Merge remote branch 'mst/for_anthony' into staging

Makefile.objs

@@ -168,7 +168,8 @@ hw-obj-$(CONFIG_VIRTIO) += virtio.o virtio-console.o
 hw-obj-y += fw_cfg.o
 # FIXME: Core PCI code and its direct dependencies are required by the
 # QMP query-pci command.
-hw-obj-y += pci.o pci_bridge.o msix.o msi.o
+hw-obj-y += pci.o pci_bridge.o
+hw-obj-$(CONFIG_PCI) += msix.o msi.o
 hw-obj-$(CONFIG_PCI) += pci_host.o pcie_host.o
 hw-obj-$(CONFIG_PCI) += ioh3420.o xio3130_upstream.o xio3130_downstream.o
 hw-obj-y += watchdog.o

cpus.c

@@ -111,6 +111,8 @@ static void do_vm_stop(int reason)
         vm_running = 0;
         pause_all_vcpus();
         vm_state_notify(0, reason);
+        qemu_aio_flush();
+        bdrv_flush_all();
         monitor_protocol_event(QEVENT_STOP, NULL);
     }
 }

hw/pc_piix.c

@@ -217,6 +217,14 @@ static QEMUMachine pc_machine = {
     .desc = "Standard PC",
     .init = pc_init_pci,
     .max_cpus = 255,
+    .compat_props = (GlobalProperty[]) {
+        {
+            .driver   = "PCI",
+            .property = "command_serr_enable",
+            .value    = "off",
+        },
+        { /* end of list */ }
+    },
     .is_default = 1,
 };
 
@@ -265,6 +273,10 @@ static QEMUMachine pc_machine_v0_12 = {
             .driver   = "vmware-svga",
             .property = "rombar",
             .value    = stringify(0),
+        },{
+            .driver   = "PCI",
+            .property = "command_serr_enable",
+            .value    = "off",
         },
         { /* end of list */ }
     }
@@ -300,6 +312,10 @@ static QEMUMachine pc_machine_v0_11 = {
             .driver   = "PCI",
             .property = "rombar",
             .value    = stringify(0),
+        },{
+            .driver   = "PCI",
+            .property = "command_serr_enable",
+            .value    = "off",
         },
         { /* end of list */ }
     }
@@ -347,6 +363,10 @@ static QEMUMachine pc_machine_v0_10 = {
             .driver   = "PCI",
             .property = "rombar",
             .value    = stringify(0),
+        },{
+            .driver   = "PCI",
+            .property = "command_serr_enable",
+            .value    = "off",
         },
         { /* end of list */ }
     },

hw/pci.c

@@ -25,8 +25,6 @@
 #include "pci.h"
 #include "pci_bridge.h"
 #include "pci_internals.h"
-#include "msix.h"
-#include "msi.h"
 #include "monitor.h"
 #include "net.h"
 #include "sysemu.h"
@@ -59,6 +57,8 @@ struct BusInfo pci_bus_info = {
         DEFINE_PROP_UINT32("rombar",  PCIDevice, rom_bar, 1),
         DEFINE_PROP_BIT("multifunction", PCIDevice, cap_present,
                         QEMU_PCI_CAP_MULTIFUNCTION_BITNR, false),
+        DEFINE_PROP_BIT("command_serr_enable", PCIDevice, cap_present,
+                        QEMU_PCI_CAP_SERR_BITNR, true),
         DEFINE_PROP_END_OF_LIST()
     }
 };
@@ -570,6 +570,9 @@ static void pci_init_wmask(PCIDevice *dev)
     pci_set_word(dev->wmask + PCI_COMMAND,
                  PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
                  PCI_COMMAND_INTX_DISABLE);
+    if (dev->cap_present & QEMU_PCI_CAP_SERR) {
+        pci_word_test_and_set_mask(dev->wmask + PCI_COMMAND, PCI_COMMAND_SERR);
+    }
 
     memset(dev->wmask + PCI_CONFIG_HEADER_SIZE, 0xff,
            config_size - PCI_CONFIG_HEADER_SIZE);
@@ -1096,23 +1099,6 @@ static void pci_set_irq(void *opaque, int irq_num, int level)
     pci_change_irq_level(pci_dev, irq_num, change);
 }
 
