[v2,8/8] net/virtio: introduce Vhost-vDPA backend

  vhost-vDPA is a new virtio backend type introduced by vDPA kernel
framework, which provides abstruction to the vDPA devices and
exposes an unified control interface through a char dev.

This patch adds support to the vhost-vDPA backend. As similar to
the existing vhost kernel backend, a set of virtio_user ops were
introduced for vhost-vDPA backend to handle device specific operations
such as:
 - device setup
 - ioctl message handling
 - queue pair enabling
 - dma map/unmap
vDPA relevant ioctl codes and data structures are also defined in
this patch.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 drivers/net/virtio/meson.build                |   1 +
 drivers/net/virtio/virtio_user/vhost.h        |   1 +
 drivers/net/virtio/virtio_user/vhost_vdpa.c   | 298 ++++++++++++++++++
 .../net/virtio/virtio_user/virtio_user_dev.c  |   6 +
 4 files changed, 306 insertions(+)
 create mode 100644 drivers/net/virtio/virtio_user/vhost_vdpa.c
  

Hi Maxime,

I see there's a compile issue in patchwork.

In vhost_vdpa_dma_unmap, len is size_t. And you use '0ULL -1' outside. In i686,
ULL is 64 bit but size_t is 32 bit. Although -1 is all F and the code logic is fine
to convert 64 '1's to 32 '1's, the compiler will treat it as an error?

