libxl: consistent handling of libxc errors

Lots of places in libxl return -1 as an error which is inconsistent with
libxl error codes since that is ERROR_VERSION.  Also in other places the
xc_* function to implement a command is called but the return value is
either never checked or not passed on.

This patch makes callers of libxc functions use XL_LOG_ERRNO to log a
suitable message including the contents of errno, before returning
ERROR_FAIL, if an xc call fails.  (Except for pci device removals and
domain destroys where release of resources ought to continue even if
an error occurs in an early step. In this case the error is still
logged at least.)

Also a bug is fixed where a caller depends on errno being set but is
cleared by cleanup code which calls in to library functions which modify
errno as a side-effect.

This is version 2 of the patch previously applied as 91c486918e02.
Changed since then: Removed mapping from libxc error codes to libxl -
this is redundant because libxl ought to return -1 with errno set to a
meaningful value.

Signed-off-by: Gianni Tedesco <gianni.tedesco@citrix.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>
Committed-by: Ian Jackson <ian.jackson@eu.citrix.com>

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index f064e10caf1fbe15fe10779f576ced06d0a258f6..de87c1d03aa7dac247b7bdff253f0e1e9f9c065c 100644 (file)
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -433,10 +433,16 @@ struct libxl_dominfo * libxl_list_domain(struct libxl_ctx *ctx, int *nb_domain)
     int size = 1024;
 
     ptr = calloc(size, sizeof(struct libxl_dominfo));
-    if (!ptr) return NULL;
+    if (!ptr) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "allocating domain info");
+        return NULL;
+    }
 
     ret = xc_domain_getinfolist(ctx->xch, 0, 1024, info);
-    if (ret<0) return NULL;
+    if (ret<0) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "geting domain info list");
+        return NULL;
+    }
 
     for (i = 0; i < ret; i++) {
         xcinfo2xlinfo(&info[i], &ptr[i]);
@@ -451,7 +457,10 @@ int libxl_domain_info(struct libxl_ctx *ctx, struct libxl_dominfo *info_r,
     int ret;
 
     ret = xc_domain_getinfolist(ctx->xch, domid, 1, &xcinfo);
-    if (ret<0) return ERROR_FAIL;
+    if (ret<0) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "geting domain info list");
+        return ERROR_FAIL;
+    }
     if (ret==0 || xcinfo.domain != domid) return ERROR_INVAL;
 
     xcinfo2xlinfo(&xcinfo, info_r);
@@ -466,10 +475,16 @@ struct libxl_poolinfo * libxl_list_pool(struct libxl_ctx *ctx, int *nb_pool)
     int size = 256;
 
     ptr = calloc(size, sizeof(struct libxl_poolinfo));
-    if (!ptr) return NULL;
+    if (!ptr) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "allocating cpupool info");
+        return NULL;
+    }
 
     ret = xc_cpupool_getinfo(ctx->xch, 0, 256, info);
-    if (ret<0) return NULL;
+    if (ret<0) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "getting cpupool info");
+        return NULL;
+    }
 
     for (i = 0; i < ret; i++) {
         ptr[i].poolid = info[i].cpupool_id;
@@ -491,6 +506,10 @@ struct libxl_vminfo * libxl_list_vm(struct libxl_ctx *ctx, int *nb_vm)
         return NULL;
 
     ret = xc_domain_getinfolist(ctx->xch, 1, 1024, info);
+    if (ret<0) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "geting domain info list");
+        return NULL;
+    }
     for (index = i = 0; i < ret; i++) {
         if (libxl_is_stubdom(ctx, info[i].domain, NULL))
             continue;
@@ -518,14 +537,25 @@ int libxl_domain_suspend(struct libxl_ctx *ctx, libxl_domain_suspend_info *info,
 
 int libxl_domain_pause(struct libxl_ctx *ctx, uint32_t domid)
 {
-    xc_domain_pause(ctx->xch, domid);
+    int ret;
+    ret = xc_domain_pause(ctx->xch, domid);
+    if (ret<0) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "pausing domain %d", domid);
+        return ERROR_FAIL;
+    }
     return 0;
 }
 