-bool pci_msi_enabled(PCIDevice *dev)
-{
-    return msix_enabled(dev) || msi_enabled(dev);
-}
-
-void pci_msi_notify(PCIDevice *dev, unsigned int vector)
-{
-    if (msix_enabled(dev)) {
-        msix_notify(dev, vector);
-    } else if (msi_enabled(dev)) {
-        msi_notify(dev, vector);
-    } else {
-        /* MSI/MSI-X must be enabled */
-        abort();
-    }
-}
-
 /***********************************************************/
 /* monitor info on PCI */
 

hw/pci.h

@@ -118,6 +118,10 @@ enum {
     /* multifunction capable device */
 #define QEMU_PCI_CAP_MULTIFUNCTION_BITNR        3
     QEMU_PCI_CAP_MULTIFUNCTION = (1 << QEMU_PCI_CAP_MULTIFUNCTION_BITNR),
+
+    /* command register SERR bit enabled */
+#define QEMU_PCI_CAP_SERR_BITNR 4
+    QEMU_PCI_CAP_SERR = (1 << QEMU_PCI_CAP_SERR_BITNR),
 };
 
 struct PCIDevice {
@@ -257,9 +261,6 @@ void do_pci_info_print(Monitor *mon, const QObject *data);
 void do_pci_info(Monitor *mon, QObject **ret_data);
 void pci_bridge_update_mappings(PCIBus *b);
 
-bool pci_msi_enabled(PCIDevice *dev);
-void pci_msi_notify(PCIDevice *dev, unsigned int vector);
-
 static inline void
 pci_set_byte(uint8_t *config, uint8_t val)
 {

hw/pcie.c

@@ -167,10 +167,12 @@ static void hotplug_event_notify(PCIDevice *dev)
      * The Port may optionally send an MSI when there are hot-plug events that
      * occur while interrupt generation is disabled, and interrupt generation is
      * subsequently enabled. */
-    if (!pci_msi_enabled(dev)) {
+    if (msix_enabled(dev)) {
+        msix_notify(dev, pcie_cap_flags_get_vector(dev));
+    } else if (msi_enabled(dev)) {
+        msi_notify(dev, pcie_cap_flags_get_vector(dev));
+    } else {
         qemu_set_irq(dev->irq[dev->exp.hpev_intx], dev->exp.hpev_notified);
-    } else if (dev->exp.hpev_notified) {
-        pci_msi_notify(dev, pcie_cap_flags_get_vector(dev));
     }
 }
 

hw/pcie_aer.c

@@ -257,30 +257,49 @@ static unsigned int pcie_aer_root_get_vector(PCIDevice *dev)
     return (root_status & PCI_ERR_ROOT_IRQ) >> PCI_ERR_ROOT_IRQ_SHIFT;
 }
 
+/* Given a status register, get corresponding bits in the command register */
+static uint32_t pcie_aer_status_to_cmd(uint32_t status)
+{
+    uint32_t cmd = 0;
+    if (status & PCI_ERR_ROOT_COR_RCV) {
+        cmd |= PCI_ERR_ROOT_CMD_COR_EN;
+    }
+    if (status & PCI_ERR_ROOT_NONFATAL_RCV) {
+        cmd |= PCI_ERR_ROOT_CMD_NONFATAL_EN;
+    }
+    if (status & PCI_ERR_ROOT_FATAL_RCV) {
+        cmd |= PCI_ERR_ROOT_CMD_FATAL_EN;
+    }
+    return cmd;
+}
+
+static void pcie_aer_root_notify(PCIDevice *dev)
+{
+    if (msix_enabled(dev)) {
+        msix_notify(dev, pcie_aer_root_get_vector(dev));
+    } else if (msi_enabled(dev)) {
+        msi_notify(dev, pcie_aer_root_get_vector(dev));
+    } else {
+        qemu_set_irq(dev->irq[dev->exp.aer_intx], 1);
+    }
+}
+
 /*
- * return value:
- * true: error message is sent up
- * false: error message is masked
- *
  * 6.2.6 Error Message Control
  * Figure 6-3
  * root port part
  */
-static bool pcie_aer_msg_root_port(PCIDevice *dev, const PCIEAERMsg *msg)
+static void pcie_aer_msg_root_port(PCIDevice *dev, const PCIEAERMsg *msg)
 {
-    bool msg_sent;
     uint16_t cmd;
     uint8_t *aer_cap;
     uint32_t root_cmd;
-    uint32_t root_status;
+    uint32_t root_status, prev_status;
-    bool msi_trigger;
 
