Save all tap fd's in canonical order, leveraging the index argument of
cpr_save_fd. For the i'th queue, the tap device fd is saved at index 2*i,
and the vhostfd (if any) at index 2*i+1.
tap and vhost fd's are passed by name to the monitor when a NIC is hot
plugged, but the name is not known to qemu after cpr-exec. Allow the
manager to pass -1 for the fd "name" in the new qemu args to indicate that
qemu should search for a saved value. Example:
-netdev tap,id=hostnet2,fds=-1:-1,vhostfds=-1:-1
Signed-off-by: Steve Sistare <steven.sist...@oracle.com>
---
net/tap.c | 55 +++++++++++++++++++++++++++++++++++++++++--------------
1 file changed, 41 insertions(+), 14 deletions(-)
diff --git a/net/tap.c b/net/tap.c
index 20e4dae..4d57a53 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -35,6 +35,7 @@
#include "net/eth.h"
#include "net/net.h"
#include "clients.h"
+#include "migration/cpr.h"
#include "monitor/monitor.h"
#include "sysemu/sysemu.h"
#include "qapi/error.h"
@@ -290,6 +291,8 @@ static void tap_cleanup(NetClientState *nc)
{
TAPState *s = DO_UPCAST(TAPState, nc, nc);
+ cpr_delete_fd_all(nc->name);
+
if (s->vhost_net) {
vhost_net_cleanup(s->vhost_net);
g_free(s->vhost_net);
@@ -636,13 +639,17 @@ static int net_tap_init(const NetdevTapOptions *tap, int
*vnet_hdr,
return fd;
}
+/* CPR fd's for each queue are saved at these indices */
+#define TAP_FD_INDEX(queue) (2 * (queue) + 0)
+#define TAP_VHOSTFD_INDEX(queue) (2 * (queue) + 1)
+
#define MAX_TAP_QUEUES 1024
static void net_init_tap_one(const NetdevTapOptions *tap, NetClientState *peer,
const char *model, const char *name,
const char *ifname, const char *script,
const char *downscript, const char *vhostfdname,
- int vnet_hdr, int fd, Error **errp)
+ int vnet_hdr, int fd, int index, Error **errp)
{
Error *err = NULL;
TAPState *s = net_tap_fd_init(peer, model, name, fd, vnet_hdr);
@@ -682,7 +689,7 @@ static void net_init_tap_one(const NetdevTapOptions *tap,
NetClientState *peer,
}
if (vhostfdname) {
- vhostfd = monitor_fd_param(monitor_cur(), vhostfdname, &err);
+ vhostfd = cpr_get_fd_param(name, vhostfdname, index, &err);
if (vhostfd == -1) {
error_propagate(errp, err);
goto failed;
@@ -693,7 +700,10 @@ static void net_init_tap_one(const NetdevTapOptions *tap,
NetClientState *peer,
goto failed;
}
} else {
- vhostfd = open("/dev/vhost-net", O_RDWR);
+ vhostfd = cpr_find_fd(name, index);
+ if (vhostfd < 0) {
+ vhostfd = open("/dev/vhost-net", O_RDWR);
+ }
if (vhostfd < 0) {
error_setg_errno(errp, errno,
"tap: open vhost char device failed");
@@ -703,6 +713,7 @@ static void net_init_tap_one(const NetdevTapOptions *tap,
NetClientState *peer,
error_setg_errno(errp, errno, "Failed to set FD nonblocking");
goto failed;
}
+ cpr_resave_fd(name, index, vhostfd);
}
options.opaque = (void *)(uintptr_t)vhostfd;
options.nvqs = 2;
