[libvirt] [PATCHv3 3/4] Add domainSave/Restore to libxl driver
Daniel Veillard
veillard at redhat.com
Tue May 31 05:05:10 UTC 2011
On Mon, May 30, 2011 at 11:53:02AM +0200, Markus Groß wrote:
> v3:
> * initialize xml pointer to avoid segfault
> * throw error message if domain is paused as
> libxenlight itself will pause it
>
> v2:
> * header is now padded and has a version field
> * the correct restore function from libxl is used
> * only create the restore event once in libxlVmStart
>
> ---
> src/libxl/libxl_conf.h | 14 +++
> src/libxl/libxl_driver.c | 229 +++++++++++++++++++++++++++++++++++++++++++---
> 2 files changed, 228 insertions(+), 15 deletions(-)
>
> diff --git a/src/libxl/libxl_conf.h b/src/libxl/libxl_conf.h
> index bf5a50d..2820afb 100644
> --- a/src/libxl/libxl_conf.h
> +++ b/src/libxl/libxl_conf.h
> @@ -1,5 +1,6 @@
> /*---------------------------------------------------------------------------*/
> /* Copyright (c) 2011 SUSE LINUX Products GmbH, Nuernberg, Germany.
> + * Copyright (C) 2011 Univention GmbH.
> *
> * This library is free software; you can redistribute it and/or
> * modify it under the terms of the GNU Lesser General Public
> @@ -17,6 +18,7 @@
> *
> * Authors:
> * Jim Fehlig <jfehlig at novell.com>
> + * Markus Groß <gross at univention.de>
> */
> /*---------------------------------------------------------------------------*/
>
> @@ -81,6 +83,18 @@ struct _libxlDomainObjPrivate {
> int eventHdl;
> };
>
> +# define LIBXL_SAVE_MAGIC "libvirt-xml\n \0 \r"
> +# define LIBXL_SAVE_VERSION 1
> +
> +typedef struct _libxlSavefileHeader libxlSavefileHeader;
> +typedef libxlSavefileHeader *libxlSavefileHeaderPtr;
> +struct _libxlSavefileHeader {
> + char magic[sizeof(LIBXL_SAVE_MAGIC)-1];
> + uint32_t version;
> + uint32_t xmlLen;
> + /* 24 bytes used, pad up to 64 bytes */
> + uint32_t unused[10];
> +};
>
> # define libxlError(code, ...) \
> virReportErrorHelper(VIR_FROM_LIBXL, code, __FILE__, \
> diff --git a/src/libxl/libxl_driver.c b/src/libxl/libxl_driver.c
> index 86b01b2..0a2401a 100644
> --- a/src/libxl/libxl_driver.c
> +++ b/src/libxl/libxl_driver.c
> @@ -29,6 +29,7 @@
> #include <sys/utsname.h>
> #include <math.h>
> #include <libxl.h>
> +#include <fcntl.h>
>
> #include "internal.h"
> #include "logging.h"
> @@ -60,11 +61,10 @@
>
> static libxlDriverPrivatePtr libxl_driver = NULL;
>
> -
> /* Function declarations */
> static int
> -libxlVmStart(libxlDriverPrivatePtr driver,
> - virDomainObjPtr vm, bool start_paused);
> +libxlVmStart(libxlDriverPrivatePtr driver, virDomainObjPtr vm,
> + bool start_paused, int restore_fd);
>
>
> /* Function definitions */
> @@ -168,7 +168,7 @@ libxlAutostartDomain(void *payload, const void *name ATTRIBUTE_UNUSED,
> virResetLastError();
>
> if (vm->autostart && !virDomainObjIsActive(vm) &&
> - libxlVmStart(driver, vm, false) < 0) {
