| Message ID | 20210428110100.27757-7-dgilbert@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | virtiofs dax patches | expand |
* Dr. David Alan Gilbert (git) (dgilbert@redhat.com) wrote: > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com> > > Add virtio-fs definitions to libvhost-user > > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com> > Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> I'm going to need to rework this > +/* Structures carried over the slave channel back to QEMU */ > +#define VHOST_USER_FS_SLAVE_MAX_ENTRIES 32 > + > +/* For the flags field of VhostUserFSSlaveMsg */ > +#define VHOST_USER_FS_FLAG_MAP_R (1u << 0) > +#define VHOST_USER_FS_FLAG_MAP_W (1u << 1) > + > +typedef struct { > + /* Offsets within the file being mapped */ > + uint64_t fd_offset; > + /* Offsets within the cache */ > + uint64_t c_offset; > + /* Lengths of sections */ > + uint64_t len; > + /* Flags, from VHOST_USER_FS_FLAG_* */ > + uint64_t flags; > +} VhostUserFSSlaveMsgEntry; > + > +typedef struct { > + /* Number of entries */ > + uint16_t count; > + /* Spare */ > + uint16_t align; > + > + VhostUserFSSlaveMsgEntry entries[]; > +} VhostUserFSSlaveMsg; > + > typedef struct VhostUserMemoryRegion { > uint64_t guest_phys_addr; > uint64_t memory_size; > @@ -197,6 +224,7 @@ typedef struct VhostUserMsg { > VhostUserConfig config; > VhostUserVringArea area; > VhostUserInflight inflight; > + VhostUserFSSlaveMsg fs; > } payload; > > int fds[VHOST_MEMORY_BASELINE_NREGIONS]; This fails Clang's build; because 'fs' is part of a union and given it's entries[] is a variable length type, and is not at the end of the union. It's got a good point - I really don't know how gcc copes here; but also, what are vhost-user's rules on the length of 'payload' - it looks like me putting a larger message in there will break other demons. I'd changed it from a fixed size array to variable size based on Chirantan's comments on v1; but now I'm not even convinced the fixed size was right, given that I'm not convinced I'm allowed to change the length of payload. Dave > @@ -693,4 +721,16 @@ void vu_queue_get_avail_bytes(VuDev *vdev, VuVirtq *vq, unsigned int *in_bytes, > bool vu_queue_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int in_bytes, > unsigned int out_bytes); > > +/** > + * vu_fs_cache_request: Send a slave message for an fs client > + * @dev: a VuDev context > + * @req: The request type (map, unmap, sync) > + * @fd: an fd (only required for map, else must be -1) > + * @fsm: The body of the message > + * > + * Returns: 0 or above for success, nevative errno on error > + */ > +int64_t vu_fs_cache_request(VuDev *dev, VhostUserSlaveRequest req, int fd, > + VhostUserFSSlaveMsg *fsm); > + > #endif /* LIBVHOST_USER_H */ > -- > 2.31.1 > >
diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c index 68eb165755..97c909c6a8 100644 --- a/subprojects/libvhost-user/libvhost-user.c +++ b/subprojects/libvhost-user/libvhost-user.c @@ -2918,3 +2918,51 @@ vu_queue_push(VuDev *dev, VuVirtq *vq, vu_queue_flush(dev, vq, 1); vu_queue_inflight_post_put(dev, vq, elem->index); } + +int64_t vu_fs_cache_request(VuDev *dev, VhostUserSlaveRequest req, int fd, + VhostUserFSSlaveMsg *fsm) +{ + int fd_num = 0; + bool res; + uint64_t payload = 0; + VhostUserMsg vmsg = { + .request = req, + .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK, + .payload.fs = *fsm, + }; + + if (fsm->count > VHOST_USER_FS_SLAVE_MAX_ENTRIES) { + return -EINVAL; + } + + vmsg.size = sizeof(VhostUserFSSlaveMsg) + + fsm->count * sizeof(VhostUserFSSlaveMsgEntry); + memcpy(&vmsg.payload.fs, fsm, vmsg.size); + + if (fd != -1) { + vmsg.fds[fd_num++] = fd; + } + + vmsg.fd_num = fd_num; + + if (!vu_has_protocol_feature(dev, VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD)) { + return -EINVAL; + } + + pthread_mutex_lock(&dev->slave_mutex); + if (!vu_message_write(dev, dev->slave_fd, &vmsg)) { + pthread_mutex_unlock(&dev->slave_mutex); + return -EIO; + } + + /* Also unlocks the slave_mutex */ + res = vu_process_message_reply(dev, &vmsg, &payload); + if (!res) { + return -EIO; + } + /* + * Payload is delivered as uint64_t but is actually signed for + * errors. + */ + return (int64_t)payload; +} diff --git a/subprojects/libvhost-user/libvhost-user.h b/subprojects/libvhost-user/libvhost-user.h index 330b61c005..70fc61171f 100644 --- a/subprojects/libvhost-user/libvhost-user.h +++ b/subprojects/libvhost-user/libvhost-user.h @@ -122,6 +122,33 @@ typedef enum VhostUserSlaveRequest { VHOST_USER_SLAVE_MAX } VhostUserSlaveRequest; +/* Structures carried over the slave channel back to QEMU */ +#define VHOST_USER_FS_SLAVE_MAX_ENTRIES 32 + +/* For the flags field of VhostUserFSSlaveMsg */ +#define VHOST_USER_FS_FLAG_MAP_R (1u << 0) +#define VHOST_USER_FS_FLAG_MAP_W (1u << 1) + +typedef struct { + /* Offsets within the file being mapped */ + uint64_t fd_offset; + /* Offsets within the cache */ + uint64_t c_offset; + /* Lengths of sections */ + uint64_t len; + /* Flags, from VHOST_USER_FS_FLAG_* */ + uint64_t flags; +} VhostUserFSSlaveMsgEntry; + +typedef struct { + /* Number of entries */ + uint16_t count; + /* Spare */ + uint16_t align; + + VhostUserFSSlaveMsgEntry entries[]; +} VhostUserFSSlaveMsg; + typedef struct VhostUserMemoryRegion { uint64_t guest_phys_addr; uint64_t memory_size; @@ -197,6 +224,7 @@ typedef struct VhostUserMsg { VhostUserConfig config; VhostUserVringArea area; VhostUserInflight inflight; + VhostUserFSSlaveMsg fs; } payload; int fds[VHOST_MEMORY_BASELINE_NREGIONS]; @@ -693,4 +721,16 @@ void vu_queue_get_avail_bytes(VuDev *vdev, VuVirtq *vq, unsigned int *in_bytes, bool vu_queue_avail_bytes(VuDev *dev, VuVirtq *vq, unsigned int in_bytes, unsigned int out_bytes); +/** + * vu_fs_cache_request: Send a slave message for an fs client + * @dev: a VuDev context + * @req: The request type (map, unmap, sync) + * @fd: an fd (only required for map, else must be -1) + * @fsm: The body of the message + * + * Returns: 0 or above for success, nevative errno on error + */ +int64_t vu_fs_cache_request(VuDev *dev, VhostUserSlaveRequest req, int fd, + VhostUserFSSlaveMsg *fsm); + #endif /* LIBVHOST_USER_H */