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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 27CB6C433EF for ; Thu, 6 Jan 2022 01:52:41 +0000 (UTC) Received: from localhost ([::1]:48654 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1n5HxH-0001uX-Th for qemu-devel@archiver.kernel.org; Wed, 05 Jan 2022 20:52:39 -0500 Received: from eggs.gnu.org ([209.51.188.92]:57756) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n5HvI-00015S-B6 for qemu-devel@nongnu.org; Wed, 05 Jan 2022 20:50:36 -0500 Received: from szxga02-in.huawei.com ([45.249.212.188]:3068) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1n5HvE-0006qm-R0 for qemu-devel@nongnu.org; Wed, 05 Jan 2022 20:50:36 -0500 Received: from dggpeml500025.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4JTq6S54XBzbjrY; Thu, 6 Jan 2022 09:49:52 +0800 (CST) Received: from dggpeml100025.china.huawei.com (7.185.36.37) by dggpeml500025.china.huawei.com (7.185.36.35) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Thu, 6 Jan 2022 09:50:27 +0800 Received: from dggpeml100016.china.huawei.com (7.185.36.216) by dggpeml100025.china.huawei.com (7.185.36.37) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.20; Thu, 6 Jan 2022 09:50:27 +0800 Received: from dggpeml100016.china.huawei.com ([7.185.36.216]) by dggpeml100016.china.huawei.com ([7.185.36.216]) with mapi id 15.01.2308.020; Thu, 6 Jan 2022 09:50:27 +0800 To: Cornelia Huck , "stefanha@redhat.com" , "mst@redhat.com" , "jasowang@redhat.com" , "sgarzare@redhat.com" CC: "pbonzini@redhat.com" , "Gonglei (Arei)" , Yechuan , Huangzhichao , "qemu-devel@nongnu.org" Subject: RE: [RFC 01/10] virtio: get class_id and pci device id by the virtio id Thread-Topic: [RFC 01/10] virtio: get class_id and pci device id by the virtio id Thread-Index: AQHYAc9vCeFWPgdrrU+qsnWZQ04FAaxTuSQAgAF7zAA= Date: Thu, 6 Jan 2022 01:50:27 +0000 Message-ID: <3ce8898bceba45a8a2ecd2189ee9dee2@huawei.com> References: <20220105005900.860-1-longpeng2@huawei.com> <20220105005900.860-2-longpeng2@huawei.com> <87h7aiwjdf.fsf@redhat.com> In-Reply-To: <87h7aiwjdf.fsf@redhat.com> Accept-Language: zh-CN, en-US Content-Language: zh-CN X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.174.148.223] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.188; envelope-from=longpeng2@huawei.com; helo=szxga02-in.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Reply-to: "Longpeng (Mike, Cloud Infrastructure Service Product Dept.)" From: longpeng2--- via > -----Original Message----- > From: Cornelia Huck [mailto:cohuck@redhat.com] > Sent: Wednesday, January 5, 2022 6:46 PM > To: Longpeng (Mike, Cloud Infrastructure Service Product Dept.) > ; stefanha@redhat.com; mst@redhat.com; > jasowang@redhat.com; sgarzare@redhat.com > Cc: pbonzini@redhat.com; Gonglei (Arei) ; Yechua= n > ; Huangzhichao ; > qemu-devel@nongnu.org; Longpeng (Mike, Cloud Infrastructure Service Produ= ct > Dept.) > Subject: Re: [RFC 01/10] virtio: get class_id and pci device id by the vi= rtio > id >=20 > On Wed, Jan 05 2022, "Longpeng(Mike)" wrote: >=20 > > From: Longpeng > > > > Add helpers to get the "Transitional PCI Device ID" and "class_id" of t= he > > deivce which is specificed by the "Virtio Device ID". > > > > These helpers will be used to build the generic vDPA device later. > > > > Signed-off-by: Longpeng > > --- > > hw/virtio/virtio-pci.c | 93 ++++++++++++++++++++++++++++++++++++++++++ > > hw/virtio/virtio-pci.h | 4 ++ > > 2 files changed, 97 insertions(+) > > > > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > > index 750aa47ec1..843085c4ea 100644 > > --- a/hw/virtio/virtio-pci.c > > +++ b/hw/virtio/virtio-pci.c > > @@ -19,6 +19,7 @@ > > > > #include "exec/memop.h" > > #include "standard-headers/linux/virtio_pci.h" > > +#include "standard-headers/linux/virtio_ids.h" > > #include "hw/boards.h" > > #include "hw/virtio/virtio.h" > > #include "migration/qemu-file-types.h" > > @@ -213,6 +214,95 @@ static int virtio_pci_load_queue(DeviceState *d, i= nt n, > QEMUFile *f) > > return 0; > > } > > > > +typedef struct VirtIOPCIIDInfo { > > + uint16_t vdev_id; /* virtio id */ > > + uint16_t pdev_id; /* pci device id */ > > + uint16_t class_id; > > +} VirtIOPCIIDInfo; > > + > > +static const VirtIOPCIIDInfo virtio_pci_id_info[] =3D { > > + { > > + .vdev_id =3D VIRTIO_ID_NET, > > + .pdev_id =3D PCI_DEVICE_ID_VIRTIO_NET, > > + .class_id =3D PCI_CLASS_NETWORK_ETHERNET, > > + }, > > + { > > + .vdev_id =3D VIRTIO_ID_BLOCK, > > + .pdev_id =3D PCI_DEVICE_ID_VIRTIO_BLOCK, > > + .class_id =3D PCI_CLASS_STORAGE_SCSI, > > + }, > > + { > > + .vdev_id =3D VIRTIO_ID_CONSOLE, > > + .pdev_id =3D PCI_DEVICE_ID_VIRTIO_CONSOLE, > > + .class_id =3D PCI_CLASS_COMMUNICATION_OTHER, > > + }, > > + { > > + .vdev_id =3D VIRTIO_ID_SCSI, > > + .pdev_id =3D PCI_DEVICE_ID_VIRTIO_SCSI, > > + .class_id =3D PCI_CLASS_STORAGE_SCSI, > > + }, > > + { > > + .vdev_id =3D VIRTIO_ID_9P, > > + .pdev_id =3D PCI_DEVICE_ID_VIRTIO_9P, > > + .class_id =3D PCI_BASE_CLASS_NETWORK, > > + }, > > + { > > + .vdev_id =3D VIRTIO_ID_VSOCK, > > + .pdev_id =3D PCI_DEVICE_ID_VIRTIO_VSOCK, > > + .class_id =3D PCI_CLASS_COMMUNICATION_OTHER, > > + }, > > + { > > + .vdev_id =3D VIRTIO_ID_IOMMU, > > + .pdev_id =3D PCI_DEVICE_ID_VIRTIO_IOMMU, > > + .class_id =3D PCI_CLASS_OTHERS, > > + }, > > + { > > + .vdev_id =3D VIRTIO_ID_MEM, > > + .pdev_id =3D PCI_DEVICE_ID_VIRTIO_MEM, > > + .class_id =3D PCI_CLASS_OTHERS, > > + }, > > + { > > + .vdev_id =3D VIRTIO_ID_PMEM, > > + .pdev_id =3D PCI_DEVICE_ID_VIRTIO_PMEM, > > + .class_id =3D PCI_CLASS_OTHERS, > > + }, > > + { > > + .vdev_id =3D VIRTIO_ID_RNG, > > + .pdev_id =3D PCI_DEVICE_ID_VIRTIO_RNG, > > + .class_id =3D PCI_CLASS_OTHERS, > > + }, > > + { > > + .vdev_id =3D VIRTIO_ID_BALLOON, > > + .pdev_id =3D PCI_DEVICE_ID_VIRTIO_BALLOON, > > + .class_id =3D PCI_CLASS_OTHERS, > > + }, > > +}; > > + > > +static VirtIOPCIIDInfo virtio_pci_get_id_info(uint16_t vdev_id) > > +{ > > + VirtIOPCIIDInfo info =3D {}; > > + int i; > > + > > + for (i =3D 0; i < ARRAY_SIZE(virtio_pci_id_info); i++) { > > + if (virtio_pci_id_info[i].vdev_id =3D=3D vdev_id) { > > + info =3D virtio_pci_id_info[i]; > > + break; > > + } > > + } > > + > > + return info; > > +} > > + > > +uint16_t virtio_pci_get_pci_devid(uint16_t device_id) > > +{ > > + return virtio_pci_get_id_info(device_id).pdev_id; > > +} > > + > > +uint16_t virtio_pci_get_class_id(uint16_t device_id) > > +{ > > + return virtio_pci_get_id_info(device_id).class_id; > > +} >=20 > What happens if these functions are called for a device_id that is not > in the array, e.g. if we forgot to add a new id to the array? >=20 It would return pdev_id=3D0 or class_id=3D0 as a result, the virtio device with pdev_id=3D0 is undefined and class_id=3D0 is also treated as undefined (PCI_CLASS_NOT_DEFINED), so the caller should check the returned value. > Can the array be generated in some way? For PCI Device ID: - If we need to support Transitional VIRTIO devices, there's no algorithm can map a VIRTIO ID to a PCI Device ID. - If we only need to support 1.0+ VIRTIO devices, then we can calculate t= he PCI Device ID based on the VIRTIO ID. For Class ID, seems no way :(