On Fri, Oct 07, 2022 at 05:56:39PM +0100, Usama Arif wrote: > Hi, > > This patch series introduces device and driver auxiliary notifications > as a new set of virtio device resources, as well as vhost-user device > backend that uses these resources. > > Driver auxiliary notifications allow the device to send notifications > other than configuration changes and used buffer notifications to the > driver, these are optional and their meaning is **device-specific**. > > Device auxiliary notifcations allow the driver to send notifcations > other than available buffer notifications to the device for example > through a device register, these are optional and their meaning is > **device-specific**. > > These resources are used in the last patch by the virtio-vhost-user > device in order to send/receive notifications to/from the driver > regarding activity on the vhost-user virtqueues. By standardizing > these resources as standalone virtio device resources, other future > devices will be able to use them as well.
Hi Michael, Do you have time to review this? I have been too involved in virtio-vhost-user in the past to do a truly independent review and your VIRTIO + vhost expertise would be perfect here. Thanks, Stefan > > The last patch introduces the vhost-user device backend which facilitates > vhost-user device emulation through vhost-user protocol exchanges and > access to shared memory. Software-defined networking, storage, and other > I/O appliances can provide services through this device. > > This device is based on Wei Wang's vhost-pci work. The virtio-vhost-user > device differs from vhost-pci because it is a single virtio > device type that exposes the vhost-user protocol instead of a family of > new virtio device types, one for each vhost-user device type. > > A HTML version with the changes is available at [1]. > > For more information about virtio-vhost-user, see [2]. > > These patches are based on the work initially done by Stefan Hajnoczi [2] > and continued by Nikos Dragazis [3], [4]. > > A working prototype implementing this spec can be reproduced using > instructions in [5] utilizing QEMU [6] and DPDK [7]. > This is also based on the work initially done by Stefan > and continued later by Nikos. The prototype code uses the terms > "doorbell"/"device-specific notification" and "master"/"slave" instead of > "device auxiliary notification"/"driver auxiliary notification" and > "frontend"/"backend". This is based on older work, however, their > functionality is the same. If these virtio-spec changes get approved, > I will refractor the patches for QEMU/DPDK and send them for review > according to the final patches in the respective mailing list. > > Thanks and looking forward to your response! > Usama > > [1] https://uarif1.github.io/vvu/v3/virtio-v1.2-cs01 > [2] https://wiki.qemu.org/Features/VirtioVhostUser > [3] https://ndragazis.github.io/dpdk-vhost-vvu-demo.html > [4] https://lists.oasis-open.org/archives/virtio-dev/202005/msg00132.html > [5] https://uarif1.github.io/vvu/dpdk-vvu-instructions > [6] https://github.com/uarif1/qemu/tree/vvu > [7] https://github.com/uarif1/dpdk/tree/vvu > ---------- > v2->v3: > Mostly addressing comments made by Michael S. Tsirkin: > - Give a clearer relation between backend driver, backend device and frontend > at > beginning of the Vhost-user Device Backend section. > - change uuid to id. > - Add information about inflight memory. > > v1->v2: > - Shortened device aux. notification section > - Make data width of device aux. notifications device specific and not > limited to 2 bytes. > - Added information about the minimum number of MSIX vectors. > - Split virtio-mmio implementation of driver aux. notifications into 2 > registers, DeviceAuxNotificationIndex and DeviceAuxNotificationData. > - Made the shared memory section in virtio vhost-user clearer and added > the shared memory would look like when > VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS has been negotiated. > > Usama Arif (4): > content: Introduce driver/device auxiliary notifications > content: Introduce driver/device aux. notification cfg type for PCI > content: Introduce driver/device auxiliary notifications for MMIO > vhost-user: add vhost-user device type > > conformance.tex | 29 +++- > content.tex | 254 +++++++++++++++++++++++++++++----- > introduction.tex | 3 + > virtio-vhost-user.tex | 309 ++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 554 insertions(+), 41 deletions(-) > create mode 100644 virtio-vhost-user.tex > > -- > 2.25.1 >
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