On 3/8/22 10:44, David Marchand wrote:
Following a rework, external message handlers were receiving a pointer to a vhost_user message (as stated in the API), but lost the ability to interact with fds attached to the message. Restore the original layout and put a build check and reminders. Bugzilla ID: 953 Fixes: 5e0099dc709e ("vhost: remove payload size limitation") Reported-by: Fan Zhang <roy.fan.zh...@intel.com> Signed-off-by: David Marchand <david.march...@redhat.com> --- Changes since v1: - fixed build with clang, --- lib/vhost/vhost_user.c | 8 ++++---- lib/vhost/vhost_user.h | 7 +++++-- 2 files changed, 9 insertions(+), 6 deletions(-) diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c index 723c6890c3..589b950458 100644 --- a/lib/vhost/vhost_user.c +++ b/lib/vhost/vhost_user.c @@ -3023,8 +3023,8 @@ vhost_user_msg_handler(int vid, int fd)handled = false;if (dev->extern_ops.pre_msg_handle) { - ret = (*dev->extern_ops.pre_msg_handle)(dev->vid, - (void *)&ctx.msg); + RTE_BUILD_BUG_ON(offsetof(struct vhu_msg_context, msg) != 0); + ret = (*dev->extern_ops.pre_msg_handle)(dev->vid, &ctx); switch (ret) { case RTE_VHOST_MSG_RESULT_REPLY: send_vhost_reply(dev, fd, &ctx); @@ -3069,8 +3069,8 @@ vhost_user_msg_handler(int vid, int fd) skip_to_post_handle: if (ret != RTE_VHOST_MSG_RESULT_ERR && dev->extern_ops.post_msg_handle) { - ret = (*dev->extern_ops.post_msg_handle)(dev->vid, - (void *)&ctx.msg); + RTE_BUILD_BUG_ON(offsetof(struct vhu_msg_context, msg) != 0); + ret = (*dev->extern_ops.post_msg_handle)(dev->vid, &ctx); switch (ret) { case RTE_VHOST_MSG_RESULT_REPLY: send_vhost_reply(dev, fd, &ctx); diff --git a/lib/vhost/vhost_user.h b/lib/vhost/vhost_user.h index be53669f3b..c946cc2ef4 100644 --- a/lib/vhost/vhost_user.h +++ b/lib/vhost/vhost_user.h @@ -152,10 +152,13 @@ typedef struct VhostUserMsg { /* Nothing should be added after the payload */ } __rte_packed VhostUserMsg;-struct vhu_msg_context {+/* Note: this structure and VhostUserMsg can't be changed carelessly as + * external message handlers rely on them. + */ +struct __rte_packed vhu_msg_context { + VhostUserMsg msg; int fds[VHOST_MEMORY_MAX_NREGIONS]; int fd_num; - VhostUserMsg msg; };#define VHOST_USER_HDR_SIZE offsetof(VhostUserMsg, payload.u64)
Reviewed-by: Maxime Coquelin <maxime.coque...@redhat.com> Thanks, Maxime
