@@ -2918,3 +2918,44 @@ 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,
+ .size = sizeof(vmsg.payload.fs),
+ .payload.fs = *fsm,
+ };
+
+ 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;
+}
@@ -122,6 +122,24 @@ typedef enum VhostUserSlaveRequest {
VHOST_USER_SLAVE_MAX
} VhostUserSlaveRequest;
+/* Structures carried over the slave channel back to QEMU */
+#define VHOST_USER_FS_SLAVE_ENTRIES 8
+
+/* For the flags field of VhostUserFSSlaveMsg */
+#define VHOST_USER_FS_FLAG_MAP_R (1ull << 0)
+#define VHOST_USER_FS_FLAG_MAP_W (1ull << 1)
+
+typedef struct {
+ /* Offsets within the file being mapped */
+ uint64_t fd_offset[VHOST_USER_FS_SLAVE_ENTRIES];
+ /* Offsets within the cache */
+ uint64_t c_offset[VHOST_USER_FS_SLAVE_ENTRIES];
+ /* Lengths of sections */
+ uint64_t len[VHOST_USER_FS_SLAVE_ENTRIES];
+ /* Flags, from VHOST_USER_FS_FLAG_* */
+ uint64_t flags[VHOST_USER_FS_SLAVE_ENTRIES];
+} VhostUserFSSlaveMsg;
+
typedef struct VhostUserMemoryRegion {
uint64_t guest_phys_addr;
uint64_t memory_size;
@@ -197,6 +215,7 @@ typedef struct VhostUserMsg {
VhostUserConfig config;
VhostUserVringArea area;
VhostUserInflight inflight;
+ VhostUserFSSlaveMsg fs;
} payload;
int fds[VHOST_MEMORY_BASELINE_NREGIONS];
@@ -693,4 +712,16 @@ 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 */