-int libxl_domain_core_dump(struct libxl_ctx *ctx, uint32_t domid, const char *filename)
+int libxl_domain_core_dump(struct libxl_ctx *ctx, uint32_t domid,
+                           const char *filename)
 {
-    if ( xc_domain_dumpcore(ctx->xch, domid, filename) )
+    int ret;
+    ret = xc_domain_dumpcore(ctx->xch, domid, filename);
+    if (ret<0) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "core dumping domain %d to %s",
+                     domid, filename);
         return ERROR_FAIL;
+    }
     return 0;
 }
 
@@ -533,6 +563,7 @@ int libxl_domain_unpause(struct libxl_ctx *ctx, uint32_t domid)
 {
     char *path;
     char *state;
+    int ret;
 
     if (is_hvm(ctx, domid)) {
         path = libxl_sprintf(ctx, "/local/domain/0/device-model/%d/state", domid);
@@ -542,8 +573,11 @@ int libxl_domain_unpause(struct libxl_ctx *ctx, uint32_t domid)
             libxl_wait_for_device_model(ctx, domid, "running", NULL, NULL);
         }
     }
-    xc_domain_unpause(ctx->xch, domid);
-
+    ret = xc_domain_unpause(ctx->xch, domid);
+    if (ret<0) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "unpausing domain %d", domid);
+        return ERROR_FAIL;
+    }
     return 0;
 }
 
@@ -573,10 +607,24 @@ int libxl_domain_shutdown(struct libxl_ctx *ctx, uint32_t domid, int req)
     if (is_hvm(ctx,domid)) {
         unsigned long acpi_s_state = 0;
         unsigned long pvdriver = 0;
-        xc_get_hvm_param(ctx->xch, domid, HVM_PARAM_ACPI_S_STATE, &acpi_s_state);
-        xc_get_hvm_param(ctx->xch, domid, HVM_PARAM_CALLBACK_IRQ, &pvdriver);
-        if (!pvdriver || acpi_s_state != 0)
-            xc_domain_shutdown(ctx->xch, domid, req);
+        int ret;
+        ret = xc_get_hvm_param(ctx->xch, domid, HVM_PARAM_ACPI_S_STATE, &acpi_s_state);
+        if (ret<0) {
+            XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "getting ACPI S-state");
+            return ERROR_FAIL;
+        }
+        ret = xc_get_hvm_param(ctx->xch, domid, HVM_PARAM_CALLBACK_IRQ, &pvdriver);
+        if (ret<0) {
+            XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "getting HVM callback IRQ");
+            return ERROR_FAIL;
+        }
+        if (!pvdriver || acpi_s_state != 0) {
+            ret = xc_domain_shutdown(ctx->xch, domid, req);
+            if (ret<0) {
+                XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "unpausing domain");
+                return ERROR_FAIL;
+            }
+       }
     }
     return 0;
 }
@@ -623,7 +671,7 @@ int libxl_get_event(struct libxl_ctx *ctx, libxl_event *event)
     char **events = xs_read_watch(ctx->xsh, &num);
     if (num != 2) {
         free(events);
-        return -1;
+        return ERROR_FAIL;
     }
     event->path = strdup(events[XS_WATCH_PATH]);
     event->token = strdup(events[XS_WATCH_TOKEN]);
@@ -635,7 +683,7 @@ int libxl_get_event(struct libxl_ctx *ctx, libxl_event *event)
 int libxl_stop_waiting(struct libxl_ctx *ctx, libxl_waiter *waiter)
 {
     if (!xs_unwatch(ctx->xsh, waiter->path, waiter->token))
-        return -1;
+        return ERROR_FAIL;
     else
         return 0;
 }
@@ -715,7 +763,7 @@ static int libxl_destroy_device_model(struct libxl_ctx *ctx, uint32_t domid)
         int stubdomid = libxl_get_stubdom_id(ctx, domid);
         if (!stubdomid) {
             XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "Couldn't find device model's pid");
-            return -1;
+            return ERROR_INVAL;
         }
         XL_LOG(ctx, XL_LOG_ERROR, "Device model is a stubdom, domid=%d\n", stubdomid);
         return libxl_domain_destroy(ctx, stubdomid, 0);
@@ -753,7 +801,7 @@ int libxl_domain_destroy(struct libxl_ctx *ctx, uint32_t domid, int force)
 
     dom_path = libxl_xs_get_dompath(ctx, domid);
     if (!dom_path)
-        return -1;
+        return ERROR_FAIL;
 
     if (libxl_device_pci_shutdown(ctx, domid) < 0)
         XL_LOG(ctx, XL_LOG_ERROR, "pci shutdown failed for domid %d", domid);
@@ -765,7 +813,6 @@ int libxl_domain_destroy(struct libxl_ctx *ctx, uint32_t domid, int force)
     rc = xc_domain_pause(ctx->xch, domid);
     if (rc < 0) {
         XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "xc_domain_pause failed for %d", domid);
-        return -1;
     }
     if (dm_present) {
         if (libxl_destroy_device_model(ctx, domid) < 0)
@@ -797,7 +844,7 @@ int libxl_domain_destroy(struct libxl_ctx *ctx, uint32_t domid, int force)
     rc = xc_domain_destroy(ctx->xch, domid);
     if (rc < 0) {
         XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "xc_domain_destroy failed for %d", domid);
-        return -1;
+        return ERROR_FAIL;
     }
     return 0;
 }
@@ -1163,7 +1210,11 @@ static int libxl_create_stubdom(struct libxl_ctx *ctx,
     libxl_xs_write(ctx, XBT_NULL,
                    libxl_sprintf(ctx, "%s/target", libxl_xs_get_dompath(ctx, domid)),
                    "%d", info->domid);
-    xc_domain_set_target(ctx->xch, domid, info->domid);
+    ret = xc_domain_set_target(ctx->xch, domid, info->domid);
+    if (ret<0) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "setting target domain %d -> %d", domid, info->domid);
+        return ERROR_FAIL;
+    }
     xs_set_target(ctx->xsh, domid, info->domid);
 
     perm[0].id = domid;
@@ -1215,11 +1266,11 @@ retry_transaction:
     }
     if (libxl_create_xenpv_qemu(ctx, vfb, num_console, console, &dm_starting) < 0) {
         free(args);
-        return -1;
+        return ERROR_FAIL;
     }
     if (libxl_confirm_device_model_startup(ctx, dm_starting) < 0) {
         free(args);
-        return -1;
+        return ERROR_FAIL;
     }
 
     libxl_domain_unpause(ctx, domid);
@@ -1401,7 +1452,7 @@ int libxl_device_disk_add(struct libxl_ctx *ctx, uint32_t domid, libxl_device_di
                 const char *dev = libxl_blktap_devpath(ctx,
                                                disk->physpath, disk->phystype);
                 if (!dev)
-                    return -1;
+                    return ERROR_FAIL;
                 flexarray_set(back, boffset++, "tapdisk-params");
                 flexarray_set(back, boffset++, libxl_sprintf(ctx, "%s:%s", device_disk_string_of_phystype(disk->phystype), disk->physpath));
                 flexarray_set(back, boffset++, "params");
@@ -2099,7 +2150,7 @@ int libxl_cdrom_insert(struct libxl_ctx *ctx, uint32_t domid, libxl_device_disk
     }
     if (i == num) {
         XL_LOG(ctx, XL_LOG_ERROR, "Virtual device not found");
-        return -1;
+        return ERROR_FAIL;
     }
     libxl_device_disk_del(ctx, disks + i, 1);
     libxl_device_disk_add(ctx, domid, disk);
@@ -2349,7 +2400,7 @@ static int libxl_device_pci_add_xenstore(struct libxl_ctx *ctx, uint32_t domid,
 
     if (!is_hvm(ctx, domid)) {
         if (libxl_wait_for_backend(ctx, be_path, "4") < 0)
-            return -1;
+            return ERROR_FAIL;
     }
 
     back = flexarray_make(16, 1);
@@ -2398,13 +2449,13 @@ static int libxl_device_pci_remove_xenstore(struct libxl_ctx *ctx, uint32_t domi
     num_devs_path = libxl_sprintf(ctx, "%s/num_devs", be_path);
     num_devs = libxl_xs_read(ctx, XBT_NULL, num_devs_path);
     if (!num_devs)
-        return -1;
+        return ERROR_INVAL;
     num = atoi(num_devs);
 
     if (!is_hvm(ctx, domid)) {
         if (libxl_wait_for_backend(ctx, be_path, "4") < 0) {
             XL_LOG(ctx, XL_LOG_DEBUG, "pci backend at %s is not ready", be_path);
-            return -1;
+            return ERROR_FAIL;
         }
     }
 
@@ -2418,7 +2469,7 @@ static int libxl_device_pci_remove_xenstore(struct libxl_ctx *ctx, uint32_t domi
     }
     if (i == num) {
         XL_LOG(ctx, XL_LOG_ERROR, "Couldn't find the device on xenstore");
-        return -1;
+        return ERROR_INVAL;
     }
 
 retry_transaction:
@@ -2432,7 +2483,7 @@ retry_transaction:
     if (!is_hvm(ctx, domid)) {
         if (libxl_wait_for_backend(ctx, be_path, "4") < 0) {
             XL_LOG(ctx, XL_LOG_DEBUG, "pci backend at %s is not ready", be_path);
-            return -1;
+            return ERROR_FAIL;
         }
     }
 
@@ -2512,7 +2563,7 @@ int libxl_device_pci_add(struct libxl_ctx *ctx, uint32_t domid, libxl_device_pci
     hvm = is_hvm(ctx, domid);
     if (hvm) {
         if (libxl_wait_for_device_model(ctx, domid, "running", NULL, NULL) < 0) {
-            return -1;
+            return ERROR_FAIL;
         }
         path = libxl_sprintf(ctx, "/local/domain/0/device-model/%d/state", domid);
         state = libxl_xs_read(ctx, XBT_NULL, path);
@@ -2542,7 +2593,7 @@ int libxl_device_pci_add(struct libxl_ctx *ctx, uint32_t domid, libxl_device_pci
 
         if (f == NULL) {
             XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "Couldn't open %s", sysfs_path);
-            return -1;
+            return ERROR_FAIL;
         }
         for (i = 0; i < PROC_PCI_NUM_RESOURCES; i++) {
             if (fscanf(f, "0x%llx 0x%llx 0x%llx\n", &start, &end, &flags) != 3)
@@ -2551,13 +2602,19 @@ int libxl_device_pci_add(struct libxl_ctx *ctx, uint32_t domid, libxl_device_pci
             if (start) {
                 if (flags & PCI_BAR_IO) {
                     rc = xc_domain_ioport_permission(ctx->xch, domid, start, size, 1);
-                    if (rc < 0)
+                    if (rc < 0) {
                         XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "Error: xc_domain_ioport_permission error 0x%llx/0x%llx", start, size);
+                        fclose(f);
+                        return ERROR_FAIL;
+                    }
                 } else {
                     rc = xc_domain_iomem_permission(ctx->xch, domid, start>>XC_PAGE_SHIFT,
                                                     (size+(XC_PAGE_SIZE-1))>>XC_PAGE_SHIFT, 1);
-                    if (rc < 0)
+                    if (rc < 0) {
                         XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "Error: xc_domain_iomem_permission error 0x%llx/0x%llx", start, size);
+                        fclose(f);
+                        return ERROR_FAIL;
+                    }
                 }
             }
         }
@@ -2573,10 +2630,14 @@ int libxl_device_pci_add(struct libxl_ctx *ctx, uint32_t domid, libxl_device_pci
             rc = xc_physdev_map_pirq(ctx->xch, domid, irq, &irq);
             if (rc < 0) {
                 XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "Error: xc_physdev_map_pirq irq=%d", irq);
+                fclose(f);
+                return ERROR_FAIL;
             }
             rc = xc_domain_irq_permission(ctx->xch, domid, irq, 1);
             if (rc < 0) {
                 XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "Error: xc_domain_irq_permission irq=%d", irq);
+                fclose(f);
+                return ERROR_FAIL;
             }
         }
         fclose(f);
@@ -2584,8 +2645,10 @@ int libxl_device_pci_add(struct libxl_ctx *ctx, uint32_t domid, libxl_device_pci
 out:
     if (!libxl_is_stubdom(ctx, domid, NULL)) {
         rc = xc_assign_device(ctx->xch, domid, pcidev->value);
-        if (rc < 0)
+        if (rc < 0) {
             XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "xc_assign_device failed");
+            return ERROR_FAIL;
+        }
     }
 
