From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48250) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cQv7D-0006C9-J5 for qemu-devel@nongnu.org; Tue, 10 Jan 2017 07:01:26 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cQv7A-00004r-Cu for qemu-devel@nongnu.org; Tue, 10 Jan 2017 07:01:23 -0500 Received: from mx1.redhat.com ([209.132.183.28]:52656) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cQv7A-0008Ub-2F for qemu-devel@nongnu.org; Tue, 10 Jan 2017 07:01:20 -0500 Date: Tue, 10 Jan 2017 12:01:12 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20170110120111.GF2423@work-vm> References: <1483981368-9965-1-git-send-email-ashijeetacharya@gmail.com> <1483981368-9965-4-git-send-email-ashijeetacharya@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1483981368-9965-4-git-send-email-ashijeetacharya@gmail.com> Subject: Re: [Qemu-devel] [PATCH v4 3/4] migration: disallow migrate_add_blocker during migration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ashijeet Acharya Cc: jsnow@redhat.com, amit.shah@redhat.com, pbonzini@redhat.com, kwolf@redhat.com, armbru@redhat.com, quintela@redhat.com, mst@redhat.com, marcandre.lureau@redhat.com, groug@kaod.org, aneesh.kumar@linux.vnet.ibm.com, peter.maydell@linaro.org, qemu-devel@nongnu.org * Ashijeet Acharya (ashijeetacharya@gmail.com) wrote: > If a migration is already in progress and somebody attempts > to add a migration blocker, this should rightly fail. > > Add an errp parameter and a retcode return value to migrate_add_blocker. > > Signed-off-by: John Snow > Signed-off-by: Ashijeet Acharya > --- > block/qcow.c | 6 +++++- > block/vdi.c | 6 +++++- > block/vhdx.c | 16 ++++++++++------ > block/vmdk.c | 7 ++++++- > block/vpc.c | 10 +++++++--- > block/vvfat.c | 20 ++++++++++++-------- > hw/9pfs/9p.c | 18 +++++++++++++----- > hw/display/virtio-gpu.c | 29 ++++++++++++++++------------- > hw/intc/arm_gic_kvm.c | 16 ++++++++++------ > hw/intc/arm_gicv3_its_kvm.c | 18 +++++++++++------- > hw/intc/arm_gicv3_kvm.c | 19 ++++++++++++------- > hw/misc/ivshmem.c | 11 +++++++---- > hw/scsi/vhost-scsi.c | 25 +++++++++++++++++++------ > hw/virtio/vhost.c | 8 +++++++- > include/migration/migration.h | 6 +++++- > migration/migration.c | 35 +++++++++++++++++++++++++++++++++-- > stubs/migr-blocker.c | 3 ++- > target-i386/kvm.c | 16 +++++++++++++--- > 18 files changed, 193 insertions(+), 76 deletions(-) > > diff --git a/block/qcow.c b/block/qcow.c > index 7540f43..11526a1 100644 > --- a/block/qcow.c > +++ b/block/qcow.c > @@ -252,7 +252,11 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, > error_setg(&s->migration_blocker, "The qcow format used by node '%s' " > "does not support live migration", > bdrv_get_device_or_node_name(bs)); > - migrate_add_blocker(s->migration_blocker); > + ret = migrate_add_blocker(s->migration_blocker, errp); > + if (ret < 0) { > + error_free(s->migration_blocker); > + goto fail; > + } > > qemu_co_mutex_init(&s->lock); > return 0; > diff --git a/block/vdi.c b/block/vdi.c > index 96b78d5..2b56f52 100644 > --- a/block/vdi.c > +++ b/block/vdi.c > @@ -471,7 +471,11 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags, > error_setg(&s->migration_blocker, "The vdi format used by node '%s' " > "does not support live migration", > bdrv_get_device_or_node_name(bs)); > - migrate_add_blocker(s->migration_blocker); > + ret = migrate_add_blocker(s->migration_blocker, errp); > + if (ret < 0) { > + error_free(s->migration_blocker); > + goto fail_free_bmap; > + } > > qemu_co_mutex_init(&s->write_lock); > > diff --git a/block/vhdx.c b/block/vhdx.c > index 0ba2f0a..d81941b 100644 > --- a/block/vhdx.c > +++ b/block/vhdx.c > @@ -991,6 +991,16 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags, > } > } > > + /* Disable migration when VHDX images are used */ > + error_setg(&s->migration_blocker, "The vhdx format used by node '%s' " > + "does not support live migration", > + bdrv_get_device_or_node_name(bs)); > + ret = migrate_add_blocker(s->migration_blocker, errp); > + if (ret < 0) { > + error_free(s->migration_blocker); > + goto fail; > + } > + > if (flags & BDRV_O_RDWR) { > ret = vhdx_update_headers(bs, s, false, NULL); > if (ret < 0) { > @@ -1000,12 +1010,6 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags, > > /* TODO: differencing files */ > > - /* Disable migration when VHDX images are used */ > - error_setg(&s->migration_blocker, "The vhdx format used by node '%s' " > - "does not support live migration", > - bdrv_get_device_or_node_name(bs)); > - migrate_add_blocker(s->migration_blocker); > - > return 0; > fail: > vhdx_close(bs); > diff --git a/block/vmdk.c b/block/vmdk.c > index a11c27a..4a45a83 100644 > --- a/block/vmdk.c > +++ b/block/vmdk.c > @@ -976,7 +976,12 @@ static int vmdk_open(BlockDriverState *bs, QDict *options, int flags, > error_setg(&s->migration_blocker, "The vmdk format used by node '%s' " > "does not support live migration", > bdrv_get_device_or_node_name(bs)); > - migrate_add_blocker(s->migration_blocker); > + ret = migrate_add_blocker(s->migration_blocker, errp); > + if (ret < 0) { > + error_free(s->migration_blocker); > + goto fail; > + } > + > g_free(buf); > return 0; > > diff --git a/block/vpc.c b/block/vpc.c > index 8d5886f..299a8c8 100644 > --- a/block/vpc.c > +++ b/block/vpc.c > @@ -422,13 +422,17 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, > #endif > } > > - qemu_co_mutex_init(&s->lock); > - > /* Disable migration when VHD images are used */ > error_setg(&s->migration_blocker, "The vpc format used by node '%s' " > "does not support live migration", > bdrv_get_device_or_node_name(bs)); > - migrate_add_blocker(s->migration_blocker); > + ret = migrate_add_blocker(s->migration_blocker, errp); > + if (ret < 0) { > + error_free(s->migration_blocker); > + goto fail; > + } > + > + qemu_co_mutex_init(&s->lock); > > return 0; > > diff --git a/block/vvfat.c b/block/vvfat.c > index ded2109..3de3320 100644 > --- a/block/vvfat.c > +++ b/block/vvfat.c > @@ -1185,22 +1185,26 @@ static int vvfat_open(BlockDriverState *bs, QDict *options, int flags, > > s->sector_count = s->faked_sectors + s->sectors_per_cluster*s->cluster_count; > > - if (s->first_sectors_number == 0x40) { > - init_mbr(s, cyls, heads, secs); > - } > - > - // assert(is_consistent(s)); > - qemu_co_mutex_init(&s->lock); > - > /* Disable migration when vvfat is used rw */ > if (s->qcow) { > error_setg(&s->migration_blocker, > "The vvfat (rw) format used by node '%s' " > "does not support live migration", > bdrv_get_device_or_node_name(bs)); > - migrate_add_blocker(s->migration_blocker); > + ret = migrate_add_blocker(s->migration_blocker, errp); > + if (ret < 0) { > + error_free(s->migration_blocker); > + goto fail; > + } > + } > + > + if (s->first_sectors_number == 0x40) { > + init_mbr(s, cyls, heads, secs); > } > > + // assert(is_consistent(s)); > + qemu_co_mutex_init(&s->lock); > + > ret = 0; > fail: > qemu_opts_del(opts); > diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c > index faebd91..c823a44 100644 > --- a/hw/9pfs/9p.c > +++ b/hw/9pfs/9p.c > @@ -1013,20 +1013,28 @@ static void coroutine_fn v9fs_attach(void *opaque) > goto out; > } > err += offset; > - memcpy(&s->root_qid, &qid, sizeof(qid)); > - trace_v9fs_attach_return(pdu->tag, pdu->id, > - qid.type, qid.version, qid.path); > + > /* > * disable