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

[Jason Wang <jasowang@redhat.com>]

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.

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
>