[Qemu-devel] [PULL 36/57] postcopy: Incoming initialisation
From: "Dr. David Alan Gilbert"
Signed-off-by: Dr. David Alan Gilbert
Reviewed-by: David Gibson
Reviewed-by: Amit Shah
Reviewed-by: Juan Quintela
Signed-off-by: Juan Quintela
---
include/migration/migration.h| 3 ++
include/migration/postcopy-ram.h | 12 +
migration/postcopy-ram.c | 104 +++
migration/ram.c | 11 +
migration/savevm.c | 6 +++
trace-events | 2 +
6 files changed, 138 insertions(+)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index b382d77..6e42b58 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -86,6 +86,8 @@ struct MigrationIncomingState {
*/
QemuEvent main_thread_load_event;
+/* For the kernel to send us notifications */
+int userfault_fd;
QEMUFile *to_src_file;
QemuMutex rp_mutex;/* We send replies from multiple threads */
@@ -204,6 +206,7 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms);
/* For incoming postcopy discard */
int ram_discard_range(MigrationIncomingState *mis, const char *block_name,
uint64_t start, size_t length);
+int ram_postcopy_incoming_init(MigrationIncomingState *mis);
/**
* @migrate_add_blocker - prevent migration from proceeding
diff --git a/include/migration/postcopy-ram.h b/include/migration/postcopy-ram.h
index de79fa7..f87020c 100644
--- a/include/migration/postcopy-ram.h
+++ b/include/migration/postcopy-ram.h
@@ -17,6 +17,18 @@
bool postcopy_ram_supported_by_host(void);
/*
+ * Initialise postcopy-ram, setting the RAM to a state where we can go into
+ * postcopy later; must be called prior to any precopy.
+ * called from ram.c's similarly named ram_postcopy_incoming_init
+ */
+int postcopy_ram_incoming_init(MigrationIncomingState *mis, size_t ram_pages);
+
+/*
+ * At the end of a migration where postcopy_ram_incoming_init was called.
+ */
+int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis);
+
+/*
* Discard the contents of 'length' bytes from 'start'
* We can assume that if we've been called postcopy_ram_hosttest returned true
*/
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 261feda..8478bfd 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -184,6 +184,97 @@ int postcopy_ram_discard_range(MigrationIncomingState
*mis, uint8_t *start,
return 0;
}
+/*
+ * Setup an area of RAM so that it *can* be used for postcopy later; this
+ * must be done right at the start prior to pre-copy.
+ * opaque should be the MIS.
+ */
+static int init_range(const char *block_name, void *host_addr,
+ ram_addr_t offset, ram_addr_t length, void *opaque)
+{
+MigrationIncomingState *mis = opaque;
+
+trace_postcopy_init_range(block_name, host_addr, offset, length);
+
+/*
+ * We need the whole of RAM to be truly empty for postcopy, so things
+ * like ROMs and any data tables built during init must be zero'd
+ * - we're going to get the copy from the source anyway.
+ * (Precopy will just overwrite this data, so doesn't need the discard)
+ */
+if (postcopy_ram_discard_range(mis, host_addr, length)) {
+return -1;
+}
+
+return 0;
+}
+
+/*
+ * At the end of migration, undo the effects of init_range
+ * opaque should be the MIS.
+ */
+static int cleanup_range(const char *block_name, void *host_addr,
+ram_addr_t offset, ram_addr_t length, void *opaque)
+{
+MigrationIncomingState *mis = opaque;
+struct uffdio_range range_struct;
+trace_postcopy_cleanup_range(block_name, host_addr, offset, length);
+
+/*
+ * We turned off hugepage for the precopy stage with postcopy enabled
+ * we can turn it back on now.
+ */
+#ifdef MADV_HUGEPAGE
+if (madvise(host_addr, length, MADV_HUGEPAGE)) {
+error_report("%s HUGEPAGE: %s", __func__, strerror(errno));
+return -1;
+}
+#endif
+
+/*
+ * We can also turn off userfault now since we should have all the
+ * pages. It can be useful to leave it on to debug postcopy
+ * if you're not sure it's always getting every page.
+ */
+range_struct.start = (uintptr_t)host_addr;
+range_struct.len = length;
+
+if (ioctl(mis->userfault_fd, UFFDIO_UNREGISTER, &range_struct)) {
+error_report("%s: userfault unregister %s", __func__, strerror(errno));
+
+return -1;
+}
+
+return 0;
+}
+
+/*
+ * Initialise postcopy-ram, setting the RAM to a state where we can go into
+ * postcopy later; must be called prior to any precopy.
