>Eric Blake <eblake@xxxxxxxxxx> wrote on 30/04/2010 18:26:04:
> From: Eric Blake <eblake@xxxxxxxxxx>
> To: Cole Robinson <crobinso@xxxxxxxxxx>
> Cc: Kenneth Nagin/Haifa/IBM@IBMIL, list libvirt <libvir-list@xxxxxxxxxx>
> Date: 30/04/2010 18:26
> Subject: Re: [libvirt] (Resend) Live Migration with non-shared storage
for kvm
>
> On 04/30/2010 06:42 AM, Cole Robinson wrote:
> > Other than that, the code generally looks like (except for the compiler
and
> > syntax-check warnings).
> >
> > - Cole
> >
> > (Here's the patch inline for the benefit of other reviewers)
>
> In addition to Cole's comments, here's some style nits that 'make
> syntax-check' won't pick up on...
>
> >> +++ b/src/qemu/qemu_driver.c
> >> @@ -4871,7 +4871,7 @@ static int qemudDomainSaveFlag(virDomainPtr
> dom, const char *path,
> >> if (header.compressed == QEMUD_SAVE_FORMAT_RAW) {
> >> const char *args[] = { "cat", NULL };
> >> qemuDomainObjEnterMonitorWithDriver(driver, vm);
> >> - rc = qemuMonitorMigrateToCommand(priv->mon, 1, args, path);
> >> + rc = qemuMonitorMigrateToCommand(priv->mon,
> QEMU_MONITOR_MIGRATE_BACKGROUND, args, path);
>
> Where possible, wrap lines to fit 80 columns. For example,
>
> rc = qemuMonitorMigrateToCommand(priv->mon,
> QEMU_MONITOR_MIGRATE_BACKGROUND,
> args, path);
>
> >> - unsigned long flags ATTRIBUTE_UNUSED,
> >> + unsigned long flags ,
>
> s/flags ,/flags,/
>
> >> const char *dname ATTRIBUTE_UNUSED,
> >> unsigned long resource)
> >> {
> >> int ret = -1;
> >> xmlURIPtr uribits = NULL;
> >> qemuDomainObjPrivatePtr priv = vm->privateData;
> >> + int background_flags = 0;
>
> Flags should generally be 'unsigned int', to make it less likely to
> cause problems with inadvertent sign extension if we ever reach 32 flags.
>
> >>
> >> /* Issue the migrate command. */
> >> if (STRPREFIX(uri, "tcp:") && !STRPREFIX(uri, "tcp://")) {
> >> @@ -9684,7 +9685,13 @@ static int doNativeMigrate(struct
> qemud_driver *driver,
> >> goto cleanup;
> >> }
> >>
> >> - if (qemuMonitorMigrateToHost(priv->mon, 1, uribits->server,
> uribits->port) < 0) {
> >> + if (flags & VIR_MIGRATE_NON_SHARED_DISK)
> >> + background_flags |= QEMU_MONITOR_MIGRATE_NON_SHARED_DISK;
>
> That TAB will be caught by 'make syntax-check'.
>
> >> +++ b/src/qemu/qemu_monitor_text.c
> >> @@ -1132,18 +1132,19 @@ static int qemuMonitorTextMigrate
> (qemuMonitorPtr mon,
> >> char *info = NULL;
> >> int ret = -1;
> >> char *safedest = qemuMonitorEscapeArg(dest);
> >> - const char *extra;
> >> + //const char *extra;
>
> No point leaving a dead comment; version-control is there to let us see
> what extra was declared as before your patch changed it to:
>
> >> + const char extra[25] = " ";
>
> Why 25? That seems like a magic number, and it wastes space compared to
> the maximum amount that you strcat() into it below.
>
> >>
> >> if (!safedest) {
> >> virReportOOMError();
> >> return -1;
> >> }
> >> -
> >> - if (background)
> >> - extra = "-d ";
> >> - else
> >> - extra = " ";
> >> -
> >> + if (background & QEMU_MONITOR_MIGRATE_BACKGROUND)
> >> + strcat(extra," -d");
> >> + if (background & QEMU_MONITOR_MIGRATE_NON_SHARED_DISK)
> >> + strcat(extra," -b");
> >> + if (background & QEMU_MONITOR_MIGRATE_NON_SHARED_INC)
> >> + strcat(extra," -i");
> >> if (virAsprintf(&cmd, "migrate %s\"%s\"", extra, safedest) < 0) {
>
> That combination of strcat() and virAsprintf() looks bad. In general,
> you should avoid strcat() (it often has overflow problems). And since
> there is already allocation going on with virAsprintf, it seems like the
> better way to write this would be to convert both strcat and virAsprintf
> into multiple uses of the virBuffer* API, in order to build a single
> malloc'd string incrementally.
>
> --
> Eric Blake eblake@xxxxxxxxxx +1-801-349-2682
> Libvirt virtualization library http://libvirt.org
>
> [attachment "signature.asc" deleted by Kenneth Nagin/Haifa/IBM]
I implemented the suggested changes by Cole and Eric, namely:
replaced tabs with blanks (Cole)
replace virsh flag names with copy-storage-all and copy-storage-inc
(Cole)
replaced strcat with virBuffer* API (Eric)
replaced char extra[25] with virBuffer declaration (Eric)
replace int background with unsigned int background (Eric)
I did not make changes to JSON (suggested by Cole) because I didn't know
how to verify the fixes.
I did not replace flags with unsigned int in qemuMonitorMigrateToCommand
(suggested by Eric) because these flags are part of the external interface
and past with rpcgen. I worried that the change might create more
problems, and not worth the small benefit in style.
This the fix:
diff --git a/include/libvirt/libvirt.h.in b/include/libvirt/libvirt.h.in
index f296d16..db107cc 100644
--- a/include/libvirt/libvirt.h.in
+++ b/include/libvirt/libvirt.h.in
@@ -411,6 +411,10 @@ typedef enum {
VIR_MIGRATE_PERSIST_DEST = (1 << 3), /* persist the VM on the
destination */
VIR_MIGRATE_UNDEFINE_SOURCE = (1 << 4), /* undefine the VM on the
source */
VIR_MIGRATE_PAUSED = (1 << 5), /* pause on remote side */
+ VIR_MIGRATE_NON_SHARED_DISK = (1 << 6), /* migration with non-shared
storage with full disk copy */
+ VIR_MIGRATE_NON_SHARED_INC = (1 << 7), /* migration with non-shared
storage with incremental copy */
+ /* (same base image shared
between source and destination) */
+
} virDomainMigrateFlags;
/* Domain migration. */
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 08cff00..9a3461d 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -4958,7 +4958,7 @@ static int qemudDomainSaveFlag(virDomainPtr dom,
const char *path,
if (header.compressed == QEMUD_SAVE_FORMAT_RAW) {
const char *args[] = { "cat", NULL };
qemuDomainObjEnterMonitorWithDriver(driver, vm);
- rc = qemuMonitorMigrateToFile(priv->mon, 1, args, path, offset);
+ rc = qemuMonitorMigrateToFile(priv->mon,
QEMU_MONITOR_MIGRATE_BACKGROUND, args, path, offset);
qemuDomainObjExitMonitorWithDriver(driver, vm);
} else {
const char *prog = qemudSaveCompressionTypeToString
(header.compressed);
