This is something I previously submitted as part of one of the LXC patches, but I figure it makes sense on its own, since OpenVZ needs this now too. This adds two new XML elements to the domain XML format: - An <init> block within <os> allowing specification of the path for a binary to run when starting the container - aka 'init' by any other name. First we also specify that all containers will use an OS type of 'exe' - as in executable - the container equivalent of 'hvm' <os> <type>exe</type> <init>/sbin/init</init> </os> - An <filesystem> element for specifying how the container's filesystem is to be provided. This can actually be useful for full-machine virt too such as KVM which have host filesystem pass-through. There are various ways to configure it: eg to use '/some/directory' as the root filesystem for a container <filesystem type='mount'> <source dir='/some/directory'/> <target dir='/'/> </filesystem> eg to use a template called 'fedora9web' as the root filesystem for a container <filesystem type='template'> <source name='fedora9web'/> <target dir='/'/> </filesystem> eg to use a file containing a filesystem as the root filesystem <filesystem type='file'> <source file='/some/file.img'/> <target dir='/'/> </filesystem> eg to use a disk partition or other block device (eg LVM) containing a filesystem as the root filesystem <filesystem type='block'> <source dev='/dev/VolGroup00/Fedora9Web'/> <target dir='/'/> </filesystem> If setting the root filesystem, the target path will be '/', some container based virt allows the host OS root filesystem to be used in the guest, and merely specify additive mounts at specific locations, eg to override just /home within a container <filesystem type='mount'> <source dir='/some/directory'/> <target dir='/home'/> </filesystem> I believe this should satisfy all the OpenVZ, LXC and Linux-VServer drivers' requirements around filesystems Daniel diff -r 5614da5fe9ef src/domain_conf.c --- a/src/domain_conf.c Fri Jul 25 15:38:46 2008 +0100 +++ b/src/domain_conf.c Tue Jul 29 16:03:38 2008 +0100 @@ -86,6 +86,12 @@ "virtio", "xen") +VIR_ENUM_IMPL(virDomainFS, VIR_DOMAIN_FS_TYPE_LAST, + "mount", + "block", + "file", + "template") + VIR_ENUM_IMPL(virDomainNet, VIR_DOMAIN_NET_TYPE_LAST, "user", "ethernet", @@ -234,6 +240,18 @@ VIR_FREE(def->driverType); virDomainDiskDefFree(def->next); + VIR_FREE(def); +} + +void virDomainFSDefFree(virDomainFSDefPtr def) +{ + if (!def) + return; + + VIR_FREE(def->src); + VIR_FREE(def->dst); + + virDomainFSDefFree(def->next); VIR_FREE(def); } @@ -345,6 +363,7 @@ virDomainGraphicsDefFree(def->graphics); virDomainInputDefFree(def->inputs); virDomainDiskDefFree(def->disks); + virDomainFSDefFree(def->fss); virDomainNetDefFree(def->nets); virDomainChrDefFree(def->serials); virDomainChrDefFree(def->parallels); @@ -355,6 +374,7 @@ VIR_FREE(def->os.type); VIR_FREE(def->os.arch); VIR_FREE(def->os.machine); + VIR_FREE(def->os.init); VIR_FREE(def->os.kernel); VIR_FREE(def->os.initrd); VIR_FREE(def->os.cmdline); @@ -620,6 +640,89 @@ error: virDomainDiskDefFree(def); + def = NULL; + goto cleanup; +} + + +/* Parse the XML definition for a disk + * @param node XML nodeset to parse for disk definition + */ +static virDomainFSDefPtr +virDomainFSDefParseXML(virConnectPtr conn, + xmlNodePtr node) { + virDomainFSDefPtr def; + xmlNodePtr cur; + char *type = NULL; + char *source = NULL; + char *target = NULL; + + if (VIR_ALLOC(def) < 0) { + virDomainReportError(conn, VIR_ERR_NO_MEMORY, NULL); + return NULL; + } + + type = virXMLPropString(node, "type"); + if (type) { + if ((def->type = virDomainFSTypeFromString(type)) < 0) { + virDomainReportError(conn, VIR_ERR_INTERNAL_ERROR, + _("unknown