-    msg_sent = false;
     cmd = pci_get_word(dev->config + PCI_COMMAND);
     aer_cap = dev->config + dev->exp.aer_cap;
     root_cmd = pci_get_long(aer_cap + PCI_ERR_ROOT_COMMAND);
-    root_status = pci_get_long(aer_cap + PCI_ERR_ROOT_STATUS);
+    prev_status = root_status = pci_get_long(aer_cap + PCI_ERR_ROOT_STATUS);
-    msi_trigger = false;
 
     if (cmd & PCI_COMMAND_SERR) {
         /* System Error.
@@ -299,25 +318,14 @@ static bool pcie_aer_msg_root_port(PCIDevice *dev, const PCIEAERMsg *msg)
         if (root_status & PCI_ERR_ROOT_COR_RCV) {
             root_status |= PCI_ERR_ROOT_MULTI_COR_RCV;
         } else {
-            if (root_cmd & PCI_ERR_ROOT_CMD_COR_EN) {
-                msi_trigger = true;
-            }
             pci_set_word(aer_cap + PCI_ERR_ROOT_COR_SRC, msg->source_id);
         }
         root_status |= PCI_ERR_ROOT_COR_RCV;
         break;
     case PCI_ERR_ROOT_CMD_NONFATAL_EN:
-        if (!(root_status & PCI_ERR_ROOT_NONFATAL_RCV) &&
-            root_cmd & PCI_ERR_ROOT_CMD_NONFATAL_EN) {
-            msi_trigger = true;
-        }
         root_status |= PCI_ERR_ROOT_NONFATAL_RCV;
         break;
     case PCI_ERR_ROOT_CMD_FATAL_EN:
-        if (!(root_status & PCI_ERR_ROOT_FATAL_RCV) &&
-            root_cmd & PCI_ERR_ROOT_CMD_FATAL_EN) {
-            msi_trigger = true;
-        }
         if (!(root_status & PCI_ERR_ROOT_UNCOR_RCV)) {
             root_status |= PCI_ERR_ROOT_FIRST_FATAL;
         }
@@ -337,18 +345,17 @@ static bool pcie_aer_msg_root_port(PCIDevice *dev, const PCIEAERMsg *msg)
     }
     pci_set_long(aer_cap + PCI_ERR_ROOT_STATUS, root_status);
 
-    if (root_cmd & msg->severity) {
     /* 6.2.4.1.2 Interrupt Generation */
-        if (pci_msi_enabled(dev)) {
+    /* All the above did was set some bits in the status register.
-            if (msi_trigger) {
+     * Specifically these that match message severity.
-                pci_msi_notify(dev, pcie_aer_root_get_vector(dev));
+     * The below code relies on this fact. */
+    if (!(root_cmd & msg->severity) ||
+        (pcie_aer_status_to_cmd(prev_status) & root_cmd)) {
+        /* Condition is not being set or was already true so nothing to do. */
+        return;
     }
-        } else {
+
-            qemu_set_irq(dev->irq[dev->exp.aer_intx], 1);
+    pcie_aer_root_notify(dev);
-        }
-        msg_sent = true;
-    }
-    return msg_sent;
 }
 
