On Fri, 18 Oct 2019 22:20:40 +0200
Jens Freimann <jfreim...@redhat.com> wrote:
> As usual block all vfio-pci devices from being migrated, but make an
> exception for failover primary devices. This is achieved by setting
> unmigratable to 0 but also add a migration blocker for all vfio-pci
> devices except failover primary devices. These will be unplugged before
> migration happens by the migration handler of the corresponding
> virtio-net standby device.
>
> Signed-off-by: Jens Freimann <jfreim...@redhat.com>
> ---
> hw/vfio/pci.c | 31 +++++++++++++++++++++++++------
> hw/vfio/pci.h | 1 +
> 2 files changed, 26 insertions(+), 6 deletions(-)
>
> diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
> index 12fac39804..a15b83c6b6 100644
> --- a/hw/vfio/pci.c
> +++ b/hw/vfio/pci.c
> @@ -40,6 +40,9 @@
> #include "pci.h"
> #include "trace.h"
> #include "qapi/error.h"
> +#include "migration/blocker.h"
> +#include "qemu/option.h"
> +#include "qemu/option_int.h"
>
> #define TYPE_VFIO_PCI "vfio-pci"
> #define PCI_VFIO(obj) OBJECT_CHECK(VFIOPCIDevice, obj, TYPE_VFIO_PCI)
> @@ -2712,12 +2715,26 @@ static void vfio_realize(PCIDevice *pdev, Error
> **errp)
> int i, ret;
> bool is_mdev;
>
> + if (!pdev->net_failover_pair_id) {
> + error_setg(&vdev->migration_blocker,
> + "VFIO device doesn't support migration");
> + ret = migrate_add_blocker(vdev->migration_blocker, &err);
> + if (err) {
> + error_propagate(errp, err);
> + goto error;
This looks wrong, you haven't set up vbasedev.name yet.
> + }
> + } else {
> + pdev->qdev.allow_unplug_during_migration = true;
> + }
> +
> if (!vdev->vbasedev.sysfsdev) {
> if (!(~vdev->host.domain || ~vdev->host.bus ||
> ~vdev->host.slot || ~vdev->host.function)) {
> error_setg(errp, "No provided host device");
> error_append_hint(errp, "Use -device vfio-pci,host=DDDD:BB:DD.F "
> "or -device
> vfio-pci,sysfsdev=PATH_TO_DEVICE\n");
> + migrate_del_blocker(vdev->migration_blocker);
> + error_free(vdev->migration_blocker);
> return;
> }
> vdev->vbasedev.sysfsdev =
> @@ -2729,6 +2746,8 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
> if (stat(vdev->vbasedev.sysfsdev, &st) < 0) {
> error_setg_errno(errp, errno, "no such host device");
> error_prepend(errp, VFIO_MSG_PREFIX, vdev->vbasedev.sysfsdev);
> + migrate_del_blocker(vdev->migration_blocker);
> + error_free(vdev->migration_blocker);
> return;
> }
Might be a bit easier cleanup-wise if you set up the blocker resp.
allow unplug during migration only here. The only difference is that
you'll get a different error message when trying to set up a
non-failover device with invalid specs on a migratable-only setup.
>
> @@ -3008,6 +3027,8 @@ out_teardown:
> vfio_bars_exit(vdev);
> error:
> error_prepend(errp, VFIO_MSG_PREFIX, vdev->vbasedev.name);
> + migrate_del_blocker(vdev->migration_blocker);
> + error_free(vdev->migration_blocker);
Shouldn't you check whether migration_block has been set up, like in
the finalize routine?
> }
>
> static void vfio_instance_finalize(Object *obj)
> @@ -3019,6 +3040,10 @@ static void vfio_instance_finalize(Object *obj)
> vfio_bars_finalize(vdev);
> g_free(vdev->emulated_config_bits);
> g_free(vdev->rom);
> + if (vdev->migration_blocker) {
> + migrate_del_blocker(vdev->migration_blocker);
> + error_free(vdev->migration_blocker);
> + }
> /*
> * XXX Leaking igd_opregion is not an oversight, we can't remove the
> * fw_cfg entry therefore leaking this allocation seems like the safest