     libxl_device_pci_add_xenstore(ctx, domid, pcidev);
@@ -2605,7 +2668,7 @@ int libxl_device_pci_remove(struct libxl_ctx *ctx, uint32_t domid, libxl_device_
     hvm = is_hvm(ctx, domid);
     if (hvm) {
         if (libxl_wait_for_device_model(ctx, domid, "running", NULL, NULL) < 0) {
-            return -1;
+            return ERROR_FAIL;
         }
         path = libxl_sprintf(ctx, "/local/domain/0/device-model/%d/state", domid);
         state = libxl_xs_read(ctx, XBT_NULL, path);
@@ -2616,7 +2679,7 @@ int libxl_device_pci_remove(struct libxl_ctx *ctx, uint32_t domid, libxl_device_
         xs_write(ctx->xsh, XBT_NULL, path, "pci-rem", strlen("pci-rem"));
         if (libxl_wait_for_device_model(ctx, domid, "pci-removed", NULL, NULL) < 0) {
             XL_LOG(ctx, XL_LOG_ERROR, "Device Model didn't respond in time");
-            return -1;
+            return ERROR_FAIL;
         }
         path = libxl_sprintf(ctx, "/local/domain/0/device-model/%d/state", domid);
         xs_write(ctx->xsh, XBT_NULL, path, state, strlen(state));
@@ -2740,7 +2803,7 @@ int libxl_device_pci_shutdown(struct libxl_ctx *ctx, uint32_t domid)
     pcidevs = libxl_device_pci_list(ctx, domid, &num);
     for (i = 0; i < num; i++) {
         if (libxl_device_pci_remove(ctx, domid, pcidevs + i) < 0)
-            return -1;
+            return ERROR_FAIL;
     }
     free(pcidevs);
     return 0;
@@ -2851,7 +2914,8 @@ int libxl_get_physinfo(struct libxl_ctx *ctx, struct libxl_physinfo *physinfo)
 
     rc = xc_physinfo(ctx->xch, &xcphysinfo);
     if (rc != 0) {
-        return rc;
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "getting physinfo");
+        return ERROR_FAIL;
     }
     physinfo->threads_per_core = xcphysinfo.threads_per_core;
     physinfo->cores_per_socket = xcphysinfo.cores_per_socket;
@@ -2922,9 +2986,11 @@ struct libxl_vcpuinfo *libxl_list_vcpu(struct libxl_ctx *ctx, uint32_t domid,
     xc_physinfo_t physinfo = { 0 };
 