@@ -721,6 +732,7 @@ static void net_init_tap_one(const NetdevTapOptions *tap,
NetClientState *peer,
return;
failed:
+ cpr_delete_fd_all(name);
qemu_del_net_client(&s->nc);
}
@@ -789,7 +801,7 @@ int net_init_tap(const Netdev *netdev, const char *name,
goto out;
}
- fd = monitor_fd_param(monitor_cur(), tap->fd, errp);
+ fd = cpr_get_fd_param(name, tap->fd, TAP_FD_INDEX(0), errp);
if (fd == -1) {
ret = -1;
goto out;
@@ -812,13 +824,14 @@ int net_init_tap(const Netdev *netdev, const char *name,
net_init_tap_one(tap, peer, "tap", name, NULL,
script, downscript,
- vhostfdname, vnet_hdr, fd, &err);
+ vhostfdname, vnet_hdr, fd, TAP_VHOSTFD_INDEX(0),
&err);
if (err) {
error_propagate(errp, err);
close(fd);
ret = -1;
goto out;
}
+
} else if (tap->fds) {
char **fds;
char **vhost_fds;
@@ -849,7 +862,7 @@ int net_init_tap(const Netdev *netdev, const char *name,
}
for (i = 0; i < nfds; i++) {
- fd = monitor_fd_param(monitor_cur(), fds[i], errp);
+ fd = cpr_get_fd_param(name, fds[i], TAP_FD_INDEX(i), errp);
if (fd == -1) {
ret = -1;
goto free_fail;
@@ -878,7 +891,7 @@ int net_init_tap(const Netdev *netdev, const char *name,
net_init_tap_one(tap, peer, "tap", name, ifname,
script, downscript,
tap->vhostfds ? vhost_fds[i] : NULL,
- vnet_hdr, fd, &err);
+ vnet_hdr, fd, TAP_VHOSTFD_INDEX(i), &err);
if (err) {
error_propagate(errp, err);
ret = -1;
@@ -906,9 +919,12 @@ free_fail:
goto out;
}
- fd = net_bridge_run_helper(tap->helper,
- tap->br ?: DEFAULT_BRIDGE_INTERFACE,
- errp);
+ fd = cpr_find_fd(name, TAP_FD_INDEX(0));
+ if (fd < 0) {
+ fd = net_bridge_run_helper(tap->helper,
+ tap->br ?: DEFAULT_BRIDGE_INTERFACE,
+ errp);
+ }
if (fd == -1) {
ret = -1;
goto out;
@@ -928,13 +944,15 @@ free_fail:
net_init_tap_one(tap, peer, "bridge", name, ifname,
script, downscript, vhostfdname,
- vnet_hdr, fd, &err);
+ vnet_hdr, fd, TAP_VHOSTFD_INDEX(0), &err);
if (err) {
error_propagate(errp, err);
close(fd);
ret = -1;
goto out;
}
+ cpr_resave_fd(name, TAP_FD_INDEX(0), fd);
+
} else {
g_autofree char *default_script = NULL;
g_autofree char *default_downscript = NULL;
@@ -959,8 +977,11 @@ free_fail:
}
for (i = 0; i < queues; i++) {
- fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script,
- ifname, sizeof ifname, queues > 1, errp);
+ fd = cpr_find_fd(name, TAP_FD_INDEX(i));
+ if (fd < 0) {
+ fd = net_tap_init(tap, &vnet_hdr, i >= 1 ? "no" : script,
+ ifname, sizeof ifname, queues > 1, errp);
+ }
if (fd == -1) {
ret = -1;
goto out;
@@ -978,17 +999,23 @@ free_fail:
net_init_tap_one(tap, peer, "tap", name, ifname,
i >= 1 ? "no" : script,
i >= 1 ? "no" : downscript,
- vhostfdname, vnet_hdr, fd, &err);
+ vhostfdname, vnet_hdr,
+ fd, TAP_VHOSTFD_INDEX(i),
+ &err);
if (err) {
error_propagate(errp, err);
close(fd);
ret = -1;
goto out;
}
+ cpr_resave_fd(name, TAP_FD_INDEX(i), fd);
}
}
out:
+ if (ret) {
+ cpr_delete_fd_all(name);
+ }
return ret;
}
--
1.8.3.1