> + libxlVmStart(driver, vm, false, -1) < 0) {
> err = virGetLastError();
> VIR_ERROR(_("Failed to autostart VM '%s': %s"),
> vm->def->name,
> @@ -376,7 +376,7 @@ static void libxlEventHandler(int watch,
> break;
> case SHUTDOWN_reboot:
> libxlVmReap(driver, vm, 0, VIR_DOMAIN_SHUTOFF_SHUTDOWN);
> - libxlVmStart(driver, vm, 0);
> + libxlVmStart(driver, vm, 0, -1);
> break;
> default:
> VIR_INFO("Unhandled shutdown_reason %d", info.shutdown_reason);
> @@ -542,8 +542,8 @@ libxlFreeMem(libxlDomainObjPrivatePtr priv, libxl_domain_config *d_config)
> * virDomainObjPtr should be locked on invocation
> */
> static int
> -libxlVmStart(libxlDriverPrivatePtr driver,
> - virDomainObjPtr vm, bool start_paused)
> +libxlVmStart(libxlDriverPrivatePtr driver, virDomainObjPtr vm,
> + bool start_paused, int restore_fd)
> {
> libxl_domain_config d_config;
> virDomainDefPtr def = vm->def;
> @@ -566,12 +566,23 @@ libxlVmStart(libxlDriverPrivatePtr driver,
> goto error;
> }
>
> - ret = libxl_domain_create_new(&priv->ctx, &d_config,
> - NULL, &child_console_pid, &domid);
> + if (restore_fd < 0)
> + ret = libxl_domain_create_new(&priv->ctx, &d_config,
> + NULL, &child_console_pid, &domid);
> + else
> + ret = libxl_domain_create_restore(&priv->ctx, &d_config, NULL,
> + &child_console_pid, &domid,
> + restore_fd);
> +
> if (ret) {
> - libxlError(VIR_ERR_INTERNAL_ERROR,
> - _("libxenlight failed to create new domain '%s'"),
> - d_config.c_info.name);
> + if (restore_fd < 0)
> + libxlError(VIR_ERR_INTERNAL_ERROR,
> + _("libxenlight failed to create new domain '%s'"),
> + d_config.c_info.name);
> + else
> + libxlError(VIR_ERR_INTERNAL_ERROR,
> + _("libxenlight failed to restore domain '%s'"),
> + d_config.c_info.name);
> goto error;
> }
>
> @@ -604,7 +615,9 @@ libxlVmStart(libxlDriverPrivatePtr driver,
> goto error;
>
> event = virDomainEventNewFromObj(vm, VIR_DOMAIN_EVENT_STARTED,
> - VIR_DOMAIN_EVENT_STARTED_BOOTED);
> + restore_fd < 0 ?
> + VIR_DOMAIN_EVENT_STARTED_BOOTED :
> + VIR_DOMAIN_EVENT_STARTED_RESTORED);
> libxlDomainEventQueue(driver, event);
>
> libxl_domain_config_destroy(&d_config);
> @@ -1082,7 +1095,8 @@ libxlDomainCreateXML(virConnectPtr conn, const char *xml,
> goto cleanup;
> def = NULL;
>
> - if (libxlVmStart(driver, vm, (flags & VIR_DOMAIN_START_PAUSED) != 0) < 0) {
> + if (libxlVmStart(driver, vm, (flags & VIR_DOMAIN_START_PAUSED) != 0,
> + -1) < 0) {
> virDomainRemoveInactive(&driver->domains, vm);
> vm = NULL;
> goto cleanup;
> @@ -1634,6 +1648,189 @@ libxlDomainGetState(virDomainPtr dom,
> }
>
> static int
> +libxlDomainSave(virDomainPtr dom, const char *to)
> +{
> + libxlDriverPrivatePtr driver = dom->conn->privateData;
> + virDomainObjPtr vm;
> + libxlDomainObjPrivatePtr priv;
> + libxlSavefileHeader hdr;
> + virDomainEventPtr event = NULL;
> + char *xml = NULL;
> + uint32_t xml_len;
> + int fd;
> + int ret = -1;
> +