 /*
@@ -739,40 +746,26 @@ void pcie_aer_root_reset(PCIDevice *dev)
      */
 }
 
-static bool pcie_aer_root_does_trigger(uint32_t cmd, uint32_t status)
-{
-    return
-        ((cmd & PCI_ERR_ROOT_CMD_COR_EN) && (status & PCI_ERR_ROOT_COR_RCV)) ||
-        ((cmd & PCI_ERR_ROOT_CMD_NONFATAL_EN) &&
-         (status & PCI_ERR_ROOT_NONFATAL_RCV)) ||
-        ((cmd & PCI_ERR_ROOT_CMD_FATAL_EN) &&
-         (status & PCI_ERR_ROOT_FATAL_RCV));
-}
-
 void pcie_aer_root_write_config(PCIDevice *dev,
                                 uint32_t addr, uint32_t val, int len,
                                 uint32_t root_cmd_prev)
 {
     uint8_t *aer_cap = dev->config + dev->exp.aer_cap;
-
-    /* root command register */
-    uint32_t root_cmd = pci_get_long(aer_cap + PCI_ERR_ROOT_COMMAND);
-    if (root_cmd & PCI_ERR_ROOT_CMD_EN_MASK) {
-        /* 6.2.4.1.2 Interrupt Generation */
-
-        /* 0 -> 1 */
-        uint32_t root_cmd_set = (root_cmd_prev ^ root_cmd) & root_cmd;
     uint32_t root_status = pci_get_long(aer_cap + PCI_ERR_ROOT_STATUS);
+    uint32_t enabled_cmd = pcie_aer_status_to_cmd(root_status);
+    uint32_t root_cmd = pci_get_long(aer_cap + PCI_ERR_ROOT_COMMAND);
+    /* 6.2.4.1.2 Interrupt Generation */
+    if (!msix_enabled(dev) && !msi_enabled(dev)) {
+        qemu_set_irq(dev->irq[dev->exp.aer_intx], !!(root_cmd & enabled_cmd));
+        return;
+    }
 
-        if (pci_msi_enabled(dev)) {
+    if ((root_cmd_prev & enabled_cmd) || !(root_cmd & enabled_cmd)) {
-            if (pcie_aer_root_does_trigger(root_cmd_set, root_status)) {
+        /* Send MSI on transition from false to true. */
-                pci_msi_notify(dev, pcie_aer_root_get_vector(dev));
+        return;
-            }
-        } else {
-            int int_level = pcie_aer_root_does_trigger(root_cmd, root_status);
-            qemu_set_irq(dev->irq[dev->exp.aer_intx], int_level);
-        }
     }
+
+    pcie_aer_root_notify(dev);
 }
 
 static const VMStateDescription vmstate_pcie_aer_err = {

hw/virtio-net.c

@@ -99,9 +99,14 @@ static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
     }
 }
 
-static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
+static bool virtio_net_started(VirtIONet *n, uint8_t status)
+{
+    return (status & VIRTIO_CONFIG_S_DRIVER_OK) &&
+        (n->status & VIRTIO_NET_S_LINK_UP) && n->vm_running;
+}
+
+static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
 {
-    VirtIONet *n = to_virtio_net(vdev);
     if (!n->nic->nc.peer) {
         return;
     }
@@ -112,9 +117,7 @@ static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
     if (!tap_get_vhost_net(n->nic->nc.peer)) {
         return;
     }
-    if (!!n->vhost_started == ((status & VIRTIO_CONFIG_S_DRIVER_OK) &&
+    if (!!n->vhost_started == virtio_net_started(n, status)) {
-                               (n->status & VIRTIO_NET_S_LINK_UP) &&
-                               n->vm_running)) {
         return;
     }
     if (!n->vhost_started) {
@@ -131,6 +134,32 @@ static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
     }
 }
 
