From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40429) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dQIDj-0004d0-DU for qemu-devel@nongnu.org; Wed, 28 Jun 2017 15:01:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dQIDf-00088O-G6 for qemu-devel@nongnu.org; Wed, 28 Jun 2017 15:01:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52382) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dQIDf-000886-8M for qemu-devel@nongnu.org; Wed, 28 Jun 2017 15:01:43 -0400 From: "Dr. David Alan Gilbert (git)" Date: Wed, 28 Jun 2017 20:00:27 +0100 Message-Id: <20170628190047.26159-10-dgilbert@redhat.com> In-Reply-To: <20170628190047.26159-1-dgilbert@redhat.com> References: <20170628190047.26159-1-dgilbert@redhat.com> Subject: [Qemu-devel] [RFC 09/29] vhub: Support sending fds back to qemu List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, a.perevalov@samsung.com, marcandre.lureau@redhat.com, maxime.coquelin@redhat.com, mst@redhat.com, quintela@redhat.com, peterx@redhat.com, lvivier@redhat.com, aarcange@redhat.com From: "Dr. David Alan Gilbert" Allow replies with fds (for postcopy) Signed-off-by: Dr. David Alan Gilbert --- contrib/libvhost-user/libvhost-user.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c index ca7af5453a..e3a32755cf 100644 --- a/contrib/libvhost-user/libvhost-user.c +++ b/contrib/libvhost-user/libvhost-user.c @@ -214,6 +214,30 @@ vu_message_write(VuDev *dev, int conn_fd, VhostUserMsg *vmsg) { int rc; uint8_t *p = (uint8_t *)vmsg; + char control[CMSG_SPACE(VHOST_MEMORY_MAX_NREGIONS * sizeof(int))] = { }; + struct iovec iov = { + .iov_base = (char *)vmsg, + .iov_len = VHOST_USER_HDR_SIZE, + }; + struct msghdr msg = { + .msg_iov = &iov, + .msg_iovlen = 1, + .msg_control = control, + }; + struct cmsghdr *cmsg; + + memset(control, 0, sizeof(control)); + if (vmsg->fds) { + size_t fdsize = vmsg->fd_num * sizeof(int); + msg.msg_controllen = CMSG_SPACE(fdsize); + cmsg = CMSG_FIRSTHDR(&msg); + cmsg->cmsg_len = CMSG_LEN(fdsize); + cmsg->cmsg_level = SOL_SOCKET; + cmsg->cmsg_type = SCM_RIGHTS; + memcpy(CMSG_DATA(cmsg), vmsg->fds, fdsize); + } else { + msg.msg_controllen = 0; + } /* Set the version in the flags when sending the reply */ vmsg->flags &= ~VHOST_USER_VERSION_MASK; @@ -221,7 +245,7 @@ vu_message_write(VuDev *dev, int conn_fd, VhostUserMsg *vmsg) vmsg->flags |= VHOST_USER_REPLY_MASK; do { - rc = write(conn_fd, p, VHOST_USER_HDR_SIZE); + rc = sendmsg(conn_fd, &msg, 0); } while (rc < 0 && (errno == EINTR || errno == EAGAIN)); do { @@ -314,6 +338,7 @@ vu_get_features_exec(VuDev *dev, VhostUserMsg *vmsg) } vmsg->size = sizeof(vmsg->payload.u64); + vmsg->fd_num = 0; DPRINT("Sending back to guest u64: 0x%016"PRIx64"\n", vmsg->payload.u64); @@ -455,6 +480,7 @@ vu_set_log_base_exec(VuDev *dev, VhostUserMsg *vmsg) dev->log_size = log_mmap_size; vmsg->size = sizeof(vmsg->payload.u64); + vmsg->fd_num = 0; return true; } @@ -699,6 +725,7 @@ vu_get_protocol_features_exec(VuDev *dev, VhostUserMsg *vmsg) vmsg->payload.u64 = features; vmsg->size = sizeof(vmsg->payload.u64); + vmsg->fd_num = 0; return true; } -- 2.13.0