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![Tiwei Bie](/assets/img/avatar_default.png)
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 <tiwei.bie@intel.com> Signed-off-by: Eugenio Pérez <eperezma@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20200326140125.19794-8-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
143 lines
5.9 KiB
C
143 lines
5.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
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#ifndef _LINUX_VHOST_H
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#define _LINUX_VHOST_H
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/* Userspace interface for in-kernel virtio accelerators. */
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/* vhost is used to reduce the number of system calls involved in virtio.
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*
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* Existing virtio net code is used in the guest without modification.
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*
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* This header includes interface used by userspace hypervisor for
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* device configuration.
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*/
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#include <linux/vhost_types.h>
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#include <linux/types.h>
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#include <linux/ioctl.h>
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/* ioctls */
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#define VHOST_VIRTIO 0xAF
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/* Features bitmask for forward compatibility. Transport bits are used for
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* vhost specific features. */
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#define VHOST_GET_FEATURES _IOR(VHOST_VIRTIO, 0x00, __u64)
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#define VHOST_SET_FEATURES _IOW(VHOST_VIRTIO, 0x00, __u64)
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/* Set current process as the (exclusive) owner of this file descriptor. This
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* must be called before any other vhost command. Further calls to
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* VHOST_OWNER_SET fail until VHOST_OWNER_RESET is called. */
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#define VHOST_SET_OWNER _IO(VHOST_VIRTIO, 0x01)
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/* Give up ownership, and reset the device to default values.
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* Allows subsequent call to VHOST_OWNER_SET to succeed. */
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#define VHOST_RESET_OWNER _IO(VHOST_VIRTIO, 0x02)
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/* Set up/modify memory layout */
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#define VHOST_SET_MEM_TABLE _IOW(VHOST_VIRTIO, 0x03, struct vhost_memory)
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/* Write logging setup. */
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/* Memory writes can optionally be logged by setting bit at an offset
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* (calculated from the physical address) from specified log base.
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* The bit is set using an atomic 32 bit operation. */
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/* Set base address for logging. */
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#define VHOST_SET_LOG_BASE _IOW(VHOST_VIRTIO, 0x04, __u64)
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/* Specify an eventfd file descriptor to signal on log write. */
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#define VHOST_SET_LOG_FD _IOW(VHOST_VIRTIO, 0x07, int)
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/* Ring setup. */
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/* Set number of descriptors in ring. This parameter can not
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* be modified while ring is running (bound to a device). */
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#define VHOST_SET_VRING_NUM _IOW(VHOST_VIRTIO, 0x10, struct vhost_vring_state)
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/* Set addresses for the ring. */
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#define VHOST_SET_VRING_ADDR _IOW(VHOST_VIRTIO, 0x11, struct vhost_vring_addr)
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/* Base value where queue looks for available descriptors */
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#define VHOST_SET_VRING_BASE _IOW(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
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/* Get accessor: reads index, writes value in num */
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#define VHOST_GET_VRING_BASE _IOWR(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
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/* Set the vring byte order in num. Valid values are VHOST_VRING_LITTLE_ENDIAN
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* or VHOST_VRING_BIG_ENDIAN (other values return -EINVAL).
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* The byte order cannot be changed while the device is active: trying to do so
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* returns -EBUSY.
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* This is a legacy only API that is simply ignored when VIRTIO_F_VERSION_1 is
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* set.
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* Not all kernel configurations support this ioctl, but all configurations that
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* support SET also support GET.
