Hi Stephen, > -----Original Message----- > From: Stephen Hemminger <[email protected]> > Sent: Saturday, December 19, 2020 1:18 AM > To: Xia, Chenbo <[email protected]> > Cc: [email protected]; [email protected]; [email protected]; Liang, > Cunming <[email protected]>; Lu, Xiuchun <[email protected]>; Li, > Miao <[email protected]>; Wu, Jingjing <[email protected]> > Subject: Re: [PATCH 1/9] lib: introduce vfio-user library > > On Fri, 18 Dec 2020 15:38:43 +0800 > Chenbo Xia <[email protected]> wrote: > > > +typedef struct vfio_user_msg { > > + uint16_t msg_id; > > + uint16_t cmd; > > + uint32_t size; > > +#define VFIO_USER_TYPE_CMD (0x0) /* Message type is COMMAND */ > > +#define VFIO_USER_TYPE_REPLY (0x1 << 0) /* Message type is REPLY > */ > > +#define VFIO_USER_NEED_NO_RP (0x1 << 4) /* Message needs no > > reply > */ > > +#define VFIO_USER_ERROR (0x1 << 5) /* Reply message has > > error > */ > > + uint32_t flags; > > + uint32_t err; /* Valid in reply, optional */ > > + union { > > + struct vfio_user_version ver; > > + } payload; > > + int fds[VFIO_USER_MAX_FD]; > > + int fd_num; > > +} __attribute((packed)) VFIO_USER_MSG; > > Please don't introduce all capitals typedefs.
OK. Will fix in v2. > Don't use packed, it generates slower code. Better to use tools > like pahole and make the layout of the structure naturally packed. Thanks for the heads up 😊. Will check pahole then. > Also, if you put fds[] at the end you could use dynamic sized array > and not be constrained by VFIO_USER_MAX_FD. I put this constraint just because one vfio-user message in theory will not send so many fds. And since I am just planning to optimize the message structure, I will consider this to make it more flexible and reasonable. > > > Since this is DPDK library the symbols should all start with rte_ I think structs in this file are not exposed. Do we add rte_ in this case? If yes, I will fix it in v2 then. Thanks for all the good catches! Chenbo
