Hi Tiwei， thanks.
> -----Original Message-----
> From: Bie, Tiwei
> Sent: Wednesday, July 10, 2019 3:18 PM
> To: Yu, Jin <[email protected]>
> Cc: [email protected]; Liu, Changpeng <[email protected]>;
> [email protected]; Wang, Zhihong <[email protected]>;
> LinLi <[email protected]>; XunNi <[email protected]>; YuZhang
> <[email protected]>
> Subject: Re: [PATCH v2 1/2] vhost: support inflight share memory protocol
> feature
>
> On Wed, Jul 10, 2019 at 06:43:55PM +0800, 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.
> >
> > Firstly, qemu uses VHOST_USER_GET_INFLIGHT_FD to get the shared buffer
> > from backend. Then qemu should send it back through
> > VHOST_USER_SET_INFLIGHT_FD each time we start vhost-user.
> >
> > This shared buffer is used to process inflight I/O when backend
> > reconnect.
>
> I saw you send several patch sets for v2. It's a bit confusing. Please bump
> the
> version when you send a new series. Besides, please keep the cover letter.
Sorry for the confusion. There are some misoperations and I have set them
superseded.
>
> >
> > Signed-off-by: LinLi <[email protected]>
> > Signed-off-by: XunNi <[email protected]>
> > Signed-off-by: YuZhang <[email protected]>
> > Signed-off-by: JinYu <[email protected]>
>
> There should be a space between FirstName and LastName.
Got it.
>
> [...]
> >
> > +struct inflight_desc_split {
> > + uint8_t inflight;
> > + uint8_t padding[5];
> > + uint16_t next;
> > + uint64_t counter;
> > +};
> > +
> > +struct inflight_info_split {
> > + uint64_t features;
> > + uint16_t version;
> > + uint16_t desc_num;
> > + uint16_t last_inflight_io;
> > + uint16_t used_idx;
> > + struct inflight_desc_split desc[0];
> > +};
>
> I haven't looked into the details yet. Is it necessary to expose above
> definitions to applications? It seems they are not used in your example code.
Will revise in the next version.
>
> > +
> > +struct resubmit_desc {
> > + uint16_t index;
> > + uint64_t counter;
> > +};
> > +
> > +struct resubmit_info {
> > + struct resubmit_desc *resubmit_list;
> > + uint16_t resubmit_num;
> > +};
>
> The rte_vhost_ prefix is needed for vhost APIs.
>
> > +
> > +struct rte_vhost_ring_inflight_split {
> > + union {
> > + struct inflight_info_split *inflight_split;
> > + /* TODO */
> > + };
>
> Ditto. Seems it's not used in example code.
>
> > +
> > + struct resubmit_info *resubmit_inflight_split; };
> > +
> > struct rte_vhost_vring {
> > struct vring_desc *desc;
> > struct vring_avail *avail;
> > @@ -603,6 +642,22 @@ uint16_t rte_vhost_dequeue_burst(int vid,
> uint16_t queue_id,
> > */
> > int rte_vhost_get_mem_table(int vid, struct rte_vhost_memory **mem);
> >
> > +/**
> > + * Get guest inflight vring info, including inflight ring and resubmit
> > list.
> > + *
> > + * @param vid
> > + * vhost device ID
> > + * @param vring_idx
> > + * vring index
> > + * @param vring
> > + * the structure to hold the requested inflight vring info
> > + * @return
> > + * 0 on success, -1 on failure
> > + */
> > +int __rte_experimental
> > +rte_vhost_get_vhost_ring_inflight_split(int vid, uint16_t vring_idx,
> > + struct rte_vhost_ring_inflight_split *vring);
> > +
> > /**
> > * Get guest vring info, including the vring address, vring size, etc.
> > *
> > @@ -631,6 +686,56 @@ int rte_vhost_get_vhost_vring(int vid, uint16_t
> vring_idx,
> > */
> > int rte_vhost_vring_call(int vid, uint16_t vring_idx);
> >
> > +/**
> > + * set inflight flag for a desc.
> > + *
> > + * @param vid
> > + * vhost device ID
> > + * @param vring_idx
> > + * vring index
> > + * @param idx
> > + * inflight entry index
> > + * @return
> > + * 0 on success, -1 on failure
> > + */
> > +int __rte_experimental
> > +rte_vhost_set_inflight_desc_split(int vid, uint16_t vring_idx,
> > + uint16_t idx);
> [...]
> > +int __rte_experimental
> > +rte_vhost_clr_inflight_desc_split(int vid, uint16_t vring_idx,
> > + uint16_t last_used_idx, uint16_t idx);
> [...]
> > +int __rte_experimental
> > +rte_vhost_set_last_inflight_io_split(int vid, uint16_t vring_idx,
> > + uint16_t idx);
>
> What will be different in the function prototype when we design above three
> APIs for packed ring?
The whole process is quite different as there are no avail ring and userd ring.
