From 4c8cf31885f69e86be0b5b9e6677a26797365e1d Mon Sep 17 00:00:00 2001 From: Tiwei Bie Date: Thu, 26 Mar 2020 22:01:23 +0800 Subject: vhost: introduce vDPA-based backend MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch introduces a vDPA-based vhost backend. This backend is built on top of the same interface defined in virtio-vDPA and provides a generic vhost interface for userspace to accelerate the virtio devices in guest. This backend is implemented as a vDPA device driver on top of the same ops used in virtio-vDPA. It will create char device entry named vhost-vdpa-$index for userspace to use. Userspace can use vhost ioctls on top of this char device to setup the backend. Vhost ioctls are extended to make it type agnostic and behave like a virtio device, this help to eliminate type specific API like what vhost_net/scsi/vsock did: - VHOST_VDPA_GET_DEVICE_ID: get the virtio device ID which is defined by virtio specification to differ from different type of devices - VHOST_VDPA_GET_VRING_NUM: get the maximum size of virtqueue supported by the vDPA device - VHSOT_VDPA_SET/GET_STATUS: set and get virtio status of vDPA device - VHOST_VDPA_SET/GET_CONFIG: access virtio config space - VHOST_VDPA_SET_VRING_ENABLE: enable a specific virtqueue For memory mapping, IOTLB API is mandated for vhost-vDPA which means userspace drivers are required to use VHOST_IOTLB_UPDATE/VHOST_IOTLB_INVALIDATE to add or remove mapping for a specific userspace memory region. The vhost-vDPA API is designed to be type agnostic, but it allows net device only in current stage. Due to the lacking of control virtqueue support, some features were filter out by vhost-vdpa. We will enable more features and devices in the near future. Signed-off-by: Tiwei Bie Signed-off-by: Eugenio Pérez Signed-off-by: Jason Wang Link: https://lore.kernel.org/r/20200326140125.19794-8-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin --- drivers/vhost/Kconfig | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/vhost/Kconfig') diff --git a/drivers/vhost/Kconfig b/drivers/vhost/Kconfig index 128238488078..362b832f5338 100644 --- a/drivers/vhost/Kconfig +++ b/drivers/vhost/Kconfig @@ -59,6 +59,18 @@ config VHOST_VSOCK To compile this driver as a module, choose M here: the module will be called vhost_vsock. +config VHOST_VDPA + tristate "Vhost driver for vDPA-based backend" + depends on EVENTFD + select VHOST + select VDPA + help + This kernel module can be loaded in host kernel to accelerate + guest virtio devices with the vDPA-based backends. + + To compile this driver as a module, choose M here: the module + will be called vhost_vdpa. + config VHOST_CROSS_ENDIAN_LEGACY bool "Cross-endian support for vhost" default n -- cgit