qemu-kvm/SOURCES/kvm-vhost-user-allow-slave-to-send-fds-via-slave-channel.patch

145 lines
4.6 KiB
Diff

From 6fceacad0e3d27cec6cef4e105c1dabacccb875c Mon Sep 17 00:00:00 2001
From: "plai@redhat.com" <plai@redhat.com>
Date: Thu, 21 Jun 2018 18:54:42 +0200
Subject: [PATCH 163/268] vhost-user: allow slave to send fds via slave channel
RH-Author: plai@redhat.com
Message-id: <1529607285-9942-8-git-send-email-plai@redhat.com>
Patchwork-id: 80935
O-Subject: [RHEL7.6 PATCH BZ 1526645 07/10] vhost-user: allow slave to send fds via slave channel
Bugzilla: 1526645
RH-Acked-by: Michael S. Tsirkin <mst@redhat.com>
RH-Acked-by: Maxime Coquelin <maxime.coquelin@redhat.com>
RH-Acked-by: Laurent Vivier <lvivier@redhat.com>
From: Tiwei Bie <tiwei.bie@intel.com>
Introduce VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD protocol
feature to allow slave to send at most 8 descriptors
in each message to master via ancillary data using the
slave channel.
Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit 5f57fbeaaf7c4cd33152d7f2e449caab4d4209d9)
Signed-off-by: Paul Lai <plai@redhat.com>
Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
docs/interop/vhost-user.txt | 5 +++++
hw/virtio/vhost-user.c | 27 +++++++++++++++++----------
2 files changed, 22 insertions(+), 10 deletions(-)
diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
index 534caab..682a683 100644
--- a/docs/interop/vhost-user.txt
+++ b/docs/interop/vhost-user.txt
@@ -367,6 +367,10 @@ The fd is provided via VHOST_USER_SET_SLAVE_REQ_FD ancillary data.
A slave may then send VHOST_USER_SLAVE_* messages to the master
using this fd communication channel.
+If VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD protocol feature is negotiated,
+slave can send file descriptors (at most 8 descriptors in each message)
+to master via ancillary data using this fd communication channel.
+
Protocol features
-----------------
@@ -380,6 +384,7 @@ Protocol features
#define VHOST_USER_PROTOCOL_F_CRYPTO_SESSION 7
#define VHOST_USER_PROTOCOL_F_PAGEFAULT 8
#define VHOST_USER_PROTOCOL_F_CONFIG 9
+#define VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD 10
Master message types
--------------------
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index ebb946a..e8027ad 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -30,6 +30,7 @@
#define VHOST_MEMORY_MAX_NREGIONS 8
#define VHOST_USER_F_PROTOCOL_FEATURES 30
+#define VHOST_USER_SLAVE_MAX_FDS 8
/*
* Maximum size of virtio device config space
@@ -47,6 +48,7 @@ enum VhostUserProtocolFeature {
VHOST_USER_PROTOCOL_F_CRYPTO_SESSION = 7,
VHOST_USER_PROTOCOL_F_PAGEFAULT = 8,
VHOST_USER_PROTOCOL_F_CONFIG = 9,
+ VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD = 10,
VHOST_USER_PROTOCOL_F_MAX
};
@@ -854,10 +856,10 @@ static void slave_read(void *opaque)
int size, ret = 0;
struct iovec iov;
struct msghdr msgh;
- int fd = -1;
+ int fd[VHOST_USER_SLAVE_MAX_FDS];
char control[CMSG_SPACE(sizeof(fd))];
struct cmsghdr *cmsg;
- size_t fdsize;
+ int i, fdsize = 0;
memset(&msgh, 0, sizeof(msgh));
msgh.msg_iov = &iov;
@@ -865,6 +867,8 @@ static void slave_read(void *opaque)
msgh.msg_control = control;
msgh.msg_controllen = sizeof(control);
+ memset(fd, -1, sizeof(fd));
+
/* Read header */
iov.iov_base = &hdr;
iov.iov_len = VHOST_USER_HDR_SIZE;
@@ -885,7 +889,7 @@ static void slave_read(void *opaque)
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_RIGHTS) {
fdsize = cmsg->cmsg_len - CMSG_LEN(0);
- memcpy(&fd, CMSG_DATA(cmsg), fdsize);
+ memcpy(fd, CMSG_DATA(cmsg), fdsize);
break;
}
}
@@ -913,14 +917,15 @@ static void slave_read(void *opaque)
break;
default:
error_report("Received unexpected msg type.");
- if (fd != -1) {
- close(fd);
- }
ret = -EINVAL;
}
- /* Message handlers need to make sure that fd will be consumed. */
- fd = -1;
+ /* Close the remaining file descriptors. */
+ for (i = 0; i < fdsize; i++) {
+ if (fd[i] != -1) {
+ close(fd[i]);
+ }
+ }
/*
* REPLY_ACK feature handling. Other reply types has to be managed
@@ -954,8 +959,10 @@ err:
qemu_set_fd_handler(u->slave_fd, NULL, NULL, NULL);
close(u->slave_fd);
u->slave_fd = -1;
- if (fd != -1) {
- close(fd);
+ for (i = 0; i < fdsize; i++) {
+ if (fd[i] != -1) {
+ close(fd[i]);
+ }
}
return;
}
--
1.8.3.1