Am Montag 23 Mai 2011 04:30:12 schrieb Jim Fehlig:
> Jim Fehlig wrote:
> > Markus Groà wrote:
> >
> >> This patch adds save/restore functionality to the libxl driver.
> >>
> >> It is a v2 of this patch:
> >> https://www.redhat.com/archives/libvir-list/2011-April/msg00338.html
> >>
> >> 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
> >>
> >>
> >
> > Hi Markus,
> >
> > Finally found time to try your patch. Thanks for the patience :-).
> >
> >
> >> However I ran into a reproducible segfault.
> >> Assume you saved a vm with:
> >> # virsh save domU foo.img
> >>
> >>
> >
> > I think the problem actually lies in the save function. The domain does
> > not appear to be cleaned up properly. From xl's perspective after virsh
> > save domU foo.img
> >
> > xen33: # xl list
> > Name ID Mem VCPUs State
> > Time(s)
> > Domain-0 0 2023 8
> > r----- 330.0
> > (null) 11 1
> > 2 --pssd 27.1
> >
> > The orphaned domain disappears after libvirtd restart.
>
> I manged to track down this problem, patch posted to xen-devel
>
> http://lists.xensource.com/archives/html/xen-devel/2011-05/msg01314.html
>
Great! I attached the current version of the save/restore patch.
It is rebased against the current master.
>
> >
> >> If you restore the save image,
> >> destroy the vm and restore it again, a segfault occurs:
> >> # virsh restore foo.img
> >> # virsh destroy domU
> >> # virsh restore foo.img
> >> # segfault
> >>
>
> But I still see the segfault, in addition to domain not booting and
> consuming 100% cpu on first restore :-(. I'll look at these issues next.
>
> Regards,
> Jim
>
>
diff --git a/src/libxl/libxl_conf.h b/src/libxl/libxl_conf.h
index 65110cf..e75e418 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@xxxxxxxxxx>
+ * Markus Groà <gross@xxxxxxxxxxxxx>
*/
/*---------------------------------------------------------------------------*/
@@ -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 b2cc0e8..9bc71fd 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,
@@ -369,7 +369,7 @@ 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);
@@ -535,8 +535,8 @@ 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;
@@ -559,12 +559,23 @@ 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;
}
@@ -597,7 +608,9 @@ 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);
@@ -1075,7 +1088,8 @@ 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;
@@ -1627,6 +1641,184 @@ libxlDomainGetState(virDomainPtr dom,
}
static int
+libxlDomainSave(virDomainPtr dom, const char *to)
+{
+ libxlDriverPrivatePtr driver = dom->conn->privateData;
+ virDomainObjPtr vm;
+ libxlDomainObjPrivatePtr priv;
+ virDomainEventPtr event = NULL;
+ libxlSavefileHeader hdr;
+ char *xml;
+ 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) {
+
+ 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
libxlDomainSetVcpusFlags(virDomainPtr dom, unsigned int nvcpus,
unsigned int flags)
{
@@ -2096,7 +2288,7 @@ 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)
@@ -2722,6 +2914,8 @@ 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 */
.domainSetVcpus = libxlDomainSetVcpus, /* 0.9.0 */
.domainSetVcpusFlags = libxlDomainSetVcpusFlags, /* 0.9.0 */
.domainGetVcpusFlags = libxlDomainGetVcpusFlags, /* 0.9.0 */
--
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