2023年2月4日(土) 7:15 Frank Li <frank.li@xxxxxxx>: > > > > > Caution: EXT Email > > > > On Fri, Feb 03, 2023 at 07:04:18PM +0900, Shunsuke Mie wrote: > > > Add a new endpoint(EP) function driver to provide virtio-net device. This > > > function not only shows virtio-net device for PCIe host system, but also > > > provides virtio-net device to EP side(local) system. Virtualy those network > > > devices are connected, so we can use to communicate over IP like a simple > > > NIC. > > > > > > Architecture overview is following: > > > > > > to Host | to Endpoint > > > network stack | network stack > > > | | | > > > +-----------+ | +-----------+ +-----------+ > > > |virtio-net | | |virtio-net | |virtio-net | > > > |driver | | |EP function|---|driver | > > > +-----------+ | +-----------+ +-----------+ > > > | | | > > > +-----------+ | +-----------+ > > > |PCIeC | | |PCIeC | > > > |Rootcomplex|-|-|Endpoint | > > > +-----------+ | +-----------+ > > > Host side | Endpoint side > > > > > > This driver uses PCIe EP framework to show virtio-net (pci) device Host > > > side, and generate virtual virtio-net device and register to EP side. > > > A communication date > > > > data? > > > > > is diractly > > > > directly? > > > > > transported between virtqueue level > > > with each other using PCIe embedded DMA controller. > > > > > > by a limitation of the hardware and Linux EP framework, this function > > > follows a virtio legacy specification. > > > > what exactly is the limitation and why does it force legacy? > > > > > This function driver has beed tested on S4 Rcar (r8a779fa-spider) board but > > > just use the PCIe EP framework and depends on the PCIe EDMA. > > > > > > Signed-off-by: Shunsuke Mie <mie@xxxxxxxxxx> > > > Signed-off-by: Takanari Hayama <taki@xxxxxxxxxx> > > > --- > > > drivers/pci/endpoint/functions/Kconfig | 12 + > > > drivers/pci/endpoint/functions/Makefile | 1 + > > > .../pci/endpoint/functions/pci-epf-vnet-ep.c | 343 ++++++++++ > > It is actually that not related vnet. Just virtio. > I think pci-epf-virtio.c is better. Yes, it have to be. > > > .../pci/endpoint/functions/pci-epf-vnet-rc.c | 635 ++++++++++++++++++ > > It is epf driver. rc is quite confused. > Maybe you can combine pci-epf-vnet-ep.c and pci-epf-vnet-rc.c to one file. I agree. Try to combine them > > > drivers/pci/endpoint/functions/pci-epf-vnet.c | 387 +++++++++++ > > This file setup dma transfer according virtio-ring. > How about pci-epf-virtio-dma.c ? I attempt to rearrange the location of code and filenames. > > > + > > > + epf_vnet_rc_set_config16(vnet, VIRTIO_PCI_ISR, > > VIRTIO_PCI_ISR_QUEUE); > > > + /* > > > + * Initialize the queue notify and selector to outside of the appropriate > > > + * virtqueue index. It is used to detect change with polling. There is no > > > + * other ways to detect host side driver updateing those values > > > + */ > > I am try to use gic-its or other msi controller as doorbell. > https://lore.kernel.org/imx/20221125192729.1722913-1-Frank.Li@xxxxxxx/T/#u > > but it may need update host side pci virtio driver. Thanks, is it possible to use MSI-X as well? The virtio spec indicates to use legacy irq or MSI-X only. > > > + epf_vnet_rc_set_config16(vnet, VIRTIO_PCI_QUEUE_NOTIFY, > > default_qindex); > > > + epf_vnet_rc_set_config16(vnet, VIRTIO_PCI_QUEUE_SEL, > > default_qindex); > > > + /* This pfn is also set to 0 for the polling as well */ > > > + epf_vnet_rc_set_config16(vnet, VIRTIO_PCI_QUEUE_PFN, 0); > > > + > > -- > > > 2.25.1 > Best, Shunsuke.
