On 8/29/19 4:12 PM, JinYu wrote:
> This patch introduces two new messages VHOST_USER_GET_INFLIGHT_FD
> and VHOST_USER_SET_INFLIGHT_FD to support transferring a shared
> buffer between qemu and backend.
>
> Signed-off-by: Lin Li <lili...@baidu.com>
> Signed-off-by: Xun Ni <ni...@baidu.com>
> Signed-off-by: Yu Zhang <zhangy...@baidu.com>
> Signed-off-by: Jin Yu <jin...@intel.com>
> ---
> lib/librte_vhost/vhost.h | 7 +
> lib/librte_vhost/vhost_user.c | 242 ++++++++++++++++++++++++++++++++++
> lib/librte_vhost/vhost_user.h | 4 +-
> 3 files changed, 252 insertions(+), 1 deletion(-)
>
> diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
> index 884befa85..39f645b97 100644
> --- a/lib/librte_vhost/vhost.h
> +++ b/lib/librte_vhost/vhost.h
> @@ -286,6 +286,12 @@ struct guest_page {
> uint64_t size;
> };
>
> +struct inflight_mem_info {
> + int fd;
> + void *addr;
> + uint64_t size;
> +};
> +
> /**
> * Device structure contains all configuration information relating
> * to the device.
> @@ -303,6 +309,7 @@ struct virtio_net {
> uint32_t nr_vring;
> int dequeue_zero_copy;
> struct vhost_virtqueue *virtqueue[VHOST_MAX_QUEUE_PAIRS * 2];
> + struct inflight_mem_info inflight_info;
Could it be a pointer and allocated only if the feature
has been negotiated?
> #define IF_NAME_SZ (PATH_MAX > IFNAMSIZ ? PATH_MAX : IFNAMSIZ)
> char ifname[IF_NAME_SZ];
> uint64_t log_size;
> diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> index c9e29ece8..647929234 100644
> --- a/lib/librte_vhost/vhost_user.c
> +++ b/lib/librte_vhost/vhost_user.c
> @@ -49,6 +49,15 @@
> #define VIRTIO_MIN_MTU 68
> #define VIRTIO_MAX_MTU 65535
>
> +#define INFLIGHT_ALIGNMENT 64
> +#define INFLIGHT_VERSION 0xabcd
> +#define VIRTQUEUE_MAX_SIZE 1024
> +
> +#define CLOEXEC 0x0001U
> +
> +#define ALIGN_DOWN(n, m) ((n) / (m) * (m))
> +#define ALIGN_UP(n, m) ALIGN_DOWN((n) + (m) - 1, (m))
> +
> static const char *vhost_message_str[VHOST_USER_MAX] = {
> [VHOST_USER_NONE] = "VHOST_USER_NONE",
> [VHOST_USER_GET_FEATURES] = "VHOST_USER_GET_FEATURES",
> @@ -78,6 +87,8 @@ static const char *vhost_message_str[VHOST_USER_MAX] = {
> [VHOST_USER_POSTCOPY_ADVISE] = "VHOST_USER_POSTCOPY_ADVISE",
> [VHOST_USER_POSTCOPY_LISTEN] = "VHOST_USER_POSTCOPY_LISTEN",
> [VHOST_USER_POSTCOPY_END] = "VHOST_USER_POSTCOPY_END",
> + [VHOST_USER_GET_INFLIGHT_FD] = "VHOST_USER_GET_INFLIGHT_FD",
> + [VHOST_USER_SET_INFLIGHT_FD] = "VHOST_USER_SET_INFLIGHT_FD",
> };
>
> static int send_vhost_reply(int sockfd, struct VhostUserMsg *msg);
> @@ -160,6 +171,16 @@ vhost_backend_cleanup(struct virtio_net *dev)
> dev->log_addr = 0;
> }
>
> + if (dev->inflight_info.addr) {
> + munmap(dev->inflight_info.addr, dev->inflight_info.size);
> + dev->inflight_info.addr = NULL;
> + }
> +
> + if (dev->inflight_info.fd > 0) {
> + close(dev->inflight_info.fd);
> + dev->inflight_info.fd = -1;
> + }
> +
> if (dev->slave_req_fd >= 0) {
> close(dev->slave_req_fd);
> dev->slave_req_fd = -1;
> @@ -1165,6 +1186,225 @@ virtio_is_ready(struct virtio_net *dev)
> return 1;
> }
>
> +static int
> +mem_create(const char *name, unsigned int flags)
> +{
> +#ifdef __NR_memfd_create
> + return syscall(__NR_memfd_create, name, flags);
> +#else
> + return -1;
> +#endif
> +}
Maybe you could use memfd_create, as done in:
lib/librte_eal/linux/eal/eal_memalloc.c
