[PATCH 20/21] libxl: further fixups re LIBXL_DOMAIN_TYPE

[Ian Jackson <ian.jackson@eu.citrix.com>]

* Abolish the macro LIBXL__DOMAIN_IS_TYPE which had incorrect error
  handling.  At every call site, replace it with an open-coded call to
  libxl_domain_type and check against LIBXL_DOMAIN_TYPE_INVALID.

* This involves adding an `out:' to libxl_domain_unpause.

* In libxl_domain_destroy and do_pci_add, do not `default: abort();'
  if the domain type cannot be found.  Instead switch on
  LIBXL_DOMAIN_TYPE_INVALID specifically and do some actual error
  handling.

* In libxl__primary_console_find, remove a spurious default clause
  from the domain type switch.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

Changes in v5:
 * Add `default: abort()' to libxl__domain_type switch.

Changes in v4 of series:
 * Hunk
     In libxl_domain_suspend (as reorganised) error check, check for
     LIBXL_DOMAIN_TYPE_INVALID and remove a pointless extra log message.
   merged into the earlier patch where the slightly-wrong code was
   introduced.
---
 tools/libxl/libxl.c          |   28 +++++++++++++++++++++++-----
 tools/libxl/libxl_internal.h |    5 +++--
 tools/libxl/libxl_pci.c      |   18 +++++++++++++-----
 3 files changed, 39 insertions(+), 12 deletions(-)

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 1a7404a..1b84398 100644
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -390,7 +390,13 @@ int libxl_domain_resume(libxl_ctx *ctx, uint32_t domid, int suspend_cancel)
         goto out;
     }
 
-    if (LIBXL__DOMAIN_IS_TYPE(gc,  domid, HVM)) {
+    libxl_domain_type type = libxl__domain_type(gc, domid);
+    if (type == LIBXL_DOMAIN_TYPE_INVALID) {
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    if (type == LIBXL_DOMAIN_TYPE_HVM) {
         rc = libxl__domain_resume_device_model(gc, domid);
         if (rc) {
             LIBXL__LOG(ctx, LIBXL__LOG_ERROR,
@@ -788,7 +794,13 @@ int libxl_domain_unpause(libxl_ctx *ctx, uint32_t domid)
     char *state;
     int ret, rc = 0;
 
-    if (LIBXL__DOMAIN_IS_TYPE(gc,  domid, HVM)) {
+    libxl_domain_type type = libxl__domain_type(gc, domid);
+    if (type == LIBXL_DOMAIN_TYPE_INVALID) {
+        rc = ERROR_FAIL;
+        goto out;
+    }
+
+    if (type == LIBXL_DOMAIN_TYPE_HVM) {
         path = libxl__sprintf(gc, "/local/domain/0/device-model/%d/state", domid);
         state = libxl__xs_read(gc, XBT_NULL, path);
         if (state != NULL && !strcmp(state, "paused")) {
@@ -802,6 +814,7 @@ int libxl_domain_unpause(libxl_ctx *ctx, uint32_t domid)
         LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "unpausing domain %d", domid);
         rc = ERROR_FAIL;
     }
+ out:
     GC_FREE;
     return rc;
 }
@@ -813,7 +826,11 @@ int libxl__domain_pvcontrol_available(libxl__gc *gc, uint32_t domid)
     unsigned long pvdriver = 0;
     int ret;
 
-    if (LIBXL__DOMAIN_IS_TYPE(gc, domid, PV))
+    libxl_domain_type domtype = libxl__domain_type(gc, domid);
+    if (domtype == LIBXL_DOMAIN_TYPE_INVALID)
+        return ERROR_FAIL;
+
+    if (domtype == LIBXL_DOMAIN_TYPE_PV)
         return 1;
 
     ret = xc_get_hvm_param(ctx->xch, domid, HVM_PARAM_CALLBACK_IRQ, &pvdriver);
@@ -1213,6 +1230,9 @@ int libxl_domain_destroy(libxl_ctx *ctx, uint32_t domid)
         pid = libxl__xs_read(gc, XBT_NULL, libxl__sprintf(gc, "/local/domain/%d/image/device-model-pid", domid));
         dm_present = (pid != NULL);
         break;
+    case LIBXL_DOMAIN_TYPE_INVALID:
+        rc = ERROR_FAIL;
+        goto out;
     default:
         abort();
     }
@@ -1362,8 +1382,6 @@ static int libxl__primary_console_find(libxl_ctx *ctx, uint32_t domid_vm,
         case LIBXL_DOMAIN_TYPE_INVALID:
             rc = ERROR_INVAL;
             goto out;
-        default:
-            abort();
         }
     }
 
