libxenlight: Clean up logging arrangements

* Introduce new variants of the logging functions which include
  errno values (converted using strerror) in the messages passed to
  the
  application's logging callback.

* Use the new errno-including logging functions everywhere where
  appropriate.  In general, xc_... functions return errno values or 0;
  xs_... functions return 0 or -1 (or some such) setting errno.

* When libxl_xs_get_dompath fails, do not treat it as an allocation
  error.  It isn't: it usually means xenstored failed.

* Remove many spurious \n's from log messages.  (The applications log
  callback is expected to add a \n if it wants to do that, so libxl's
  logging functions should be passed strings without \n.)

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>

diff --git a/tools/libxl/libxl.c b/tools/libxl/libxl.c
index 1fd76690939385edbd4d85a1bb7a19ac25e72637..2eea3a813872b2fed308c7c563b9fb65b611da03 100644 (file)
--- a/tools/libxl/libxl.c
+++ b/tools/libxl/libxl.c
@@ -106,14 +106,17 @@ int libxl_domain_make(struct libxl_ctx *ctx, libxl_domain_create_info *info,
 
     ret = xc_domain_create(ctx->xch, info->ssidref, handle, flags, domid);
     if (ret < 0) {
-        XL_LOG(ctx, XL_LOG_ERROR, "domain creation fail: %d", ret);
+        XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, ret, "domain creation fail");
         return ERROR_FAIL;
     }
 
     dom_path = libxl_xs_get_dompath(ctx, *domid);
+    if (!dom_path)
+        return ERROR_FAIL;
+
     vm_path = libxl_sprintf(ctx, "/vm/%s", uuid_string);
     vss_path = libxl_sprintf(ctx, "/vss/%s", uuid_string);
-    if (!dom_path || !vm_path || !vss_path) {
+    if (!vm_path || !vss_path) {
         XL_LOG(ctx, XL_LOG_ERROR, "cannot allocate create paths");
         return ERROR_FAIL;
     }
@@ -326,6 +329,9 @@ int libxl_domain_shutdown(struct libxl_ctx *ctx, uint32_t domid, int req)
         return ERROR_INVAL;
 
     dom_path = libxl_xs_get_dompath(ctx, domid);
+    if (!dom_path)
+        return ERROR_FAIL;
+
     shutdown_path = libxl_sprintf(ctx, "%s/control/shutdown", dom_path);
 
     xs_write(ctx->xsh, XBT_NULL, shutdown_path, req_table[req], strlen(req_table[req]));
@@ -347,20 +353,21 @@ static int libxl_destroy_device_model(struct libxl_ctx *ctx, uint32_t domid)
 
     pid = libxl_xs_read(ctx, XBT_NULL, libxl_sprintf(ctx, "/local/domain/%d/image/device-model-pid", domid));
     if (!pid) {
-        XL_LOG(ctx, XL_LOG_ERROR, "Couldn't find device model's pid\n");
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "Couldn't find device model's pid");
         return -1;
     }
     xs_rm(ctx->xsh, XBT_NULL, libxl_sprintf(ctx, "/local/domain/0/device-model/%d", domid));
 
     ret = kill(atoi(pid), SIGHUP);
     if (ret < 0 && errno == ESRCH) {
-        XL_LOG(ctx, XL_LOG_DEBUG, "Device Model already exited\n");
+        XL_LOG(ctx, XL_LOG_DEBUG, "Device Model already exited");
         ret = 0;
     } else if (ret == 0) {
-        XL_LOG(ctx, XL_LOG_DEBUG, "Device Model signaled\n");
+        XL_LOG(ctx, XL_LOG_DEBUG, "Device Model signaled");
         ret = 0;
     } else {
-        XL_LOG(ctx, XL_LOG_ERROR, "kill %d returned %d errno=%d\n", atoi(pid), ret, errno);
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "failed to kill Device Model [%d]",
+                     atoi(pid));
     }
     return ret;
 }
@@ -369,38 +376,40 @@ int libxl_domain_destroy(struct libxl_ctx *ctx, uint32_t domid, int force)
 {
     char *dom_path, vm_path[41];
     xen_uuid_t *uuid;
+    int rc;
 