migration if we haven't done already. > * attach could get called multiple times for the same export. > */ > if (!s->migration_blocker) { > - s->root_fid = fid; > error_setg(&s->migration_blocker, > "Migration is disabled when VirtFS export path '%s' is mounted in the guest using mount_tag '%s'", > s->ctx.fs_root ? s->ctx.fs_root : "NULL", s->tag); > - migrate_add_blocker(s->migration_blocker); > + err = migrate_add_blocker(s->migration_blocker, NULL); > + if (err < 0) { > + error_free(s->migration_blocker); > + s->migration_blocker = NULL; > + clunk_fid(s, fid); > + goto out; > + } > + s->root_fid = fid; > } > + > + memcpy(&s->root_qid, &qid, sizeof(qid)); > + trace_v9fs_attach_return(pdu->tag, pdu->id, > + qid.type, qid.version, qid.path); > out: > put_fid(pdu, fidp); > out_nofid: > diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c > index 5f32e1a..6e60b8c 100644 > --- a/hw/display/virtio-gpu.c > +++ b/hw/display/virtio-gpu.c > @@ -1108,14 +1108,6 @@ static void virtio_gpu_device_realize(DeviceState *qdev, Error **errp) > return; > } > > - g->config_size = sizeof(struct virtio_gpu_config); > - g->virtio_config.num_scanouts = g->conf.max_outputs; > - virtio_init(VIRTIO_DEVICE(g), "virtio-gpu", VIRTIO_ID_GPU, > - g->config_size); > - > - g->req_state[0].width = 1024; > - g->req_state[0].height = 768; > - > g->use_virgl_renderer = false; > #if !defined(CONFIG_VIRGL) || defined(HOST_WORDS_BIGENDIAN) > have_virgl = false; > @@ -1127,6 +1119,22 @@ static void virtio_gpu_device_realize(DeviceState *qdev, Error **errp) > } > > if (virtio_gpu_virgl_enabled(g->conf)) { > + error_setg(&g->migration_blocker, "virgl is not yet migratable"); > + if (migrate_add_blocker(g->migration_blocker, errp) < 0) { > + error_free(g->migration_blocker); > + return; > + } > + } > + > + g->config_size = sizeof(struct virtio_gpu_config); > + g->virtio_config.num_scanouts = g->conf.max_outputs; > + virtio_init(VIRTIO_DEVICE(g), "virtio-gpu", VIRTIO_ID_GPU, > + g->config_size); > + > + g->req_state[0].width = 1024; > + g->req_state[0].height = 768; > + > + if (virtio_gpu_virgl_enabled(g->conf)) { > /* use larger control queue in 3d mode */ > g->ctrl_vq = virtio_add_queue(vdev, 256, virtio_gpu_handle_ctrl_cb); > g->cursor_vq = virtio_add_queue(vdev, 16, virtio_gpu_handle_cursor_cb); > @@ -1152,11 +1160,6 @@ static void virtio_gpu_device_realize(DeviceState *qdev, Error **errp) > dpy_gfx_replace_surface(g->scanout[i].con, NULL); > } > } > - > - if (virtio_gpu_virgl_enabled(g->conf)) { > - error_setg(&g->migration_blocker, "virgl is not yet migratable"); > - migrate_add_blocker(g->migration_blocker); > - } > } > > static void virtio_gpu_device_unrealize(DeviceState *qdev, Error **errp) > diff --git a/hw/intc/arm_gic_kvm.c b/hw/intc/arm_gic_kvm.c > index 11729ee..3614daa 100644 > --- a/hw/intc/arm_gic_kvm.c > +++ b/hw/intc/arm_gic_kvm.c > @@ -510,6 +510,16 @@ static void kvm_arm_gic_realize(DeviceState *dev, Error **errp) > return; > } > > + if (!kvm_arm_gic_can_save_restore(s)) { > + error_setg(&s->migration_blocker, "This operating system kernel does " > + "not support vGICv2 migration"); > + ret = migrate_add_blocker(s->migration_blocker, errp); > + if (ret < 0) { > + error_free(s->migration_blocker); > + return; > + } > + } > + > gic_init_irqs_and_mmio(s, kvm_arm_gicv2_set_irq, NULL); > > for (i = 0; i < s->num_irq - GIC_INTERNAL; i++) { > @@ -558,12 +568,6 @@ static void kvm_arm_gic_realize(DeviceState *dev, Error **errp) > KVM_VGIC_V2_ADDR_TYPE_CPU, > s->dev_fd); > > - if (!kvm_arm_gic_can_save_restore(s)) { > - error_setg(&s->migration_blocker, "This operating system kernel does " > - "not support vGICv2 migration"); > - migrate_add_blocker(s->migration_blocker); > - } > - > if (kvm_has_gsi_routing()) { > /* set up irq routing */ > kvm_init_irq_routing(kvm_state); > diff --git a/hw/intc/arm_gicv3_its_kvm.c b/hw/intc/arm_gicv3_its_kvm.c > index fc246e0..950a02f 100644 > --- a/hw/intc/arm_gicv3_its_kvm.c > +++ b/hw/intc/arm_gicv3_its_kvm.c > @@ -63,6 +63,17 @@ static void kvm_arm_its_realize(DeviceState *dev, Error **errp) > return; > } > > + /* > + * Block migration of a KVM GICv3 ITS device: the API for saving and > + * restoring the state in the kernel is not yet available > + */ > + error_setg(&s->migration_blocker, "vITS migration is not implemented"); > + ret = migrate_add_blocker(s->migration_blocker, errp); > + if (ret < 0) { > + error_free(s->migration_blocker); > + return; > + } > + > /* explicit init of the ITS */ > kvm_device_access(s->dev_fd, KVM_DEV_ARM_VGIC_GRP_CTRL, > KVM_DEV_ARM_VGIC_CTRL_INIT, NULL, true); > @@ -73,13 +84,6 @@ static void kvm_arm_its_realize(DeviceState *dev, Error **errp) > > gicv3_its_init_mmio(s, NULL); > > - /* > - * Block migration of a KVM GICv3 ITS device: the API for saving and > - * restoring the state in the kernel is not yet available > - */ > - error_setg(&s->migration_blocker, "vITS migration is not implemented"); > - migrate_add_blocker(s->migration_blocker); > - > kvm_msi_use_devid = true; > kvm_gsi_direct_mapping = false; > kvm_msi_via_irqfd_allowed = kvm_irqfds_enabled(); > diff --git a/hw/intc/arm_gicv3_kvm.c b/hw/intc/arm_gicv3_kvm.c > index 199a439..06f6f30 100644 > --- a/hw/intc/arm_gicv3_kvm.c > +++ b/hw/intc/arm_gicv3_kvm.c > @@ -86,6 +86,7 @@ static void kvm_arm_gicv3_realize(DeviceState *dev, Error **errp) > KVMARMGICv3Class *kgc = KVM_ARM_GICV3_GET_CLASS(s); > Error *local_err = NULL; > int i; > + int ret; > > DPRINTF("kvm_arm_gicv3_realize\n"); > > @@ -110,6 +111,17 @@ static void kvm_arm_gicv3_realize(DeviceState *dev, Error **errp) > return; > } > > + /* Block migration of a KVM GICv3 device: the API for saving and restoring > + * the state in the kernel is not yet finalised in the kernel or > + * implemented in QEMU. > + */ > + error_setg(&s->migration_blocker, "vGICv3 migration is not implemented"); > + ret = migrate_add_blocker(s->migration_blocker, errp); > + if (ret < 0) { > + error_free(s->migration_blocker); > + return; > + } > + Shouldn't this go a little earlier in the function - before the kvm_create_device call? > kvm_device_access(s->dev_fd, KVM_DEV_ARM_VGIC_GRP_NR_IRQS, > 0, &s->num_irq, true); > > @@ -122,13 +134,6 @@ static void kvm_arm_gicv3_realize(DeviceState *dev, Error **errp) > kvm_arm_register_device(&s->iomem_redist, -1, KVM_DEV_ARM_VGIC_GRP_ADDR, > KVM_VGIC_V3_ADDR_TYPE_REDIST, s->dev_fd); > > - /* Block migration of a KVM GICv3 device: the API for saving and restoring > - * the state in the kernel is not yet finalised in the kernel or > - * implemented in QEMU. > - */ > - error_setg(&s->migration_blocker, "vGICv3 migration is not implemented"); > - migrate_add_blocker(s->migration_blocker); > - > if (kvm_has_gsi_routing()) { > /* set up irq routing */ > kvm_init_irq_routing(kvm_state); > diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c > index abeaf3d..585cc5b 100644 > --- a/hw/misc/ivshmem.c > +++ b/hw/misc/ivshmem.c > @@ -903,9 +903,6 @@ static void ivshmem_common_realize(PCIDevice *dev, Error **errp) > } > } > > - vmstate_register_ram(s->ivshmem_bar2, DEVICE(s)); > - pci_register_bar(PCI_DEVICE(s), 2, attr, s->ivshmem_bar2); > - > if (s->master == ON_OFF_AUTO_AUTO) { > s->master = s->vm_id == 0 ? ON_OFF_AUTO_ON : ON_OFF_AUTO_OFF; > } > @@ -913,8 +910,14 @@ static void ivshmem_common_realize(PCIDevice *dev, Error **errp) > if (!ivshmem_is_master(s)) { > error_setg(&s->migration_blocker, > "Migration is disabled when using feature 'peer mode' in device 'ivshmem'"); > - migrate_add_blocker(s->migration_blocker); > + if (migrate_add_blocker(s->migration_blocker, errp) < 0) { > + error_free(s->migration_blocker); > + return; > + } > } > + > + vmstate_register_ram(s->ivshmem_bar2, DEVICE(s)); > + pci_register_bar(PCI_DEVICE(s), 2, attr, s->ivshmem_bar2); > } > > static void ivshmem_exit(PCIDevice *dev) > diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c > index 5b26946..ff503d0 100644 > --- a/hw/scsi/vhost-scsi.c > +++ b/hw/scsi/vhost-scsi.c > @@ -238,8 +238,14 @@ static void vhost_scsi_realize(DeviceState *dev, Error **errp) > vhost_dummy_handle_output); > if (err != NULL) { > error_propagate(errp, err); > - close(vhostfd); > - return; > + goto close_fd; > + } > + > + error_setg(&s->migration_blocker, > + "vhost-scsi does not support migration"); > + ret = migrate_add_blocker(s->migration_blocker, errp); > + if (ret < 0) { > + goto free_blocker; > } > > s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues; > @@ -252,7 +258,7 @@ static void vhost_scsi_realize(DeviceState *dev, Error **errp) > if (ret < 0) { > error_setg(errp, "vhost-scsi: vhost initialization failed: %s", > strerror(-ret)); > - return; > + goto free_vqs; > } > > /* At present, channel and lun both are 0 for bootable vhost-scsi disk */ > @@ -261,9 +267,16 @@ static void vhost_scsi_realize(DeviceState *dev, Error **errp) > /* Note: we can also get the minimum tpgt from kernel */ > s->target = vs->conf.boot_tpgt; > > - error_setg(&s->migration_blocker, > - "vhost-scsi does not support migration"); > - migrate_add_blocker(s->migration_blocker); > + return; > + > + free_vqs: > + migrate_del_blocker(s->migration_blocker); > + g_free(s->dev.vqs); > + free_blocker: > + error_free(s->migration_blocker); > + close_fd: > + close(vhostfd); > + return; > } > > static void vhost_scsi_unrealize(DeviceState *dev, Error **errp) > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c > index f7f7023..416fada 100644 > --- a/hw/virtio/vhost.c > +++ b/hw/virtio/vhost.c > @@ -1157,7 +1157,13 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque, > } > > if (hdev->migration_blocker != NULL) { > - migrate_add_blocker(hdev->migration_blocker); > + Error *local_err; > + r = migrate_add_blocker(hdev->migration_blocker, &local_err); > + if (r < 0) { > + error_report_err(local_err); > + error_free(hdev->migration_blocker); > + goto fail_busyloop; > + } > } > > hdev->mem = g_malloc0(offsetof(struct vhost_memory, regions)); > diff --git a/include/migration/migration.h b/include/migration/migration.h > index 40b3697..46a4bb5 100644 > --- a/include/migration/migration.h > +++ b/include/migration/migration.h > @@ -243,6 +243,7 @@ void remove_migration_state_change_notifier(Notifier *notify); > MigrationState *migrate_init(const MigrationParams *params); > bool migration_is_blocked(Error **errp); > bool migration_in_setup(MigrationState *); > +bool migration_is_idle(MigrationState *s); > bool migration_has_finished(MigrationState *); > bool migration_has_failed(MigrationState *); > /* True if outgoing migration has entered postcopy phase */ > @@ -287,8 +288,11 @@ int ram_postcopy_incoming_init(MigrationIncomingState *mis); > * @migrate_add_blocker - prevent migration from proceeding > * > * @reason - an error to be returned whenever migration is attempted > + * @errp - [out] The reason (if any) we cannot block migration right now. > + * > + * @returns - 0 on success, -EBUSY on failure, with errp set. > */ > -void migrate_add_blocker(Error *reason); > +int migrate_add_blocker(Error *reason, Error **errp); > > /** > * @migrate_del_blocker - remove a blocking error from migration > diff --git a/migration/migration.c b/migration/migration.c > index f498ab8..713e012 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -1044,6 +1044,31 @@ bool migration_in_postcopy_after_devices(MigrationState *s) > return migration_in_postcopy(s) && s->postcopy_after_devices; > } > > +bool migration_is_idle(MigrationState *s) > +{ > + if (!s) { > + s = migrate_get_current(); > + } > + > + switch (s->state) { > + case MIGRATION_STATUS_NONE: > + case MIGRATION_STATUS_CANCELLED: > + case MIGRATION_STATUS_COMPLETED: > + case MIGRATION_STATUS_FAILED: > + return true; > + case MIGRATION_STATUS_SETUP: > + case MIGRATION_STATUS_CANCELLING: > + case MIGRATION_STATUS_ACTIVE: > + case MIGRATION_STATUS_POSTCOPY_ACTIVE: > + case MIGRATION_STATUS_COLO: > + return false; > + case MIGRATION_STATUS__MAX: > + g_assert_not_reached(); > + } > + > + return false; > +} > + > MigrationState *migrate_init(const MigrationParams *params) > { > MigrationState *s = migrate_get_current(); > @@ -1086,9 +1111,15 @@ MigrationState *migrate_init(const MigrationParams *params) > > static GSList *migration_blockers; > > -void migrate_add_blocker(Error *reason) > +int migrate_add_blocker(Error *reason, Error **errp) > { > - migration_blockers = g_slist_prepend(migration_blockers, reason); > + if (migration_is_idle(NULL)) { > + migration_blockers = g_slist_prepend(migration_blockers, reason); > + return 0; > + } > + > + error_setg(errp, "Cannot block a migration already in-progress"); > + return -EBUSY; > } > > void migrate_del_blocker(Error *reason) > diff --git a/stubs/migr-blocker.c b/stubs/migr-blocker.c > index 8ab3604..a5ba18f 100644 > --- a/stubs/migr-blocker.c > +++ b/stubs/migr-blocker.c > @@ -2,8 +2,9 @@ > #include "qemu-common.h" > #include "migration/migration.h" > > -void migrate_add_blocker(Error *reason) > +int migrate_add_blocker(Error *reason, Error **errp) > { > + return 0; > } > > void migrate_del_blocker(Error *reason) > diff --git a/target-i386/kvm.c b/target-i386/kvm.c > index f62264a..6031a1c 100644 > --- a/target-i386/kvm.c > +++ b/target-i386/kvm.c > @@ -961,7 +961,11 @@ int kvm_arch_init_vcpu(CPUState *cs) > error_setg(&invtsc_mig_blocker, > "State blocked by non-migratable CPU device" > " (invtsc flag)"); > - migrate_add_blocker(invtsc_mig_blocker); > + r = migrate_add_blocker(invtsc_mig_blocker, NULL); > + if (r < 0) { > + error_report("kvm: migrate_add_blocker failed"); > + goto efail; > + } > /* for savevm */ > vmstate_x86_cpu.unmigratable = 1; > } > @@ -969,12 +973,12 @@ int kvm_arch_init_vcpu(CPUState *cs) > cpuid_data.cpuid.padding = 0; > r = kvm_vcpu_ioctl(cs, KVM_SET_CPUID2, &cpuid_data); > if (r) { > - return r; > + goto fail; > } > > r = kvm_arch_set_tsc_khz(cs); > if (r < 0) { > - return r; > + goto fail; > } > > /* vcpu's TSC frequency is either specified by user, or following > @@ -1001,6 +1005,12 @@ int kvm_arch_init_vcpu(CPUState *cs) > } > > return 0; > + > + fail: > + migrate_del_blocker(invtsc_mig_blocker); > + efail: > + error_free(invtsc_mig_blocker); > + return r; > } Couldn't that be simplified just to always do the migrate_del_blocker? I don't think there's any harm in calling migrate_del_blocker if the add failed. Dave > void kvm_arch_reset_vcpu(X86CPU *cpu) > -- > 2.6.2 > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK