Like in the normal ram_load() path, put the received pages into the
colo cache and mark the pages in the bitmap so that they will be
flushed to the guest later.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Lukas Straub <lukasstraub2@web.de>
---
migration/meson.build | 2 +-
migration/multifd-colo.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++
migration/multifd-colo.h | 26 ++++++++++++++++++++++
migration/multifd.c | 14 +++++++++---
4 files changed, 95 insertions(+), 4 deletions(-)
diff --git a/migration/meson.build b/migration/meson.build
index 16909d54c5110fc5d8187fd3a68c4a5b08b59ea7..1e59fe4f1f0bbfffed90df38e8f39fa87bceb9b9 100644
--- a/migration/meson.build
+++ b/migration/meson.build
@@ -40,7 +40,7 @@ system_ss.add(files(
), gnutls, zlib)
if get_option('replication').allowed()
- system_ss.add(files('colo-failover.c', 'colo.c'))
+ system_ss.add(files('colo-failover.c', 'colo.c', 'multifd-colo.c'))
else
system_ss.add(files('colo-stubs.c'))
endif
diff --git a/migration/multifd-colo.c b/migration/multifd-colo.c
new file mode 100644
index 0000000000000000000000000000000000000000..05a81e57b2bda517cbc0844b4f03dc78453f6af8
--- /dev/null
+++ b/migration/multifd-colo.c
@@ -0,0 +1,57 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * multifd colo implementation
+ *
+ * Copyright (c) Lukas Straub <lukasstraub2@web.de>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "exec/target_page.h"
+#include "qemu/error-report.h"
+#include "qapi/error.h"
+#include "ram.h"
+#include "multifd.h"
+#include "options.h"
+#include "io/channel-socket.h"
+#include "migration/colo.h"
+#include "multifd-colo.h"
+#include "system/ramblock.h"
+
+void multifd_colo_prepare_recv(MultiFDRecvParams *p)
+{
+ if (!migrate_colo()) {
+ return;
+ }
+
+ assert(p->block->colo_cache);
+
+ /*
+ * While we're still in precopy state (not yet in colo state), we copy
+ * received pages to both guest and cache. No need to set dirty bits,
+ * since guest and cache memory are in sync.
+ */
+ if (migration_incoming_in_colo_state()) {
+ colo_record_bitmap(p->block, p->normal, p->normal_num);
+ }
+ p->host = p->block->colo_cache;
+}
+
+void multifd_colo_process_recv(MultiFDRecvParams *p)
+{
+ if (!migrate_colo()) {
+ return;
+ }
+
+ if (!migration_incoming_in_colo_state()) {
+ for (int i = 0; i < p->normal_num; i++) {
+ void *guest = p->block->host + p->normal[i];
+ void *cache = p->host + p->normal[i];
+ memcpy(guest, cache, multifd_ram_page_size());
+ }
+ }
+ p->host = p->block->host;
+}
diff --git a/migration/multifd-colo.h b/migration/multifd-colo.h
new file mode 100644
index 0000000000000000000000000000000000000000..82eaf3f48c47de2f090f9de52f9d57a337d4754a
--- /dev/null
+++ b/migration/multifd-colo.h
@@ -0,0 +1,26 @@
+/*
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ * multifd colo header
+ *
+ * Copyright (c) Lukas Straub <lukasstraub2@web.de>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef QEMU_MIGRATION_MULTIFD_COLO_H
+#define QEMU_MIGRATION_MULTIFD_COLO_H
+
+#ifdef CONFIG_REPLICATION
+
+void multifd_colo_prepare_recv(MultiFDRecvParams *p);
+void multifd_colo_process_recv(MultiFDRecvParams *p);
+
+#else
+
+static inline void multifd_colo_prepare_recv(MultiFDRecvParams *p) {}
+static inline void multifd_colo_process_recv(MultiFDRecvParams *p) {}
+
+#endif
+#endif
diff --git a/migration/multifd.c b/migration/multifd.c
index bf6da85af8a1e207235ce06b8dbace33beded6d8..9006f73cc5b52e8814da107c0b5c867ee6d03a95 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -29,6 +29,7 @@
#include "qemu-file.h"
#include "trace.h"
#include "multifd.h"
+#include "multifd-colo.h"
#include "threadinfo.h"
#include "options.h"
#include "qemu/yank.h"
@@ -1398,11 +1399,18 @@ static void *multifd_recv_thread(void *opaque)
if (is_device_state) {
assert(use_packets);
ret = multifd_device_state_recv(p, &local_err);
+ if (ret != 0) {
+ break;
+ }
} else {
+ multifd_colo_prepare_recv(p);
+
ret = multifd_recv_state->ops->recv(p, &local_err);
- }
- if (ret != 0) {
- break;
+ if (ret != 0) {
+ break;
+ }
+
+ multifd_colo_process_recv(p);
}
} else if (is_device_state) {
error_setg(&local_err,
--
2.39.5On Tue, Dec 30, 2025 at 03:05:44PM +0100, Lukas Straub wrote:
> Like in the normal ram_load() path, put the received pages into the
> colo cache and mark the pages in the bitmap so that they will be
> flushed to the guest later.