     dom_path = libxl_xs_get_dompath(ctx, domid);
-    if (!dom_path) {
-        XL_LOG(ctx, XL_LOG_ERROR, "dompath doesn't exist for %d\n", domid);
+    if (!dom_path)
         return -1;
-    }
+
     if (libxl_domid_to_uuid(ctx, &uuid, domid) < 0) {
-        XL_LOG(ctx, XL_LOG_ERROR, "failed ot get uuid for %d\n", domid);
+        XL_LOG(ctx, XL_LOG_ERROR, "failed ot get uuid for %d", domid);
         return -1;
     }
     if (libxl_device_pci_shutdown(ctx, domid) < 0)
-        XL_LOG(ctx, XL_LOG_ERROR, "pci shutdown failed for domid %d\n", domid);
+        XL_LOG(ctx, XL_LOG_ERROR, "pci shutdown failed for domid %d", domid);
     xs_write(ctx->xsh, XBT_NULL,
              libxl_sprintf(ctx, "/local/domain/0/device-model/%d/command", domid),
              "shutdown", strlen("shutdown"));
-    if (xc_domain_pause(ctx->xch, domid) < 0) {
-        XL_LOG(ctx, XL_LOG_ERROR, "xc_domain_pause failed for %d\n", domid);
+    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 (xc_domain_destroy(ctx->xch, domid) < 0) {
-        XL_LOG(ctx, XL_LOG_ERROR, "xc_domain_destroy failed for %d\n", domid);
+    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;
     }
     if (libxl_devices_destroy(ctx, domid, force) < 0)
-        XL_LOG(ctx, XL_LOG_ERROR, "libxl_destroy_devices failed for %d\n", domid);
+        XL_LOG(ctx, XL_LOG_ERROR, "libxl_destroy_devices failed for %d", domid);
     if (libxl_destroy_device_model(ctx, domid) < 0)
-        XL_LOG(ctx, XL_LOG_ERROR, "libxl_destroy_device_model failed for %d\n", domid);
+        XL_LOG(ctx, XL_LOG_ERROR, "libxl_destroy_device_model failed for %d", domid);
     if (!xs_rm(ctx->xsh, XBT_NULL, dom_path))
-        XL_LOG(ctx, XL_LOG_ERROR, "xs_rm failed for %s\n", dom_path);
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "xs_rm failed for %s", dom_path);
     snprintf(vm_path, sizeof(vm_path), "/vm/%s", libxl_uuid_to_string(ctx, uuid));
     if (!xs_rm(ctx->xsh, XBT_NULL, vm_path))
-        XL_LOG(ctx, XL_LOG_ERROR, "xs_rm failed for %s\n", vm_path);
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "xs_rm failed for %s", vm_path);
     return 0;
 }
 
@@ -524,6 +533,8 @@ int libxl_create_device_model(struct libxl_ctx *ctx,
         return ERROR_FAIL;
 
     dom_path = libxl_xs_get_dompath(ctx, info->domid);
+    if (!dom_path)
+        return ERROR_FAIL;
 
     path = libxl_sprintf(ctx, "/local/domain/0/device-model/%d", info->domid);
     xs_mkdir(ctx->xsh, XBT_NULL, path);
@@ -1017,7 +1028,7 @@ static int libxl_create_pci_backend(struct libxl_ctx *ctx, uint32_t domid, libxl
     if (!back)
         return ERROR_NOMEM;
 
-    XL_LOG(ctx, XL_LOG_DEBUG, "Creating pci backend\n");
+    XL_LOG(ctx, XL_LOG_DEBUG, "Creating pci backend");
 
     /* add pci device */
     device.backend_devid = 0;
@@ -1088,7 +1099,7 @@ static int libxl_device_pci_add_xenstore(struct libxl_ctx *ctx, uint32_t domid,
     if (!back)
         return ERROR_NOMEM;
 
-    XL_LOG(ctx, XL_LOG_DEBUG, "Adding new pci device to xenstore\n");
+    XL_LOG(ctx, XL_LOG_DEBUG, "Adding new pci device to xenstore");
     num = atoi(num_devs);
     flexarray_set(back, boffset++, libxl_sprintf(ctx, "key-%d", num));
     flexarray_set(back, boffset++, libxl_sprintf(ctx, PCI_BDF, pcidev->domain, pcidev->bus, pcidev->dev, pcidev->func));
@@ -1140,7 +1151,7 @@ static int libxl_device_pci_remove_xenstore(struct libxl_ctx *ctx, uint32_t domi
 
