Modern (v1.0) virtio pci device defines several pci capabilities.
Each cap has a configure structure corresponding to it, and the
cap.bar and cap.offset fields tell us where to find it.
Firstly, we map the pci resources by rte_eal_pci_map_device().
We then could easily locate a cfg structure by:
cfg_addr = dev->mem_resources[cap.bar].addr + cap.offset;
Therefore, the entrance of enabling modern (v1.0) pci device support
is to iterate the pci capability lists, and to locate some configs
we care; and they are:
- common cfg
For generic virtio and virtqueue configuration, such as setting/getting
features, enabling a specific queue, and so on.
- nofity cfg
Combining with `queue_notify_off' from common cfg, we could use it to
notify a specific virt queue.
- device cfg
Where virtio_net_config structure is located.
- isr cfg
Where to read isr (interrupt status).
If any of above cap is not found, we fallback to the legacy virtio
handling.
If succeed, hw->vtpci_ops is assigned to modern_ops, where all
operations are implemented by reading/writing a (or few) specific
configuration space from above 4 cfg structures. And that's basically
how this patch works.
Besides those changes, virtio 1.0 introduces a new status field:
FEATURES_OK, which is set after features negotiation is done.
Last, set the VIRTIO_F_VERSION_1 feature flag.
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Tested-by: Qian Xu <qian.q.xu@intel.com>
Reviewed-by: Tetsuya Mukawa <mukawa@igel.co.jp>
Tested-by: Tetsuya Mukawa <mukawa@igel.co.jp>
Acked-by: Huawei Xie <huawei.xie@intel.com>
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