From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57642) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cPXZb-0004df-Qq for qemu-devel@nongnu.org; Fri, 06 Jan 2017 11:41:01 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cPXZX-0002WD-Ld for qemu-devel@nongnu.org; Fri, 06 Jan 2017 11:40:59 -0500 Received: from mo69.mail-out.ovh.net ([178.32.228.69]:53918) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cPXZX-0002Vd-BS for qemu-devel@nongnu.org; Fri, 06 Jan 2017 11:40:55 -0500 Received: from player696.ha.ovh.net (b7.ovh.net [213.186.33.57]) by mo69.mail-out.ovh.net (Postfix) with ESMTP id D531CFC7E for ; Fri, 6 Jan 2017 17:40:53 +0100 (CET) Date: Fri, 6 Jan 2017 17:40:39 +0100 From: Greg Kurz Message-ID: <20170106174039.62523cdd@bahia.lan> In-Reply-To: <1483533149-12807-5-git-send-email-ashijeetacharya@gmail.com> References: <1483533149-12807-1-git-send-email-ashijeetacharya@gmail.com> <1483533149-12807-5-git-send-email-ashijeetacharya@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v3 4/4] migration: Fail migration blocker for --only-migratble List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ashijeet Acharya Cc: dgilbert@redhat.com, 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, aneesh.kumar@linux.vnet.ibm.com, peter.maydell@linaro.org, qemu-devel@nongnu.org On Wed, 4 Jan 2017 18:02:29 +0530 Ashijeet Acharya wrote: > migrate_add_blocker should rightly fail if the '--only-migratable' > option was specified and the device in use should not be able to > perform the action which results in an unmigratable VM. > > Make migrate_add_blocker return -EACCES in this case. > > Signed-off-by: Ashijeet Acharya > --- > block/qcow.c | 5 ++++- > block/vdi.c | 5 ++++- > block/vhdx.c | 6 ++++-- > block/vmdk.c | 5 ++++- > block/vpc.c | 5 ++++- > block/vvfat.c | 6 ++++-- > hw/9pfs/9p.c | 8 +++++++- > hw/display/virtio-gpu.c | 9 +++++++-- > hw/intc/arm_gic_kvm.c | 5 ++++- > hw/intc/arm_gicv3_its_kvm.c | 5 ++++- > hw/intc/arm_gicv3_kvm.c | 5 ++++- > hw/misc/ivshmem.c | 10 ++++++++-- > hw/scsi/vhost-scsi.c | 8 +++++--- > hw/virtio/vhost.c | 6 ++++-- > migration/migration.c | 7 +++++++ > target-i386/kvm.c | 5 ++++- > 16 files changed, 78 insertions(+), 22 deletions(-) > > diff --git a/block/qcow.c b/block/qcow.c > index 11526a1..bdc6446 100644 > --- a/block/qcow.c > +++ b/block/qcow.c > @@ -254,7 +254,10 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags, > bdrv_get_device_or_node_name(bs)); > ret = migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret == -EACCES) { > + error_append_hint(errp, "Cannot use a node with qcow format as " > + "it does not support live migration"); > + } > goto fail; > } > > diff --git a/block/vdi.c b/block/vdi.c > index 2b56f52..0b011ea 100644 > --- a/block/vdi.c > +++ b/block/vdi.c > @@ -473,7 +473,10 @@ static int vdi_open(BlockDriverState *bs, QDict *options, int flags, > bdrv_get_device_or_node_name(bs)); > ret = migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret == -EACCES) { > + error_append_hint(errp, "Cannot use a node with vdi format as " > + "it does not support live migration"); > + } > goto fail_free_bmap; > } > > diff --git a/block/vhdx.c b/block/vhdx.c > index d81941b..b8d53ec 100644 > --- a/block/vhdx.c > +++ b/block/vhdx.c > @@ -997,10 +997,12 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags, > bdrv_get_device_or_node_name(bs)); > ret = migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret == -EACCES) { > + error_append_hint(errp, "Cannot use a node with vhdx format as " > + "it does not support live migration"); > + } > goto fail; > } > - > if (flags & BDRV_O_RDWR) { > ret = vhdx_update_headers(bs, s, false, NULL); > if (ret < 0) { > diff --git a/block/vmdk.c b/block/vmdk.c > index 4a45a83..defe400 100644 > --- a/block/vmdk.c > +++ b/block/vmdk.c > @@ -978,7 +978,10 @@ static int vmdk_open(BlockDriverState *bs, QDict *options, int