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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 3/5] libxl: domain restore: reshuffle, preparing for ao
We are going to arrange that libxl, instead of calling
xc_domain_restore, calls a stub function which forks and execs a
helper program, so that restore can be asynchronous rather than
blocking the whole toolstack.
This stub function will be called libxl__xc_domain_restore.
However, its prospective call site is unsuitable for a function which
needs to make a callback, and is buried in two nested single-call-site
functions which are logically part of the domain creation procedure.
So we first abolish those single-call-site functions, integrate their
contents into domain creation in their proper temporal order, and
break out libxl__xc_domain_restore ready for its reimplementation.
No functional change - just the following reorganisation:
* Abolish libxl__domain_restore_common, as it had only one caller.
Move its contents into (what was) domain_restore.
* There is a new stage function domcreate_rebuild_done containing what
used to be the bulk of domcreate_bootloader_done, since
domcreate_bootloader_done now simply starts the restore (or does the
rebuild) and arranges to call the next stage.
* Move the contents of domain_restore into its correct place in the
domain creation sequence. We put it inside
domcreate_bootloader_done, which now either calls
libxl__xc_domain_restore which will call the new function
domcreate_rebuild_done.
* Various general-purpose local variables (`i' etc.) and convenience
alias variables need to be shuffled about accordingly.
* Consequently libxl__toolstack_restore needs to gain external linkage
as it is now in a different file to its user.
In general the moved code remains almost identical. Two returns in
what used to be libxl__domain_restore_common have been changed to set
the return value and "goto out", and the call sites for the abolished
and new functions have been adjusted.
Signed-off-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
---
tools/libxl/Makefile | 1 +
tools/libxl/libxl_create.c | 245 ++++++++++++++++++++++++--------------
tools/libxl/libxl_dom.c | 45 +-------
tools/libxl/libxl_internal.h | 19 +++-
tools/libxl/libxl_save_callout.c | 43 +++++++
5 files changed, 213 insertions(+), 140 deletions(-)
create mode 100644 tools/libxl/libxl_save_callout.c
diff --git a/tools/libxl/Makefile b/tools/libxl/Makefile
index 5d9227e..9b84421 100644
--- a/tools/libxl/Makefile
+++ b/tools/libxl/Makefile
@@ -66,6 +66,7 @@ LIBXL_OBJS = flexarray.o libxl.o libxl_create.o libxl_dm.o
libxl_pci.o \
libxl_dom.o libxl_exec.o libxl_xshelp.o libxl_device.o \
libxl_internal.o libxl_utils.o libxl_uuid.o \
libxl_json.o libxl_aoutils.o \
+ libxl_save_callout.o \
libxl_qmp.o libxl_event.o libxl_fork.o $(LIBXL_OBJS-y)
LIBXL_OBJS += _libxl_types.o libxl_flask.o _libxl_types_internal.o
diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
index 14721eb..7f42737 100644
--- a/tools/libxl/libxl_create.c
+++ b/tools/libxl/libxl_create.c
@@ -20,7 +20,6 @@
#include "libxl_internal.h"
#include <xc_dom.h>
-#include <xenguest.h>
void libxl_domain_config_init(libxl_domain_config *d_config)
{
@@ -311,89 +310,6 @@ out:
return ret;
}
-static int domain_restore(libxl__gc *gc, libxl_domain_build_info *info,
- uint32_t domid, int fd,
- libxl__domain_build_state *state)
-{
- libxl_ctx *ctx = libxl__gc_owner(gc);
- char **vments = NULL, **localents = NULL;