+ * called from arch_init's similarly named ram_postcopy_incoming_init
+ */
+int postcopy_ram_incoming_init(MigrationIncomingState *mis, size_t ram_pages)
+{
+if (qemu_ram_foreach_block(init_range, mis)) {
+return -1;
+}
+
+return 0;
+}
+
+/*
+ * At the end of a migration where postcopy_ram_incoming_init was call
[Qemu-devel] [PULL 36/57] postcopy: Incoming initialisation
From: "Dr. David Alan Gilbert"
Signed-off-by: Dr. David Alan Gilbert
Reviewed-by: David Gibson
Reviewed-by: Amit Shah
Reviewed-by: Juan Quintela
Signed-off-by: Juan Quintela
---
include/migration/migration.h| 3 ++
include/migration/postcopy-ram.h | 12 +
migration/postcopy-ram.c | 104 +++
migration/ram.c | 11 +
migration/savevm.c | 6 +++
trace-events | 2 +
6 files changed, 138 insertions(+)
diff --git a/include/migration/migration.h b/include/migration/migration.h
index b382d77..6e42b58 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -86,6 +86,8 @@ struct MigrationIncomingState {
*/
QemuEvent main_thread_load_event;
+/* For the kernel to send us notifications */
+int userfault_fd;
QEMUFile *to_src_file;
QemuMutex rp_mutex;/* We send replies from multiple threads */
@@ -204,6 +206,7 @@ int ram_postcopy_send_discard_bitmap(MigrationState *ms);
/* For incoming postcopy discard */
int ram_discard_range(MigrationIncomingState *mis, const char *block_name,
uint64_t start, size_t length);
+int ram_postcopy_incoming_init(MigrationIncomingState *mis);
/**
* @migrate_add_blocker - prevent migration from proceeding
diff --git a/include/migration/postcopy-ram.h b/include/migration/postcopy-ram.h
index de79fa7..f87020c 100644
--- a/include/migration/postcopy-ram.h
+++ b/include/migration/postcopy-ram.h
@@ -17,6 +17,18 @@
bool postcopy_ram_supported_by_host(void);
/*
+ * Initialise postcopy-ram, setting the RAM to a state where we can go into
+ * postcopy later; must be called prior to any precopy.
+ * called from ram.c's similarly named ram_postcopy_incoming_init
+ */
+int postcopy_ram_incoming_init(MigrationIncomingState *mis, size_t ram_pages);
+
+/*
+ * At the end of a migration where postcopy_ram_incoming_init was called.
+ */
+int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis);
+
+/*
* Discard the contents of 'length' bytes from 'start'
* We can assume that if we've been called postcopy_ram_hosttest returned true
*/
diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c
index 261feda..8478bfd 100644
--- a/migration/postcopy-ram.c
+++ b/migration/postcopy-ram.c
@@ -184,6 +184,97 @@ int postcopy_ram_discard_range(MigrationIncomingState
*mis, uint8_t *start,
return 0;
}
+/*
+ * Setup an area of RAM so that it *can* be used for postcopy later; this
+ * must be done right at the start prior to pre-copy.
+ * opaque should be the MIS.
+ */
+static int init_range(const char *block_name, void *host_addr,
+ ram_addr_t offset, ram_addr_t length, void *opaque)
+{
+MigrationIncomingState *mis = opaque;
+
+trace_postcopy_init_range(block_name, host_addr, offset, length);
+
+/*
+ * We need the whole of RAM to be truly empty for postcopy, so things
+ * like ROMs and any data tables built during init must be zero'd
+ * - we're going to get the copy from the source anyway.
+ * (Precopy will just overwrite this data, so doesn't need the discard)
+ */
+if (postcopy_ram_discard_range(mis, host_addr, length)) {
+return -1;
+}
+
+return 0;
+}
+
+/*
+ * At the end of migration, undo the effects of init_range
+ * opaque should be the MIS.
+ */
+static int cleanup_range(const char *block_name, void *host_addr,
+ram_addr_t offset, ram_addr_t length, void *opaque)
+{
+MigrationIncomingState *mis = opaque;
+struct uffdio_range range_struct;
+trace_postcopy_cleanup_range(block_name, host_addr, offset, length);
+
+/*
+ * We turned off hugepage for the precopy stage with postcopy enabled
+ * we can turn it back on now.
+ */
+#ifdef MADV_HUGEPAGE
+if (madvise(host_addr, length, MADV_HUGEPAGE)) {
+error_report("%s HUGEPAGE: %s", __func__, strerror(errno));
+return -1;
+}
+#endif
+
+/*
+ * We can also turn off userfault now since we should have all the
+ * pages. It can be useful to leave it on to debug postcopy
+ * if you're not sure it's always getting every page.
+ */
+range_struct.start = (uintptr_t)host_addr;
+range_struct.len = length;
+
+if (ioctl(mis->userfault_fd, UFFDIO_UNREGISTER, &range_struct)) {
+error_report("%s: userfault unregister %s", __func__, strerror(errno));
+
+return -1;
+}
+
+return 0;
+}
+
+/*
+ * Initialise postcopy-ram, setting the RAM to a state where we can go into
+ * postcopy later; must be called prior to any precopy.
+ * called from arch_init's similarly named ram_postcopy_incoming_init
+ */
+int postcopy_ram_incoming_init(MigrationIncomingState *mis, size_t ram_pages)
+{
+if (qemu_ram_foreach_block(init_range, mis)) {
+return -1;
+}
+
+return 0;
+}
+
+/*
+ * At the end of a migration where postcopy_ram_incoming_init was call