@@ -4968,7 +4968,7 @@ static int qemudDomainSaveFlag(virDomainPtr dom,
const char *path,
NULL
};
qemuDomainObjEnterMonitorWithDriver(driver, vm);
- rc = qemuMonitorMigrateToFile(priv->mon, 1, args, path, offset);
+ rc = qemuMonitorMigrateToFile(priv->mon,
QEMU_MONITOR_MIGRATE_BACKGROUND, args, path, offset);
qemuDomainObjExitMonitorWithDriver(driver, vm);
}
@@ -5286,9 +5286,8 @@ static int qemudDomainCoreDump(virDomainPtr dom,
}
qemuDomainObjEnterMonitorWithDriver(driver, vm);
- ret = qemuMonitorMigrateToFile(priv->mon, 1, args, path, 0);
+ ret = qemuMonitorMigrateToFile(priv->mon,
QEMU_MONITOR_MIGRATE_BACKGROUND, args, path, 0);
qemuDomainObjExitMonitorWithDriver(driver, vm);
-
if (ret < 0)
goto endjob;
@@ -9885,13 +9884,14 @@ cleanup:
static int doNativeMigrate(struct qemud_driver *driver,
virDomainObjPtr vm,
const char *uri,
- unsigned long flags ATTRIBUTE_UNUSED,
+ unsigned long flags ,
const char *dname ATTRIBUTE_UNUSED,
unsigned long resource)
{
int ret = -1;
xmlURIPtr uribits = NULL;
qemuDomainObjPrivatePtr priv = vm->privateData;
+ unsigned int background_flags = 0;
/* Issue the migrate command. */
if (STRPREFIX(uri, "tcp:") && !STRPREFIX(uri, "tcp://")) {
@@ -9919,7 +9919,13 @@ static int doNativeMigrate(struct qemud_driver
*driver,
goto cleanup;
}
- if (qemuMonitorMigrateToHost(priv->mon, 1, uribits->server, uribits->
port) < 0) {
+ if (flags & VIR_MIGRATE_NON_SHARED_DISK)
+ background_flags |= QEMU_MONITOR_MIGRATE_NON_SHARED_DISK;
+
+ if (flags & VIR_MIGRATE_NON_SHARED_INC)
+ background_flags |= QEMU_MONITOR_MIGRATE_NON_SHARED_INC;
+
+ if (qemuMonitorMigrateToHost(priv->mon, background_flags, uribits->
server, uribits->port) < 0) {
qemuDomainObjExitMonitorWithDriver(driver, vm);
goto cleanup;
}
@@ -10004,7 +10010,7 @@ static int doTunnelMigrate(virDomainPtr dom,
unsigned long long qemuCmdFlags;
int status;
unsigned long long transferred, remaining, total;
-
+ unsigned int background_flags = QEMU_MONITOR_MIGRATE_BACKGROUND;
/*
* The order of operations is important here to avoid touching
* the source VM until we are very sure we can successfully
@@ -10089,11 +10095,16 @@ static int doTunnelMigrate(virDomainPtr dom,
/* 3. start migration on source */
qemuDomainObjEnterMonitorWithDriver(driver, vm);
- if (qemuCmdFlags & QEMUD_CMD_FLAG_MIGRATE_QEMU_UNIX)
- internalret = qemuMonitorMigrateToUnix(priv->mon, 1, unixfile);
+ if (flags & VIR_MIGRATE_NON_SHARED_DISK)
+ background_flags |= QEMU_MONITOR_MIGRATE_NON_SHARED_DISK;
+ if (flags & VIR_MIGRATE_NON_SHARED_INC)
+ background_flags |= QEMU_MONITOR_MIGRATE_NON_SHARED_INC;
+ if (qemuCmdFlags & QEMUD_CMD_FLAG_MIGRATE_QEMU_UNIX){
+ internalret = qemuMonitorMigrateToUnix(priv->mon,
background_flags, unixfile);
+ }
else if (qemuCmdFlags & QEMUD_CMD_FLAG_MIGRATE_QEMU_EXEC) {
const char *args[] = { "nc", "-U", unixfile, NULL };
- internalret = qemuMonitorMigrateToCommand(priv->mon, 1, args);
+ internalret = qemuMonitorMigrateToCommand(priv->mon,
QEMU_MONITOR_MIGRATE_BACKGROUND, args);
} else {
internalret = -1;
}
diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
index fca8590..443d216 100644
--- a/src/qemu/qemu_monitor.c
+++ b/src/qemu/qemu_monitor.c
@@ -1161,7 +1161,7 @@ int qemuMonitorGetMigrationStatus(qemuMonitorPtr mon,
