On Tue, 9 Jul 2019 15:19:12 +0530
Kirti Wankhede <kwankh...@nvidia.com> wrote:
> - Migration functions are implemented for VFIO_DEVICE_TYPE_PCI device in this
> patch series.
> - VFIO device supports migration or not is decided based of migration region
> query. If migration region query is successful and migration region
> initialization is successful then migration is supported else migration is
> blocked.
>
> Signed-off-by: Kirti Wankhede <kwankh...@nvidia.com>
> Reviewed-by: Neo Jia <c...@nvidia.com>
> ---
> hw/vfio/Makefile.objs | 2 +-
> hw/vfio/migration.c | 145
> ++++++++++++++++++++++++++++++++++++++++++
> hw/vfio/trace-events | 3 +
> include/hw/vfio/vfio-common.h | 14 ++++
> 4 files changed, 163 insertions(+), 1 deletion(-)
> create mode 100644 hw/vfio/migration.c
>
(...)
> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> new file mode 100644
> index 000000000000..a2cfbd5af2e1
> --- /dev/null
> +++ b/hw/vfio/migration.c
> @@ -0,0 +1,145 @@
> +/*
> + * Migration support for VFIO devices
> + *
> + * Copyright NVIDIA, Inc. 2019
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2. See
> + * the COPYING file in the top-level directory.
> + */
> +
> +#include "qemu/osdep.h"
> +#include <linux/vfio.h>
> +
> +#include "hw/vfio/vfio-common.h"
> +#include "cpu.h"
> +#include "migration/migration.h"
> +#include "migration/qemu-file.h"
> +#include "migration/register.h"
> +#include "migration/blocker.h"
> +#include "migration/misc.h"
> +#include "qapi/error.h"
> +#include "exec/ramlist.h"
> +#include "exec/ram_addr.h"
> +#include "pci.h"
> +#include "trace.h"
> +
> +static void vfio_migration_region_exit(VFIODevice *vbasedev)
> +{
> + VFIOMigration *migration = vbasedev->migration;
> +
> + if (!migration) {
> + return;
> + }
> +
> + if (migration->region.buffer.size) {
> + vfio_region_exit(&migration->region.buffer);
> + vfio_region_finalize(&migration->region.buffer);
> + }
> +}
> +
> +static int vfio_migration_region_init(VFIODevice *vbasedev)
> +{
> + VFIOMigration *migration = vbasedev->migration;
> + Object *obj = NULL;
> + int ret = -EINVAL;
> +
> + if (!migration) {
You're checking for vbasedev->migration here...
> + return ret;
> + }
> +
> + if (!vbasedev->ops || !vbasedev->ops->vfio_get_object) {
> + return ret;
> + }
> +
> + obj = vbasedev->ops->vfio_get_object(vbasedev);
> + if (!obj) {
> + return ret;
> + }
> +
> + ret = vfio_region_setup(obj, vbasedev, &migration->region.buffer,
> + migration->region.index, "migration");
> + if (ret) {
> + error_report("%s: Failed to setup VFIO migration region %d: %s",
> + vbasedev->name, migration->region.index,
> strerror(-ret));
> + goto err;
> + }
> +
> + if (!migration->region.buffer.size) {
> + ret = -EINVAL;
> + error_report("%s: Invalid region size of VFIO migration region %d:
> %s",
> + vbasedev->name, migration->region.index,
> strerror(-ret));
> + goto err;
> + }
> +
> + return 0;
> +
> +err:
> + vfio_migration_region_exit(vbasedev);
> + return ret;
> +}
> +
> +static int vfio_migration_init(VFIODevice *vbasedev,
> + struct vfio_region_info *info)
> +{
> + int ret;
> +
> + vbasedev->migration = g_new0(VFIOMigration, 1);
...but always allocate it before calling the function above here. What
am I missing?
> + vbasedev->migration->region.index = info->index;
> +
> + ret = vfio_migration_region_init(vbasedev);
> + if (ret) {
> + error_report("%s: Failed to initialise migration region",
> + vbasedev->name);
> + return ret;
It feels a bit odd that you don't free ->migration again here, but
delay it until finalize.
> + }
> +
> + return 0;
> +}
> +
> +/* ---------------------------------------------------------------------- */
> +
> +int vfio_migration_probe(VFIODevice *vbasedev, Error **errp)
> +{
> + struct vfio_region_info *info;
> + Error *local_err = NULL;
> + int ret;
> +
> + ret = vfio_get_dev_region_info(vbasedev, VFIO_REGION_TYPE_MIGRATION,
> + VFIO_REGION_SUBTYPE_MIGRATION, &info);
> + if (ret) {
> + goto add_blocker;
So you don't even call init if the region is not present (which seems
reasonable)...
> + }
> +
> + ret = vfio_migration_init(vbasedev, info);
> + if (ret) {
> + goto add_blocker;
> + }
> +
> + trace_vfio_migration_probe(vbasedev->name, info->index);
> + return 0;
> +
> +add_blocker:
> + error_setg(&vbasedev->migration_blocker,
> + "VFIO device doesn't support migration");
> + ret = migrate_add_blocker(vbasedev->migration_blocker, &local_err);
> + if (local_err) {
> + error_propagate(errp, local_err);
> + error_free(vbasedev->migration_blocker);
> + }
> + return ret;
> +}
> +
> +void vfio_migration_finalize(VFIODevice *vbasedev)
> +{
> + if (!vbasedev->migration) {
...but you're doing a quick exit here in that case. Shouldn't you get
rid of the blocker here?
> + return;
> + }
> +
> + if (vbasedev->migration_blocker) {
> + migrate_del_blocker(vbasedev->migration_blocker);
> + error_free(vbasedev->migration_blocker);
> + }
> +
> + vfio_migration_region_exit(vbasedev);
> + g_free(vbasedev->migration);
> +}
