Messages in this thread | ![/](/images/icornerl.gif) | | Date | Mon, 17 Apr 2023 11:11:46 +0900 | Subject | Re: [EXT] [RFC PATCH 0/3] Introduce a PCIe endpoint virtio console | From | Shunsuke Mie <> |
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On 2023/04/14 23:39, Frank Li wrote: > >> -----Original Message----- >> From: Shunsuke Mie <mie@igel.co.jp> >> Sent: Friday, April 14, 2023 7:39 AM >> To: Lorenzo Pieralisi <lpieralisi@kernel.org> >> Cc: Krzysztof Wilczyński <kw@linux.com>; Manivannan Sadhasivam >> <mani@kernel.org>; Kishon Vijay Abraham I <kishon@kernel.org>; Bjorn >> Helgaas <bhelgaas@google.com>; Michael S. Tsirkin <mst@redhat.com>; >> Jason Wang <jasowang@redhat.com>; Shunsuke Mie <mie@igel.co.jp>; >> Frank Li <frank.li@nxp.com>; Jon Mason <jdmason@kudzu.us>; Randy >> Dunlap <rdunlap@infradead.org>; Ren Zhijie <renzhijie2@huawei.com>; >> linux-kernel@vger.kernel.org; linux-pci@vger.kernel.org; >> virtualization@lists.linux-foundation.org >> Subject: [EXT] [RFC PATCH 0/3] Introduce a PCIe endpoint virtio console >> >> Caution: EXT Email >> >> PCIe endpoint framework provides APIs to implement PCIe endpoint >> function. >> This framework allows defining various PCIe endpoint function behaviors in >> software. This patch extend the framework for virtio pci device. The >> virtio is defined to communicate guest on virtual machine and host side. >> Advantage of the virtio is the efficiency of data transfer and the conciseness >> of implementation device using software. It also be applied to PCIe >> endpoint function. >> >> We designed and implemented a PCIe EP virtio console function driver using >> the extended PCIe endpoint framework for virtio. It can be communicate >> host and endpoint over virtio as console. >> >> An architecture of the function driver is following: >> >> ┌────────────┐ ┌────────────── >> ────────┬────────────┐ >> │virtio │ │ │virtio │ >> │console drv │ ├───────────────┐ │console >> drv │ >> ├────────────┤ │(virtio console│ ├───── >> ───────┤ >> │ virtio bus │ │ device) │◄────►│ virtio bus │ >> ├────────────┤ ├---------------┤ └────── >> ──────┤ >> │ │ │ pci ep virtio │ │ >> │ pci bus │ │ console drv │ │ >> │ │ pcie ├───────────────┤ │ >> │ │ ◄─────► │ pci ep Bus │ │ >> └────────────┘ └────────────── >> ─┴───────────────────┘ >> PCIe Root PCIe Endpoint >> > [Frank Li] Some basic question, > I see you call register_virtio_device at epf_vcon_setup_vdev, > Why call it as virtio console? I suppose it should be virtiobus directly?
I'm sorry I didn't understand your question. What do you mean the virtiobus directly?
> > Previous you use virtio-net, why change to virtio-console here? Does it matter?
No, it doesn't. Just I'd like to break down the changes into smaller steps to make it easier to review and merge the changes.
As a first step, I propose adding a simplest virtio function driver with the extension defined in pci-epf-virtio.{h,c}.
> All virtio-XXX should work? Yes, the extension is designed to use any type of virtio device. > > You removed EDMA support this version? I planed the support will be added with epf virtio-net patches. > >> Introduced driver is `pci ep virtio console drv` in the figure. It works >> as ep function for PCIe root and virtual virtio console device for PCIe >> endpoint. Each side of virtio console driver has virtqueue, and >> introduced driver transfers data on the virtqueue to each other. A data >> on root tx queue is transfered to endpoint rx queue and vice versa. >> >> This patchset is depend follwing patches which are under discussion. >> >> - [RFC PATCH 0/3] Deal with alignment restriction on EP side >> link: >> https://lore.k/ >> ernel.org%2Flinux-pci%2F20230113090350.1103494-1- >> mie%40igel.co.jp%2F&data=05%7C01%7CFrank.Li%40nxp.com%7Cea6513dbf >> 4084b80ced208db3ce54133%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7 >> C0%7C638170727558800720%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4w >> LjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C >> %7C%7C&sdata=jYgy%2Bxk84ZXZRVfqm0GCXoRnCTLMrX4zTfV%2Bs5Mmsvo >> %3D&reserved=0 >> - [RFC PATCH v2 0/7] Introduce a vringh accessor for IO memory >> link: >> https://lore.k/ >> ernel.org%2Fvirtualization%2F20230202090934.549556-1- >> mie%40igel.co.jp%2F&data=05%7C01%7CFrank.Li%40nxp.com%7Cea6513dbf >> 4084b80ced208db3ce54133%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7 >> C0%7C638170727558800720%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4w >> LjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C >> %7C%7C&sdata=K4El76GSAGtsWkNBXJK5%2Fn7flCN20eEMZpZYTX2WIZ0%3 >> D&reserved=0 >> >> First of this patchset is introduce a helper function to realize pci >> virtio function using PCIe endpoint framework. The second one is adding >> a missing definition for virtio pci header. The last one is for PCIe >> endpoint virtio console driver. >> >> This is tested on linux-20230406 and RCar S4 board as PCIe endpoint. >> >> Shunsuke Mie (3): >> PCI: endpoint: introduce a helper to implement pci ep virtio function >> virtio_pci: add a definition of queue flag in ISR >> PCI: endpoint: Add EP function driver to provide virtio-console >> functionality >> >> drivers/pci/endpoint/functions/Kconfig | 19 + >> drivers/pci/endpoint/functions/Makefile | 2 + >> drivers/pci/endpoint/functions/pci-epf-vcon.c | 554 ++++++++++++++++++ >> .../pci/endpoint/functions/pci-epf-virtio.c | 469 +++++++++++++++ >> .../pci/endpoint/functions/pci-epf-virtio.h | 123 ++++ >> include/uapi/linux/virtio_pci.h | 3 + >> 6 files changed, 1170 insertions(+) >> create mode 100644 drivers/pci/endpoint/functions/pci-epf-vcon.c >> create mode 100644 drivers/pci/endpoint/functions/pci-epf-virtio.c >> create mode 100644 drivers/pci/endpoint/functions/pci-epf-virtio.h >> >> -- >> 2.25.1
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