RE: [RFC 01/10] virtio: get class_id and pci device id by the virtio id

[longpeng2--- via <qemu-devel@nongnu.org>]

> -----Original Message-----
> From: Jason Wang [mailto:jasowang@redhat.com]
> Sent: Wednesday, January 5, 2022 2:15 PM
> To: Longpeng (Mike, Cloud Infrastructure Service Product Dept.)
> <longpeng2@huawei.com>
> Cc: Stefan Hajnoczi <stefanha@redhat.com>; mst <mst@redhat.com>; Stefano
> Garzarella <sgarzare@redhat.com>; Cornelia Huck <cohuck@redhat.com>; pbonzini
> <pbonzini@redhat.com>; Gonglei (Arei) <arei.gonglei@huawei.com>; Yechuan
> <yechuan@huawei.com>; Huangzhichao <huangzhichao@huawei.com>; qemu-devel
> <qemu-devel@nongnu.org>
> Subject: Re: [RFC 01/10] virtio: get class_id and pci device id by the virtio
> id
> 
> On Wed, Jan 5, 2022 at 1:48 PM Longpeng (Mike, Cloud Infrastructure
> Service Product Dept.) <longpeng2@huawei.com> wrote:
> >
> >
> >
> > > -----Original Message-----
> > > From: Jason Wang [mailto:jasowang@redhat.com]
> > > Sent: Wednesday, January 5, 2022 12:38 PM
> > > To: Longpeng (Mike, Cloud Infrastructure Service Product Dept.)
> > > <longpeng2@huawei.com>
> > > Cc: Stefan Hajnoczi <stefanha@redhat.com>; mst <mst@redhat.com>; Stefano
> > > Garzarella <sgarzare@redhat.com>; Cornelia Huck <cohuck@redhat.com>;
> pbonzini
> > > <pbonzini@redhat.com>; Gonglei (Arei) <arei.gonglei@huawei.com>; Yechuan
> > > <yechuan@huawei.com>; Huangzhichao <huangzhichao@huawei.com>; qemu-devel
> > > <qemu-devel@nongnu.org>
> > > Subject: Re: [RFC 01/10] virtio: get class_id and pci device id by the virtio
> > > id
> > >
> > > On Wed, Jan 5, 2022 at 8:59 AM Longpeng(Mike) <longpeng2@huawei.com> wrote:
> > > >
> > > > From: Longpeng <longpeng2@huawei.com>
> > > >
> > > > Add helpers to get the "Transitional PCI Device ID" and "class_id" of the
> > > > 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 <longpeng2@huawei.com>
> > > > ---
> > > >  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, int
> 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[] = {
> > > > +    {
> > >
> > > Any way to get rid of this array? E.g using the algorithm that is used
> > > by the kernel virtio driver.
> > >
> >
> > For device id, we can use the algorithm if we no need to support
> > Transitional id. But how to get the class id ?
> 
> Right, I miss this. So the current code should be fine.
> 

Maybe the following way would be better? It can save about 40 lines.

#define VIRTIO_PCI_ID_INFO(name, class)   \
    {VIRTIO_ID_##name, PCI_DEVICE_ID_VIRTIO_##name, class}

static const VirtIOPCIIDInfo virtio_pci_id_info[] = {
    VIRTIO_PCI_ID_INFO(NET,     PCI_CLASS_NETWORK_ETHERNET),
    VIRTIO_PCI_ID_INFO(BLOCK,   PCI_CLASS_STORAGE_SCSI),
    VIRTIO_PCI_ID_INFO(SCSI,    PCI_CLASS_STORAGE_SCSI),
    VIRTIO_PCI_ID_INFO(CONSOLE, PCI_CLASS_COMMUNICATION_OTHER),
    VIRTIO_PCI_ID_INFO(VSOCK,   PCI_CLASS_COMMUNICATION_OTHER),
    VIRTIO_PCI_ID_INFO(IOMMU,   PCI_CLASS_OTHERS),
    VIRTIO_PCI_ID_INFO(MEM,     PCI_CLASS_OTHERS),
    VIRTIO_PCI_ID_INFO(PMEM,    PCI_CLASS_OTHERS),
    VIRTIO_PCI_ID_INFO(RNG,     PCI_CLASS_OTHERS),
    VIRTIO_PCI_ID_INFO(BALLOON, PCI_CLASS_OTHERS),
    VIRTIO_PCI_ID_INFO(9P,      PCI_BASE_CLASS_NETWORK),
};


> Thanks
> 
> >
> > > Thanks
> > >
> > > > +        .vdev_id = VIRTIO_ID_NET,
> > > > +        .pdev_id = PCI_DEVICE_ID_VIRTIO_NET,
> > > > +        .class_id = PCI_CLASS_NETWORK_ETHERNET,
> > > > +    },
> > > > +    {
> > > > +        .vdev_id = VIRTIO_ID_BLOCK,
> > > > +        .pdev_id = PCI_DEVICE_ID_VIRTIO_BLOCK,
> > > > +        .class_id = PCI_CLASS_STORAGE_SCSI,
> > > > +    },
> > > > +    {
> > > > +        .vdev_id = VIRTIO_ID_CONSOLE,
> > > > +        .pdev_id = PCI_DEVICE_ID_VIRTIO_CONSOLE,
> > > > +        .class_id = PCI_CLASS_COMMUNICATION_OTHER,
> > > > +    },
> > > > +    {
> > > > +        .vdev_id = VIRTIO_ID_SCSI,
> > > > +        .pdev_id = PCI_DEVICE_ID_VIRTIO_SCSI,
> > > > +        .class_id = PCI_CLASS_STORAGE_SCSI,
> > > > +    },
> > > > +    {
> > > > +        .vdev_id = VIRTIO_ID_9P,
> > > > +        .pdev_id = PCI_DEVICE_ID_VIRTIO_9P,
> > > > +        .class_id = PCI_BASE_CLASS_NETWORK,
> > > > +    },
> > > > +    {
> > > > +        .vdev_id = VIRTIO_ID_VSOCK,
> > > > +        .pdev_id = PCI_DEVICE_ID_VIRTIO_VSOCK,
> > > > +        .class_id = PCI_CLASS_COMMUNICATION_OTHER,
> > > > +    },
> > > > +    {
> > > > +        .vdev_id = VIRTIO_ID_IOMMU,
> > > > +        .pdev_id = PCI_DEVICE_ID_VIRTIO_IOMMU,
> > > > +        .class_id = PCI_CLASS_OTHERS,
> > > > +    },
> > > > +    {
> > > > +        .vdev_id = VIRTIO_ID_MEM,
> > > > +        .pdev_id = PCI_DEVICE_ID_VIRTIO_MEM,
> > > > +        .class_id = PCI_CLASS_OTHERS,
> > > > +    },
> > > > +    {
> > > > +        .vdev_id = VIRTIO_ID_PMEM,
> > > > +        .pdev_id = PCI_DEVICE_ID_VIRTIO_PMEM,
> > > > +        .class_id = PCI_CLASS_OTHERS,
> > > > +    },
> > > > +    {
> > > > +        .vdev_id = VIRTIO_ID_RNG,
> > > > +        .pdev_id = PCI_DEVICE_ID_VIRTIO_RNG,
> > > > +        .class_id = PCI_CLASS_OTHERS,
> > > > +    },
> > > > +    {
> > > > +        .vdev_id = VIRTIO_ID_BALLOON,
> > > > +        .pdev_id = PCI_DEVICE_ID_VIRTIO_BALLOON,
> > > > +        .class_id = PCI_CLASS_OTHERS,
> > > > +    },
> > > > +};
> > > > +
> > > > +static VirtIOPCIIDInfo virtio_pci_get_id_info(uint16_t vdev_id)
> > > > +{
> > > > +    VirtIOPCIIDInfo info = {};
> > > > +    int i;
> > > > +
> > > > +    for (i = 0; i < ARRAY_SIZE(virtio_pci_id_info); i++) {
> > > > +        if (virtio_pci_id_info[i].vdev_id == vdev_id) {
> > > > +            info = 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;
> > > > +}
> > > > +
> > > >  static bool virtio_pci_ioeventfd_enabled(DeviceState *d)
> > > >  {
> > > >      VirtIOPCIProxy *proxy = to_virtio_pci_proxy(d);
> > > > @@ -1674,6 +1764,9 @@ static void virtio_pci_device_plugged(DeviceState
> *d,
> > > Error **errp)
> > > >           * is set to PCI_SUBVENDOR_ID_REDHAT_QUMRANET by default.
> > > >           */
> > > >          pci_set_word(config + PCI_SUBSYSTEM_ID,
> > > virtio_bus_get_vdev_id(bus));
> > > > +        if (proxy->pdev_id) {
> > > > +            pci_config_set_device_id(config, proxy->pdev_id);
> > > > +        }
> > > >      } else {
> > > >          /* pure virtio-1.0 */
> > > >          pci_set_word(config + PCI_VENDOR_ID,
> > > > diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
> > > > index 2446dcd9ae..06aa59436e 100644
> > > > --- a/hw/virtio/virtio-pci.h
> > > > +++ b/hw/virtio/virtio-pci.h
> > > > @@ -146,6 +146,7 @@ struct VirtIOPCIProxy {
> > > >      bool disable_modern;
> > > >      bool ignore_backend_features;
> > > >      OnOffAuto disable_legacy;
> > > > +    uint16_t pdev_id;
> > > >      uint32_t class_code;
> > > >      uint32_t nvectors;
> > > >      uint32_t dfselect;
> > > > @@ -158,6 +159,9 @@ struct VirtIOPCIProxy {
> > > >      VirtioBusState bus;
> > > >  };
> > > >
> > > > +uint16_t virtio_pci_get_pci_devid(uint16_t device_id);
> > > > +uint16_t virtio_pci_get_class_id(uint16_t device_id);
> > > > +
> > > >  static inline bool virtio_pci_modern(VirtIOPCIProxy *proxy)
> > > >  {
> > > >      return !proxy->disable_modern;
> > > > --
> > > > 2.23.0
> > > >
> >