- struct timeval start_time;
- int i, ret, esave, flags;
-
- ret = libxl__build_pre(gc, domid, info, state);
- if (ret)
- goto out;
-
- ret = libxl__domain_restore_common(gc, domid, info, state, fd);
- if (ret)
- goto out;
-
- gettimeofday(&start_time, NULL);
-
- switch (info->type) {
- case LIBXL_DOMAIN_TYPE_HVM:
- vments = libxl__calloc(gc, 7, sizeof(char *));
- vments[0] = "rtc/timeoffset";
- vments[1] = (info->u.hvm.timeoffset) ? info->u.hvm.timeoffset : "";
- vments[2] = "image/ostype";
- vments[3] = "hvm";
- vments[4] = "start_time";
- vments[5] = libxl__sprintf(gc, "%lu.%02d",
start_time.tv_sec,(int)start_time.tv_usec/10000);
- break;
- case LIBXL_DOMAIN_TYPE_PV:
- vments = libxl__calloc(gc, 11, sizeof(char *));
- i = 0;
- vments[i++] = "image/ostype";
- vments[i++] = "linux";
- vments[i++] = "image/kernel";
- vments[i++] = (char*) info->u.pv.kernel.path;
- vments[i++] = "start_time";
- vments[i++] = libxl__sprintf(gc, "%lu.%02d",
start_time.tv_sec,(int)start_time.tv_usec/10000);
- if (info->u.pv.ramdisk.path) {
- vments[i++] = "image/ramdisk";
- vments[i++] = (char*) info->u.pv.ramdisk.path;
- }
- if (info->u.pv.cmdline) {
- vments[i++] = "image/cmdline";
- vments[i++] = (char*) info->u.pv.cmdline;
- }
- break;
- default:
- ret = ERROR_INVAL;
- goto out;
- }
- ret = libxl__build_post(gc, domid, info, state, vments, localents);
- if (ret)
- goto out;
-
- if (info->type == LIBXL_DOMAIN_TYPE_HVM) {
- ret = asprintf(&state->saved_state,
- XC_DEVICE_MODEL_RESTORE_FILE".%d", domid);
- ret = (ret < 0) ? ERROR_FAIL : 0;
- }
-
-out:
- if (info->type == LIBXL_DOMAIN_TYPE_PV) {
- libxl__file_reference_unmap(&info->u.pv.kernel);
- libxl__file_reference_unmap(&info->u.pv.ramdisk);
- }
-
- esave = errno;
-
- flags = fcntl(fd, F_GETFL);
- if (flags == -1) {
- LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "unable to get flags on
restore fd");
- } else {
- flags &= ~O_NONBLOCK;
- if (fcntl(fd, F_SETFL, flags) == -1)
- LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "unable to put restore fd"
- " back to blocking mode");
- }
-
- errno = esave;
- return ret;
-}
-
int libxl__domain_make(libxl__gc *gc, libxl_domain_create_info *info,
uint32_t *domid)
{
@@ -574,10 +490,13 @@ static void
domcreate_bootloader_console_available(libxl__egc *egc,
static void domcreate_bootloader_done(libxl__egc *egc,
libxl__bootloader_state *bl,
int rc);
-
static void domcreate_console_available(libxl__egc *egc,
libxl__domain_create_state *dcs);
+static void domcreate_rebuild_done(libxl__egc *egc,
+ libxl__domain_create_state *dcs,
+ int ret);
+
/* Our own function to clean up and call the user's callback.
* The final call in the sequence. */
static void domcreate_complete(libxl__egc *egc,
@@ -660,20 +579,19 @@ static void domcreate_console_available(libxl__egc *egc,
static void domcreate_bootloader_done(libxl__egc *egc,
libxl__bootloader_state *bl,
- int ret)
+ int rc)
{
libxl__domain_create_state *dcs = CONTAINER_OF(bl, *dcs, bl);
STATE_AO_GC(bl->ao);
- int i;
/* convenience aliases */
const uint32_t domid = dcs->guest_domid;
libxl_domain_config *const d_config = dcs->guest_config;
+ libxl_domain_build_info *const info = &d_config->b_info;
const int restore_fd = dcs->restore_fd;
libxl__domain_build_state *const state = &dcs->build_state;
- libxl_ctx *const ctx = CTX;
- if (ret) goto error_out;
+ if (rc) domcreate_rebuild_done(egc, dcs, rc);
/* We might be going to call libxl__spawn_local_dm, or _spawn_stub_dm.
