Commit 8e84865e authored by Amit Shah's avatar Amit Shah Committed by Aurelien Jarno
Browse files

migration: Accept 'cont' only after successful incoming migration 



When a 'cont' is issued on a VM that's just waiting for an incoming
migration, the VM reboots and boots into the guest, possibly corrupting
its storage since it could be shared with another VM running elsewhere.

Ensure that a VM started with '-incoming' is only run when an incoming
migration successfully completes.

A new qerror, QERR_MIGRATION_EXPECTED, is added to signal that 'cont'
failed due to no incoming migration has been attempted yet.

Reported-by: default avatarLaine Stump <laine@redhat.com>
Signed-off-by: default avatarAmit Shah <amit.shah@redhat.com>
Reviewed-by: default avatarLuiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: default avatarAurelien Jarno <aurelien@aurel32.net>
parent 7899f799

migration.c

+2 −0
Original line number Diff line number Diff line
@@ -67,6 +67,8 @@ void process_incoming_migration(QEMUFile *f) 
    qemu_announce_self();

    DPRINTF("successfully loaded vm state\n");



    incoming_expected = false;



    if (autostart)

        vm_start();

}

monitor.c

+4 −0
Original line number Diff line number Diff line
@@ -1056,6 +1056,10 @@ static int do_cont(Monitor *mon, const QDict *qdict, QObject **ret_data) 
{

    struct bdrv_iterate_context context = { mon, 0 };



    if (incoming_expected) {

        qerror_report(QERR_MIGRATION_EXPECTED);

        return -1;

    }

    bdrv_iterate(encrypted_bdrv_it, &context);

    /* only resume the vm if all keys are set and valid */

    if (!context.err) {

qerror.c

+4 −0
Original line number Diff line number Diff line
@@ -140,6 +140,10 @@ static const QErrorStringTable qerror_table[] = { 
        .error_fmt = QERR_KVM_MISSING_CAP,

        .desc      = "Using KVM without %(capability), %(feature) unavailable",

    },

    {

        .error_fmt = QERR_MIGRATION_EXPECTED,

        .desc      = "An incoming migration is expected before this command can be executed",

    },

    {

        .error_fmt = QERR_MISSING_PARAMETER,

        .desc      = "Parameter '%(name)' is missing",

qerror.h

+3 −0
Original line number Diff line number Diff line
@@ -121,6 +121,9 @@ QError *qobject_to_qerror(const QObject *obj); 
#define QERR_KVM_MISSING_CAP \

    "{ 'class': 'KVMMissingCap', 'data': { 'capability': %s, 'feature': %s } }"



#define QERR_MIGRATION_EXPECTED \

    "{ 'class': 'MigrationExpected', 'data': {} }"



#define QERR_MISSING_PARAMETER \

    "{ 'class': 'MissingParameter', 'data': { 'name': %s } }"

sysemu.h

+1 −0
Original line number Diff line number Diff line
@@ -99,6 +99,7 @@ typedef enum DisplayType 
} DisplayType;



extern int autostart;

extern int incoming_expected;

extern int bios_size;



typedef enum {