From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Notify the vhost-user client on reception of the 'postcopy-listen'
event from the source.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
---
contrib/libvhost-user/libvhost-user.c | 19 +++++++++++++++++++
contrib/libvhost-user/libvhost-user.h | 2 ++
docs/interop/vhost-user.txt | 11 +++++++++++
hw/virtio/trace-events | 3 +++
hw/virtio/vhost-user.c | 34 ++++++++++++++++++++++++++++++++++
migration/postcopy-ram.h | 1 +
migration/savevm.c | 7 +++++++
7 files changed, 77 insertions(+)
diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
index 0b563fc5ae..beec7695a8 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -98,6 +98,7 @@ vu_request_to_string(unsigned int req)
REQ(VHOST_USER_GET_CONFIG),
REQ(VHOST_USER_SET_CONFIG),
REQ(VHOST_USER_POSTCOPY_ADVISE),
+ REQ(VHOST_USER_POSTCOPY_LISTEN),
REQ(VHOST_USER_MAX),
};
#undef REQ
@@ -933,6 +934,22 @@ out:
return true; /* = send a reply */
}
+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)
{
@@ -1006,6 +1023,8 @@ 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 074b7860f6..ed505cf0c1 100644
--- a/contrib/libvhost-user/libvhost-user.h
+++ b/contrib/libvhost-user/libvhost-user.h
@@ -86,6 +86,7 @@ typedef enum VhostUserRequest {
VHOST_USER_CREATE_CRYPTO_SESSION = 26,
VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
VHOST_USER_POSTCOPY_ADVISE = 28,
+ VHOST_USER_POSTCOPY_LISTEN = 29,
VHOST_USER_MAX
} VhostUserRequest;
@@ -285,6 +286,7 @@ 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 acc4186c79..7cc7006ef3 100644
--- a/docs/interop/vhost-user.txt
+++ b/docs/interop/vhost-user.txt
@@ -709,6 +709,17 @@ 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: 29
+ Master payload: N/A
+
+ Master advises slave that a transition to postcopy mode has happened.
+ The slave must ensure that shared memory is registered with userfaultfd
+ to cause faulting of non-present pages.
+
+ This is always sent sometime after a VHOST_USER_POSTCOPY_ADVISE, and
+ thus only when VHOST_USER_PROTOCOL_F_PAGEFAULT is supported.
+
Slave message types
-------------------
diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 742ff0f90b..06ec03d6e7 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -6,6 +6,9 @@ vhost_region_add_section(const char *name, uint64_t gpa, uint64_t size, uint64_t
vhost_region_add_section_abut(const char *name, uint64_t new_size) "%s: 0x%"PRIx64
vhost_section(const char *name, int r) "%s:%d"
+# 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 9f74111e92..ee200f703e 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -20,6 +20,7 @@
#include "sysemu/cryptodev.h"
#include "migration/migration.h"
#include "migration/postcopy-ram.h"
+#include "trace.h"
#include <sys/ioctl.h>
#include <sys/socket.h>
@@ -79,6 +80,7 @@ typedef enum VhostUserRequest {
VHOST_USER_CREATE_CRYPTO_SESSION = 26,
VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
VHOST_USER_POSTCOPY_ADVISE = 28,
+ VHOST_USER_POSTCOPY_LISTEN = 29,
VHOST_USER_MAX
} VhostUserRequest;
@@ -172,6 +174,8 @@ struct vhost_user {
int slave_fd;
NotifierWithReturn postcopy_notifier;
struct PostCopyFD postcopy_fd;
+ /* True once we've entered postcopy_listen */
+ bool postcopy_listen;
};
static bool ioeventfd_enabled(void)
@@ -858,6 +862,33 @@ 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)
+{
+ struct vhost_user *u = dev->opaque;
+ int ret;
+ VhostUserMsg msg = {
+ .hdr.request = VHOST_USER_POSTCOPY_LISTEN,
+ .hdr.flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
+ };
+ u->postcopy_listen = true;
+ 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)
{
@@ -880,6 +911,9 @@ 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 f21eef6702..c8ced3470b 100644
--- a/migration/postcopy-ram.h
+++ b/migration/postcopy-ram.h
@@ -131,6 +131,7 @@ 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 1f2bf12a28..305c3ceaf5 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1618,6 +1618,8 @@ 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;
@@ -1643,6 +1645,11 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
}
}
+ 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;
--
2.14.3
Hi
On Thu, Mar 8, 2018 at 8:57 PM, Dr. David Alan Gilbert (git)
<dgilbert@redhat.com> wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> Notify the vhost-user client on reception of the 'postcopy-listen'
> event from the source.
