|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH for-4.6 v2 4/6] tools/libxl: Prepare to write multiple records with EMULATOR headers
With the newly specified EMULATOR_XENSTORE_DATA record, there are two
libxl records with an emulator subheader. Refactor the existing code to
make future additions easier, and rename some functions for consistency
with the new scheme.
* Calculate the subheader at stream start time, rather than on the fly.
Its contents are not going to change.
* Introduce a new setup_emulator_write() to insert a sub header in the
appropriate place before a blob of data.
* Rename *toolstack_* to *emulator_xenstore_*
* Rename *emulator_* to *emulator_context_*
No functional change.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Ian Campbell <Ian.Campbell@xxxxxxxxxx>
CC: Ian Jackson <Ian.Jackson@xxxxxxxxxxxxx>
CC: Wei Liu <wei.liu2@xxxxxxxxxx>
v2:
* Extra renaming for consistency.
---
tools/libxl/libxl_internal.h | 3 +-
tools/libxl/libxl_stream_write.c | 182 +++++++++++++++++++++++---------------
2 files changed, 113 insertions(+), 72 deletions(-)
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index da2a785..fdef45e 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -3016,10 +3016,11 @@ struct libxl__stream_write_state {
libxl__datacopier_state dc;
sws_record_done_cb record_done_callback;
- /* Only used when constructing an EMULATOR record. */
+ /* Only used when constructing EMULATOR records. */
libxl__datacopier_state emu_dc;
libxl__carefd *emu_carefd;
libxl__sr_rec_hdr emu_rec_hdr;
+ libxl__sr_emulator_hdr emu_sub_hdr;
void *emu_body;
};
diff --git a/tools/libxl/libxl_stream_write.c b/tools/libxl/libxl_stream_write.c
index be8f548..55439dd 100644
--- a/tools/libxl/libxl_stream_write.c
+++ b/tools/libxl/libxl_stream_write.c
@@ -38,14 +38,16 @@
* The main loop for a plain VM writes:
* - Stream header
* - Libxc record
- * - Toolstack record
- * - if (hvm), Qemu record
+ * - (optional) Emulator xenstore record
+ * - if (hvm)
+ * - Emulator context record
* - End record
*
* For checkpointed stream, there is a second loop which is triggered by a
* save-helper checkpoint callback. It writes:
- * - Toolstack record
- * - if (hvm), Qemu record
+ * - (optional) Emulator xenstore record
+ * - if (hvm)
+ * - Emulator context record
* - Checkpoint end record
*/
@@ -69,17 +71,17 @@ static void stream_header_done(libxl__egc *egc,
static void libxc_header_done(libxl__egc *egc,
libxl__stream_write_state *stream);
/* libxl__xc_domain_save_done() lives here, event-order wise. */
-static void write_toolstack_record(libxl__egc *egc,
- libxl__stream_write_state *stream);
-static void toolstack_record_done(libxl__egc *egc,
- libxl__stream_write_state *stream);
-static void write_emulator_record(libxl__egc *egc,
- libxl__stream_write_state *stream);
-static void emulator_read_done(libxl__egc *egc,
- libxl__datacopier_state *dc,
- int rc, int onwrite, int errnoval);
-static void emulator_record_done(libxl__egc *egc,
- libxl__stream_write_state *stream);
+static void write_emulator_xenstore_record(libxl__egc *egc,
+ libxl__stream_write_state *stream);
+static void emulator_xenstore_record_done(libxl__egc *egc,
+ libxl__stream_write_state *stream);
+static void write_emulator_context_record(libxl__egc *egc,
+ libxl__stream_write_state *stream);
+static void emulator_context_read_done(libxl__egc *egc,
+ libxl__datacopier_state *dc,
+ int rc, int onwrite, int errnoval);
+static void emulator_context_record_done(libxl__egc *egc,
+ libxl__stream_write_state *stream);
static void write_end_record(libxl__egc *egc,
libxl__stream_write_state *stream);
@@ -95,12 +97,14 @@ static void write_done(libxl__egc *egc,