     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\n");
+            XL_LOG(ctx, XL_LOG_DEBUG, "pci backend at %s is not ready");
             return -1;
         }
     }
@@ -1154,7 +1165,7 @@ 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\n");
+        XL_LOG(ctx, XL_LOG_ERROR, "Couldn't find the device on xenstore");
         return -1;
     }
 
@@ -1196,7 +1207,7 @@ int libxl_device_pci_add(struct libxl_ctx *ctx, uint32_t domid, libxl_device_pci
         snprintf(path, sizeof(path), "/local/domain/0/device-model/%d/command", domid);
         xs_write(ctx->xsh, XBT_NULL, path, "pci-ins", strlen("pci-ins"));
         if (libxl_wait_for_device_model(ctx, domid, "pci-inserted") < 0)
-            XL_LOG(ctx, XL_LOG_ERROR, "Device Model didn't respond in time\n");
+            XL_LOG(ctx, XL_LOG_ERROR, "Device Model didn't respond in time");
         snprintf(path, sizeof(path), "/local/domain/0/device-model/%d/parameter", domid);
         vdevfn = libxl_xs_read(ctx, XBT_NULL, path);
         sscanf(vdevfn + 2, "%x", &pcidev->vdevfn);
@@ -1211,22 +1222,22 @@ int libxl_device_pci_add(struct libxl_ctx *ctx, uint32_t domid, libxl_device_pci
         int i;
 
         if (f == NULL) {
-            XL_LOG(ctx, XL_LOG_ERROR, "Couldn't open %s\n", sysfs_path);
+            XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "Couldn't open %s", sysfs_path);
             return -1;
         }
         for (i = 0; i < PROC_PCI_NUM_RESOURCES; i++) {
-            fscanf(f, "0x%x 0x%x 0x%x\n", &start, &end, &flags);
+            fscanf(f, "0x%x 0x%x 0x%x", &start, &end, &flags);
             size = end - start + 1;
             if (start) {
                 if (flags & PCI_BAR_IO) {
                     rc = xc_domain_ioport_permission(ctx->xch, domid, start, size, 1);
                     if (rc < 0)
-                        XL_LOG(ctx, XL_LOG_ERROR, "Error: xc_domain_ioport_permission error 0x%x/0x%x:  %d\n", start, size, rc);
+                        XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "Error: xc_domain_ioport_permission error 0x%x/0x%x", start, size);
                 } 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)
-                        XL_LOG(ctx, XL_LOG_ERROR, "Error: xc_domain_iomem_permission error 0x%x/0x%x:  %d\n", start, size, rc);
+                        XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "Error: xc_domain_iomem_permission error 0x%x/0x%x", start, size);
                 }
             }
         }
@@ -1235,25 +1246,25 @@ int libxl_device_pci_add(struct libxl_ctx *ctx, uint32_t domid, libxl_device_pci
                                    pcidev->bus, pcidev->dev, pcidev->func);
         f = fopen(sysfs_path, "r");
         if (f == NULL) {
-            XL_LOG(ctx, XL_LOG_ERROR, "Couldn't open %s\n", sysfs_path);
+            XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "Couldn't open %s", sysfs_path);
             goto out;
         }
         fscanf(f, "%u", &irq);
         if (irq) {
             rc = xc_physdev_map_pirq(ctx->xch, domid, irq, &irq);
             if (rc < 0) {
-                XL_LOG(ctx, XL_LOG_ERROR, "Error: xc_physdev_map_pirq irq=%d: %d\n", irq, rc);
+                XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "Error: xc_physdev_map_pirq irq=%d", irq);
             }
             rc = xc_domain_irq_permission(ctx->xch, domid, irq, 1);
             if (rc < 0) {
-                XL_LOG(ctx, XL_LOG_ERROR, "Error: xc_domain_irq_permission irq=%d: %d\n", irq, rc);
+                XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "Error: xc_domain_irq_permission irq=%d", irq);
             }
         }
         fclose(f);
     }
 out:
     if ((rc = xc_assign_device(ctx->xch, domid, pcidev->value)) < 0)
-        XL_LOG(ctx, XL_LOG_ERROR, "Error: xc_assign_device error %d\n", rc);
+        XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "xc_assign_device failed");
 
