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bh=Q0Uqqw0vMQHQ0jthcPNOutKIY73nfeO1L0aqWtO2toE=; b=i/7tagwaMKR+OJWT8n0zMrQJwK7xMUSdlCVCdAZSHH4Alb9MTtXdrvN6P+PPJON0EvYvdi 58OyBE+jdS8lvDObKsnst7yJHLiqmWDO0vx99ydfRuCACr0lcQlB7t+8x5XI3GBjqRJTZw Bzbfwh95UFKDX3zkg7gzYU6jPIrqhls= 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-302-QPQetmxuNleoX6mgTbA1SQ-1; Thu, 09 Sep 2021 03:27:22 -0400 X-MC-Unique: QPQetmxuNleoX6mgTbA1SQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1C39880196C; Thu, 9 Sep 2021 07:27:21 +0000 (UTC) Received: from localhost (unknown [10.39.192.148]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1A71B6A902; Thu, 9 Sep 2021 07:27:16 +0000 (UTC) Date: Thu, 9 Sep 2021 08:27:16 +0100 From: Stefan Hajnoczi To: Jagannathan Raman Subject: Re: [PATCH RFC server v2 06/11] vfio-user: handle PCI config space accesses Message-ID: References: <5f371fa15eb347317ce9ce56a329a24c713129e0.1630084211.git.jag.raman@oracle.com> MIME-Version: 1.0 In-Reply-To: <5f371fa15eb347317ce9ce56a329a24c713129e0.1630084211.git.jag.raman@oracle.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 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="nlEl5rc/0XC4+xor" 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: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.393, 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=ham 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: elena.ufimtseva@oracle.com, john.g.johnson@oracle.com, thuth@redhat.com, swapnil.ingle@nutanix.com, john.levon@nutanix.com, philmd@redhat.com, qemu-devel@nongnu.org, alex.williamson@redhat.com, marcandre.lureau@gmail.com, thanos.makatos@nutanix.com, alex.bennee@linaro.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --nlEl5rc/0XC4+xor Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Fri, Aug 27, 2021 at 01:53:25PM -0400, Jagannathan Raman wrote: > +static ssize_t vfu_object_cfg_access(vfu_ctx_t *vfu_ctx, char * const buf, > + size_t count, loff_t offset, > + const bool is_write) > +{ > + VfuObject *o = vfu_get_private(vfu_ctx); > + uint32_t pci_access_width = sizeof(uint32_t); > + size_t bytes = count; > + uint32_t val = 0; > + char *ptr = buf; > + int len; > + > + while (bytes > 0) { > + len = (bytes > pci_access_width) ? pci_access_width : bytes; > + if (is_write) { > + memcpy(&val, ptr, len); > + pci_default_write_config(PCI_DEVICE(o->pci_dev), > + offset, val, len); > + trace_vfu_cfg_write(offset, val); > + } else { > + val = pci_default_read_config(PCI_DEVICE(o->pci_dev), > + offset, len); > + memcpy(ptr, &val, len); pci_default_read_config() returns a host-endian 32-bit value. This code looks wrong because it copies different bytes on big- and little-endian hosts. > + trace_vfu_cfg_read(offset, val); > + } Why call pci_default_read/write_config() directly instead of pci_dev->config_read/write()? --nlEl5rc/0XC4+xor Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEEhpWov9P5fNqsNXdanKSrs4Grc8gFAmE5t1QACgkQnKSrs4Gr c8hgiQf8DhKk0Nhh3cJ5zax1D+KjFJm7sNeDO5n1qCdemjZl+lWh/1z7B7M/llCq NBEW0LIlSi/JP5M4GOnW/Lp39EmAjfoK98vIxoKPHowxUoYxQdKJ9NWsEFKLmFkO ooVpJnt1Ju2+zIiuKepKQSIEbl2yYLHkC/PziZWX99q6i+it1HOYC726KUFj0lfP iJHTfP1kFhhTwRNRumAFxBQEWl2IWV0Ojos2HZXg7x4Z9bNy6bCt8IEESiiC4mWf v9hGfTl16hvQRuPyQikN3u2ldeFG+HF1pbS8KPaBjNkFkq1L4osLWNPInOFBqTLI ZqeEQOvjtuPERUHXQfQrO9YSOcFgAQ== =TmZl -----END PGP SIGNATURE----- --nlEl5rc/0XC4+xor--