filesystem type '%s'"), type); + goto error; + } + } else { + def->type = VIR_DOMAIN_FS_TYPE_MOUNT; + } + + cur = node->children; + while (cur != NULL) { + if (cur->type == XML_ELEMENT_NODE) { + if ((source == NULL) && + (xmlStrEqual(cur->name, BAD_CAST "source"))) { + + if (def->type == VIR_DOMAIN_FS_TYPE_MOUNT) + source = virXMLPropString(cur, "dir"); + else if (def->type == VIR_DOMAIN_FS_TYPE_FILE) + source = virXMLPropString(cur, "file"); + else if (def->type == VIR_DOMAIN_FS_TYPE_BLOCK) + source = virXMLPropString(cur, "dev"); + else if (def->type == VIR_DOMAIN_FS_TYPE_TEMPLATE) + source = virXMLPropString(cur, "name"); + } else if ((target == NULL) && + (xmlStrEqual(cur->name, BAD_CAST "target"))) { + target = virXMLPropString(cur, "dir"); + } else if (xmlStrEqual(cur->name, BAD_CAST "readonly")) { + def->readonly = 1; + } + } + cur = cur->next; + } + + if (source == NULL) { + virDomainReportError(conn, VIR_ERR_NO_SOURCE, + target ? "%s" : NULL, target); + goto error; + } + + if (target == NULL) { + virDomainReportError(conn, VIR_ERR_NO_TARGET, + source ? "%s" : NULL, source); + goto error; + } + + def->src = source; + source = NULL; + def->dst = target; + target = NULL; + +cleanup: + VIR_FREE(type); + VIR_FREE(target); + VIR_FREE(source); + + return def; + + error: + virDomainFSDefFree(def); def = NULL; goto cleanup; } @@ -1351,6 +1454,10 @@ dev->type = VIR_DOMAIN_DEVICE_DISK; if (!(dev->data.disk = virDomainDiskDefParseXML(conn, node))) goto error; + } else if (xmlStrEqual(node->name, BAD_CAST "filesystem")) { + dev->type = VIR_DOMAIN_DEVICE_FS; + if (!(dev->data.fs = virDomainFSDefParseXML(conn, node))) + goto error; } else if (xmlStrEqual(node->name, BAD_CAST "interface")) { dev->type = VIR_DOMAIN_DEVICE_NET; if (!(dev->data.net = virDomainNetDefParseXML(conn, node))) @@ -1560,7 +1667,21 @@ } } - if (!def->os.bootloader) { + /* + * Booting options for different OS types.... + * + * - A bootloader (and optional kernel+initrd) (xen) + * - A kernel + initrd (xen) + * - A boot device (and optional kernel+initrd) (hvm) + * - An init script (exe) + */ + + if (STREQ(def->os.type, "exe")) { + def->os.init = virXPathString(conn, "string(./os/init[1])", ctxt); + } + + if (STREQ(def->os.type, "xen") || + STREQ(def->os.type, "hvm")) { def->os.kernel = virXPathString(conn, "string(./os/kernel[1])", ctxt); def->os.initrd = virXPathString(conn, "string(./os/initrd[1])", ctxt); def->os.cmdline = virXPathString(conn, "string(./os/cmdline[1])", ctxt); @@ -1610,12 +1731,9 @@ def->os.type, def->os.arch, type); - if (!emulator) { - virDomainReportError(conn, VIR_ERR_INTERNAL_ERROR, - "%s", _("unsupported guest type")); - goto error; - } - if (!(def->emulator = strdup(emulator))) { + + if (emulator && + !(def->emulator = strdup(emulator))) { virDomainReportError(conn, VIR_ERR_NO_MEMORY, NULL); goto error; } @@ -1648,6 +1766,23 @@ ptr = ptr->next; } } + } + VIR_FREE(nodes); + + /* analysis of the filesystems */ + if ((n = virXPathNodeSet(conn, "./devices/filesystem", ctxt, &nodes)) < 0) { + virDomainReportError(conn, VIR_ERR_INTERNAL_ERROR, + "%s", _("cannot extract filesystem devices")); + goto error; + } + for (i = n - 1 ; i >= 0 ; i--) { + virDomainFSDefPtr fs = virDomainFSDefParseXML(conn, + nodes[i]); + if (!fs) + goto error; + + fs->next = def->fss; + def->fss = fs; } VIR_FREE(nodes); @@ -2202,6 +2337,57 @@ } static int +virDomainFSDefFormat(virConnectPtr conn, + virBufferPtr buf, + virDomainFSDefPtr def) +{ + const char *type = virDomainFSTypeToString(def->type); + + if (!type) { + virDomainReportError(conn, VIR_ERR_INTERNAL_ERROR, + _("unexpected filesystem type %d"), def->type); + return -1; + } + + virBufferVSprintf(buf, + " <filesystem type='%s'>\n", + type); + + if (def->src) { + switch (def->type) { + case VIR_DOMAIN_FS_TYPE_MOUNT: + virBufferEscapeString(buf, " <source dir='%s'/>\n", + def->src); + break; + + case VIR_DOMAIN_FS_TYPE_BLOCK: + virBufferEscapeString(buf, " <source dev='%s'/>\n", + def->src); + break; + + case VIR_DOMAIN_FS_TYPE_FILE: + virBufferEscapeString(buf, " <source file='%s'/>\n", + def->src); + break; + + case VIR_DOMAIN_FS_TYPE_TEMPLATE: + virBufferEscapeString(buf, " <source name='%s'/>\n", + def->src); + } + } + + virBufferVSprintf(buf, " <target dir='%s'/>\n", + def->dst); + + if (def->readonly) + virBufferAddLit(buf, " <readonly/>\n"); + + virBufferAddLit(buf, " </filesystem>\n"); + + return 0; +} + +static int virDomainNetDefFormat(virConnectPtr conn, virBufferPtr buf, virDomainNetDefPtr def) @@ -2479,6 +2665,7 @@ unsigned char *uuid; char uuidstr[VIR_UUID_STRING_BUFLEN]; virDomainDiskDefPtr disk; + virDomainFSDefPtr fs; virDomainNetDefPtr net; virDomainSoundDefPtr sound; virDomainInputDefPtr input; @@ -2548,6 +2735,9 @@ else virBufferVSprintf(&buf, ">%s</type>\n", def->os.type); + if (def->os.init) + virBufferEscapeString(&buf, " <init>%s</init>\n", + def->os.init); if (def->os.loader) virBufferEscapeString(&buf, " <loader>%s</loader>\n", def->os.loader); @@ -2621,6 +2811,13 @@ if (virDomainDiskDefFormat(conn, &buf, disk) < 0) goto cleanup; disk = disk->next; + } + + fs = def->fss; + while (fs) { + if (virDomainFSDefFormat(conn, &buf, fs) < 0) + goto cleanup; + fs = fs->next; } net = def->nets; diff -r 5614da5fe9ef src/domain_conf.h --- a/src/domain_conf.h Fri Jul 25 15:38:46 2008 +0100 +++ b/src/domain_conf.h Tue Jul 29 16:03:38 2008 +0100 @@ -91,6 +91,28 @@ unsigned int shared : 1; virDomainDiskDefPtr next; +}; + + +/* Two types of disk backends */ +enum virDomainFSType { + VIR_DOMAIN_FS_TYPE_MOUNT, /* Better named 'bind' */ + VIR_DOMAIN_FS_TYPE_BLOCK, + VIR_DOMAIN_FS_TYPE_FILE, + VIR_DOMAIN_FS_TYPE_TEMPLATE, + + VIR_DOMAIN_FS_TYPE_LAST +}; + +typedef struct _virDomainFSDef virDomainFSDef; +typedef virDomainFSDef *virDomainFSDefPtr; +struct _virDomainFSDef { + int type; + char *src; + char *dst; + unsigned int readonly : 1; + + virDomainFSDefPtr next; }; @@ -262,6 +284,7 @@ /* Flags for the 'type' field in next struct */ enum virDomainDeviceType { VIR_DOMAIN_DEVICE_DISK, + VIR_DOMAIN_DEVICE_FS, VIR_DOMAIN_DEVICE_NET, VIR_DOMAIN_DEVICE_INPUT, VIR_DOMAIN_DEVICE_SOUND, @@ -273,6 +296,7 @@ int type; union { virDomainDiskDefPtr disk; + virDomainFSDefPtr fs; virDomainNetDefPtr net; virDomainInputDefPtr input; virDomainSoundDefPtr sound; @@ -318,6 +342,7 @@ char *machine; int nBootDevs; int bootDevs[VIR_DOMAIN_BOOT_LAST]; + char *init; char *kernel; char *initrd; char *cmdline; @@ -357,6 +382,7 @@ virDomainGraphicsDefPtr graphics; virDomainDiskDefPtr disks; + virDomainFSDefPtr fss; virDomainNetDefPtr nets; virDomainInputDefPtr inputs; virDomainSoundDefPtr sounds; @@ -411,6 +437,7 @@ void virDomainGraphicsDefFree(virDomainGraphicsDefPtr def); void virDomainInputDefFree(virDomainInputDefPtr def); void virDomainDiskDefFree(virDomainDiskDefPtr def); +void virDomainFSDefFree(virDomainFSDefPtr def); void virDomainNetDefFree(virDomainNetDefPtr def); void virDomainChrDefFree(virDomainChrDefPtr def); void virDomainSoundDefFree(virDomainSoundDefPtr def); @@ -481,6 +508,7 @@ VIR_ENUM_DECL(virDomainDisk) VIR_ENUM_DECL(virDomainDiskDevice) VIR_ENUM_DECL(virDomainDiskBus) +VIR_ENUM_DECL(virDomainFS) VIR_ENUM_DECL(virDomainNet) VIR_ENUM_DECL(virDomainChr) VIR_ENUM_DECL(virDomainSoundModel) -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://ovirt.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|