     libxl_device_pci_add_xenstore(ctx, domid, pcidev);
     return 0;
@@ -1280,7 +1291,7 @@ int libxl_device_pci_remove(struct libxl_ctx *ctx, uint32_t domid, libxl_device_
         snprintf(path, sizeof(path), "/local/domain/0/device-model/%d/command", domid);
         xs_write(ctx->xsh, XBT_NULL, path, "pci-rem", strlen("pci-rem"));
         if (libxl_wait_for_device_model(ctx, domid, "pci-removed") < 0) {
-            XL_LOG(ctx, XL_LOG_ERROR, "Device Model didn't respond in time\n");
+            XL_LOG(ctx, XL_LOG_ERROR, "Device Model didn't respond in time");
             return -1;
         }
         snprintf(path, sizeof(path), "/local/domain/0/device-model/%d/state", domid);
@@ -1294,7 +1305,7 @@ int libxl_device_pci_remove(struct libxl_ctx *ctx, uint32_t domid, libxl_device_
         int i;
 
         if (f == NULL) {
-            XL_LOG(ctx, XL_LOG_ERROR, "Couldn't open %s\n", sysfs_path);
+            XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "Couldn't open %s", sysfs_path);
             goto skip1;
         }
         for (i = 0; i < PROC_PCI_NUM_RESOURCES; i++) {
@@ -1304,12 +1315,12 @@ int libxl_device_pci_remove(struct libxl_ctx *ctx, uint32_t domid, libxl_device_
                 if (flags & PCI_BAR_IO) {
                     rc = xc_domain_ioport_permission(ctx->xch, domid, start, size, 0);
                     if (rc < 0)
-                        XL_LOG(ctx, XL_LOG_ERROR, "Error: xc_domain_ioport_permission error 0x%x/0x%x:  %d\n", start, size, rc);
+                        XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "xc_domain_ioport_permission error 0x%x/0x%x", start, size);
                 } else {
                     rc = xc_domain_iomem_permission(ctx->xch, domid, start>>XC_PAGE_SHIFT,
                                                     (size+(XC_PAGE_SIZE-1))>>XC_PAGE_SHIFT, 0);
                     if (rc < 0)
-                        XL_LOG(ctx, XL_LOG_ERROR, "Error: xc_domain_iomem_permission error 0x%x/0x%x:  %d\n", start, size, rc);
+                        XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "xc_domain_iomem_permission error 0x%x/0x%x", start, size);
                 }
             }
         }
@@ -1319,18 +1330,18 @@ skip1:
                                    pcidev->bus, pcidev->dev, pcidev->func);
         f = fopen(sysfs_path, "r");
         if (f == NULL) {
-            XL_LOG(ctx, XL_LOG_ERROR, "Couldn't open %s\n", sysfs_path);
+            XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "Couldn't open %s", sysfs_path);
             goto out;
         }
         fscanf(f, "%u", &irq);
         if (irq) {
             rc = xc_physdev_unmap_pirq(ctx->xch, domid, irq);
             if (rc < 0) {
-                XL_LOG(ctx, XL_LOG_ERROR, "Error: xc_physdev_map_pirq irq=%d: %d\n", irq, rc);
+                XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "xc_physdev_map_pirq irq=%d", irq);
             }
             rc = xc_domain_irq_permission(ctx->xch, domid, irq, 0);
             if (rc < 0) {
-                XL_LOG(ctx, XL_LOG_ERROR, "Error: xc_domain_irq_permission irq=%d: %d\n", irq, rc);
+                XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "xc_domain_irq_permission irq=%d", irq);
             }
         }
         fclose(f);
@@ -1341,7 +1352,7 @@ out:
     libxl_device_pci_flr(ctx, pcidev->domain, pcidev->bus, pcidev->dev, pcidev->func);
 
     if ((rc = xc_deassign_device(ctx->xch, domid, pcidev->value)) < 0)
-        XL_LOG(ctx, XL_LOG_ERROR, "Error: xc_deassign_device error %d\n", rc);
+        XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, rc, "xc_deassign_device failed");
     return 0;
 }
 