Thanks!
Chenbo 

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Friday, September 25, 2020 8:31 PM
> To: dev@dpdk.org; Xia, Chenbo <chenbo.xia@intel.com>; Fu, Patrick
> <patrick.fu@intel.com>; amorenoz@redhat.com
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: [PATCH v2 8/8] net/virtio: introduce Vhost-vDPA backend
> 
> vhost-vDPA is a new virtio backend type introduced by vDPA kernel
> framework, which provides abstruction to the vDPA devices and
> exposes an unified control interface through a char dev.
> 
> This patch adds support to the vhost-vDPA backend. As similar to
> the existing vhost kernel backend, a set of virtio_user ops were
> introduced for vhost-vDPA backend to handle device specific operations
> such as:
>  - device setup
>  - ioctl message handling
>  - queue pair enabling
>  - dma map/unmap
> vDPA relevant ioctl codes and data structures are also defined in
> this patch.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  drivers/net/virtio/meson.build                |   1 +
>  drivers/net/virtio/virtio_user/vhost.h        |   1 +
>  drivers/net/virtio/virtio_user/vhost_vdpa.c   | 298 ++++++++++++++++++
>  .../net/virtio/virtio_user/virtio_user_dev.c  |   6 +
>  4 files changed, 306 insertions(+)
>  create mode 100644 drivers/net/virtio/virtio_user/vhost_vdpa.c
> 
> diff --git a/drivers/net/virtio/meson.build
> b/drivers/net/virtio/meson.build
> index 3fd6051f4b..eaed46373d 100644
> --- a/drivers/net/virtio/meson.build
> +++ b/drivers/net/virtio/meson.build
> @@ -42,6 +42,7 @@ if is_linux
>  		'virtio_user/vhost_kernel.c',
>  		'virtio_user/vhost_kernel_tap.c',
>  		'virtio_user/vhost_user.c',
> +		'virtio_user/vhost_vdpa.c',
>  		'virtio_user/virtio_user_dev.c')
>  	deps += ['bus_vdev']
>  endif
> diff --git a/drivers/net/virtio/virtio_user/vhost.h
> b/drivers/net/virtio/virtio_user/vhost.h
> index 2e71995a79..210a3704e7 100644
> --- a/drivers/net/virtio/virtio_user/vhost.h
> +++ b/drivers/net/virtio/virtio_user/vhost.h
> @@ -113,5 +113,6 @@ struct virtio_user_backend_ops {
> 
>  extern struct virtio_user_backend_ops virtio_ops_user;
>  extern struct virtio_user_backend_ops virtio_ops_kernel;
> +extern struct virtio_user_backend_ops virtio_ops_vdpa;
> 
>  #endif
> diff --git a/drivers/net/virtio/virtio_user/vhost_vdpa.c
> b/drivers/net/virtio/virtio_user/vhost_vdpa.c
> new file mode 100644
> index 0000000000..d592ca8817
> --- /dev/null
> +++ b/drivers/net/virtio/virtio_user/vhost_vdpa.c
> @@ -0,0 +1,298 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright(c) 2020 Red Hat Inc.
> + */
> +
> +#include <sys/ioctl.h>
> +#include <sys/types.h>
> +#include <sys/stat.h>
> +#include <fcntl.h>
> +#include <unistd.h>
> +
> +#include <rte_memory.h>
> +
> +#include "vhost.h"
> +#include "virtio_user_dev.h"
> +
> +/* vhost kernel & vdpa ioctls */
> +#define VHOST_VIRTIO 0xAF
> +#define VHOST_GET_FEATURES _IOR(VHOST_VIRTIO, 0x00, __u64)
> +#define VHOST_SET_FEATURES _IOW(VHOST_VIRTIO, 0x00, __u64)
> +#define VHOST_SET_OWNER _IO(VHOST_VIRTIO, 0x01)
> +#define VHOST_RESET_OWNER _IO(VHOST_VIRTIO, 0x02)
> +#define VHOST_SET_MEM_TABLE _IOW(VHOST_VIRTIO, 0x03, void *)
> +#define VHOST_SET_LOG_BASE _IOW(VHOST_VIRTIO, 0x04, __u64)
> +#define VHOST_SET_LOG_FD _IOW(VHOST_VIRTIO, 0x07, int)
> +#define VHOST_SET_VRING_NUM _IOW(VHOST_VIRTIO, 0x10, struct
> vhost_vring_state)
> +#define VHOST_SET_VRING_ADDR _IOW(VHOST_VIRTIO, 0x11, struct
> vhost_vring_addr)
> +#define VHOST_SET_VRING_BASE _IOW(VHOST_VIRTIO, 0x12, struct
> vhost_vring_state)
> +#define VHOST_GET_VRING_BASE _IOWR(VHOST_VIRTIO, 0x12, struct
> vhost_vring_state)
> +#define VHOST_SET_VRING_KICK _IOW(VHOST_VIRTIO, 0x20, struct
> vhost_vring_file)
> +#define VHOST_SET_VRING_CALL _IOW(VHOST_VIRTIO, 0x21, struct
> vhost_vring_file)
> +#define VHOST_SET_VRING_ERR _IOW(VHOST_VIRTIO, 0x22, struct
> vhost_vring_file)
> +#define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct
> vhost_vring_file)
> +#define VHOST_VDPA_GET_DEVICE_ID _IOR(VHOST_VIRTIO, 0x70, __u32)