int qemuMonitorMigrateToHost(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char *hostname,
int port)
{
@@ -1178,7 +1178,7 @@ int qemuMonitorMigrateToHost(qemuMonitorPtr mon,
int qemuMonitorMigrateToCommand(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char * const *argv)
{
int ret;
@@ -1193,7 +1193,7 @@ int qemuMonitorMigrateToCommand(qemuMonitorPtr mon,
}
int qemuMonitorMigrateToFile(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char * const *argv,
const char *target,
unsigned long long offset)
@@ -1217,7 +1217,7 @@ int qemuMonitorMigrateToFile(qemuMonitorPtr mon,
}
int qemuMonitorMigrateToUnix(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char *unixfile)
{
int ret;
diff --git a/src/qemu/qemu_monitor.h b/src/qemu/qemu_monitor.h
index 3fa83b7..9760b4c 100644
--- a/src/qemu/qemu_monitor.h
+++ b/src/qemu/qemu_monitor.h
@@ -241,25 +241,32 @@ int qemuMonitorGetMigrationStatus(qemuMonitorPtr mon,
unsigned long long *remaining,
unsigned long long *total);
+typedef enum {
+ QEMU_MONITOR_MIGRATE_BACKGROUND = 1 << 0,
+ QEMU_MONITOR_MIGRATE_NON_SHARED_DISK = 1 << 1, /* migration with
non-shared storage with full disk copy */
+ QEMU_MONITOR_MIGRATE_NON_SHARED_INC = 1 << 2, /* migration with
non-shared storage with incremental copy */
+ QEMU_MONITOR_MIGRATION_FLAGS_LAST
+} QEMU_MONITOR_MIGRATE;
+
int qemuMonitorMigrateToHost(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char *hostname,
int port);
int qemuMonitorMigrateToCommand(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char * const *argv);
# define QEMU_MONITOR_MIGRATE_TO_FILE_BS 512llu
int qemuMonitorMigrateToFile(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char * const *argv,
const char *target,
unsigned long long offset);
int qemuMonitorMigrateToUnix(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char *unixfile);
int qemuMonitorMigrateCancel(qemuMonitorPtr mon);
diff --git a/src/qemu/qemu_monitor_text.c b/src/qemu/qemu_monitor_text.c
index 3f917bf..ff79663 100644
--- a/src/qemu/qemu_monitor_text.c
+++ b/src/qemu/qemu_monitor_text.c
@@ -38,6 +38,7 @@
#include "driver.h"
#include "datatypes.h"
#include "virterror_internal.h"
+#include "buf.h"
#define VIR_FROM_THIS VIR_FROM_QEMU
@@ -1125,26 +1126,32 @@ cleanup:
static int qemuMonitorTextMigrate(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char *dest)
{
char *cmd = NULL;
char *info = NULL;
int ret = -1;
char *safedest = qemuMonitorEscapeArg(dest);
- const char *extra;
+ virBuffer extra = VIR_BUFFER_INITIALIZER;
if (!safedest) {
virReportOOMError();
return -1;
}
-
- if (background)
- extra = "-d ";
- else
- extra = " ";
-
- if (virAsprintf(&cmd, "migrate %s\"%s\"", extra, safedest) < 0) {
+ virBufferAddLit(&extra, " ");
+ if (background & QEMU_MONITOR_MIGRATE_BACKGROUND)
+ virBufferAddLit(&extra, " -d");
+ if (background & QEMU_MONITOR_MIGRATE_NON_SHARED_DISK)
+ virBufferAddLit(&extra, " -b");
+ if (background & QEMU_MONITOR_MIGRATE_NON_SHARED_INC)
+ virBufferAddLit(&extra, " -i");
+ if (virBufferError(&extra)) {
+ virBufferFreeAndReset(&extra);
+ virReportOOMError();
+ return -1;
+ }
+ if (virAsprintf(&cmd, "migrate %s\"%s\"", virBufferContentAndReset
