From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50650) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cQvGs-00044i-OU for qemu-devel@nongnu.org; Tue, 10 Jan 2017 07:11:28 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cQvGp-0005LG-IH for qemu-devel@nongnu.org; Tue, 10 Jan 2017 07:11:22 -0500 Received: from mx1.redhat.com ([209.132.183.28]:60878) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cQvGp-0005Ko-9D for qemu-devel@nongnu.org; Tue, 10 Jan 2017 07:11:19 -0500 Date: Tue, 10 Jan 2017 12:11:13 +0000 From: "Dr. David Alan Gilbert" Message-ID: <20170110121112.GG2423@work-vm> References: <1483981368-9965-1-git-send-email-ashijeetacharya@gmail.com> <1483981368-9965-5-git-send-email-ashijeetacharya@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable In-Reply-To: <1483981368-9965-5-git-send-email-ashijeetacharya@gmail.com> Subject: Re: [Qemu-devel] [PATCH v4 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: 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: > 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. >=20 > Make migrate_add_blocker return -EACCES in this case. >=20 > 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/display/virtio-gpu.c | 9 +++++++-- > hw/intc/arm_gic_kvm.c | 7 +++++-- > 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 ++++- > 15 files changed, 72 insertions(+), 22 deletions(-) >=20 > 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 *op= tions, int flags, > bdrv_get_device_or_node_name(bs)); > ret =3D migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret =3D=3D -EACCES) { > + error_append_hint(errp, "Cannot use a node with qcow format = as " > + "it does not support live migration"); > + } > goto fail; > } > =20 > 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 *opt= ions, int flags, > bdrv_get_device_or_node_name(bs)); > ret =3D migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret =3D=3D -EACCES) { > + error_append_hint(errp, "Cannot use a node with vdi format a= s " > + "it does not support live migration"); > + } > goto fail_free_bmap; > } > =20 > 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 *o= ptions, int flags, > bdrv_get_device_or_node_name(bs)); > ret =3D migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret =3D=3D -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 =3D 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 *op= tions, int flags, > bdrv_get_device_or_node_name(bs)); > ret =3D migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret =3D=3D -EACCES) { > + error_append_hint(errp, "Cannot use a node with vmdk format = as " > + "it does not support live migration"); > + } > goto fail; > } > =20 > 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 *opt= ions, int flags, > bdrv_get_device_or_node_name(bs)); > ret =3D migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret =3D=3D -EACCES) { > + error_append_hint(errp, "Cannot use a node with vpc format a= s " > + "it does not support live migration"); > + } > goto fail; > } > =20 > 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 =3D migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret =3D=3D -EACCES) { > + error_append_hint(errp, "Cannot use a node with vvfat fo= rmat " > + "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); > } > =20 > - // assert(is_consistent(s)); > qemu_co_mutex_init(&s->lock); > =20 > ret =3D 0; > 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 =3D VIRTIO_GPU(qdev); > bool have_virgl; > int i; > + int ret; > =20 > if (g->conf.max_outputs > VIRTIO_GPU_MAX_SCANOUTS) { > error_setg(errp, "invalid max_outputs > %d", VIRTIO_GPU_MAX_SCAN= OUTS); > @@ -1120,8 +1121,12 @@ static void virtio_gpu_device_realize(DeviceState = *qdev, Error **errp) > =20 > 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 =3D migrate_add_blocker(g->migration_blocker, errp); > + if (ret < 0) { > + if (ret =3D=3D -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..2097808 100644 > --- a/hw/intc/arm_gic_kvm.c > +++ b/hw/intc/arm_gic_kvm.c > @@ -514,8 +514,11 @@ static void kvm_arm_gic_realize(DeviceState *dev, Er= ror **errp) > error_setg(&s->migration_blocker, "This operating system kernel = does " > "not support vGICv2 migration"= ); > ret =3D migrate_add_blocker(s->migration_blocker, errp); > - if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret < 0 ) { > + if (ret =3D=3D -EACCES) { > + error_append_hint(errp, "Failed to realize vGICv2 as its" > + " migrataion is not implemented yet"); Typo of migrataion. Also is that message right? I think that should mention the OS kernel. > + } > 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, Erro= r **errp) > error_setg(&s->migration_blocker, "vITS migration is not implemented= "); > ret =3D migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret =3D=3D -EACCES) { > + error_append_hint(errp, "Failed to realize vITS as its migra= tion " > + "is not implemented yet"); > + } > return; > } > =20 > 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 implement= ed"); > ret =3D migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - error_free(s->migration_blocker); > + if (ret =3D=3D -EACCES) { > + error_append_hint(errp, "Failed to realize vGICv3 as its mig= ration" > + "is not implemented yet"); > + } > return; > } > =20 > 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, Er= ror **errp) > { > IVShmemState *s =3D IVSHMEM_COMMON(dev); > Error *err =3D NULL; > + int ret; > uint8_t *pci_conf; > uint8_t attr =3D PCI_BASE_ADDRESS_SPACE_MEMORY | > PCI_BASE_ADDRESS_MEM_PREFETCH; > @@ -910,8 +911,13 @@ static void ivshmem_common_realize(PCIDevice *dev, E= rror **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 =3D migrate_add_blocker(s->migration_blocker, errp); > + if (ret < 0) { > + if (ret =3D=3D -EACCES) { > + error_append_hint(errp, "Cannot use the 'peer mode' feat= ure " > + "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, Err= or **errp) > "vhost-scsi does not support migration"); > ret =3D migrate_add_blocker(s->migration_blocker, errp); > if (ret < 0) { > - goto free_blocker; > + if (ret =3D=3D -EACCES) { > + error_append_hint(errp, "Cannot use vhost-scsi as it does no= t " > + "support live migration"); > + } > + goto close_fd; > } > =20 > s->dev.nvqs =3D VHOST_SCSI_VQ_NUM_FIXED + vs->conf.num_queues; > @@ -272,8 +276,6 @@ static void vhost_scsi_realize(DeviceState *dev, Erro= r **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 *o= paque, > Error *local_err; > r =3D migrate_add_blocker(hdev->migration_blocker, &local_err); > if (r < 0) { > - error_report_err(local_err); > - error_free(hdev->migration_blocker); > + if (r =3D=3D -EACCES) { > + error_append_hint(&local_err, "Cannot use vhost drivers = as " > + "it does not support live migration"); In this case there are 2 different reasons that it might be disabled; we've lost that text. It seems best in this case to use the message =66rom hdev->migration_blocker. > + } > 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 **err= p) > { > if (migration_is_idle(NULL)) { > migration_blockers =3D g_slist_prepend(migration_blockers, reaso= n); > + error_free(reason); That free doesn't look right there; isn't that freeing the reason that is a= dded to the list and will get used later if someone tries to start a migration? Dave > return 0; > } > =20 > + if (only_migratable) { > + error_setg(errp, "Failed to add migration blocker: --only-migrat= able " > + "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 =3D migrate_add_blocker(invtsc_mig_blocker, NULL); > if (r < 0) { > + if (r =3D=3D -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; > } > =20 > --=20 > 2.6.2 >=20 -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK