From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
Notify the vhost-user client on reception of the 'postcopy-listen'
event from the source.
Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
---
contrib/libvhost-user/libvhost-user.c | 21 +++++++++++++++++++++
contrib/libvhost-user/libvhost-user.h | 2 ++
docs/interop/vhost-user.txt | 6 ++++++
hw/virtio/trace-events | 3 +++
hw/virtio/vhost-user.c | 30 ++++++++++++++++++++++++++++++
migration/postcopy-ram.h | 1 +
migration/savevm.c | 7 +++++++
7 files changed, 70 insertions(+)
diff --git a/contrib/libvhost-user/libvhost-user.c
b/contrib/libvhost-user/libvhost-user.c
index f9b5b12b28..e8accf11db 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -15,7 +15,9 @@
#include <qemu/osdep.h>
#include <sys/eventfd.h>
+#include <sys/ioctl.h>
#include <sys/syscall.h>
+#include <linux/userfaultfd.h>
#include <linux/vhost.h>
#include "qemu/atomic.h"
@@ -64,6 +66,7 @@ vu_request_to_string(int req)
REQ(VHOST_USER_IOTLB_MSG),
REQ(VHOST_USER_SET_VRING_ENDIAN),
REQ(VHOST_USER_POSTCOPY_ADVISE),
+ REQ(VHOST_USER_POSTCOPY_LISTEN),
REQ(VHOST_USER_MAX),
};
#undef REQ
@@ -802,6 +805,22 @@ out:
}
static bool
+vu_set_postcopy_listen(VuDev *dev, VhostUserMsg *vmsg)
+{
+ vmsg->payload.u64 = -1;
+ vmsg->size = sizeof(vmsg->payload.u64);
+
+ if (dev->nregions) {
+ vu_panic(dev, "Regions already registered at postcopy-listen");
+ return true;
+ }
+ dev->postcopy_listening = true;
+
+ vmsg->flags = VHOST_USER_VERSION | VHOST_USER_REPLY_MASK;
+ vmsg->payload.u64 = 0; /* Success */
+ return true;
+}
+static bool
vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
{
int do_reply = 0;
@@ -868,6 +887,8 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
break;
case VHOST_USER_POSTCOPY_ADVISE:
return vu_set_postcopy_advise(dev, vmsg);
+ case VHOST_USER_POSTCOPY_LISTEN:
+ return vu_set_postcopy_listen(dev, vmsg);
default:
vmsg_close_fds(vmsg);
vu_panic(dev, "Unhandled request: %d", vmsg->request);
diff --git a/contrib/libvhost-user/libvhost-user.h
b/contrib/libvhost-user/libvhost-user.h
index 3e8efdd919..29c11ba56c 100644
--- a/contrib/libvhost-user/libvhost-user.h
+++ b/contrib/libvhost-user/libvhost-user.h
@@ -67,6 +67,7 @@ typedef enum VhostUserRequest {
VHOST_USER_IOTLB_MSG = 22,
VHOST_USER_SET_VRING_ENDIAN = 23,
VHOST_USER_POSTCOPY_ADVISE = 24,
+ VHOST_USER_POSTCOPY_LISTEN = 25,
VHOST_USER_MAX
} VhostUserRequest;
@@ -237,6 +238,7 @@ struct VuDev {
/* Postcopy data */
int postcopy_ufd;
+ bool postcopy_listening;
};
typedef struct VuVirtqElement {
diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt
index dad2a1b343..73c3dd74db 100644
--- a/docs/interop/vhost-user.txt
+++ b/docs/interop/vhost-user.txt
@@ -615,6 +615,12 @@ Master message types
the slave must open a userfaultfd for later use.
Note that at this stage the migration is still in precopy mode.
+ * VHOST_USER_POSTCOPY_LISTEN
+ Id: 25
+ Master payload: N/A
+
+ Master advises slave that a transition to postcopy mode has happened.