     if (xc_domain_getinfolist(ctx->xch, domid, 1, &domaininfo) != 1) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "getting infolist");
         return NULL;
     }
     if (xc_physinfo(ctx->xch, &physinfo) == -1) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "getting physinfo");
         return NULL;
     }
     *cpusize = physinfo.max_cpu_id + 1;
@@ -2940,9 +3006,11 @@ struct libxl_vcpuinfo *libxl_list_vcpu(struct libxl_ctx *ctx, uint32_t domid,
             return NULL;
         }
         if (xc_vcpu_getinfo(ctx->xch, domid, *nb_vcpu, &vcpuinfo) == -1) {
+            XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "getting vcpu info");
             return NULL;
         }
         if (xc_vcpu_getaffinity(ctx->xch, domid, *nb_vcpu, ptr->cpumap, *cpusize) == -1) {
+            XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "getting vcpu affinity");
             return NULL;
         }
         ptr->vcpuid = *nb_vcpu;
@@ -2958,7 +3026,11 @@ struct libxl_vcpuinfo *libxl_list_vcpu(struct libxl_ctx *ctx, uint32_t domid,
 int libxl_set_vcpuaffinity(struct libxl_ctx *ctx, uint32_t domid, uint32_t vcpuid,
                            uint64_t *cpumap, int cpusize)
 {
-    return (xc_vcpu_setaffinity(ctx->xch, domid, vcpuid, cpumap, cpusize));
+    if (xc_vcpu_setaffinity(ctx->xch, domid, vcpuid, cpumap, cpusize)) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "setting vcpu affinity");
+        return ERROR_FAIL;
+    }
+    return 0;
 }
 
 int libxl_set_vcpucount(struct libxl_ctx *ctx, uint32_t domid, uint32_t count)
@@ -2968,6 +3040,7 @@ int libxl_set_vcpucount(struct libxl_ctx *ctx, uint32_t domid, uint32_t count)
     int i;
 
     if (xc_domain_getinfolist(ctx->xch, domid, 1, &domaininfo) != 1) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "getting domain info list");
         return ERROR_FAIL;
     }
     if (!count || ((domaininfo.max_vcpu_id + 1) < count)) {
@@ -2986,14 +3059,15 @@ int libxl_set_vcpucount(struct libxl_ctx *ctx, uint32_t domid, uint32_t count)
 
 /*
  * returns one of the XEN_SCHEDULER_* constants from public/domctl.h
- * or -1 if an error occured.
  */
 int libxl_get_sched_id(struct libxl_ctx *ctx)
 {
     int sched, ret;
 
-    if ((ret = xc_sched_id(ctx->xch, &sched)) != 0)
-        return ret;
+    if ((ret = xc_sched_id(ctx->xch, &sched)) != 0) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "getting domain info list");
+        return ERROR_FAIL;
+    }
     return sched;
 }
 
@@ -3003,8 +3077,10 @@ int libxl_sched_credit_domain_get(struct libxl_ctx *ctx, uint32_t domid, struct
     int rc;
 
     rc = xc_sched_credit_domain_get(ctx->xch, domid, &sdom);
-    if (rc != 0)
-        return rc;
+    if (rc != 0) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "setting domain sched credit");
+        return ERROR_FAIL;
+    }
 
     scinfo->weight = sdom.weight;
     scinfo->cap = sdom.cap;
@@ -3019,29 +3095,35 @@ int libxl_sched_credit_domain_set(struct libxl_ctx *ctx, uint32_t domid, struct
     int rc;
 
     rc = xc_domain_getinfolist(ctx->xch, domid, 1, &domaininfo);
+    if (rc < 0) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "getting domain info list");
+        return ERROR_FAIL;
+    }
     if (rc != 1 || domaininfo.domain != domid)
-        return rc;
+        return ERROR_INVAL;
 
 
     if (scinfo->weight < 1 || scinfo->weight > 65535) {
         XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc,
             "Cpu weight out of range, valid values are within range from 1 to 65535");
-        return -1;
+        return ERROR_INVAL;
     }
 
     if (scinfo->cap < 0 || scinfo->cap > (domaininfo.max_vcpu_id + 1) * 100) {
         XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc,
             "Cpu cap out of range, valid range is from 0 to %d for specified number of vcpus",
             ((domaininfo.max_vcpu_id + 1) * 100));
-        return -1;
+        return ERROR_INVAL;
     }
 
     sdom.weight = scinfo->weight;
     sdom.cap = scinfo->cap;
 