(&extra), safedest) < 0) {
virReportOOMError();
goto cleanup;
}
@@ -1180,7 +1187,7 @@ cleanup:
}
int qemuMonitorTextMigrateToHost(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char *hostname,
int port)
{
@@ -1201,7 +1208,7 @@ int qemuMonitorTextMigrateToHost(qemuMonitorPtr mon,
int qemuMonitorTextMigrateToCommand(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char * const *argv)
{
char *argstr;
@@ -1228,7 +1235,7 @@ cleanup:
}
int qemuMonitorTextMigrateToFile(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char * const *argv,
const char *target,
unsigned long long offset)
@@ -1269,7 +1276,7 @@ cleanup:
}
int qemuMonitorTextMigrateToUnix(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char *unixfile)
{
char *dest = NULL;
diff --git a/src/qemu/qemu_monitor_text.h b/src/qemu/qemu_monitor_text.h
index 23c3a45..7d1bc56 100644
--- a/src/qemu/qemu_monitor_text.h
+++ b/src/qemu/qemu_monitor_text.h
@@ -93,22 +93,22 @@ int qemuMonitorTextGetMigrationStatus(qemuMonitorPtr
mon,
unsigned long long *total);
int qemuMonitorTextMigrateToHost(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char *hostname,
int port);
int qemuMonitorTextMigrateToCommand(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char * const *argv);
int qemuMonitorTextMigrateToFile(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char * const *argv,
const char *target,
unsigned long long offset);
int qemuMonitorTextMigrateToUnix(qemuMonitorPtr mon,
- int background,
+ unsigned int background,
const char *unixfile);
int qemuMonitorTextMigrateCancel(qemuMonitorPtr mon);
diff --git a/tools/virsh.c b/tools/virsh.c
index eb11a78..f96d31a 100644
--- a/tools/virsh.c
+++ b/tools/virsh.c
@@ -2851,6 +2851,8 @@ static const vshCmdOptDef opts_migrate[] = {
{"persistent", VSH_OT_BOOL, 0, N_("persist VM on destination")},
{"undefinesource", VSH_OT_BOOL, 0, N_("undefine VM on source")},
{"suspend", VSH_OT_BOOL, 0, N_("do not restart the domain on the
destination host")},
+ {"copy-storage-all", VSH_OT_BOOL, 0, N_("migration with non-shared
storage with full disk copy")},
+ {"copy-storage-inc", VSH_OT_BOOL, 0, N_("migration with non-shared
storage with incremental copy (same base image shared between source and
destination)")},
{"domain", VSH_OT_DATA, VSH_OFLAG_REQ, N_("domain name, id or uuid")},
{"desturi", VSH_OT_DATA, VSH_OFLAG_REQ, N_("connection URI of the
destination host")},
{"migrateuri", VSH_OT_DATA, 0, N_("migration URI, usually can be
omitted")},
@@ -2898,6 +2900,12 @@ cmdMigrate (vshControl *ctl, const vshCmd *cmd)
if (vshCommandOptBool (cmd, "suspend"))
flags |= VIR_MIGRATE_PAUSED;
+ if (vshCommandOptBool (cmd, "copy-storage-all"))
+ flags |= VIR_MIGRATE_NON_SHARED_DISK;
+
+ if (vshCommandOptBool (cmd, "copy-storage-inc"))
+ flags |= VIR_MIGRATE_NON_SHARED_INC;
+
if ((flags & VIR_MIGRATE_PEER2PEER) ||
vshCommandOptBool (cmd, "direct")) {
/* For peer2peer migration or direct migration we only expect one
URI
This the patch file:
(See attached file: libvirt_migration_ns_100503.patch)
regards,
Kenneth NaginAttachment:
libvirt_migration_ns_100503.patch
Description: Binary data
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