diff --git a/tools/libxl/libxl_device.c b/tools/libxl/libxl_device.c
index eee0a40e0d3dbfbe8b9c94f2dda0d4d3efecd478..82a2a305809d8275f934abff7e881ca42ea5a45a 100644 (file)
--- a/tools/libxl/libxl_device.c
+++ b/tools/libxl/libxl_device.c
@@ -92,7 +92,7 @@ retry_transaction:
         if (errno == EAGAIN)
             goto retry_transaction;
         else
-            XL_LOG(ctx, XL_LOG_ERROR, "xs transaction failed errno=%d\n", errno);
+            XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "xs transaction failed");
     }
     return 0;
 }
@@ -213,7 +213,7 @@ int libxl_devices_destroy(struct libxl_ctx *ctx, uint32_t domid, int force)
     path = libxl_sprintf(ctx, "/local/domain/%d/device", domid);
     l1 = libxl_xs_directory(ctx, XBT_NULL, path, &num1);
     if (!l1) {
-        XL_LOG(ctx, XL_LOG_ERROR, "%s is empty\n", path);
+        XL_LOG(ctx, XL_LOG_ERROR, "%s is empty", path);
         return -1;
     }
     for (i = 0; i < num1; i++) {
@@ -248,7 +248,7 @@ int libxl_devices_destroy(struct libxl_ctx *ctx, uint32_t domid, int force)
                     if (!state || atoi(state) == 6) {
                         xs_unwatch(ctx->xsh, l1[0], l1[1]);
                         xs_rm(ctx->xsh, XBT_NULL, l1[1]);
-                        XL_LOG(ctx, XL_LOG_DEBUG, "Destroyed device backend at %s\n", l1[1]);
+                        XL_LOG(ctx, XL_LOG_DEBUG, "Destroyed device backend at %s", l1[1]);
                         n_watches--;
                     }
                 }
@@ -267,15 +267,20 @@ int libxl_devices_destroy(struct libxl_ctx *ctx, uint32_t domid, int force)
 int libxl_device_pci_flr(struct libxl_ctx *ctx, unsigned int domain, unsigned int bus,
                          unsigned int dev, unsigned int func)
 {
+    char *do_flr= "/sys/bus/pci/drivers/pciback/do_flr";
     FILE *fd;
 
-    fd = fopen("/sys/bus/pci/drivers/pciback/do_flr", "w");
+    fd = fopen(do_flr, "w");
     if (fd != NULL) {
         fprintf(fd, PCI_BDF, domain, bus, dev, func);
         fclose(fd);
         return 0;
     }
-    XL_LOG(ctx, XL_LOG_ERROR, "Pciback doesn't support do_flr, cannot flr the device\n");
+    if (errno == ENOENT) {
+        XL_LOG(ctx, XL_LOG_ERROR, "Pciback doesn't support do_flr, cannot flr the device");
+    } else {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "Failed to access pciback path %s", do_flr);
+    }
     return -1;
 }
 
@@ -303,7 +308,7 @@ int libxl_wait_for_device_model(struct libxl_ctx *ctx, uint32_t domid, char *sta
             }
         }
     }
-    XL_LOG(ctx, XL_LOG_ERROR, "Device Model not ready\n");
+    XL_LOG(ctx, XL_LOG_ERROR, "Device Model not ready");
     return -1;
 }
 
@@ -317,7 +322,13 @@ int libxl_wait_for_backend(struct libxl_ctx *ctx, char *be_path, char *state)
     while (watchdog > 0) {
         p = xs_read(ctx->xsh, XBT_NULL, path, &len);
         if (p == NULL) {
-            XL_LOG(ctx, XL_LOG_ERROR, "Backend %s does not exist\n", be_path);
+            if (errno == ENOENT) {
+                XL_LOG(ctx, XL_LOG_ERROR, "Backend %s does not exist",
+                       be_path);
+            } else {
+                XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "Failed to access backend %s",
+                       be_path);
+            }
             return -1;
         } else {
             if (!strcmp(p, state)) {
@@ -328,7 +339,7 @@ int libxl_wait_for_backend(struct libxl_ctx *ctx, char *be_path, char *state)
             }
         }
     }
-    XL_LOG(ctx, XL_LOG_ERROR, "Backend %s not ready\n", be_path);
+    XL_LOG(ctx, XL_LOG_ERROR, "Backend %s not ready", be_path);
     return -1;
 }
 

diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index a98daee19be60e5bfb16901564794540db305c30..e3cf4374c5a901a83174c6357becb339d5a23be0 100644 (file)
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -83,6 +83,9 @@ int build_post(struct libxl_ctx *ctx, uint32_t domid,
     ents[9] = libxl_sprintf(ctx, "%lu", state->store_mfn);
 