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 9df0db5..36c75ed 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -797,8 +797,7 @@ _hidden int libxl__domain_cpupool(libxl__gc *gc, uint32_t domid);
 _hidden libxl_scheduler libxl__domain_scheduler(libxl__gc *gc, uint32_t domid);
 _hidden int libxl__sched_set_params(libxl__gc *gc, uint32_t domid,
                                     libxl_domain_sched_params *scparams);
-#define LIBXL__DOMAIN_IS_TYPE(gc, domid, type) \
-    libxl__domain_type((gc), (domid)) == LIBXL_DOMAIN_TYPE_##type
+
 typedef struct {
     uint32_t store_port;
     uint32_t store_domid;
@@ -841,7 +840,9 @@ _hidden int libxl__domain_resume_device_model(libxl__gc *gc, uint32_t domid);
 
 _hidden void libxl__userdata_destroyall(libxl__gc *gc, uint32_t domid);
 
+/* returns 0 or 1, or a libxl error code */
 _hidden int libxl__domain_pvcontrol_available(libxl__gc *gc, uint32_t domid);
+
 _hidden char * libxl__domain_pvcontrol_read(libxl__gc *gc,
                                             xs_transaction_t t, uint32_t domid);
 _hidden int libxl__domain_pvcontrol_write(libxl__gc *gc, xs_transaction_t t,
diff --git a/tools/libxl/libxl_pci.c b/tools/libxl/libxl_pci.c
index de1b79f..81438be 100644
--- a/tools/libxl/libxl_pci.c
+++ b/tools/libxl/libxl_pci.c
@@ -128,7 +128,11 @@ static int libxl__device_pci_add_xenstore(libxl__gc *gc, uint32_t domid, libxl_d
     if (!num_devs)
         return libxl__create_pci_backend(gc, domid, pcidev, 1);
 
-    if (!starting && LIBXL__DOMAIN_IS_TYPE(gc, domid, PV)) {
+    libxl_domain_type domtype = libxl__domain_type(gc, domid);
+    if (domtype == LIBXL_DOMAIN_TYPE_INVALID)
+        return ERROR_FAIL;
+
+    if (!starting && domtype == LIBXL_DOMAIN_TYPE_PV) {
         if (libxl__wait_for_backend(gc, be_path, "4") < 0)
             return ERROR_FAIL;
     }
@@ -171,7 +175,11 @@ static int libxl__device_pci_remove_xenstore(libxl__gc *gc, uint32_t domid, libx
         return ERROR_INVAL;
     num = atoi(num_devs);
 
-    if (LIBXL__DOMAIN_IS_TYPE(gc, domid, PV)) {
+    libxl_domain_type domtype = libxl__domain_type(gc, domid);
+    if (domtype == LIBXL_DOMAIN_TYPE_INVALID)
+        return ERROR_FAIL;
+
+    if (domtype == LIBXL_DOMAIN_TYPE_PV) {
         if (libxl__wait_for_backend(gc, be_path, "4") < 0) {
             LIBXL__LOG(ctx, LIBXL__LOG_DEBUG, "pci backend at %s is not ready", be_path);
             return ERROR_FAIL;
@@ -199,7 +207,7 @@ retry_transaction:
         if (errno == EAGAIN)
             goto retry_transaction;
 
-    if (LIBXL__DOMAIN_IS_TYPE(gc, domid, PV)) {
+    if (domtype == LIBXL_DOMAIN_TYPE_PV) {
         if (libxl__wait_for_backend(gc, be_path, "4") < 0) {
             LIBXL__LOG(ctx, LIBXL__LOG_DEBUG, "pci backend at %s is not ready", be_path);
             return ERROR_FAIL;
@@ -939,8 +947,8 @@ static int do_pci_add(libxl__gc *gc, uint32_t domid, libxl_device_pci *pcidev, i
         }
         break;
     }
-    default:
-        abort();
+    case LIBXL_DOMAIN_TYPE_INVALID:
+        return ERROR_FAIL;
     }
 out:
     if (!libxl_is_stubdom(ctx, domid, NULL)) {
-- 
1.7.2.5