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[Qemu-devel] [PULL 36/57] postcopy: Incoming initialisation
From: |
Juan Quintela |
Subject: |
[Qemu-devel] [PULL 36/57] postcopy: Incoming initialisation |
Date: |
Mon, 9 Nov 2015 18:28:40 +0100 |
From: "Dr. David Alan Gilbert" <address@hidden>
Signed-off-by: Dr. David Alan Gilbert <address@hidden>
Reviewed-by: David Gibson <address@hidden>
Reviewed-by: Amit Shah <address@hidden>
Reviewed-by: Juan Quintela <address@hidden>
Signed-off-by: Juan Quintela <address@hidden>
---
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 called.
+ */
+int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
+{
+ /* TODO: Join the fault thread once we're sure it will exit */
+ if (qemu_ram_foreach_block(cleanup_range, mis)) {
+ return -1;
+ }
+
+ return 0;
+}
+
#else
/* No target OS support, stubs just fail */
bool postcopy_ram_supported_by_host(void)
@@ -192,10 +283,23 @@ bool postcopy_ram_supported_by_host(void)
return false;
}
+int postcopy_ram_incoming_init(MigrationIncomingState *mis, size_t ram_pages)
+{
+ error_report("postcopy_ram_incoming_init: No OS support");
+ return -1;
+}
+
+int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis)
+{
+ assert(0);
+ return -1;
+}
+
int postcopy_ram_discard_range(MigrationIncomingState *mis, uint8_t *start,
size_t length)
{
assert(0);
+ return -1;
}
#endif
diff --git a/migration/ram.c b/migration/ram.c
index b481d55..2e27b26 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1794,6 +1794,17 @@ static void decompress_data_with_multi_threads(uint8_t
*compbuf,
}
}
+/*
+ * Allocate data structures etc needed by incoming migration with postcopy-ram
+ * postcopy-ram's similarly names postcopy_ram_incoming_init does the work
+ */
+int ram_postcopy_incoming_init(MigrationIncomingState *mis)
+{
+ size_t ram_pages = last_ram_offset() >> TARGET_PAGE_BITS;
+
+ return postcopy_ram_incoming_init(mis, ram_pages);
+}
+
static int ram_load(QEMUFile *f, void *opaque, int version_id)
{
int flags = 0, ret = 0;
diff --git a/migration/savevm.c b/migration/savevm.c
index 573e810..8cf4c53 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1281,6 +1281,12 @@ static int
loadvm_postcopy_handle_advise(MigrationIncomingState *mis)
return -1;
}
+ if (ram_postcopy_incoming_init(mis)) {
+ return -1;
+ }
+
+ postcopy_state_set(POSTCOPY_INCOMING_ADVISE);
+
return 0;
}
diff --git a/trace-events b/trace-events
index e74675e..47d3be3 100644
--- a/trace-events
+++ b/trace-events
@@ -1537,6 +1537,8 @@
rdma_start_outgoing_migration_after_rdma_source_init(void) ""
postcopy_discard_send_finish(const char *ramblock, int nwords, int ncmds) "%s
mask words sent=%d in %d commands"
postcopy_discard_send_range(const char *ramblock, unsigned long start,
unsigned long length) "%s:%lx/%lx"
postcopy_ram_discard_range(void *start, size_t length) "%p,+%zx"
+postcopy_cleanup_range(const char *ramblock, void *host_addr, size_t offset,
size_t length) "%s: %p offset=%zx length=%zx"
+postcopy_init_range(const char *ramblock, void *host_addr, size_t offset,
size_t length) "%s: %p offset=%zx length=%zx"
# kvm-all.c
kvm_ioctl(int type, void *arg) "type 0x%x, arg %p"
--
2.5.0
- [Qemu-devel] [PULL 31/57] MIGRATION_STATUS_POSTCOPY_ACTIVE: Add new migration state, (continued)
- [Qemu-devel] [PULL 31/57] MIGRATION_STATUS_POSTCOPY_ACTIVE: Add new migration state, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 28/57] postcopy: OS support test, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 30/57] migration_completion: Take current state, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 32/57] Avoid sending vmdescription during postcopy, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 29/57] migrate_start_postcopy: Command to trigger transition to postcopy, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 33/57] Add qemu_savevm_state_complete_postcopy, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 35/57] migration_completion: Take current state, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 36/57] postcopy: Incoming initialisation,
Juan Quintela <=
- [Qemu-devel] [PULL 34/57] Postcopy: Maintain unsentmap, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 38/57] Postcopy: Postcopy startup in migration thread, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 37/57] postcopy: ram_enable_notify to switch on userfault, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 39/57] Postcopy: End of iteration, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 40/57] Page request: Add MIG_RP_MSG_REQ_PAGES reverse command, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 42/57] Page request: Consume pages off the post-copy queue, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 46/57] Don't sync dirty bitmaps in postcopy, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 44/57] Postcopy: Use helpers to map pages during migration, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 43/57] postcopy_ram.c: place_page and helpers, Juan Quintela, 2015/11/09
- [Qemu-devel] [PULL 49/57] Round up RAMBlock sizes to host page sizes, Juan Quintela, 2015/11/09