+static void virtio_net_set_status(struct VirtIODevice *vdev, uint8_t status)
+{
+    VirtIONet *n = to_virtio_net(vdev);
+
+    virtio_net_vhost_status(n, status);
+
+    if (!n->tx_waiting) {
+        return;
+    }
+
+    if (virtio_net_started(n, status) && !n->vhost_started) {
+        if (n->tx_timer) {
+            qemu_mod_timer(n->tx_timer,
+                           qemu_get_clock(vm_clock) + n->tx_timeout);
+        } else {
+            qemu_bh_schedule(n->tx_bh);
+        }
+    } else {
+        if (n->tx_timer) {
+            qemu_del_timer(n->tx_timer);
+        } else {
+            qemu_bh_cancel(n->tx_bh);
+        }
+    }
+}
+
 static void virtio_net_set_link_status(VLANClientState *nc)
 {
     VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
@@ -424,6 +453,9 @@ static void virtio_net_handle_rx(VirtIODevice *vdev, VirtQueue *vq)
 static int virtio_net_can_receive(VLANClientState *nc)
 {
     VirtIONet *n = DO_UPCAST(NICState, nc, nc)->opaque;
+    if (!n->vm_running) {
+        return 0;
+    }
 
     if (!virtio_queue_ready(n->rx_vq) ||
         !(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK))
@@ -672,11 +704,12 @@ static int32_t virtio_net_flush_tx(VirtIONet *n, VirtQueue *vq)
 {
     VirtQueueElement elem;
     int32_t num_packets = 0;
-
     if (!(n->vdev.status & VIRTIO_CONFIG_S_DRIVER_OK)) {
         return num_packets;
     }
 
+    assert(n->vm_running);
+
     if (n->async_tx.elem.out_num) {
         virtio_queue_set_notification(n->tx_vq, 0);
         return num_packets;
@@ -735,6 +768,12 @@ static void virtio_net_handle_tx_timer(VirtIODevice *vdev, VirtQueue *vq)
 {
     VirtIONet *n = to_virtio_net(vdev);
 
+    /* This happens when device was stopped but VCPU wasn't. */
+    if (!n->vm_running) {
+        n->tx_waiting = 1;
+        return;
+    }
+
     if (n->tx_waiting) {
         virtio_queue_set_notification(vq, 1);
         qemu_del_timer(n->tx_timer);
@@ -755,14 +794,19 @@ static void virtio_net_handle_tx_bh(VirtIODevice *vdev, VirtQueue *vq)
     if (unlikely(n->tx_waiting)) {
         return;
     }
+    n->tx_waiting = 1;
+    /* This happens when device was stopped but VCPU wasn't. */
+    if (!n->vm_running) {
+        return;
+    }
     virtio_queue_set_notification(vq, 0);
     qemu_bh_schedule(n->tx_bh);
-    n->tx_waiting = 1;
 }
 
 static void virtio_net_tx_timer(void *opaque)
 {
     VirtIONet *n = opaque;
+    assert(n->vm_running);
 
     n->tx_waiting = 0;
 
@@ -779,6 +823,8 @@ static void virtio_net_tx_bh(void *opaque)
     VirtIONet *n = opaque;
     int32_t ret;
 
+    assert(n->vm_running);
+
     n->tx_waiting = 0;
 
     /* Just in case the driver is not ready on more */
@@ -923,15 +969,6 @@ static int virtio_net_load(QEMUFile *f, void *opaque, int version_id)
         }
     }
     n->mac_table.first_multi = i;
-
-    if (n->tx_waiting) {
-        if (n->tx_timer) {
-            qemu_mod_timer(n->tx_timer,
-                           qemu_get_clock(vm_clock) + n->tx_timeout);
-        } else {
-            qemu_bh_schedule(n->tx_bh);
-        }
-    }
     return 0;
 }
 

migration.c

@@ -370,8 +370,6 @@ void migrate_fd_put_ready(void *opaque)
         DPRINTF("done iterating\n");
         vm_stop(0);
 
-        qemu_aio_flush();
-        bdrv_flush_all();
         if ((qemu_savevm_state_complete(s->mon, s->file)) < 0) {
             if (old_vm_running) {
                 vm_start();

net.c

@@ -1050,6 +1050,10 @@ static const struct {
                 .name = "mcast",
                 .type = QEMU_OPT_STRING,
                 .help = "UDP multicast address and port number",
+            }, {
+                .name = "localaddr",
+                .type = QEMU_OPT_STRING,
+                .help = "source address for multicast packets",
             },
             { /* end of list */ }
         },

net/socket.c

@@ -149,7 +149,7 @@ static void net_socket_send_dgram(void *opaque)
     qemu_send_packet(&s->nc, s->buf, size);
 }
 