     rc = xc_sched_credit_domain_set(ctx->xch, domid, &sdom);
-    if (rc != 0)
-        return rc;
+    if ( rc < 0 ) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "setting domain sched credit");
+        return ERROR_FAIL;
+    }
 
     return 0;
 }
@@ -3070,15 +3152,17 @@ int libxl_send_trigger(struct libxl_ctx *ctx, uint32_t domid, char *trigger_name
     if (trigger_type == -1) {
         XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, -1,
             "Invalid trigger, valid triggers are <nmi|reset|init|power|sleep>");
-        return -1;
+        return ERROR_INVAL;
     }
 
     rc = xc_domain_send_trigger(ctx->xch, domid, trigger_type, vcpuid);
-    if (rc != 0)
+    if (rc != 0) {
         XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc,
             "Send trigger '%s' failed", trigger_name);
+        return ERROR_FAIL;
+    }
 
-    return rc;
+    return 0;
 }
 
 int libxl_send_sysrq(struct libxl_ctx *ctx, uint32_t domid, char sysrq)
@@ -3092,7 +3176,13 @@ int libxl_send_sysrq(struct libxl_ctx *ctx, uint32_t domid, char sysrq)
 
 int libxl_send_debug_keys(struct libxl_ctx *ctx, char *keys)
 {
-    return xc_send_debug_keys(ctx->xch, keys);
+    int ret;
+    ret = xc_send_debug_keys(ctx->xch, keys);
+    if ( ret < 0 ) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "sending debug keys");
+        return ERROR_FAIL;
+    }
+    return 0;
 }
 
 struct libxl_xen_console_reader *
@@ -3141,6 +3231,10 @@ int libxl_xen_console_read_line(struct libxl_ctx *ctx,
     memset(cr->buffer, 0, cr->size);
     ret = xc_readconsolering(ctx->xch, &cr->buffer, &cr->count,
                              cr->clear, cr->incremental, &cr->index);
+    if (ret < 0) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "reading console ring buffer");
+        return ERROR_FAIL;
+    }
     if (!ret) {
         if (cr->count) {
             *line_r = cr->buffer;
@@ -3204,7 +3298,7 @@ int libxl_tmem_freeze(struct libxl_ctx *ctx, uint32_t domid)
     if (rc < 0) {
         XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc,
             "Can not freeze tmem pools");
-        return -1;
+        return ERROR_FAIL;
     }
 
     return rc;
@@ -3219,7 +3313,7 @@ int libxl_tmem_destroy(struct libxl_ctx *ctx, uint32_t domid)
     if (rc < 0) {
         XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc,
             "Can not destroy tmem pools");
-        return -1;
+        return ERROR_FAIL;
     }
 
     return rc;
@@ -3234,7 +3328,7 @@ int libxl_tmem_thaw(struct libxl_ctx *ctx, uint32_t domid)
     if (rc < 0) {
         XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc,
             "Can not thaw tmem pools");
-        return -1;
+        return ERROR_FAIL;
     }
 
     return rc;
@@ -3260,13 +3354,13 @@ int libxl_tmem_set(struct libxl_ctx *ctx, uint32_t domid, char* name, uint32_t s
     if (subop == -1) {
         XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, -1,
             "Invalid set, valid sets are <weight|cap|compress>");
-        return -1;
+        return ERROR_INVAL;
     }
     rc = xc_tmem_control(ctx->xch, -1, subop, domid, set, 0, 0, NULL);
     if (rc < 0) {
         XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc,
             "Can not set tmem %s", name);
-        return -1;
+        return ERROR_FAIL;
     }
 
     return rc;
@@ -3281,7 +3375,7 @@ int libxl_tmem_shared_auth(struct libxl_ctx *ctx, uint32_t domid,
     if (rc < 0) {
         XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc,
             "Can not set tmem shared auth");
-        return -1;
+        return ERROR_FAIL;
     }
 
     return rc;
@@ -3295,7 +3389,7 @@ int libxl_tmem_freeable(struct libxl_ctx *ctx)
     if (rc < 0) {
         XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc,
             "Can not get tmem freeable memory");
-        return -1;
+        return ERROR_FAIL;
     }
 