* Fill in any field required by either, including both relevant
@@ -684,12 +602,155 @@ static void domcreate_bootloader_done(libxl__egc *egc,
dcs->dmss.dm.callback = domcreate_devmodel_started;
dcs->dmss.callback = domcreate_devmodel_started;
- if ( restore_fd >= 0 ) {
- ret = domain_restore(gc, &d_config->b_info, domid, restore_fd, state);
+ if ( restore_fd < 0 ) {
+ rc = libxl__domain_build(gc, &d_config->b_info, domid, state);
+ domcreate_rebuild_done(egc, dcs, rc);
+ return;
+ }
+
+ /* Restore */
+
+ rc = libxl__build_pre(gc, domid, info, state);
+ if (rc)
+ goto out;
+
+ /* read signature */
+ int hvm, pae, superpages;
+ int no_incr_generationid;
+ xc_toolstack_restore_cb *toolstack_restore = NULL;
+ switch (info->type) {
+ case LIBXL_DOMAIN_TYPE_HVM:
+ hvm = 1;
+ superpages = 1;
+ pae = libxl_defbool_val(info->u.hvm.pae);
+ no_incr_generationid =
!libxl_defbool_val(info->u.hvm.incr_generationid);
+ toolstack_restore = libxl__toolstack_restore;
+ break;
+ case LIBXL_DOMAIN_TYPE_PV:
+ hvm = 0;
+ superpages = 0;
+ pae = 1;
+ no_incr_generationid = 0;
+ break;
+ default:
+ rc = ERROR_INVAL;
+ goto out;
+ }
+ libxl__xc_domain_restore(egc, dcs,
+ hvm, pae, superpages, no_incr_generationid,
+ toolstack_restore);
+ return;
+
+ out:
+ libxl__xc_domain_restore_done(egc, dcs, rc, 0, 0);
+}
+
+void libxl__xc_domain_restore_done(libxl__egc *egc,
+ libxl__domain_create_state *dcs,
+ int ret, int retval, int errnoval)
+{
+ STATE_AO_GC(dcs->ao);
+ libxl_ctx *ctx = libxl__gc_owner(gc);
+ char **vments = NULL, **localents = NULL;
+ struct timeval start_time;
+ int i, esave, flags;
+
+ /* convenience aliases */
+ const uint32_t domid = dcs->guest_domid;
+ libxl_domain_config *const d_config = dcs->guest_config;
+ libxl_domain_build_info *const info = &d_config->b_info;
+ libxl__domain_build_state *const state = &dcs->build_state;
+ const int restore_fd = dcs->restore_fd;
+
+ if (ret)
+ goto out;
+
+ if (retval) {
+ LOGEV(ERROR, errnoval, "restoring domain");
+ ret = ERROR_FAIL;
+ goto out;
+ }
+
+ gettimeofday(&start_time, NULL);
+
+ switch (info->type) {
+ case LIBXL_DOMAIN_TYPE_HVM:
+ vments = libxl__calloc(gc, 7, sizeof(char *));
+ vments[0] = "rtc/timeoffset";
+ vments[1] = (info->u.hvm.timeoffset) ? info->u.hvm.timeoffset : "";
+ vments[2] = "image/ostype";
+ vments[3] = "hvm";
+ vments[4] = "start_time";
+ vments[5] = libxl__sprintf(gc, "%lu.%02d",
start_time.tv_sec,(int)start_time.tv_usec/10000);
+ break;
+ case LIBXL_DOMAIN_TYPE_PV:
+ vments = libxl__calloc(gc, 11, sizeof(char *));
+ i = 0;
+ vments[i++] = "image/ostype";
+ vments[i++] = "linux";
+ vments[i++] = "image/kernel";
+ vments[i++] = (char*) info->u.pv.kernel.path;
+ vments[i++] = "start_time";
+ vments[i++] = libxl__sprintf(gc, "%lu.%02d",
start_time.tv_sec,(int)start_time.tv_usec/10000);
+ if (info->u.pv.ramdisk.path) {
+ vments[i++] = "image/ramdisk";
+ vments[i++] = (char*) info->u.pv.ramdisk.path;
+ }
+ if (info->u.pv.cmdline) {
+ vments[i++] = "image/cmdline";
+ vments[i++] = (char*) info->u.pv.cmdline;
+ }
+ break;
+ default:
+ ret = ERROR_INVAL;
+ goto out;
+ }
+ ret = libxl__build_post(gc, domid, info, state, vments, localents);
+ if (ret)
+ goto out;
+
+ if (info->type == LIBXL_DOMAIN_TYPE_HVM) {
+ ret = asprintf(&state->saved_state,
+ XC_DEVICE_MODEL_RESTORE_FILE".%d", domid);
+ ret = (ret < 0) ? ERROR_FAIL : 0;
+ }
+
+out:
+ if (info->type == LIBXL_DOMAIN_TYPE_PV) {
+ libxl__file_reference_unmap(&info->u.pv.kernel);
+ libxl__file_reference_unmap(&info->u.pv.ramdisk);
+ }
+
+ esave = errno;
+
+ flags = fcntl(restore_fd, F_GETFL);
+ if (flags == -1) {
+ LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "unable to get flags on
restore fd");
} else {
- ret = libxl__domain_build(gc, &d_config->b_info, domid, state);
+ flags &= ~O_NONBLOCK;
+ if (fcntl(restore_fd, F_SETFL, flags) == -1)
+ LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "unable to put restore fd"
+ " back to blocking mode");
}
+ errno = esave;
+
+ domcreate_rebuild_done(egc, dcs, ret);
+}
+
+static void domcreate_rebuild_done(libxl__egc *egc,
+ libxl__domain_create_state *dcs,
+ int ret)
+{
+ STATE_AO_GC(dcs->ao);
+ int i;
+
+ /* convenience aliases */
+ const uint32_t domid = dcs->guest_domid;
+ libxl_domain_config *const d_config = dcs->guest_config;
+ libxl__domain_build_state *const state = &dcs->build_state;
+ libxl_ctx *const ctx = CTX;
+
if (ret) {
LIBXL__LOG(ctx, LIBXL__LOG_ERROR, "cannot (re-)build domain: %d", ret);
ret = ERROR_FAIL;
diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
index 0dc1427..d29c705 100644
--- a/tools/libxl/libxl_dom.c
+++ b/tools/libxl/libxl_dom.c
@@ -19,7 +19,6 @@
#include <xenctrl.h>
#include <xc_dom.h>
-#include <xenguest.h>
#include <xen/hvm/hvm_info_table.h>
@@ -461,7 +460,7 @@ static inline char *restore_helper(libxl__gc *gc, uint32_t
domid,
domid, phys_offset, node);
}
-static int libxl__toolstack_restore(uint32_t domid, const uint8_t *buf,
+int libxl__toolstack_restore(uint32_t domid, const uint8_t *buf,
uint32_t size, void *data)
{
libxl__gc *gc = data;
@@ -516,48 +515,6 @@ static int libxl__toolstack_restore(uint32_t domid, const
uint8_t *buf,
return 0;
}
-int libxl__domain_restore_common(libxl__gc *gc, uint32_t domid,
- libxl_domain_build_info *info,
- libxl__domain_build_state *state,
- int fd)
-{
- libxl_ctx *ctx = libxl__gc_owner(gc);
- /* read signature */
- int rc;
- int hvm, pae, superpages;
- struct restore_callbacks callbacks;
- int no_incr_generationid;
- switch (info->type) {
- case LIBXL_DOMAIN_TYPE_HVM:
- hvm = 1;
- superpages = 1;
- pae = libxl_defbool_val(info->u.hvm.pae);
- no_incr_generationid =
!libxl_defbool_val(info->u.hvm.incr_generationid);
- callbacks.toolstack_restore = libxl__toolstack_restore;
- callbacks.data = gc;
- break;
- case LIBXL_DOMAIN_TYPE_PV:
- hvm = 0;
- superpages = 0;
- pae = 1;
- no_incr_generationid = 0;
- break;
- default:
- return ERROR_INVAL;
- }
- rc = xc_domain_restore(ctx->xch, fd, domid,
- state->store_port, &state->store_mfn,
- state->store_domid, state->console_port,
- &state->console_mfn, state->console_domid,
- hvm, pae, superpages, no_incr_generationid,
- &state->vm_generationid_addr, &callbacks);
- if ( rc ) {
- LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "restoring domain");
- return ERROR_FAIL;
- }
- return 0;
-}
-
static int libxl__domain_suspend_common_switch_qemu_logdirty
(int domid, unsigned int enable, void *data)
{
diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
index b9afeb8..fa70a00 100644
--- a/tools/libxl/libxl_internal.h
+++ b/tools/libxl/libxl_internal.h
@@ -46,6 +46,7 @@
#include <xenstore.h>
#include <xenctrl.h>
+#include <xenguest.h>
#include "xentoollog.h"
@@ -751,10 +752,8 @@ _hidden int libxl__domain_rename(libxl__gc *gc, uint32_t
domid,
const char *old_name, const char *new_name,
xs_transaction_t trans);
-_hidden int libxl__domain_restore_common(libxl__gc *gc, uint32_t domid,
- libxl_domain_build_info *info,
- libxl__domain_build_state *state,
- int fd);
+_hidden int libxl__toolstack_restore(uint32_t domid, const uint8_t *buf,
+ uint32_t size, void *data);
_hidden const char *libxl__device_model_savefile(libxl__gc *gc, uint32_t
domid);
_hidden int libxl__domain_save_device_model(libxl__gc *gc, uint32_t domid, int
fd);
_hidden void libxl__userdata_destroyall(libxl__gc *gc, uint32_t domid);
@@ -1821,6 +1820,18 @@ _hidden int libxl__domain_suspend_common(libxl__gc *gc,
uint32_t domid, int fd,
libxl_domain_type type,
int live, int debug);
+/* calls libxl__xc_domain_restore_done when done */
+_hidden void libxl__xc_domain_restore(libxl__egc *egc,
+ libxl__domain_create_state *dcs,
+ int hvm, int pae, int superpages,
+ int no_incr_generationid,
+ xc_toolstack_restore_cb*);
+/* If rc==0 then retval is the return value from xc_domain_save
+ * and errnoval is the errno value it provided.
+ * If rc!=0, retval and errnoval are undefined. */
+_hidden void libxl__xc_domain_restore_done(libxl__egc *egc,
+ libxl__domain_create_state *dcs,
+ int rc, int retval, int errnoval);
/*
diff --git a/tools/libxl/libxl_save_callout.c b/tools/libxl/libxl_save_callout.c
new file mode 100644
index 0000000..bad4e30
--- /dev/null
+++ b/tools/libxl/libxl_save_callout.c
@@ -0,0 +1,43 @@
+/*
+ * Copyright (C) 2012 Citrix Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; version 2.1 only. with the special
+ * exception on linking described in file LICENSE.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ */
+
+#include "libxl_osdeps.h"
+
+#include "libxl_internal.h"
+
+void libxl__xc_domain_restore(libxl__egc *egc, libxl__domain_create_state *dcs,
+ int hvm, int pae, int superpages,
+ int no_incr_generationid,
+ xc_toolstack_restore_cb *toolstack_restore)
+/* calls libxl__xc_domain_restore_done when done */
+{
+ STATE_AO_GC(dcs->ao);
+
+ /* Convenience aliases */
+ const uint32_t domid = dcs->guest_domid;
+ const int restore_fd = dcs->restore_fd;
+ libxl__domain_build_state *const state = &dcs->build_state;
+
+ struct restore_callbacks callbacks;
+ callbacks.toolstack_restore = toolstack_restore;
+ callbacks.data = gc;
+
+ int r = xc_domain_restore(CTX->xch, restore_fd, domid,
+ state->store_port, &state->store_mfn,
+ state->store_domid, state->console_port,
+ &state->console_mfn, state->console_domid,
+ hvm, pae, superpages, no_incr_generationid,
+ &state->vm_generationid_addr, &callbacks);
+ libxl__xc_domain_restore_done(egc, dcs, 0, r, errno);
+}
--
1.7.2.5
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