> + libxlDriverLock(driver);
> + vm = virDomainFindByUUID(&driver->domains, dom->uuid);
> +
> + if (!vm) {
> + char uuidstr[VIR_UUID_STRING_BUFLEN];
> + virUUIDFormat(dom->uuid, uuidstr);
> + libxlError(VIR_ERR_NO_DOMAIN,
> + _("No domain with matching uuid '%s'"), uuidstr);
> + goto cleanup;
> + }
> +
> + if (!virDomainObjIsActive(vm)) {
> + libxlError(VIR_ERR_OPERATION_INVALID, "%s", _("Domain is not running"));
> + goto cleanup;
> + }
> +
> + priv = vm->privateData;
> +
> + if (virDomainObjGetState(vm, NULL) == VIR_DOMAIN_PAUSED) {
> + libxlError(VIR_ERR_OPERATION_INVALID,
> + _("Domain '%d' has to be running because libxenlight will"
> + " suspend it"), dom->id);
> + goto cleanup;
> + }
> +
> + if ((fd = virFileOpenAs(to, O_CREAT|O_TRUNC|O_WRONLY, S_IRUSR|S_IWUSR,
> + getuid(), getgid(), 0)) < 0) {
> + virReportSystemError(-fd,
> + _("Failed to create domain save file '%s'"), to);
> + goto cleanup;
> + }
> +
> + if ((xml = virDomainDefFormat(vm->def, 0)) == NULL)
> + goto cleanup;
> + xml_len = strlen(xml) + 1;
> +
> + memset(&hdr, 0, sizeof(hdr));
> + memcpy(hdr.magic, LIBXL_SAVE_MAGIC, sizeof(hdr.magic));
> + hdr.version = LIBXL_SAVE_VERSION;
> + hdr.xmlLen = xml_len;
> +
> + if (safewrite(fd, &hdr, sizeof(hdr)) != sizeof(hdr)) {
> + libxlError(VIR_ERR_OPERATION_FAILED,
> + _("Failed to write save file header"));
> + goto cleanup;
> + }
> +
> + if (safewrite(fd, xml, xml_len) != xml_len) {
> + libxlError(VIR_ERR_OPERATION_FAILED,
> + _("Failed to write xml description"));
> + goto cleanup;
> + }
> +
> + if (libxl_domain_suspend(&priv->ctx, NULL, dom->id, fd) != 0) {
> + libxlError(VIR_ERR_INTERNAL_ERROR,
> + _("Failed to save domain '%d' with libxenlight"),
> + dom->id);
> + goto cleanup;
> + }
> +
> + event = virDomainEventNewFromObj(vm, VIR_DOMAIN_EVENT_STOPPED,
> + VIR_DOMAIN_EVENT_STOPPED_SAVED);
> +
> + if (libxlVmReap(driver, vm, 1, VIR_DOMAIN_SHUTOFF_SAVED) != 0) {
> + libxlError(VIR_ERR_INTERNAL_ERROR,
> + _("Failed to destroy domain '%d'"), dom->id);
> + goto cleanup;
> + }
> +
> + if (!vm->persistent) {
> + virDomainRemoveInactive(&driver->domains, vm);
> + vm = NULL;
> + }
> +
> + ret = 0;
> +
> +cleanup:
> + VIR_FREE(xml);
> + if (VIR_CLOSE(fd) < 0)
> + virReportSystemError(errno, "%s", _("cannot close file"));
> + if (vm)
> + virDomainObjUnlock(vm);
> + if (event)
> + libxlDomainEventQueue(driver, event);
> + libxlDriverUnlock(driver);
> + return ret;
> +}
> +
> +static int
> +libxlDomainRestore(virConnectPtr conn, const char *from)
> +{
> + libxlDriverPrivatePtr driver = conn->privateData;
> + virDomainDefPtr def = NULL;
> + virDomainObjPtr vm = NULL;
> + libxlSavefileHeader hdr;
> + char *xml = NULL;
> + int fd;
> + int ret = -1;
> +
> + libxlDriverLock(driver);
> +
> + if ((fd = virFileOpenAs(from, O_RDONLY, 0, getuid(), getgid(), 0)) < 0) {
> + libxlError(VIR_ERR_OPERATION_FAILED,