> +#define VHOST_VDPA_GET_STATUS _IOR(VHOST_VIRTIO, 0x71, __u8)
> +#define VHOST_VDPA_SET_STATUS _IOW(VHOST_VIRTIO, 0x72, __u8)
> +#define VHOST_VDPA_SET_VRING_ENABLE	_IOW(VHOST_VIRTIO, 0x75, \
> +					     struct vhost_vring_state)
> +
> +static uint64_t vhost_req_user_to_vdpa[] = {
> +	[VHOST_USER_SET_OWNER] = VHOST_SET_OWNER,
> +	[VHOST_USER_RESET_OWNER] = VHOST_RESET_OWNER,
> +	[VHOST_USER_SET_FEATURES] = VHOST_SET_FEATURES,
> +	[VHOST_USER_GET_FEATURES] = VHOST_GET_FEATURES,
> +	[VHOST_USER_SET_VRING_CALL] = VHOST_SET_VRING_CALL,
> +	[VHOST_USER_SET_VRING_NUM] = VHOST_SET_VRING_NUM,
> +	[VHOST_USER_SET_VRING_BASE] = VHOST_SET_VRING_BASE,
> +	[VHOST_USER_GET_VRING_BASE] = VHOST_GET_VRING_BASE,
> +	[VHOST_USER_SET_VRING_ADDR] = VHOST_SET_VRING_ADDR,
> +	[VHOST_USER_SET_VRING_KICK] = VHOST_SET_VRING_KICK,
> +	[VHOST_USER_SET_MEM_TABLE] = VHOST_SET_MEM_TABLE,
> +	[VHOST_USER_SET_STATUS] = VHOST_VDPA_SET_STATUS,
> +	[VHOST_USER_GET_STATUS] = VHOST_VDPA_GET_STATUS,
> +	[VHOST_USER_SET_VRING_ENABLE] = VHOST_VDPA_SET_VRING_ENABLE,
> +};
> +
> +/* no alignment requirement */
> +struct vhost_iotlb_msg {
> +	uint64_t iova;
> +	uint64_t size;
> +	uint64_t uaddr;
> +#define VHOST_ACCESS_RO      0x1
> +#define VHOST_ACCESS_WO      0x2
> +#define VHOST_ACCESS_RW      0x3
> +	uint8_t perm;
> +#define VHOST_IOTLB_MISS           1
> +#define VHOST_IOTLB_UPDATE         2
> +#define VHOST_IOTLB_INVALIDATE     3
> +#define VHOST_IOTLB_ACCESS_FAIL    4
> +	uint8_t type;
> +};
> +
> +#define VHOST_IOTLB_MSG_V2 0x2
> +
> +struct vhost_msg {
> +	uint32_t type;
> +	uint32_t reserved;
> +	union {
> +		struct vhost_iotlb_msg iotlb;
> +		uint8_t padding[64];
> +	};
> +};
> +
> +static int
> +vhost_vdpa_dma_map(struct virtio_user_dev *dev, void *addr,
> +				  uint64_t iova, size_t len)
> +{
> +	struct vhost_msg msg = {};
> +
> +	msg.type = VHOST_IOTLB_MSG_V2;
> +	msg.iotlb.type = VHOST_IOTLB_UPDATE;
> +	msg.iotlb.iova = iova;
> +	msg.iotlb.uaddr = (uint64_t)(uintptr_t)addr;
> +	msg.iotlb.size = len;
> +	msg.iotlb.perm = VHOST_ACCESS_RW;
> +
> +	if (write(dev->vhostfd, &msg, sizeof(msg)) != sizeof(msg)) {
> +		PMD_DRV_LOG(ERR, "Failed to send IOTLB update (%s)",
> +				strerror(errno));
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
> +static int
> +vhost_vdpa_dma_unmap(struct virtio_user_dev *dev, __rte_unused void *addr,
> +				  uint64_t iova, size_t len)
> +{
> +	struct vhost_msg msg = {};
> +
> +	msg.type = VHOST_IOTLB_MSG_V2;
> +	msg.iotlb.type = VHOST_IOTLB_INVALIDATE;
> +	msg.iotlb.iova = iova;
> +	msg.iotlb.size = len;
> +
> +	if (write(dev->vhostfd, &msg, sizeof(msg)) != sizeof(msg)) {
> +		PMD_DRV_LOG(ERR, "Failed to send IOTLB invalidate (%s)",
> +				strerror(errno));
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
> +
> +static int
> +vhost_vdpa_map_contig(const struct rte_memseg_list *msl,
> +		const struct rte_memseg *ms, size_t len, void *arg)
> +{
> +	struct virtio_user_dev *dev = arg;
> +
> +	if (msl->external)
> +		return 0;
> +
> +	return vhost_vdpa_dma_map(dev, ms->addr, ms->iova, len);
> +}
> +
> +static int
> +vhost_vdpa_map(const struct rte_memseg_list *msl, const struct rte_memseg
> *ms,
> +		void *arg)
> +{
> +	struct virtio_user_dev *dev = arg;
> +
> +	/* skip external memory that isn't a heap */
> +	if (msl->external && !msl->heap)
> +		return 0;
> +
> +	/* skip any segments with invalid IOVA addresses */
> +	if (ms->iova == RTE_BAD_IOVA)
> +		return 0;
> +
> +	/* if IOVA mode is VA, we've already mapped the internal segments */
> +	if (!msl->external && rte_eal_iova_mode() == RTE_IOVA_VA)
> +		return 0;
> +
> +	return vhost_vdpa_dma_map(dev, ms->addr, ms->iova, ms->len);
> +}
> +
> +static int
> +vhost_vdpa_dma_map_all(struct virtio_user_dev *dev)
> +{
> +	vhost_vdpa_dma_unmap(dev, 0, 0ULL, 0ULL - 1);
> +
> +	if (rte_eal_iova_mode() == RTE_IOVA_VA) {
> +		/* with IOVA as VA mode, we can get away with mapping
> contiguous
> +		 * chunks rather than going page-by-page.
> +		 */
> +		int ret = rte_memseg_contig_walk_thread_unsafe(
