Checkpointed streams need to signal the end of a consistent view of VM state,
and the start of the libxl data.
Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
CC: David Vrabel <david.vra...@citrix.com>
CC: Ian Campbell <ian.campb...@citrix.com>
CC: Ian Jackson <ian.jack...@eu.citrix.com>
CC: Wei Liu <wei.l...@citrix.com>
CC: Yang Hongyang <yan...@cn.fujitsu.com>
---
After discusions with David, we have come to the conclusion that a CHECKPOINT
record alone is sufficient for the remus case. There is no functional need to
explicitly identify the stream as being of arbitrary length.
---
docs/specs/libxc-migration-stream.pandoc | 23 ++++++++++++++++++++---
tools/libxc/xc_sr_common.c | 1 +
tools/libxc/xc_sr_stream_format.h | 1 +
3 files changed, 22 insertions(+), 3 deletions(-)
diff --git a/docs/specs/libxc-migration-stream.pandoc
b/docs/specs/libxc-migration-stream.pandoc
index 520240f..97edd7d 100644
--- a/docs/specs/libxc-migration-stream.pandoc
+++ b/docs/specs/libxc-migration-stream.pandoc
@@ -37,8 +37,6 @@ Not Yet Included
The following features are not yet fully specified and will be
included in a future draft.
-* Remus
-
* Page data compression.
* ARM
@@ -227,7 +225,9 @@ type 0x00000000: END
0x0000000D: VERIFY
- 0x0000000E - 0x7FFFFFFF: Reserved for future _mandatory_
+ 0x0000000E: CHECKPOINT
+
+ 0x0000000F - 0x7FFFFFFF: Reserved for future _mandatory_
records.
0x80000000 - 0xFFFFFFFF: Reserved for future _optional_
@@ -578,6 +578,23 @@ The verify record contains no fields; its body_length is 0.
\clearpage
+CHECKPOINT
+----------
+
+A checkpoint record indicates that the records thusfar in the stream represent
+a consistent view of VM state.
+
+ 0 1 2 3 4 5 6 7 octet
+ +-------------------------------------------------+
+
+The checkpoint record contains no fields; its body_length is 0
+
+A stream containing checkpoint records must have indicated itself as a
+checkpointed stream in the Image Header. Conversely, a stream not identified
+as checkpointed must not contain checkpoint records.
+
+\clearpage
+
Layout
======
diff --git a/tools/libxc/xc_sr_common.c b/tools/libxc/xc_sr_common.c
index 59e0c5d..945cfa6 100644
--- a/tools/libxc/xc_sr_common.c
+++ b/tools/libxc/xc_sr_common.c
@@ -34,6 +34,7 @@ const char *dhdr_type_to_str(uint32_t type)
[REC_TYPE_TOOLSTACK] = "Toolstack",
[REC_TYPE_X86_PV_VCPU_MSRS] = "x86 PV vcpu msrs",
[REC_TYPE_VERIFY] = "Verify",
+ [REC_TYPE_CHECKPOINT] = "Checkpoint",
};
const char *rec_type_to_str(uint32_t type)
diff --git a/tools/libxc/xc_sr_stream_format.h
b/tools/libxc/xc_sr_stream_format.h
index d116ca6..6d0f8fd 100644
--- a/tools/libxc/xc_sr_stream_format.h
+++ b/tools/libxc/xc_sr_stream_format.h
@@ -74,6 +74,7 @@ struct xc_sr_rhdr
#define REC_TYPE_TOOLSTACK 0x0000000bU
#define REC_TYPE_X86_PV_VCPU_MSRS 0x0000000cU
#define REC_TYPE_VERIFY 0x0000000dU
+#define REC_TYPE_CHECKPOINT 0x0000000eU
#define REC_TYPE_OPTIONAL 0x80000000U
--
1.7.10.4
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