[PATCH v4 06/29] tools/libxl: Split libxl__domain_create_state.restore_fd in two

[Andrew Cooper <andrew.cooper3@citrix.com>]

In a future patch, we shall support automatically converting a legacy
stream to a v2 stream, in which case libxc needs to read from a
different fd.

Simply overwriting restore_fd does not work; the two fd's have
different circumstances.  The restore_fd needs to be returned to its
original state before libxl_domain_create_restore() returns, while in
the converted case, the fd needs allocating and deallocating
appropriately.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Campbell <Ian.Campbell@citrix.com>
CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
CC: Wei Liu <wei.liu2@citrix.com>

---
New in v2
---
 tools/libxl/libxl_create.c       |    2 +-
 tools/libxl/libxl_internal.h     |    2 +-
 tools/libxl/libxl_save_callout.c |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index 61515da..be13204 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -1525,7 +1525,7 @@ static int do_domain_create(libxl_ctx *ctx, libxl_domain_config *d_config,
     cdcs->dcs.guest_config = d_config;
     libxl_domain_config_init(&cdcs->dcs.guest_config_saved);
     libxl_domain_config_copy(ctx, &cdcs->dcs.guest_config_saved, d_config);
-    cdcs->dcs.restore_fd = restore_fd;
+    cdcs->dcs.restore_fd = cdcs->dcs.libxc_fd = restore_fd;
     if (restore_fd > -1)
         cdcs->dcs.restore_params = *params;
     cdcs->dcs.callback = domain_create_cb;
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 6428757..e5599a3 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -3216,7 +3216,7 @@ struct libxl__domain_create_state {
     libxl__ao *ao;
     libxl_domain_config *guest_config;
     libxl_domain_config guest_config_saved; /* vanilla config */
-    int restore_fd;
+    int restore_fd, libxc_fd;
     libxl_domain_restore_params restore_params;
     libxl__domain_create_cb *callback;
     libxl_asyncprogress_how aop_console_how;
diff --git a/tools/libxl/libxl_save_callout.c b/tools/libxl/libxl_save_callout.c
index 80aae1b..1136b79 100644
--- a/tools/libxl/libxl_save_callout.c
+++ b/tools/libxl/libxl_save_callout.c
@@ -48,7 +48,7 @@ void libxl__xc_domain_restore(libxl__egc *egc, libxl__domain_create_state *dcs,
 
     /* Convenience aliases */
     const uint32_t domid = dcs->guest_domid;
-    const int restore_fd = dcs->restore_fd;
+    const int restore_fd = dcs->libxc_fd;
     libxl__domain_build_state *const state = &dcs->build_state;
 
     unsigned cbflags = libxl__srm_callout_enumcallbacks_restore
-- 
1.7.10.4