     dom_path = libxl_xs_get_dompath(ctx, domid);
+    if (!dom_path)
+        return ERROR_FAIL;
+
     vm_path = xs_read(ctx->xsh, XBT_NULL, libxl_sprintf(ctx, "%s/vm", dom_path), NULL);
 retry_transaction:
     t = xs_transaction_start(ctx->xsh);
@@ -107,7 +110,7 @@ int build_pv(struct libxl_ctx *ctx, uint32_t domid,
 
     dom = xc_dom_allocate(info->u.pv.cmdline, info->u.pv.features);
     if (!dom) {
-        XL_LOG(ctx, XL_LOG_ERROR, "xc_dom_allocate failed: %d", dom);
+        XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, dom, "xc_dom_allocate failed");
         return -1;
     }
     if ((ret = xc_dom_linux_build(ctx->xch, dom, domid, info->max_memkb / 1024,
@@ -115,7 +118,7 @@ int build_pv(struct libxl_ctx *ctx, uint32_t domid,
                                   state->store_port, &state->store_mfn,
                                   state->console_port, &state->console_mfn)) != 0) {
         xc_dom_release(dom);
-        XL_LOG(ctx, XL_LOG_ERROR, "xc_dom_linux_build failed: %d", ret);
+        XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, ret, "xc_dom_linux_build failed");
         return -2;
     }
     xc_dom_release(dom);
@@ -129,7 +132,7 @@ int build_hvm(struct libxl_ctx *ctx, uint32_t domid,
 
     ret = xc_hvm_build(ctx->xch, domid, info->max_memkb / 1024, info->kernel);
     if (ret) {
-        XL_LOG(ctx, XL_LOG_ERROR, "hvm building failed: %d", ret);
+        XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, ret, "hvm building failed");
         return ERROR_FAIL;
     }
     ret = hvm_build_set_params(ctx->xch, domid, info->u.hvm.apic, info->u.hvm.acpi,
@@ -137,7 +140,7 @@ int build_hvm(struct libxl_ctx *ctx, uint32_t domid,
                                info->max_vcpus,
                                state->store_port, &state->store_mfn);
     if (ret) {
-        XL_LOG(ctx, XL_LOG_ERROR, "hvm build set params failed: %d", ret);
+        XL_LOG_ERRNOVAL(ctx, XL_LOG_ERROR, ret, "hvm build set params failed");
         return ERROR_FAIL;
     }
     xc_cpuid_apply_policy(ctx->xch, domid);

diff --git a/tools/libxl/libxl_exec.c b/tools/libxl/libxl_exec.c
index 8d7928b4e8ea7a05bf59d76cead28a6674a0934b..8a589b676c7b23306037f923b13ed31d498b5f14 100644 (file)
--- a/tools/libxl/libxl_exec.c
+++ b/tools/libxl/libxl_exec.c
@@ -28,7 +28,7 @@ int libxl_exec(struct libxl_ctx *ctx, int stdinfd, int stdoutfd, int stderrfd,
 
     pid = fork();
     if (pid == -1) {
-        XL_LOG(ctx, XL_LOG_ERROR, "fork failed");
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "fork failed");
         return -1;
     }
     if (pid == 0) {

diff --git a/tools/libxl/libxl_internal.c b/tools/libxl/libxl_internal.c
index 407cf2230e400842446f4bdb1702a54c5a8d5b9a..7ba0c9790f2df8bc07f2fdf8b72fa369dc44e039 100644 (file)
--- a/tools/libxl/libxl_internal.c
+++ b/tools/libxl/libxl_internal.c
@@ -146,14 +146,41 @@ char *libxl_dirname(struct libxl_ctx *ctx, const char *s)
     return ptr;
 }
 
-void xl_log(struct libxl_ctx *ctx, int loglevel, const char *file, int line, const char *func, char *fmt, ...)
+void xl_logv(struct libxl_ctx *ctx, int loglevel, int errnoval,
+             const char *file, int line, const char *func,
+             char *fmt, va_list ap)
 {
-    va_list ap;
+    char *enomem = "[out of memory formatting log message]";
     char *s;
-    va_start(ap, fmt);
-    vasprintf(&s, fmt, ap);
-    va_end(ap);
+    int rc;
+
+    rc = vasprintf(&s, fmt, ap);
+    if (rc<0) { s = enomem; goto x; }
+
+    if (errnoval >= 0) {
+        char *errstr, *snew;
+        errstr = strerror(errnoval);
+        if (errstr)
+            rc = asprintf(&snew, "%s: %s", s, errstr);
+        else
+            rc = asprintf(&snew, "%s: unknown error number %d", s, errnoval);
+        free(s);
+        if (rc<0) { s = enomem; goto x; }
+        s = snew;
+    }
 