+
Slave message types
-------------------
diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 775461ae98..f736c7c84f 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -1,5 +1,8 @@
# See docs/devel/tracing.txt for syntax documentation.
+# hw/virtio/vhost-user.c
+vhost_user_postcopy_listen(void) ""
+
# hw/virtio/virtio.c
virtqueue_alloc_element(void *elem, size_t sz, unsigned in_num, unsigned
out_num) "elem %p size %zd in_num %u out_num %u"
virtqueue_fill(void *vq, const void *elem, unsigned int len, unsigned int idx)
"vq %p elem %p len %u idx %u"
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index b7898f8939..9178271ab2 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -69,6 +69,7 @@ typedef enum VhostUserRequest {
VHOST_USER_IOTLB_MSG = 22,
VHOST_USER_SET_VRING_ENDIAN = 23,
VHOST_USER_POSTCOPY_ADVISE = 24,
+ VHOST_USER_POSTCOPY_LISTEN = 25,
VHOST_USER_MAX
} VhostUserRequest;
@@ -788,6 +789,32 @@ static int vhost_user_postcopy_advise(struct vhost_dev
*dev, Error **errp)
return 0;
}
+/*
+ * Called at the switch to postcopy on reception of the 'listen' command.
+ */
+static int vhost_user_postcopy_listen(struct vhost_dev *dev, Error **errp)
+{
+ int ret;
+ VhostUserMsg msg = {
+ .request = VHOST_USER_POSTCOPY_LISTEN,
+ .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
+ };
+
+ trace_vhost_user_postcopy_listen();
+ if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
+ error_setg(errp, "Failed to send postcopy_listen to vhost");
+ return -1;
+ }
+
+ ret = process_message_reply(dev, &msg);
+ if (ret) {
+ error_setg(errp, "Failed to receive reply to postcopy_listen");
+ return ret;
+ }
+
+ return 0;
+}
+
static int vhost_user_postcopy_notifier(NotifierWithReturn *notifier,
void *opaque)
{
@@ -810,6 +837,9 @@ static int vhost_user_postcopy_notifier(NotifierWithReturn
*notifier,
case POSTCOPY_NOTIFY_INBOUND_ADVISE:
return vhost_user_postcopy_advise(dev, pnd->errp);
+ case POSTCOPY_NOTIFY_INBOUND_LISTEN:
+ return vhost_user_postcopy_listen(dev, pnd->errp);
+
default:
/* We ignore notifications we don't know */
break;
diff --git a/migration/postcopy-ram.h b/migration/postcopy-ram.h
index 28c216cc7a..873c147b68 100644
--- a/migration/postcopy-ram.h
+++ b/migration/postcopy-ram.h
@@ -129,6 +129,7 @@ void postcopy_infrastructure_init(void);
enum PostcopyNotifyReason {
POSTCOPY_NOTIFY_PROBE = 0,
POSTCOPY_NOTIFY_INBOUND_ADVISE,
+ POSTCOPY_NOTIFY_INBOUND_LISTEN,
};
struct PostcopyNotifyData {
diff --git a/migration/savevm.c b/migration/savevm.c
index d35911731d..72f084e10d 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1557,6 +1557,8 @@ static int
loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
{
PostcopyState ps = postcopy_state_set(POSTCOPY_INCOMING_LISTENING);
trace_loadvm_postcopy_handle_listen();
+ Error *local_err = NULL;
+
if (ps != POSTCOPY_INCOMING_ADVISE && ps != POSTCOPY_INCOMING_DISCARD) {
error_report("CMD_POSTCOPY_LISTEN in wrong postcopy state (%d)", ps);
return -1;
@@ -1578,6 +1580,11 @@ static int
loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
return -1;
}
+ if (postcopy_notify(POSTCOPY_NOTIFY_INBOUND_LISTEN, &local_err)) {
+ error_report_err(local_err);
+ return -1;
+ }
+
if (mis->have_listen_thread) {
error_report("CMD_POSTCOPY_RAM_LISTEN already has a listen thread");
return -1;
--
2.13.5