minor nit, please change with "vhost-user slave", since that's the
terminology we use for vhost-user protocol. (server/client is for the
socket layer relation)
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> Reviewed-by: Peter Xu <peterx@redhat.com>
> ---
> contrib/libvhost-user/libvhost-user.c | 19 +++++++++++++++++++
> contrib/libvhost-user/libvhost-user.h | 2 ++
> docs/interop/vhost-user.txt | 11 +++++++++++
> hw/virtio/trace-events | 3 +++
> hw/virtio/vhost-user.c | 34 ++++++++++++++++++++++++++++++++++
> migration/postcopy-ram.h | 1 +
> migration/savevm.c | 7 +++++++
> 7 files changed, 77 insertions(+)
>
> diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
> index 0b563fc5ae..beec7695a8 100644
> --- a/contrib/libvhost-user/libvhost-user.c
> +++ b/contrib/libvhost-user/libvhost-user.c
> @@ -98,6 +98,7 @@ vu_request_to_string(unsigned int req)
> REQ(VHOST_USER_GET_CONFIG),
> REQ(VHOST_USER_SET_CONFIG),
> REQ(VHOST_USER_POSTCOPY_ADVISE),
> + REQ(VHOST_USER_POSTCOPY_LISTEN),
> REQ(VHOST_USER_MAX),
> };
> #undef REQ
> @@ -933,6 +934,22 @@ out:
> return true; /* = send a reply */
> }
>
> +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)
> {
> @@ -1006,6 +1023,8 @@ 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 074b7860f6..ed505cf0c1 100644
> --- a/contrib/libvhost-user/libvhost-user.h
> +++ b/contrib/libvhost-user/libvhost-user.h
> @@ -86,6 +86,7 @@ typedef enum VhostUserRequest {
> VHOST_USER_CREATE_CRYPTO_SESSION = 26,
> VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
> VHOST_USER_POSTCOPY_ADVISE = 28,
> + VHOST_USER_POSTCOPY_LISTEN = 29,
> VHOST_USER_MAX
> } VhostUserRequest;
>
> @@ -285,6 +286,7 @@ 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 acc4186c79..7cc7006ef3 100644
> --- a/docs/interop/vhost-user.txt
> +++ b/docs/interop/vhost-user.txt
> @@ -709,6 +709,17 @@ 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: 29
> + Master payload: N/A
> +
> + Master advises slave that a transition to postcopy mode has happened.
> + The slave must ensure that shared memory is registered with userfaultfd
> + to cause faulting of non-present pages.
> +
> + This is always sent sometime after a VHOST_USER_POSTCOPY_ADVISE, and
> + thus only when VHOST_USER_PROTOCOL_F_PAGEFAULT is supported.