libxl__datacopier_state *dc,
int rc, int onwrite, int errnoval);
-/* Helper to set up reading some data from the stream. */
-static void setup_write(libxl__egc *egc,
- libxl__stream_write_state *stream,
- const char *what,
- libxl__sr_rec_hdr *hdr, void *body,
- sws_record_done_cb cb)
+/* Generic helper to set up writing some data to the stream. */
+static void setup_generic_write(libxl__egc *egc,
+ libxl__stream_write_state *stream,
+ const char *what,
+ libxl__sr_rec_hdr *hdr,
+ libxl__sr_emulator_hdr *emu_hdr,
+ void *body,
+ sws_record_done_cb cb)
{
static const uint8_t zero_padding[1U << REC_ALIGN_ORDER] = { 0 };
@@ -120,13 +124,21 @@ static void setup_write(libxl__egc *egc,
}
size_t padsz = ROUNDUP(hdr->length, REC_ALIGN_ORDER) - hdr->length;
+ uint32_t length = hdr->length;
/* Insert header */
libxl__datacopier_prefixdata(egc, dc, hdr, sizeof(*hdr));
+ /* Optional emulator sub-header */
+ if (emu_hdr) {
+ assert(length >= sizeof(*emu_hdr));
+ libxl__datacopier_prefixdata(egc, dc, emu_hdr, sizeof(*emu_hdr));
+ length -= sizeof(*emu_hdr);
+ }
+
/* Optional body */
if (body)
- libxl__datacopier_prefixdata(egc, dc, body, hdr->length);
+ libxl__datacopier_prefixdata(egc, dc, body, length);
/* Any required padding */
if (padsz > 0)
@@ -135,6 +147,30 @@ static void setup_write(libxl__egc *egc,
stream->record_done_callback = cb;
}
+/* Helper to set up writing a regular record to the stream. */
+static void setup_write(libxl__egc *egc,
+ libxl__stream_write_state *stream,
+ const char *what,
+ libxl__sr_rec_hdr *hdr,
+ void *body,
+ sws_record_done_cb cb)
+{
+ setup_generic_write(egc, stream, what, hdr, NULL, body, cb);
+}
+
+/* Helper to set up writing a record with an emulator prefix to the stream. */
+static void setup_emulator_write(libxl__egc *egc,
+ libxl__stream_write_state *stream,
+ const char *what,
+ libxl__sr_rec_hdr *hdr,
+ libxl__sr_emulator_hdr *emu_hdr,
+ void *body,
+ sws_record_done_cb cb)
+{
+ setup_generic_write(egc, stream, what, hdr, emu_hdr, body, cb);
+}
+
+
static void write_done(libxl__egc *egc,
libxl__datacopier_state *dc,
int rc, int onwrite, int errnoval)
@@ -169,6 +205,7 @@ void libxl__stream_write_init(libxl__stream_write_state
*stream)
FILLZERO(stream->emu_dc);
stream->emu_carefd = NULL;
FILLZERO(stream->emu_rec_hdr);
+ FILLZERO(stream->emu_sub_hdr);
stream->emu_body = NULL;
}
@@ -176,6 +213,7 @@ void libxl__stream_write_start(libxl__egc *egc,
libxl__stream_write_state *stream)
{
libxl__datacopier_state *dc = &stream->dc;
+ libxl__domain_suspend_state *dss = stream->dss;
STATE_AO_GC(stream->ao);
struct libxl__sr_hdr hdr;
int rc = 0;
@@ -184,6 +222,24 @@ void libxl__stream_write_start(libxl__egc *egc,
stream->running = true;
+ if (dss->type == LIBXL_DOMAIN_TYPE_HVM) {
+ switch (libxl__device_model_version_running(gc, dss->domid)) {
+ case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL:
+ stream->emu_sub_hdr.id = EMULATOR_QEMU_TRADITIONAL;
+ break;
+
+ case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN:
+ stream->emu_sub_hdr.id = EMULATOR_QEMU_UPSTREAM;
+ break;
+
+ default:
+ rc = ERROR_FAIL;
+ LOG(ERROR, "Unknown emulator for HVM domain\n");
+ goto err;
+ }
+ stream->emu_sub_hdr.index = 0;
+ }
+
dc->ao = ao;
dc->readfd = -1;
dc->writewhat = "stream header";
@@ -216,7 +272,7 @@ void libxl__stream_write_start_checkpoint(libxl__egc *egc,
assert(!stream->in_checkpoint);
stream->in_checkpoint = true;
- write_toolstack_record(egc, stream);
+ write_emulator_xenstore_record(egc, stream);
}
void libxl__stream_write_abort(libxl__egc *egc,
@@ -290,48 +346,47 @@ void libxl__xc_domain_save_done(libxl__egc *egc, void
*dss_void,
* If the stream is not still alive, we must not continue any work.