flags, > bdrv_get_device_or_node_name(bs)); > ret = migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret == -EACCES) { > + error_append_hint(errp, "Cannot use a node with vmdk format as " > + "it does not support live migration"); > + } > goto fail; > } > > diff --git a/block/vpc.c b/block/vpc.c > index 299a8c8..5e58d77 100644 > --- a/block/vpc.c > +++ b/block/vpc.c > @@ -428,7 +428,10 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, > bdrv_get_device_or_node_name(bs)); > ret = migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret == -EACCES) { > + error_append_hint(errp, "Cannot use a node with vpc format as " > + "it does not support live migration"); > + } > goto fail; > } > > diff --git a/block/vvfat.c b/block/vvfat.c > index 3de3320..5a6e038 100644 > --- a/block/vvfat.c > +++ b/block/vvfat.c > @@ -1193,7 +1193,10 @@ static int vvfat_open(BlockDriverState *bs, QDict *options, int flags, > bdrv_get_device_or_node_name(bs)); > ret = migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret == -EACCES) { > + error_append_hint(errp, "Cannot use a node with vvfat format " > + "as it does not support live migration"); > + } > goto fail; > } > } > @@ -1202,7 +1205,6 @@ static int vvfat_open(BlockDriverState *bs, QDict *options, int flags, > init_mbr(s, cyls, heads, secs); > } > > - // assert(is_consistent(s)); > qemu_co_mutex_init(&s->lock); > > ret = 0; > diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c > index 43cb065..3b4fd24 100644 > --- a/hw/9pfs/9p.c > +++ b/hw/9pfs/9p.c > @@ -1020,17 +1020,23 @@ static void coroutine_fn v9fs_attach(void *opaque) > */ > if (!s->migration_blocker) { > int ret; > + Error *local_err; > 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); > - ret = migrate_add_blocker(s->migration_blocker, NULL); > + ret = migrate_add_blocker(s->migration_blocker, &local_err); > if (ret < 0) { > + if (ret == -EACCES) { > + error_append_hint(&local_err, "Failed to mount VirtFS as it " > + "does not support live migration"); > + } > err = ret; > clunk_fid(s, fid); > error_free(s->migration_blocker); > s->migration_blocker = NULL; > goto out; > } > + error_free(local_err); Thinking again, I suggest you simply drop these changes: v9fs_attach() is triggered by the guest and doesn't cause QEMU to fail, so we don't really care. Cheers. -- Greg > s->root_fid = fid; > } > > diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c > index 6e60b8c..fad95bf 100644 > --- a/hw/display/virtio-gpu.c > +++ b/hw/display/virtio-gpu.c > @@ -1102,6 +1102,7 @@ static void virtio_gpu_device_realize(DeviceState *qdev, Error **errp) > VirtIOGPU *g = VIRTIO_GPU(qdev); > bool have_virgl; > int i; > + int ret; > > if (g->conf.max_outputs > VIRTIO_GPU_MAX_SCANOUTS) { > error_setg(errp, "invalid max_outputs > %d", VIRTIO_GPU_MAX_SCANOUTS); > @@ -1120,8 +1121,12 @@ 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); > + ret = migrate_add_blocker(g->migration_blocker, errp); > + if (ret < 0) { > + if (ret == -EACCES) { > + error_append_hint(errp, "Cannot use virgl as it does not " > + "support live migration yet"); > + } > return; > } > } > diff --git a/hw/intc/arm_gic_kvm.c b/hw/intc/arm_gic_kvm.c > index 3614daa..c2ef236 100644 > --- a/hw/intc/arm_gic_kvm.c > +++ b/hw/intc/arm_gic_kvm.c > @@ -515,7 +515,10 @@ static void kvm_arm_gic_realize(DeviceState *dev, Error **errp) > "not support vGICv2 migration"); > ret = migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret == -EACCES) { > + error_append_hint(errp, "Failed to realize vGICv2 as its" > + " migrataion is not implemented yet"); > + } > return; > } > } > diff --git a/hw/intc/arm_gicv3_its_kvm.c b/hw/intc/arm_gicv3_its_kvm.c > index 950a02f..3474642 100644 > --- a/hw/intc/arm_gicv3_its_kvm.c > +++ b/hw/intc/arm_gicv3_its_kvm.c > @@ -70,7 +70,10 @@ static void kvm_arm_its_realize(DeviceState *dev, Error **errp) > 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); > + if (ret == -EACCES) { > + error_append_hint(errp, "Failed to realize vITS as its migration " > + "is not implemented yet"); > + } > return; > } > > diff --git a/hw/intc/arm_gicv3_kvm.c b/hw/intc/arm_gicv3_kvm.c > index 06f6f30..be7b97c 100644 > --- a/hw/intc/arm_gicv3_kvm.c > +++ b/hw/intc/arm_gicv3_kvm.c > @@ -118,7 +118,10 @@ static void kvm_arm_gicv3_realize(DeviceState *dev, Error **errp) > 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); > + if (ret == -EACCES) { > + error_append_hint(errp, "Failed to realize vGICv3 as its migration" > + "is not implemented yet"); > + } > return; > } > > diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c > index 585cc5b..14ed60d 100644 > --- a/hw/misc/ivshmem.c > +++ b/hw/misc/ivshmem.c > @@ -837,6 +837,7 @@ static void ivshmem_common_realize(PCIDevice *dev, Error **errp) > { > IVShmemState *s = IVSHMEM_COMMON(dev); > Error *err = NULL; > + int ret; > uint8_t *pci_conf; > uint8_t attr = PCI_BASE_ADDRESS_SPACE_MEMORY | > PCI_BASE_ADDRESS_MEM_PREFETCH; > @@ -910,8 +911,13 @@ 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'"); > - if (migrate_add_blocker(s->migration_blocker, errp) < 0) { > - error_free(s->migration_blocker); > + ret = migrate_add_blocker(s->migration_blocker, errp); > + if (ret < 0) { > + if (ret == -EACCES) { > + error_append_hint(errp, "Cannot use the 'peer mode' feature " > + "in device 'ivshmem' as it does not " > + "support live migration"); > + } > return; > } > } > diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c > index ff503d0..bb731b2 100644 > --- a/hw/scsi/vhost-scsi.c > +++ b/hw/scsi/vhost-scsi.c > @@ -245,7 +245,11 @@ static void vhost_scsi_realize(DeviceState *dev, Error **errp) > "vhost-scsi does not support migration"); > ret = migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - goto free_blocker; > + if (ret == -EACCES) { > + error_append_hint(errp, "Cannot use vhost-scsi as it does not " > + "support live migration"); > + } > + goto close_fd; > } > > s->dev.nvqs = VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues; > @@ -272,8 +276,6 @@ static void vhost_scsi_realize(DeviceState *dev, Error **errp) > 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; > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c > index 416fada..6d2375a 100644 > --- a/hw/virtio/vhost.c > +++ b/hw/virtio/vhost.c > @@ -1160,8 +1160,10 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque, > 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); > + if (r == -EACCES) { > + error_append_hint(&local_err, "Cannot use vhost drivers as " > + "it does not support live migration"); > + } > goto fail_busyloop; > } > } > diff --git a/migration/migration.c b/migration/migration.c > index 713e012..ab34328 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -1115,9 +1115,16 @@ int migrate_add_blocker(Error *reason, Error **errp) > { > if (migration_is_idle(NULL)) { > migration_blockers = g_slist_prepend(migration_blockers, reason); > + error_free(reason); > return 0; > } > > + if (only_migratable) { > + error_setg(errp, "Failed to add migration blocker: --only-migratable " > + "was specified"); > + return -EACCES; > + } > + > error_setg(errp, "Cannot block a migration already in-progress"); > return -EBUSY; > } > diff --git a/target-i386/kvm.c b/target-i386/kvm.c > index 6031a1c..f2c35d8 100644 > --- a/target-i386/kvm.c > +++ b/target-i386/kvm.c > @@ -963,6 +963,10 @@ int kvm_arch_init_vcpu(CPUState *cs) > " (invtsc flag)"); > r = migrate_add_blocker(invtsc_mig_blocker, NULL); > if (r < 0) { > + if (r == -EACCES) { > + error_report("kvm: non-migratable CPU device but" > + " --only-migratable was specified"); > + } > error_report("kvm: migrate_add_blocker failed"); > goto efail; > } > @@ -1009,7 +1013,6 @@ int kvm_arch_init_vcpu(CPUState *cs) > fail: > migrate_del_blocker(invtsc_mig_blocker); > efail: > - error_free(invtsc_mig_blocker); > return r; > } >