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Re: [Qemu-devel] [PATCH v4 3/4] migration: disallow migrate_add_blocker
|
From: |
Ashijeet Acharya |
|
Subject: |
Re: [Qemu-devel] [PATCH v4 3/4] migration: disallow migrate_add_blocker during migration |
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Date: |
Wed, 11 Jan 2017 00:03:37 +0530 |
On Tue, Jan 10, 2017 at 5:31 PM, Dr. David Alan Gilbert
<address@hidden> wrote:
> * Ashijeet Acharya (address@hidden) 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 <address@hidden>
>> Signed-off-by: Ashijeet Acharya <address@hidden>
>> ---
>> 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?
Done.
>
>> 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.
Hmm, I will change it to just
fail:
migrate_del_blocker(invtsc_mig_blocker);
error_free(invtsc_mig_blocker);
return r;
Ashijeet
>
> Dave
>
>> void kvm_arch_reset_vcpu(X86CPU *cpu)
>> --
>> 2.6.2
>>
> --
> Dr. David Alan Gilbert / address@hidden / Manchester, UK
Re: [Qemu-devel] [PATCH v4 0/4] Introduce a new --only-migratable option, no-reply, 2017/01/09