-static int net_socket_mcast_create(struct sockaddr_in *mcastaddr)
+static int net_socket_mcast_create(struct sockaddr_in *mcastaddr, struct in_addr *localaddr)
 {
     struct ip_mreq imr;
     int fd;
@@ -183,7 +183,11 @@ static int net_socket_mcast_create(struct sockaddr_in *mcastaddr)
 
     /* Add host to multicast group */
     imr.imr_multiaddr = mcastaddr->sin_addr;
+    if (localaddr) {
+        imr.imr_interface = *localaddr;
+    } else {
         imr.imr_interface.s_addr = htonl(INADDR_ANY);
+    }
 
     ret = setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
                      (const char *)&imr, sizeof(struct ip_mreq));
@@ -201,6 +205,15 @@ static int net_socket_mcast_create(struct sockaddr_in *mcastaddr)
 	goto fail;
     }
 
+    /* If a bind address is given, only send packets from that address */
+    if (localaddr != NULL) {
+        ret = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF, localaddr, sizeof(*localaddr));
+        if (ret < 0) {
+            perror("setsockopt(IP_MULTICAST_IF)");
+            goto fail;
+        }
+    }
+
     socket_set_nonblock(fd);
     return fd;
 fail:
@@ -248,7 +261,7 @@ static NetSocketState *net_socket_fd_init_dgram(VLANState *vlan,
 		return NULL;
 	    }
 	    /* clone dgram socket */
-	    newfd = net_socket_mcast_create(&saddr);
+	    newfd = net_socket_mcast_create(&saddr, NULL);
 	    if (newfd < 0) {
 		/* error already reported by net_socket_mcast_create() */
 		close(fd);
@@ -468,17 +481,26 @@ static int net_socket_connect_init(VLANState *vlan,
 static int net_socket_mcast_init(VLANState *vlan,
                                  const char *model,
                                  const char *name,
-                                 const char *host_str)
+                                 const char *host_str,
+                                 const char *localaddr_str)
 {
     NetSocketState *s;
     int fd;
     struct sockaddr_in saddr;
+    struct in_addr localaddr, *param_localaddr;
 
     if (parse_host_port(&saddr, host_str) < 0)
         return -1;
 
+    if (localaddr_str != NULL) {
+        if (inet_aton(localaddr_str, &localaddr) == 0)
+            return -1;
+        param_localaddr = &localaddr;
+    } else {
+        param_localaddr = NULL;
+    }
 
-    fd = net_socket_mcast_create(&saddr);
+    fd = net_socket_mcast_create(&saddr, param_localaddr);
     if (fd < 0)
 	return -1;
 
@@ -505,8 +527,9 @@ int net_init_socket(QemuOpts *opts,
 
         if (qemu_opt_get(opts, "listen") ||
             qemu_opt_get(opts, "connect") ||
-            qemu_opt_get(opts, "mcast")) {
+            qemu_opt_get(opts, "mcast") ||
-            error_report("listen=, connect= and mcast= is invalid with fd=");
+            qemu_opt_get(opts, "localaddr")) {
+            error_report("listen=, connect=, mcast= and localaddr= is invalid with fd=\n");
             return -1;
         }
 
@@ -524,8 +547,9 @@ int net_init_socket(QemuOpts *opts,
 
         if (qemu_opt_get(opts, "fd") ||
             qemu_opt_get(opts, "connect") ||
-            qemu_opt_get(opts, "mcast")) {
+            qemu_opt_get(opts, "mcast") ||
-            error_report("fd=, connect= and mcast= is invalid with listen=");
+            qemu_opt_get(opts, "localaddr")) {
+            error_report("fd=, connect=, mcast= and localaddr= is invalid with listen=\n");
             return -1;
         }
 