>
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> Signed-off-by: Lukas Straub <lukasstraub2@web.de>
> ---
> migration/meson.build | 2 +-
> migration/multifd-colo.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++
> migration/multifd-colo.h | 26 ++++++++++++++++++++++
> migration/multifd.c | 14 +++++++++---
> 4 files changed, 95 insertions(+), 4 deletions(-)
>
> diff --git a/migration/meson.build b/migration/meson.build
> index 16909d54c5110fc5d8187fd3a68c4a5b08b59ea7..1e59fe4f1f0bbfffed90df38e8f39fa87bceb9b9 100644
> --- a/migration/meson.build
> +++ b/migration/meson.build
> @@ -40,7 +40,7 @@ system_ss.add(files(
> ), gnutls, zlib)
>
> if get_option('replication').allowed()
> - system_ss.add(files('colo-failover.c', 'colo.c'))
> + system_ss.add(files('colo-failover.c', 'colo.c', 'multifd-colo.c'))
> else
> system_ss.add(files('colo-stubs.c'))
> endif
> diff --git a/migration/multifd-colo.c b/migration/multifd-colo.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..05a81e57b2bda517cbc0844b4f03dc78453f6af8
> --- /dev/null
> +++ b/migration/multifd-colo.c
> @@ -0,0 +1,57 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + *
> + * multifd colo implementation
> + *
> + * Copyright (c) Lukas Straub <lukasstraub2@web.de>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "exec/target_page.h"
> +#include "qemu/error-report.h"
> +#include "qapi/error.h"
> +#include "ram.h"
> +#include "multifd.h"
> +#include "options.h"
> +#include "io/channel-socket.h"
> +#include "migration/colo.h"
> +#include "multifd-colo.h"
> +#include "system/ramblock.h"
> +
> +void multifd_colo_prepare_recv(MultiFDRecvParams *p)
> +{
> + if (!migrate_colo()) {
We should avoid invoking *_colo_*() function, then check COLO enabled or
not only reaching here. Instead, we'd check "migrate_colo()" first and
invoke it only if it's enabled.
> + return;
> + }
> +
> + assert(p->block->colo_cache);
> +
> + /*
> + * While we're still in precopy state (not yet in colo state), we copy
> + * received pages to both guest and cache. No need to set dirty bits,
> + * since guest and cache memory are in sync.
> + */
> + if (migration_incoming_in_colo_state()) {
> + colo_record_bitmap(p->block, p->normal, p->normal_num);
> + }
> + p->host = p->block->colo_cache;
May want to update the comment of "host" then, because it isn't always
pointing to ramblock's buffer now when COLO is enabled.
> +}
> +
> +void multifd_colo_process_recv(MultiFDRecvParams *p)
> +{
> + if (!migrate_colo()) {
Same here.
> + return;
> + }
> +
> + if (!migration_incoming_in_colo_state()) {
> + for (int i = 0; i < p->normal_num; i++) {
> + void *guest = p->block->host + p->normal[i];
> + void *cache = p->host + p->normal[i];
> + memcpy(guest, cache, multifd_ram_page_size());
> + }
> + }
> + p->host = p->block->host;
> +}
> diff --git a/migration/multifd-colo.h b/migration/multifd-colo.h
> new file mode 100644
> index 0000000000000000000000000000000000000000..82eaf3f48c47de2f090f9de52f9d57a337d4754a
> --- /dev/null
> +++ b/migration/multifd-colo.h
> @@ -0,0 +1,26 @@
> +/*
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + *
> + * multifd colo header
> + *
> + * Copyright (c) Lukas Straub <lukasstraub2@web.de>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +
> +#ifndef QEMU_MIGRATION_MULTIFD_COLO_H
> +#define QEMU_MIGRATION_MULTIFD_COLO_H
> +
> +#ifdef CONFIG_REPLICATION
> +
> +void multifd_colo_prepare_recv(MultiFDRecvParams *p);
> +void multifd_colo_process_recv(MultiFDRecvParams *p);
> +
> +#else
> +
> +static inline void multifd_colo_prepare_recv(MultiFDRecvParams *p) {}
> +static inline void multifd_colo_process_recv(MultiFDRecvParams *p) {}
> +
> +#endif
> +#endif
> diff --git a/migration/multifd.c b/migration/multifd.c
> index bf6da85af8a1e207235ce06b8dbace33beded6d8..9006f73cc5b52e8814da107c0b5c867ee6d03a95 100644
> --- a/migration/multifd.c
> +++ b/migration/multifd.c
> @@ -29,6 +29,7 @@
> #include "qemu-file.h"
> #include "trace.h"
> #include "multifd.h"
> +#include "multifd-colo.h"
> #include "threadinfo.h"
> #include "options.h"
> #include "qemu/yank.h"
> @@ -1398,11 +1399,18 @@ static void *multifd_recv_thread(void *opaque)
> if (is_device_state) {
> assert(use_packets);
> ret = multifd_device_state_recv(p, &local_err);
> + if (ret != 0) {
> + break;
> + }
> } else {
> + multifd_colo_prepare_recv(p);
> +
> ret = multifd_recv_state->ops->recv(p, &local_err);
> - }
> - if (ret != 0) {
> - break;
> + if (ret != 0) {
> + break;
> + }
> +
> + multifd_colo_process_recv(p);
Personally I'd suggest we introduce multifd_ram_state_recv() and put
everything there.
Thanks,
> }
> } else if (is_device_state) {
> error_setg(&local_err,
>
> --
> 2.39.5
>
--
Peter Xu
© 2016 - 2026 Red Hat, Inc.