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*/
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#define VHOST_VRING_LITTLE_ENDIAN 0
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#define VHOST_VRING_BIG_ENDIAN 1
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#define VHOST_SET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x13, struct vhost_vring_state)
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#define VHOST_GET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x14, struct vhost_vring_state)
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/* The following ioctls use eventfd file descriptors to signal and poll
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* for events. */
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/* Set eventfd to poll for added buffers */
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#define VHOST_SET_VRING_KICK _IOW(VHOST_VIRTIO, 0x20, struct vhost_vring_file)
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/* Set eventfd to signal when buffers have beed used */
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#define VHOST_SET_VRING_CALL _IOW(VHOST_VIRTIO, 0x21, struct vhost_vring_file)
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/* Set eventfd to signal an error */
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#define VHOST_SET_VRING_ERR _IOW(VHOST_VIRTIO, 0x22, struct vhost_vring_file)
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/* Set busy loop timeout (in us) */
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#define VHOST_SET_VRING_BUSYLOOP_TIMEOUT _IOW(VHOST_VIRTIO, 0x23, \
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struct vhost_vring_state)
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/* Get busy loop timeout (in us) */
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#define VHOST_GET_VRING_BUSYLOOP_TIMEOUT _IOW(VHOST_VIRTIO, 0x24, \
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struct vhost_vring_state)
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/* Set or get vhost backend capability */
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/* Use message type V2 */
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#define VHOST_BACKEND_F_IOTLB_MSG_V2 0x1
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#define VHOST_SET_BACKEND_FEATURES _IOW(VHOST_VIRTIO, 0x25, __u64)
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#define VHOST_GET_BACKEND_FEATURES _IOR(VHOST_VIRTIO, 0x26, __u64)
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/* VHOST_NET specific defines */
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/* Attach virtio net ring to a raw socket, or tap device.
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* The socket must be already bound to an ethernet device, this device will be
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* used for transmit. Pass fd -1 to unbind from the socket and the transmit
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* device. This can be used to stop the ring (e.g. for migration). */
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#define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct vhost_vring_file)
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/* VHOST_SCSI specific defines */
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#define VHOST_SCSI_SET_ENDPOINT _IOW(VHOST_VIRTIO, 0x40, struct vhost_scsi_target)
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#define VHOST_SCSI_CLEAR_ENDPOINT _IOW(VHOST_VIRTIO, 0x41, struct vhost_scsi_target)
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/* Changing this breaks userspace. */
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#define VHOST_SCSI_GET_ABI_VERSION _IOW(VHOST_VIRTIO, 0x42, int)
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/* Set and get the events missed flag */
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#define VHOST_SCSI_SET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x43, __u32)
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#define VHOST_SCSI_GET_EVENTS_MISSED _IOW(VHOST_VIRTIO, 0x44, __u32)
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/* VHOST_VSOCK specific defines */
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#define VHOST_VSOCK_SET_GUEST_CID _IOW(VHOST_VIRTIO, 0x60, __u64)
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#define VHOST_VSOCK_SET_RUNNING _IOW(VHOST_VIRTIO, 0x61, int)
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/* VHOST_VDPA specific defines */
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/* Get the device id. The device ids follow the same definition of
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* the device id defined in virtio-spec.
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*/
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#define VHOST_VDPA_GET_DEVICE_ID _IOR(VHOST_VIRTIO, 0x70, __u32)
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/* Get and set the status. The status bits follow the same definition
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* of the device status defined in virtio-spec.
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*/
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#define VHOST_VDPA_GET_STATUS _IOR(VHOST_VIRTIO, 0x71, __u8)
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#define VHOST_VDPA_SET_STATUS _IOW(VHOST_VIRTIO, 0x72, __u8)
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/* Get and set the device config. The device config follows the same
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* definition of the device config defined in virtio-spec.
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*/
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#define VHOST_VDPA_GET_CONFIG _IOR(VHOST_VIRTIO, 0x73, \
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struct vhost_vdpa_config)
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#define VHOST_VDPA_SET_CONFIG _IOW(VHOST_VIRTIO, 0x74, \
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struct vhost_vdpa_config)
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/* Enable/disable the ring. */
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#define VHOST_VDPA_SET_VRING_ENABLE _IOW(VHOST_VIRTIO, 0x75, \
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struct vhost_vring_state)
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/* Get the max ring size. */
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#define VHOST_VDPA_GET_VRING_NUM _IOR(VHOST_VIRTIO, 0x76, __u16)
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#endif
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