> + "%s", _("cannot read domain image"));
> + goto cleanup;
> + }
> +
> + if (saferead(fd, &hdr, sizeof(hdr)) != sizeof(hdr)) {
> + libxlError(VIR_ERR_OPERATION_FAILED,
> + "%s", _("failed to read libxl header"));
> + goto cleanup;
> + }
> +
> + if (memcmp(hdr.magic, LIBXL_SAVE_MAGIC, sizeof(hdr.magic))) {
> + libxlError(VIR_ERR_INVALID_ARG, "%s", _("image magic is incorrect"));
> + goto cleanup;
> + }
> +
> + if (hdr.version > LIBXL_SAVE_VERSION) {
> + libxlError(VIR_ERR_OPERATION_FAILED,
> + _("image version is not supported (%d > %d)"),
> + hdr.version, LIBXL_SAVE_VERSION);
> + goto cleanup;
> + }
> +
> + if (hdr.xmlLen <= 0) {
> + libxlError(VIR_ERR_OPERATION_FAILED,
> + _("invalid XML length: %d"), hdr.xmlLen);
> + goto cleanup;
> + }
> +
> + if (VIR_ALLOC_N(xml, hdr.xmlLen) < 0) {
> + virReportOOMError();
> + goto cleanup;
> + }
> +
> + if (saferead(fd, xml, hdr.xmlLen) != hdr.xmlLen) {
> + libxlError(VIR_ERR_OPERATION_FAILED, "%s", _("failed to read XML"));
> + goto cleanup;
> + }
> +
> + if (!(def = virDomainDefParseString(driver->caps, xml,
> + VIR_DOMAIN_XML_INACTIVE)))
> + goto cleanup;
> +
> + if (virDomainObjIsDuplicate(&driver->domains, def, 1) < 0)
> + goto cleanup;
> +
> + if (!(vm = virDomainAssignDef(driver->caps, &driver->domains, def, true)))
> + goto cleanup;
> +
> + def = NULL;
> +
> + if ((ret = libxlVmStart(driver, vm, false, fd)) < 0 &&
> + !vm->persistent) {
> + virDomainRemoveInactive(&driver->domains, vm);
> + vm = NULL;
> + }
> +
> +cleanup:
> + VIR_FREE(xml);
> + virDomainDefFree(def);
> + if (VIR_CLOSE(fd) < 0)
> + virReportSystemError(errno, "%s", _("cannot close file"));
> + if (vm)
> + virDomainObjUnlock(vm);
> + libxlDriverUnlock(driver);
> + return ret;
> +}
> +
> +static int
> libxlDomainCoreDump(virDomainPtr dom, const char *to, int flags)
> {
> libxlDriverPrivatePtr driver = dom->conn->privateData;
> @@ -2197,7 +2394,7 @@ libxlDomainCreateWithFlags(virDomainPtr dom,
> goto cleanup;
> }
>
> - ret = libxlVmStart(driver, vm, (flags & VIR_DOMAIN_START_PAUSED) != 0);
> + ret = libxlVmStart(driver, vm, (flags & VIR_DOMAIN_START_PAUSED) != 0, -1);
>
> cleanup:
> if (vm)
> @@ -3359,6 +3556,8 @@ static virDriver libxlDriver = {
> .domainSetMemoryFlags = libxlDomainSetMemoryFlags, /* 0.9.0 */
> .domainGetInfo = libxlDomainGetInfo, /* 0.9.0 */
> .domainGetState = libxlDomainGetState, /* 0.9.2 */
> + .domainSave = libxlDomainSave, /* 0.9.2 */
> + .domainRestore = libxlDomainRestore, /* 0.9.2 */
> .domainCoreDump = libxlDomainCoreDump, /* 0.9.2 */
> .domainSetVcpus = libxlDomainSetVcpus, /* 0.9.0 */
> .domainSetVcpusFlags = libxlDomainSetVcpusFlags, /* 0.9.0 */
> --
> 1.7.5.2
ACK,
Daniel
--
Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
daniel at veillard.com | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library http://libvirt.org/
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