/physmem: Introduce flatview_access_allowed() to check bus perms Message-ID: References: <20210823164157.751807-1-philmd@redhat.com> <20210823164157.751807-5-philmd@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210823164157.751807-5-philmd@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=stefanha@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="O53VH+xqE05Cq3WD" Content-Disposition: inline Received-SPF: pass client-ip=170.10.133.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.747, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , David Hildenbrand , Jason Wang , Li Qiang , qemu-devel@nongnu.org, Peter Xu , Qiuhao Li , Alexander Bulekov , qemu-arm@nongnu.org, Gerd Hoffmann , Paolo Bonzini , "Edgar E . Iglesias" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --O53VH+xqE05Cq3WD Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Aug 23, 2021 at 06:41:56PM +0200, Philippe Mathieu-Daud=E9 wrote: > Introduce flatview_access_allowed() to check bus permission > before running any bus transaction. For now this is a simple > stub. >=20 > Signed-off-by: Philippe Mathieu-Daud=E9 > --- > softmmu/physmem.c | 37 +++++++++++++++++++++++++++++++++++-- > 1 file changed, 35 insertions(+), 2 deletions(-) >=20 > diff --git a/softmmu/physmem.c b/softmmu/physmem.c > index e534dc69918..0d31a2f4199 100644 > --- a/softmmu/physmem.c > +++ b/softmmu/physmem.c > @@ -2754,6 +2754,27 @@ static bool prepare_mmio_access(MemoryRegion *mr) > return release_lock; > } > =20 > +/** > + * flatview_access_allowed > + * @mr: #MemoryRegion to be accessed > + * @attrs: memory transaction attributes > + * @addr: address within that memory region > + * @len: the number of bytes to access > + * @result: optional pointer to a MemTxResult or NULL > + * > + * Check if a memory transaction is allowed. If an error occurs this > + * method will return false to indicate denial, as well as setting > + * @result to contain corresponding #MemTxResult. > + * > + * Returns: true if transaction is allowed, false if denied. > + */ > +static inline bool flatview_access_allowed(MemoryRegion *mr, MemTxAttrs = attrs, > + hwaddr addr, hwaddr len, > + MemTxResult *result) > +{ > + return true; > +} The callers below don't benefit from the result pointer argument. The code would be clearer if they did: if (!flatview_access_allowed(...)) { return MEMTX_BUS_ERROR; } > + > /* Called within RCU critical section. */ > static MemTxResult flatview_write_continue(FlatView *fv, hwaddr addr, > MemTxAttrs attrs, > @@ -2768,7 +2789,9 @@ static MemTxResult flatview_write_continue(FlatView= *fv, hwaddr addr, > const uint8_t *buf =3D ptr; > =20 > for (;;) { > - if (!memory_access_is_direct(mr, true)) { > + if (!flatview_access_allowed(mr, attrs, addr1, l, &result)) { > + /* 'result' contains the error, keep going. */ > + } else if (!memory_access_is_direct(mr, true)) { > release_lock |=3D prepare_mmio_access(mr); > l =3D memory_access_size(mr, l, addr1); > /* XXX: could force current_cpu to NULL to avoid > @@ -2810,9 +2833,13 @@ static MemTxResult flatview_write(FlatView *fv, hw= addr addr, MemTxAttrs attrs, > hwaddr l; > hwaddr addr1; > MemoryRegion *mr; > + MemTxResult result =3D MEMTX_OK; > =20 > l =3D len; > mr =3D flatview_translate(fv, addr, &addr1, &l, true, attrs); > + if (!flatview_access_allowed(mr, attrs, addr, len, &result)) { > + return result; > + } > return flatview_write_continue(fv, addr, attrs, buf, len, > addr1, l, mr); > } > @@ -2831,7 +2858,9 @@ MemTxResult flatview_read_continue(FlatView *fv, hw= addr addr, > =20 > fuzz_dma_read_cb(addr, len, mr); > for (;;) { > - if (!memory_access_is_direct(mr, false)) { > + if (!flatview_access_allowed(mr, attrs, addr1, l, &result)) { > + /* 'result' contains the error, keep going. */ > + } else if (!memory_access_is_direct(mr, false)) { > /* I/O case */ > release_lock |=3D prepare_mmio_access(mr); > l =3D memory_access_size(mr, l, addr1); > @@ -2871,9 +2900,13 @@ static MemTxResult flatview_read(FlatView *fv, hwa= ddr addr, > hwaddr l; > hwaddr addr1; > MemoryRegion *mr; > + MemTxResult result =3D MEMTX_OK; > =20 > l =3D len; > mr =3D flatview_translate(fv, addr, &addr1, &l, false, attrs); > + if (!flatview_access_allowed(mr, attrs, addr, len, &result)) { > + return result; > + } > return flatview_read_continue(fv, addr, attrs, buf, len, > addr1, l, mr); > } > --=20 > 2.31.1 >=20 --O53VH+xqE05Cq3WD Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmEk8JIACgkQnKSrs4Gr c8hF6Af/ScsnqIj9L0t2/ieWLqF57Gia0cUxxwheFNxzLtH6WU7DLArHC9Fe4jJe 8rVHsa5BOEVVB9YfMDJKZb0aS/d9n9wpbPY3ts2Kpgto3mP09DQIU+CddXjEUapI zq3uD0O5r/1JVd517ZZIhpok4KK+3EC/pwpbZwwBeR2XEme9VVi7J45fLlJgR2k5 Ms03UQY8cRUCQcE1bQk8nSU160PwTDsSiwpEiVXrwdtXa56BLtt2TvxAlDGFd4lJ 27jwSe++wlMwP21DGxMPULl4EyKHW3EcGYxsUjgKlmj2joD8kLzQzuRB7q2wAb7z 0hxFeZm5JQCfV4giwvg+p27MMRXwDg== =YgB+ -----END PGP SIGNATURE----- --O53VH+xqE05Cq3WD--