On Tue, 12 Nov 2019 22:35:19 +0530
Kirti Wankhede <kwankh...@nvidia.com> wrote:
> Define flags to be used as delimeter in migration file stream.
> Added .save_setup and .save_cleanup functions. Mapped & unmapped migration
> region from these functions at source during saving or pre-copy phase.
> Set VFIO device state depending on VM's state. During live migration, VM is
> running when .save_setup is called, _SAVING | _RUNNING state is set for VFIO
> device. During save-restore, VM is paused, _SAVING state is set for VFIO
> device.
>
> Signed-off-by: Kirti Wankhede <kwankh...@nvidia.com>
> Reviewed-by: Neo Jia <c...@nvidia.com>
> ---
> hw/vfio/migration.c | 70
> ++++++++++++++++++++++++++++++++++++++++++++++++++++
> hw/vfio/trace-events | 2 ++
> 2 files changed, 72 insertions(+)
>
> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> index 7e7aeb58647e..48aac6d29876 100644
> --- a/hw/vfio/migration.c
> +++ b/hw/vfio/migration.c
> @@ -8,6 +8,7 @@
> */
>
> #include "qemu/osdep.h"
> +#include "qemu/main-loop.h"
> #include <linux/vfio.h>
>
> #include "sysemu/runstate.h"
> @@ -24,6 +25,17 @@
> #include "pci.h"
> #include "trace.h"
>
> +/*
> + * Flags used as delimiter:
> + * 0xffffffff => MSB 32-bit all 1s
> + * 0xef10 => emulated (virtual) function IO
> + * 0x0000 => 16-bits reserved for flags
> + */
> +#define VFIO_MIG_FLAG_END_OF_STATE (0xffffffffef100001ULL)
> +#define VFIO_MIG_FLAG_DEV_CONFIG_STATE (0xffffffffef100002ULL)
> +#define VFIO_MIG_FLAG_DEV_SETUP_STATE (0xffffffffef100003ULL)
> +#define VFIO_MIG_FLAG_DEV_DATA_STATE (0xffffffffef100004ULL)
> +
> static void vfio_migration_region_exit(VFIODevice *vbasedev)
> {
> VFIOMigration *migration = vbasedev->migration;
> @@ -108,6 +120,63 @@ static int vfio_migration_set_state(VFIODevice
> *vbasedev, uint32_t set_flags,
> return 0;
> }
>
> +/* ---------------------------------------------------------------------- */
> +
> +static int vfio_save_setup(QEMUFile *f, void *opaque)
> +{
> + VFIODevice *vbasedev = opaque;
> + VFIOMigration *migration = vbasedev->migration;
> + int ret;
> +
> + qemu_put_be64(f, VFIO_MIG_FLAG_DEV_SETUP_STATE);
> +
> + if (migration->region.mmaps) {
> + qemu_mutex_lock_iothread();
> + ret = vfio_region_mmap(&migration->region);
> + qemu_mutex_unlock_iothread();
Please add comment indicating why the iothread mutex handling is
necessary.
> + if (ret) {
> + error_report("%s: Failed to mmap VFIO migration region %d: %s",
> + vbasedev->name, migration->region.index,
> + strerror(-ret));
> + return ret;
mmaps are optional for the user, right? This seems like a continue'able error.
> + }
> + }
> +
> + ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_SAVING, 0);
> + if (ret) {
> + error_report("%s: Failed to set state SAVING", vbasedev->name);
> + return ret;
> + }
> +
> + qemu_put_be64(f, VFIO_MIG_FLAG_END_OF_STATE);
Why have we bothered to write anything into the migration stream yet?
> +
> + ret = qemu_file_get_error(f);
> + if (ret) {
> + return ret;
> + }
> +
> + trace_vfio_save_setup(vbasedev->name);
> + return 0;
> +}
> +
> +static void vfio_save_cleanup(void *opaque)
> +{
> + VFIODevice *vbasedev = opaque;
> + VFIOMigration *migration = vbasedev->migration;
> +
> + if (migration->region.mmaps) {
> + vfio_region_unmap(&migration->region);
> + }
> + trace_vfio_save_cleanup(vbasedev->name);
We don't need to touch device_state here?
> +}
> +
> +static SaveVMHandlers savevm_vfio_handlers = {
> + .save_setup = vfio_save_setup,
> + .save_cleanup = vfio_save_cleanup,
> +};
> +
> +/* ---------------------------------------------------------------------- */
> +
> static void vfio_vmstate_change(void *opaque, int running, RunState state)
> {
> VFIODevice *vbasedev = opaque;
> @@ -171,6 +240,7 @@ static int vfio_migration_init(VFIODevice *vbasedev,
> return ret;
> }
>
> + register_savevm_live("vfio", -1, 1, &savevm_vfio_handlers, vbasedev);
> vbasedev->vm_state =
> qemu_add_vm_change_state_handler(vfio_vmstate_change,
> vbasedev);
>
> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> index 69503228f20e..4bb43f18f315 100644
> --- a/hw/vfio/trace-events
> +++ b/hw/vfio/trace-events
> @@ -149,3 +149,5 @@ vfio_migration_probe(char *name, uint32_t index) " (%s)
> Region %d"
> vfio_migration_set_state(char *name, uint32_t state) " (%s) state %d"
> vfio_vmstate_change(char *name, int running, const char *reason, uint32_t
> dev_state) " (%s) running %d reason %s device state %d"
> vfio_migration_state_notifier(char *name, int state) " (%s) state %d"
> +vfio_save_setup(char *name) " (%s)"
> +vfio_save_cleanup(char *name) " (%s)"
