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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH for-4.6 6/8] 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.
* 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.
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>
---
tools/libxl/libxl_internal.h | 3 +-
tools/libxl/libxl_stream_write.c | 101 ++++++++++++++++++++++++++------------
2 files changed, 72 insertions(+), 32 deletions(-)
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 8426221..39a203c 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 9e9c998..3e6d399 100644
--- a/tools/libxl/libxl_stream_write.c
+++ b/tools/libxl/libxl_stream_write.c
@@ -95,12 +95,14 @@ 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 +122,21 @@ 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 +145,30 @@ 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)
@@ -164,6 +198,7 @@ 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;
}
@@ -171,6 +206,7 @@ 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;
@@ -179,6 +215,24 @@ 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";
@@ -342,7 +396,6 @@ static void write_emulator_record(libxl__egc *egc,
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;
@@ -350,7 +403,6 @@ 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);
@@ -374,23 +426,8 @@ 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;
@@ -399,8 +436,8 @@ 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->readbuf = stream->emu_body;
+ dc->bytes_to_read = st.st_size;
dc->callback = emulator_read_done;
rc = libxl__datacopier_start(dc);
@@ -429,9 +466,11 @@ 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_record_done);
}
static void emulator_record_done(libxl__egc *egc,
--
1.7.10.4
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