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

[Michael S. Tsirkin]

On Wed, Jan 05, 2022 at 08:58:51AM +0800, Longpeng(Mike) 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".

ton of typos here.

> 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;


if this is transitional as comment says make it explicit
in the names and comments.

> +
> +static const VirtIOPCIIDInfo virtio_pci_id_info[] = {
> +    {
> +        .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,
> +    },
> +};
> +


this is the list from the spec:


So this is the list from the spec:

0x1000 network card
0x1001 block device
0x1002 memory ballooning (traditional)
0x1003 console
0x1004 SCSI host
0x1005 entropy source
0x1009 9P transport


I'd drop all the rest, use the algorithm for non transitional.
And when class is other I'd just not include it in the array,
make this the default.



> +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