> +				vhost_vdpa_map_contig, dev);
> +		if (ret)
> +			return ret;
> +		/* we have to continue the walk because we've skipped the
> +		 * external segments during the config walk.
> +		 */
> +	}
> +	return rte_memseg_walk_thread_unsafe(vhost_vdpa_map, dev);
> +}
> +
> +/* with below features, vhost vdpa does not need to do the checksum and
> TSO,
> + * these info will be passed to virtio_user through virtio net header.
> + */
> +#define VHOST_VDPA_GUEST_OFFLOADS_MASK	\
> +	((1ULL << VIRTIO_NET_F_GUEST_CSUM) |	\
> +	 (1ULL << VIRTIO_NET_F_GUEST_TSO4) |	\
> +	 (1ULL << VIRTIO_NET_F_GUEST_TSO6) |	\
> +	 (1ULL << VIRTIO_NET_F_GUEST_ECN)  |	\
> +	 (1ULL << VIRTIO_NET_F_GUEST_UFO))
> +
> +#define VHOST_VDPA_HOST_OFFLOADS_MASK		\
> +	((1ULL << VIRTIO_NET_F_HOST_TSO4) |	\
> +	 (1ULL << VIRTIO_NET_F_HOST_TSO6) |	\
> +	 (1ULL << VIRTIO_NET_F_CSUM))
> +
> +static int
> +vhost_vdpa_ioctl(struct virtio_user_dev *dev,
> +		   enum vhost_user_request req,
> +		   void *arg)
> +{
> +	int ret = -1;
> +	uint64_t req_vdpa;
> +
> +	PMD_DRV_LOG(INFO, "%s", vhost_msg_strings[req]);
> +
> +	req_vdpa = vhost_req_user_to_vdpa[req];
> +
> +	if (req_vdpa == VHOST_SET_MEM_TABLE)
> +		return vhost_vdpa_dma_map_all(dev);
> +
> +	if (req_vdpa == VHOST_SET_FEATURES) {
> +		/* WORKAROUND */
> +		*(uint64_t *)arg |= 1ULL << VIRTIO_F_IOMMU_PLATFORM;
> +
> +		/* Multiqueue not supported for now */
> +		*(uint64_t *)arg &= ~(1ULL << VIRTIO_NET_F_MQ);
> +	}
> +
> +	switch (req_vdpa) {
> +	case VHOST_SET_VRING_NUM:
> +	case VHOST_SET_VRING_ADDR:
> +	case VHOST_SET_VRING_BASE:
> +	case VHOST_GET_VRING_BASE:
> +	case VHOST_SET_VRING_KICK:
> +	case VHOST_SET_VRING_CALL:
> +		PMD_DRV_LOG(DEBUG, "vhostfd=%d, index=%u",
> +			    dev->vhostfd, *(unsigned int *)arg);
> +		break;
> +	default:
> +		break;
> +	}
> +
> +	ret = ioctl(dev->vhostfd, req_vdpa, arg);
> +	if (ret < 0)
> +		PMD_DRV_LOG(ERR, "%s failed: %s",
> +			    vhost_msg_strings[req], strerror(errno));
> +
> +	return ret;
> +}
> +
> +/**
> + * Set up environment to talk with a vhost vdpa backend.
> + *
> + * @return
> + *   - (-1) if fail to set up;
> + *   - (>=0) if successful.
> + */
> +static int
> +vhost_vdpa_setup(struct virtio_user_dev *dev)
> +{
> +	uint32_t did = (uint32_t)-1;
> +
> +	dev->vhostfd = open(dev->path, O_RDWR);
> +	if (dev->vhostfd < 0) {
> +		PMD_DRV_LOG(ERR, "Failed to open %s: %s\n",
> +				dev->path, strerror(errno));
> +		return -1;
> +	}
> +
> +	if (ioctl(dev->vhostfd, VHOST_VDPA_GET_DEVICE_ID, &did) < 0 ||
> +			did != VIRTIO_ID_NETWORK) {
> +		PMD_DRV_LOG(ERR, "Invalid vdpa device ID: %u\n", did);
> +		return -1;
> +	}
> +
> +	return 0;
> +}
> +
> +static int
> +vhost_vdpa_enable_queue_pair(struct virtio_user_dev *dev,
> +			       uint16_t pair_idx,
> +			       int enable)
> +{
> +	int i;
> +
> +	if (dev->qp_enabled[pair_idx] == enable)
> +		return 0;
> +
> +	for (i = 0; i < 2; ++i) {
> +		struct vhost_vring_state state = {
> +			.index = pair_idx * 2 + i,
> +			.num   = enable,
> +		};
> +
> +		if (vhost_vdpa_ioctl(dev, VHOST_USER_SET_VRING_ENABLE, &state))
> +			return -1;
> +	}
> +
> +	dev->qp_enabled[pair_idx] = enable;
> +
> +	return 0;
> +}
> +
> +struct virtio_user_backend_ops virtio_ops_vdpa = {
> +	.setup = vhost_vdpa_setup,
> +	.send_request = vhost_vdpa_ioctl,
> +	.enable_qp = vhost_vdpa_enable_queue_pair,
> +	.dma_map = vhost_vdpa_dma_map,
> +	.dma_unmap = vhost_vdpa_dma_unmap,
> +};
> diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c
> b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> index 81257a3996..a5ba14d06a 100644
> --- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
> +++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
> @@ -389,6 +389,12 @@ virtio_user_dev_setup(struct virtio_user_dev *dev)
>  				dev->vhostfds[q] = -1;
>  				dev->tapfds[q] = -1;
>  			}
> +		} else if (dev->backend_type ==
> +				VIRTIO_USER_BACKEND_VHOST_VDPA) {
> +			dev->ops = &virtio_ops_vdpa;
> +		} else {
> +			PMD_DRV_LOG(ERR, "Unknown backend type");
> +			return -1;
>  		}
>  	}
> 
> --
> 2.26.2