*/
if (libxl__stream_write_inuse(stream))
- write_toolstack_record(egc, stream);
+ write_emulator_xenstore_record(egc, stream);
}
-static void write_toolstack_record(libxl__egc *egc,
- libxl__stream_write_state *stream)
+static void write_emulator_xenstore_record(libxl__egc *egc,
+ libxl__stream_write_state *stream)
{
libxl__domain_suspend_state *dss = stream->dss;
STATE_AO_GC(stream->ao);
struct libxl__sr_rec_hdr rec;
int rc;
- uint8_t *toolstack_buf = NULL; /* We must free this. */
- uint32_t toolstack_len;
+ uint8_t *buf = NULL; /* We must free this. */
+ uint32_t len;
- rc = libxl__toolstack_save(dss->domid, &toolstack_buf,
- &toolstack_len, dss);
+ rc = libxl__toolstack_save(dss->domid, &buf, &len, dss);
if (rc)
goto err;
FILLZERO(rec);
rec.type = REC_TYPE_XENSTORE_DATA;
- rec.length = toolstack_len;
+ rec.length = len;
- setup_write(egc, stream, "toolstack record",
- &rec, toolstack_buf,
- toolstack_record_done);
+ setup_write(egc, stream, "emulator xenstore record",
+ &rec, buf,
+ emulator_xenstore_record_done);
- free(toolstack_buf);
+ free(buf);
return;
err:
assert(rc);
- free(toolstack_buf);
+ free(buf);
stream_complete(egc, stream, rc);
}
-static void toolstack_record_done(libxl__egc *egc,
- libxl__stream_write_state *stream)
+static void emulator_xenstore_record_done(libxl__egc *egc,
+ libxl__stream_write_state *stream)
{
libxl__domain_suspend_state *dss = stream->dss;
if (dss->type == LIBXL_DOMAIN_TYPE_HVM)
- write_emulator_record(egc, stream);
+ write_emulator_context_record(egc, stream);
else {
if (stream->in_checkpoint)
write_checkpoint_end_record(egc, stream);
@@ -340,14 +395,13 @@ static void toolstack_record_done(libxl__egc *egc,
}
}
-static void write_emulator_record(libxl__egc *egc,
- libxl__stream_write_state *stream)
+static void write_emulator_context_record(libxl__egc *egc,
+ libxl__stream_write_state *stream)
{
libxl__domain_suspend_state *dss = stream->dss;
libxl__datacopier_state *dc = &stream->emu_dc;
STATE_AO_GC(stream->ao);
struct libxl__sr_rec_hdr *rec = &stream->emu_rec_hdr;
- struct libxl__sr_emulator_hdr *ehdr = NULL;
struct stat st;
int rc;
@@ -355,7 +409,6 @@ static void write_emulator_record(libxl__egc *egc,
/* Convenience aliases */
const char *const filename = dss->dm_savefile;
- const uint32_t domid = dss->domid;
libxl__carefd_begin();
int readfd = open(filename, O_RDONLY);
@@ -379,23 +432,8 @@ static void write_emulator_record(libxl__egc *egc,
}
rec->type = REC_TYPE_EMULATOR_CONTEXT;
- rec->length = st.st_size + sizeof(*ehdr);
- stream->emu_body = ehdr = libxl__malloc(NOGC, rec->length);
-
- switch(libxl__device_model_version_running(gc, domid)) {
- case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN_TRADITIONAL:
- ehdr->id = EMULATOR_QEMU_TRADITIONAL;
- break;
-
- case LIBXL_DEVICE_MODEL_VERSION_QEMU_XEN:
- ehdr->id = EMULATOR_QEMU_UPSTREAM;
- break;
-
- default:
- rc = ERROR_FAIL;
- goto err;
- }
- ehdr->index = 0;
+ rec->length = st.st_size + sizeof(stream->emu_sub_hdr);
+ stream->emu_body = libxl__malloc(NOGC, st.st_size);
FILLZERO(*dc);
dc->ao = stream->ao;
@@ -404,9 +442,9 @@ static void write_emulator_record(libxl__egc *egc,
dc->readfd = readfd;
dc->writefd = -1;
dc->maxsz = -1;
- dc->readbuf = stream->emu_body + sizeof(*ehdr);
- dc->bytes_to_read = rec->length - sizeof(*ehdr);
- dc->callback = emulator_read_done;
+ dc->readbuf = stream->emu_body;
+ dc->bytes_to_read = st.st_size;
+ dc->callback = emulator_context_read_done;
rc = libxl__datacopier_start(dc);
if (rc)
@@ -419,9 +457,9 @@ static void write_emulator_record(libxl__egc *egc,
stream_complete(egc, stream, rc);
}
-static void emulator_read_done(libxl__egc *egc,
- libxl__datacopier_state *dc,
- int rc, int onwrite, int errnoval)
+static void emulator_context_read_done(libxl__egc *egc,
+ libxl__datacopier_state *dc,
+ int rc, int onwrite, int errnoval)
{
libxl__stream_write_state *stream = CONTAINER_OF(dc, *stream, emu_dc);
STATE_AO_GC(stream->ao);
@@ -434,13 +472,15 @@ static void emulator_read_done(libxl__egc *egc,
libxl__carefd_close(stream->emu_carefd);
stream->emu_carefd = NULL;
- setup_write(egc, stream, "emulator record",
- &stream->emu_rec_hdr, stream->emu_body,
- emulator_record_done);
+ setup_emulator_write(egc, stream, "emulator record",
+ &stream->emu_rec_hdr,
+ &stream->emu_sub_hdr,
+ stream->emu_body,
+ emulator_context_record_done);
}
-static void emulator_record_done(libxl__egc *egc,
- libxl__stream_write_state *stream)
+static void emulator_context_record_done(libxl__egc *egc,
+ libxl__stream_write_state *stream)
{
free(stream->emu_body);
stream->emu_body = NULL;
--
1.7.10.4
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |