rdma: export yield_until_fd_readable()

The RDMA event channel can be made non-blocking just like a TCP
socket. Exporting this function allows us to yield so that the
QEMU monitor remains available.

Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Chegu Vinod <chegu_vinod@hp.com>
Tested-by: Chegu Vinod <chegu_vinod@hp.com>
Tested-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Michael R. Hines <mrhines@us.ibm.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/qemu-coroutine-io.c b/qemu-coroutine-io.c
index e8ad1a4..c4df35a 100644
--- a/qemu-coroutine-io.c
+++ b/qemu-coroutine-io.c
@@ -63,3 +63,26 @@ qemu_co_send_recv(int sockfd, void *buf, size_t bytes, bool do_send)
     struct iovec iov = { .iov_base = buf, .iov_len = bytes };
     return qemu_co_sendv_recvv(sockfd, &iov, 1, 0, bytes, do_send);
 }
+
+typedef struct {
+    Coroutine *co;
+    int fd;
+} FDYieldUntilData;
+
+static void fd_coroutine_enter(void *opaque)
+{
+    FDYieldUntilData *data = opaque;
+    qemu_set_fd_handler(data->fd, NULL, NULL, NULL);
+    qemu_coroutine_enter(data->co, NULL);
+}
+
+void coroutine_fn yield_until_fd_readable(int fd)
+{
+    FDYieldUntilData data;
+
+    assert(qemu_in_coroutine());
+    data.co = qemu_coroutine_self();
+    data.fd = fd;
+    qemu_set_fd_handler(fd, fd_coroutine_enter, NULL, &data);
+    qemu_coroutine_yield();
+}