+ x:
     ctx->log_callback(ctx->log_userdata, loglevel, file, line, func, s);
-    free(s);
+    if (s != enomem)
+        free(s);
+}
+
+void xl_log(struct libxl_ctx *ctx, int loglevel, int errnoval,
+            const char *file, int line,
+            const char *func, char *fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+    xl_logv(ctx, loglevel, errnoval, file, line, func, fmt, ap);
+    va_end(ap);
 }

diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index d6835be53ef8bb02edd8fe51fe74dafec9aae771..046e51d7a8c3b0195ce5c4a93c1f690d25ba33d4 100644 (file)
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -37,9 +37,13 @@
 #define XL_LOGGING_ENABLED
 
 #ifdef XL_LOGGING_ENABLED
-#define XL_LOG(ctx, loglevel, _f, _a...)   xl_log(ctx, loglevel, __FILE__, __LINE__, __func__, _f, ##_a)
+#define XL_LOG(ctx, loglevel, _f, _a...)   xl_log(ctx, loglevel, -1, __FILE__, __LINE__, __func__, _f, ##_a)
+#define XL_LOG_ERRNO(ctx, loglevel, _f, _a...)   xl_log(ctx, loglevel, errno, __FILE__, __LINE__, __func__, _f, ##_a)
+#define XL_LOG_ERRNOVAL(ctx, errnoval, loglevel, _f, _a...)   xl_log(ctx, loglevel, errnoval, __FILE__, __LINE__, __func__, _f, ##_a)
 #else
 #define XL_LOG(ctx, loglevel, _f, _a...)
+#define XL_LOG_ERRNO(ctx, loglevel, _f, _a...)
+#define XL_LOG_ERRNOVAL(ctx, loglevel, errnoval, _f, _a...)
 #endif
 
 #define XL_LOG_DEBUG 3
@@ -47,7 +51,8 @@
 #define XL_LOG_WARNING 1
 #define XL_LOG_ERROR 0
 
-void xl_log(struct libxl_ctx *ctx, int loglevel, const char *file, int line, const char *func, char *fmt, ...);
+void xl_logv(struct libxl_ctx *ctx, int errnoval, int loglevel, const char *file, int line, const char *func, char *fmt, va_list al);
+void xl_log(struct libxl_ctx *ctx, int errnoval, int loglevel, const char *file, int line, const char *func, char *fmt, ...);
 
 struct libxl_domain_build_state_ {
     uint32_t store_port;
@@ -97,7 +102,7 @@ int libxl_xs_writev(struct libxl_ctx *ctx, xs_transaction_t t,
                     char *dir, char **kvs);
 int libxl_xs_write(struct libxl_ctx *ctx, xs_transaction_t t,
                    char *path, char *fmt, ...);
-char *libxl_xs_get_dompath(struct libxl_ctx *ctx, uint32_t domid);
+char *libxl_xs_get_dompath(struct libxl_ctx *ctx, uint32_t domid); // logs errs
 char *libxl_xs_read(struct libxl_ctx *ctx, xs_transaction_t t, char *path);
 char **libxl_xs_directory(struct libxl_ctx *ctx, xs_transaction_t t, char *path, unsigned int *nb);
 

diff --git a/tools/libxl/libxl_xshelp.c b/tools/libxl/libxl_xshelp.c
index 6286d02826c4cd8ba35f50268c2a5868ede4ac03..f59eee75238d39836bae0ade851ef6bb4ba90e7c 100644 (file)
--- a/tools/libxl/libxl_xshelp.c
+++ b/tools/libxl/libxl_xshelp.c
@@ -95,6 +95,11 @@ char * libxl_xs_read(struct libxl_ctx *ctx, xs_transaction_t t, char *path)
 char *libxl_xs_get_dompath(struct libxl_ctx *ctx, uint32_t domid)
 {
     char *s = xs_get_domain_path(ctx->xsh, domid);
+    if (!s) {
+        XL_LOG_ERRNO(ctx, XL_LOG_ERROR, "failed to get dompath for %lu",
+                     domid);
+        return NULL;
+    }
     libxl_ptr_add(ctx, s);
     return s;
 }