@@ -539,8 +563,9 @@ int net_init_socket(QemuOpts *opts,
 
         if (qemu_opt_get(opts, "fd") ||
             qemu_opt_get(opts, "listen") ||
-            qemu_opt_get(opts, "mcast")) {
+            qemu_opt_get(opts, "mcast") ||
-            error_report("fd=, listen= and mcast= is invalid with connect=");
+            qemu_opt_get(opts, "localaddr")) {
+            error_report("fd=, listen=, mcast= and localaddr= is invalid with connect=\n");
             return -1;
         }
 
@@ -550,7 +575,7 @@ int net_init_socket(QemuOpts *opts,
             return -1;
         }
     } else if (qemu_opt_get(opts, "mcast")) {
-        const char *mcast;
+        const char *mcast, *localaddr;
 
         if (qemu_opt_get(opts, "fd") ||
             qemu_opt_get(opts, "connect") ||
@@ -560,8 +585,9 @@ int net_init_socket(QemuOpts *opts,
         }
 
         mcast = qemu_opt_get(opts, "mcast");
+        localaddr = qemu_opt_get(opts, "localaddr");
 
-        if (net_socket_mcast_init(vlan, "socket", name, mcast) == -1) {
+        if (net_socket_mcast_init(vlan, "socket", name, mcast, localaddr) == -1) {
             return -1;
         }
     } else {

qemu-options.hx

@@ -1061,8 +1061,9 @@ DEF("net", HAS_ARG, QEMU_OPTION_net,
 #endif
     "-net socket[,vlan=n][,name=str][,fd=h][,listen=[host]:port][,connect=host:port]\n"
     "                connect the vlan 'n' to another VLAN using a socket connection\n"
-    "-net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port]\n"
+    "-net socket[,vlan=n][,name=str][,fd=h][,mcast=maddr:port[,localaddr=addr]]\n"
     "                connect the vlan 'n' to multicast maddr and port\n"
+    "                use 'localaddr=addr' to specify the host address to send packets from\n"
 #ifdef CONFIG_VDE
     "-net vde[,vlan=n][,name=str][,sock=socketpath][,port=n][,group=groupname][,mode=octalmode]\n"
     "                connect the vlan 'n' to port 'n' of a vde switch running\n"
@@ -1256,7 +1257,7 @@ qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
                -net socket,connect=127.0.0.1:1234
 @end example
 
-@item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}] [,mcast=@var{maddr}:@var{port}]
+@item -net socket[,vlan=@var{n}][,name=@var{name}][,fd=@var{h}][,mcast=@var{maddr}:@var{port}[,localaddr=@var{addr}]]
 
 Create a VLAN @var{n} shared with another QEMU virtual
 machines using a UDP multicast socket, effectively making a bus for
@@ -1296,6 +1297,12 @@ qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
 /path/to/linux ubd0=/path/to/root_fs eth0=mcast
 @end example
 
+Example (send packets from host's 1.2.3.4):
+@example
+qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
+               -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4
+@end example
+
 @item -net vde[,vlan=@var{n}][,name=@var{name}][,sock=@var{socketpath}] [,port=@var{n}][,group=@var{groupname}][,mode=@var{octalmode}]
 Connect VLAN @var{n} to PORT @var{n} of a vde switch running on host and
 listening for incoming connections on @var{socketpath}. Use GROUP @var{groupname}

savevm.c

@@ -1575,8 +1575,6 @@ static int qemu_savevm_state(Monitor *mon, QEMUFile *f)
     saved_vm_running = vm_running;
     vm_stop(0);
 
-    bdrv_flush_all();
-
     ret = qemu_savevm_state_begin(mon, f, 0, 0);
     if (ret < 0)
         goto out;
@@ -1885,8 +1883,6 @@ void do_savevm(Monitor *mon, const QDict *qdict)
         monitor_printf(mon, "No block device can accept snapshots\n");
         return;
     }
-    /* ??? Should this occur after vm_stop?  */
-    qemu_aio_flush();
 
     saved_vm_running = vm_running;
     vm_stop(0);