> +
> Slave message types
> -------------------
>
> diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
> index 742ff0f90b..06ec03d6e7 100644
> --- a/hw/virtio/trace-events
> +++ b/hw/virtio/trace-events
> @@ -6,6 +6,9 @@ vhost_region_add_section(const char *name, uint64_t gpa, uint64_t size, uint64_t
> vhost_region_add_section_abut(const char *name, uint64_t new_size) "%s: 0x%"PRIx64
> vhost_section(const char *name, int r) "%s:%d"
>
> +# 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 9f74111e92..ee200f703e 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -20,6 +20,7 @@
> #include "sysemu/cryptodev.h"
> #include "migration/migration.h"
> #include "migration/postcopy-ram.h"
> +#include "trace.h"
>
> #include <sys/ioctl.h>
> #include <sys/socket.h>
> @@ -79,6 +80,7 @@ typedef enum VhostUserRequest {
> VHOST_USER_CREATE_CRYPTO_SESSION = 26,
> VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
> VHOST_USER_POSTCOPY_ADVISE = 28,
> + VHOST_USER_POSTCOPY_LISTEN = 29,
> VHOST_USER_MAX
> } VhostUserRequest;
>
> @@ -172,6 +174,8 @@ struct vhost_user {
> int slave_fd;
> NotifierWithReturn postcopy_notifier;
> struct PostCopyFD postcopy_fd;
> + /* True once we've entered postcopy_listen */
> + bool postcopy_listen;
> };
>
> static bool ioeventfd_enabled(void)
> @@ -858,6 +862,33 @@ 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)
> +{
> + struct vhost_user *u = dev->opaque;
> + int ret;
> + VhostUserMsg msg = {
> + .hdr.request = VHOST_USER_POSTCOPY_LISTEN,
> + .hdr.flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
> + };
> + u->postcopy_listen = true;
> + 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)
> {
> @@ -880,6 +911,9 @@ 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 f21eef6702..c8ced3470b 100644
> --- a/migration/postcopy-ram.h
> +++ b/migration/postcopy-ram.h
> @@ -131,6 +131,7 @@ 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 1f2bf12a28..305c3ceaf5 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1618,6 +1618,8 @@ 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;
> @@ -1643,6 +1645,11 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
> }
> }
>
> + 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;
> --
> 2.14.3
>
>
--
Marc-André Lureau
* Marc-André Lureau (marcandre.lureau@gmail.com) wrote:
> Hi
>
> On Thu, Mar 8, 2018 at 8:57 PM, Dr. David Alan Gilbert (git)
> <dgilbert@redhat.com> wrote:
> > From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
> >
> > Notify the vhost-user client on reception of the 'postcopy-listen'
> > event from the source.
>
> minor nit, please change with "vhost-user slave", since that's the
> terminology we use for vhost-user protocol. (server/client is for the
> socket layer relation)
Done; there are probably a few more in there!
Dave
> >
> > Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
> > Reviewed-by: Peter Xu <peterx@redhat.com>
> > ---
> > contrib/libvhost-user/libvhost-user.c | 19 +++++++++++++++++++
> > contrib/libvhost-user/libvhost-user.h | 2 ++
> > docs/interop/vhost-user.txt | 11 +++++++++++
> > hw/virtio/trace-events | 3 +++
> > hw/virtio/vhost-user.c | 34 ++++++++++++++++++++++++++++++++++
> > migration/postcopy-ram.h | 1 +
> > migration/savevm.c | 7 +++++++
> > 7 files changed, 77 insertions(+)
> >
> > diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
> > index 0b563fc5ae..beec7695a8 100644
> > --- a/contrib/libvhost-user/libvhost-user.c
> > +++ b/contrib/libvhost-user/libvhost-user.c
> > @@ -98,6 +98,7 @@ vu_request_to_string(unsigned int req)
> > REQ(VHOST_USER_GET_CONFIG),
> > REQ(VHOST_USER_SET_CONFIG),
> > REQ(VHOST_USER_POSTCOPY_ADVISE),
> > + REQ(VHOST_USER_POSTCOPY_LISTEN),
> > REQ(VHOST_USER_MAX),
> > };
> > #undef REQ
> > @@ -933,6 +934,22 @@ out:
> > return true; /* = send a reply */
> > }
> >
> > +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)
> > {
> > @@ -1006,6 +1023,8 @@ 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 074b7860f6..ed505cf0c1 100644
> > --- a/contrib/libvhost-user/libvhost-user.h
> > +++ b/contrib/libvhost-user/libvhost-user.h
> > @@ -86,6 +86,7 @@ typedef enum VhostUserRequest {
> > VHOST_USER_CREATE_CRYPTO_SESSION = 26,
> > VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
> > VHOST_USER_POSTCOPY_ADVISE = 28,
> > + VHOST_USER_POSTCOPY_LISTEN = 29,
> > VHOST_USER_MAX
> > } VhostUserRequest;
> >
> > @@ -285,6 +286,7 @@ 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 acc4186c79..7cc7006ef3 100644
> > --- a/docs/interop/vhost-user.txt
> > +++ b/docs/interop/vhost-user.txt
> > @@ -709,6 +709,17 @@ 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: 29
> > + Master payload: N/A
> > +
> > + Master advises slave that a transition to postcopy mode has happened.
> > + The slave must ensure that shared memory is registered with userfaultfd
> > + to cause faulting of non-present pages.
> > +
> > + This is always sent sometime after a VHOST_USER_POSTCOPY_ADVISE, and
> > + thus only when VHOST_USER_PROTOCOL_F_PAGEFAULT is supported.
> > +
> > Slave message types
> > -------------------
> >
> > diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
> > index 742ff0f90b..06ec03d6e7 100644
> > --- a/hw/virtio/trace-events
> > +++ b/hw/virtio/trace-events
> > @@ -6,6 +6,9 @@ vhost_region_add_section(const char *name, uint64_t gpa, uint64_t size, uint64_t
> > vhost_region_add_section_abut(const char *name, uint64_t new_size) "%s: 0x%"PRIx64
> > vhost_section(const char *name, int r) "%s:%d"
> >
> > +# 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 9f74111e92..ee200f703e 100644
> > --- a/hw/virtio/vhost-user.c
> > +++ b/hw/virtio/vhost-user.c
> > @@ -20,6 +20,7 @@
> > #include "sysemu/cryptodev.h"
> > #include "migration/migration.h"
> > #include "migration/postcopy-ram.h"
> > +#include "trace.h"
> >
> > #include <sys/ioctl.h>
> > #include <sys/socket.h>
> > @@ -79,6 +80,7 @@ typedef enum VhostUserRequest {
> > VHOST_USER_CREATE_CRYPTO_SESSION = 26,
> > VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
> > VHOST_USER_POSTCOPY_ADVISE = 28,
> > + VHOST_USER_POSTCOPY_LISTEN = 29,
> > VHOST_USER_MAX
> > } VhostUserRequest;
> >
> > @@ -172,6 +174,8 @@ struct vhost_user {
> > int slave_fd;
> > NotifierWithReturn postcopy_notifier;
> > struct PostCopyFD postcopy_fd;
> > + /* True once we've entered postcopy_listen */
> > + bool postcopy_listen;
> > };
> >
> > static bool ioeventfd_enabled(void)
> > @@ -858,6 +862,33 @@ 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)
> > +{
> > + struct vhost_user *u = dev->opaque;
> > + int ret;
> > + VhostUserMsg msg = {
> > + .hdr.request = VHOST_USER_POSTCOPY_LISTEN,
> > + .hdr.flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK,
> > + };
> > + u->postcopy_listen = true;
> > + 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)
> > {
> > @@ -880,6 +911,9 @@ 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 f21eef6702..c8ced3470b 100644
> > --- a/migration/postcopy-ram.h
> > +++ b/migration/postcopy-ram.h
> > @@ -131,6 +131,7 @@ 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 1f2bf12a28..305c3ceaf5 100644
> > --- a/migration/savevm.c
> > +++ b/migration/savevm.c
> > @@ -1618,6 +1618,8 @@ 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;
> > @@ -1643,6 +1645,11 @@ static int loadvm_postcopy_handle_listen(MigrationIncomingState *mis)
> > }
> > }
> >
> > + 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;
> > --
> > 2.14.3
> >
> >
>
>
>
> --
> Marc-André Lureau
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
© 2016 - 2026 Red Hat, Inc.