Define flags to be used as delimiter in migration stream for VFIO devices.
Added .save_setup and .save_cleanup functions. Map & unmap 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 | 102 +++++++++++++++++++++++++++++++++++++++++++++++++++
hw/vfio/trace-events | 2 +
2 files changed, 104 insertions(+)
diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index a0f0e79b9b73..94d2bdae5c54 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -8,12 +8,15 @@
*/
#include "qemu/osdep.h"
+#include "qemu/main-loop.h"
+#include "qemu/cutils.h"
#include <linux/vfio.h>
#include "sysemu/runstate.h"
#include "hw/vfio/vfio-common.h"
#include "cpu.h"
#include "migration/migration.h"
+#include "migration/vmstate.h"
#include "migration/qemu-file.h"
#include "migration/register.h"
#include "migration/blocker.h"
@@ -25,6 +28,22 @@
#include "trace.h"
#include "hw/hw.h"
+/*
+ * Flags to be used as unique delimiters for VFIO devices in the migration
+ * stream. These flags are composed as:
+ * 0xffffffff => MSB 32-bit all 1s
+ * 0xef10 => Magic ID, represents emulated (virtual) function IO
+ * 0x0000 => 16-bits reserved for flags
+ *
+ * The beginning of state information is marked by _DEV_CONFIG_STATE,
+ * _DEV_SETUP_STATE, or _DEV_DATA_STATE, respectively. The end of a
+ * certain state information is marked by _END_OF_STATE.
+ */
+#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 inline int vfio_mig_access(VFIODevice *vbasedev, void *val, int count,
off_t off, bool iswrite)
{
@@ -129,6 +148,75 @@ static int vfio_migration_set_state(VFIODevice *vbasedev,
uint32_t mask,
return 0;
}
+static void vfio_migration_cleanup(VFIODevice *vbasedev)
+{
+ VFIOMigration *migration = vbasedev->migration;
+
+ if (migration->region.mmaps) {
+ vfio_region_unmap(&migration->region);
+ }
+}
+
+/* ---------------------------------------------------------------------- */
+
+static int vfio_save_setup(QEMUFile *f, void *opaque)
+{
+ VFIODevice *vbasedev = opaque;
+ VFIOMigration *migration = vbasedev->migration;
+ int ret;
+
+ trace_vfio_save_setup(vbasedev->name);
+
+ qemu_put_be64(f, VFIO_MIG_FLAG_DEV_SETUP_STATE);
+
+ if (migration->region.mmaps) {
+ /*
+ * Calling vfio_region_mmap() from migration thread. Memory API called
+ * from this function require locking the iothread when called from
+ * outside the main loop thread.
+ */
+ qemu_mutex_lock_iothread();
+ ret = vfio_region_mmap(&migration->region);
+ qemu_mutex_unlock_iothread();
+ if (ret) {
+ error_report("%s: Failed to mmap VFIO migration region: %s",
+ vbasedev->name, strerror(-ret));
+ error_report("%s: Falling back to slow path", vbasedev->name);
+ }
+ }
+
+ ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_MASK,
+ VFIO_DEVICE_STATE_SAVING);
+ if (ret) {
+ error_report("%s: Failed to set state SAVING", vbasedev->name);
+ return ret;
+ }
+