kvm tools: Handle only relevant events in epoll

Handle only new incoming data for listener and stop fds, treat all other
events as error events which close the socket.

This fixes the bug where a 'kvm list' could have hanged because a close
event in the listener fd have been treated as a new connection.

Cc: Osier Yang <jyang@redhat.com>
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Pekka Enberg <penberg@kernel.org>

diff --git a/tools/kvm/kvm-ipc.c b/tools/kvm/kvm-ipc.c
index 3131fe8375391c828484ef309853606e9344babe..40ab4572812e61c3ee84fc9565bd2c25e87ccb8e 100644 (file)
--- a/tools/kvm/kvm-ipc.c
+++ b/tools/kvm/kvm-ipc.c
@@ -112,7 +112,7 @@ static void *kvm_ipc__thread(void *param)
                if (nfds > 0) {
                        int fd = event.data.fd;
 
-                       if (fd == stop_fd) {
+                       if (fd == stop_fd && event.events & EPOLLIN) {
                                break;
                        } else if (fd == server_fd) {
                                int client;
@@ -138,13 +138,13 @@ int kvm_ipc__start(int sock)
 
        epoll_fd = epoll_create(KVM_IPC_MAX_MSGS);
 
-       ev.events = EPOLLIN | EPOLLOUT | EPOLLPRI;
+       ev.events = EPOLLIN | EPOLLET;
        ev.data.fd = sock;
        if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev) < 0)
                die("Failed starting IPC thread");
 
        stop_fd = eventfd(0, 0);
-       ev.events = EPOLLIN | EPOLLOUT | EPOLLRDHUP | EPOLLET;
+       ev.events = EPOLLIN | EPOLLET;
        ev.data.fd = stop_fd;
        if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, stop_fd, &ev) < 0)
                die("Failed adding stop event to epoll");