     return rc;

diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 3b398cb5dbb2e2c53ba02702ce84e0d283c5ab31..1adc2bcfb5cb5cf0015b3f2ca26dc85ce2e9b5ca 100644 (file)
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -250,10 +250,16 @@ int restore_common(struct libxl_ctx *ctx, uint32_t domid,
                    int fd)
 {
     /* read signature */
-    return xc_domain_restore(ctx->xch, fd, domid,
+    int rc;
+    rc = xc_domain_restore(ctx->xch, fd, domid,
                              state->store_port, &state->store_mfn,
                              state->console_port, &state->console_mfn,
                              info->hvm, info->u.hvm.pae, 0);
+    if ( rc < 0 ) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "restoring domain");
+        return ERROR_FAIL;
+    }
+    return 0;
 }
 
 struct suspendinfo {
@@ -359,7 +365,7 @@ int core_suspend(struct libxl_ctx *ctx, uint32_t domid, int fd,
 
     si.xce = xc_evtchn_open();
     if (si.xce < 0)
-        return -1;
+        return ERROR_FAIL;
 
     if (si.xce > 0) {
         port = xs_suspend_evtchn_port(si.domid);
@@ -438,7 +444,7 @@ static const char *userdata_path(struct libxl_ctx *ctx, uint32_t domid,
     if (rc) {
         XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "unable to find domain info"
                      " for domain %"PRIu32, domid);
-        return 0;
+        return NULL;
     }
     uuid_string = string_of_uuid(ctx, info.uuid);
 
@@ -493,13 +499,13 @@ int libxl_userdata_store(struct libxl_ctx *ctx, uint32_t domid,
     size_t rs;
 
     filename = userdata_path(ctx, domid, userdata_userid, "d");
-    if (!filename) return ENOMEM;
+    if (!filename) return ERROR_NOMEM;
 
     if (!datalen)
         return userdata_delete(ctx, filename);
 
     newfilename = userdata_path(ctx, domid, userdata_userid, "n");
-    if (!newfilename) return ENOMEM;
+    if (!newfilename) return ERROR_NOMEM;
 
     fd= open(newfilename, O_RDWR|O_CREAT|O_TRUNC, 0600);
     if (fd<0) goto xe;
@@ -523,9 +529,10 @@ int libxl_userdata_store(struct libxl_ctx *ctx, uint32_t domid,
     if (f) fclose(f);
     if (fd>=0) close(fd);
 
+    errno = e;
     XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "cannot write %s for %s",
                  newfilename, filename);
-    return e;
+    return ERROR_FAIL;
 }
 
 int libxl_userdata_retrieve(struct libxl_ctx *ctx, uint32_t domid,
@@ -537,14 +544,14 @@ int libxl_userdata_retrieve(struct libxl_ctx *ctx, uint32_t domid,
     void *data = 0;
 
     filename = userdata_path(ctx, domid, userdata_userid, "d");
-    if (!filename) return ENOMEM;
+    if (!filename) return ERROR_NOMEM;
 
     e = libxl_read_file_contents(ctx, filename, data_r ? &data : 0, &datalen);
 
     if (!e && !datalen) {
         XL_LOG(ctx, XL_LOG_ERROR, "userdata file %s is empty", filename);
         if (data_r) assert(!*data_r);
-        return EPROTO;
+        return ERROR_FAIL;
     }
 
     if (data_r) *data_r = data;

diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index 05b637b0d69c8f6fd83216898440925f6c3e800d..205d37306d9a4f494391221b13ce0765ff409584 100644 (file)
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -222,5 +222,8 @@ char *libxl_abs_path(struct libxl_ctx *ctx, char *s, const char *path);
 #define XL_LOG_WARNING XTL_WARN
 #define XL_LOG_ERROR   XTL_ERROR
 
+/* Error handling */
+int libxl_xc_error(int xc_err);
+
 #endif