VM state change handler is called on change in VM's state. Based on
VM state, VFIO device state should be changed.
Added read/write helper functions for migration region.
Added function to set device_state.
Signed-off-by: Kirti Wankhede <kwankh...@nvidia.com>
Reviewed-by: Neo Jia <c...@nvidia.com>
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
---
hw/vfio/migration.c | 158 ++++++++++++++++++++++++++++++++++++++++++
hw/vfio/trace-events | 2 +
include/hw/vfio/vfio-common.h | 4 ++
3 files changed, 164 insertions(+)
diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index 5f74a3ad1d72..34f39c7e2e28 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -10,6 +10,7 @@
#include "qemu/osdep.h"
#include <linux/vfio.h>
+#include "sysemu/runstate.h"
#include "hw/vfio/vfio-common.h"
#include "cpu.h"
#include "migration/migration.h"
@@ -22,6 +23,157 @@
#include "exec/ram_addr.h"
#include "pci.h"
#include "trace.h"
+#include "hw/hw.h"
+
+static inline int vfio_mig_access(VFIODevice *vbasedev, void *val, int count,
+ off_t off, bool iswrite)
+{
+ int ret;
+
+ ret = iswrite ? pwrite(vbasedev->fd, val, count, off) :
+ pread(vbasedev->fd, val, count, off);
+ if (ret < count) {
+ error_report("vfio_mig_%s %d byte %s: failed at offset 0x%lx, err: %s",
+ iswrite ? "write" : "read", count,
+ vbasedev->name, off, strerror(errno));
+ return (ret < 0) ? ret : -EINVAL;
+ }
+ return 0;
+}
+
+static int vfio_mig_rw(VFIODevice *vbasedev, __u8 *buf, size_t count,
+ off_t off, bool iswrite)
+{
+ int ret, done = 0;
+ __u8 *tbuf = buf;
+
+ while (count) {
+ int bytes = 0;
+
+ if (count >= 8 && !(off % 8)) {
+ bytes = 8;
+ } else if (count >= 4 && !(off % 4)) {
+ bytes = 4;
+ } else if (count >= 2 && !(off % 2)) {
+ bytes = 2;
+ } else {
+ bytes = 1;
+ }
+
+ ret = vfio_mig_access(vbasedev, tbuf, bytes, off, iswrite);
+ if (ret) {
+ return ret;
+ }
+
+ count -= bytes;
+ done += bytes;
+ off += bytes;
+ tbuf += bytes;
+ }
+ return done;
+}
+
+#define vfio_mig_read(f, v, c, o) vfio_mig_rw(f, (__u8 *)v, c, o, false)
+#define vfio_mig_write(f, v, c, o) vfio_mig_rw(f, (__u8 *)v, c, o, true)
+
+#define VFIO_MIG_STRUCT_OFFSET(f) \
+ offsetof(struct vfio_device_migration_info, f)
+/*
+ * Change the device_state register for device @vbasedev. Bits set in @mask
+ * are preserved, bits set in @value are set, and bits not set in either @mask
+ * or @value are cleared in device_state. If the register cannot be accessed,
+ * the resulting state would be invalid, or the device enters an error state,
+ * an error is returned.
+ */
+
+static int vfio_migration_set_state(VFIODevice *vbasedev, uint32_t mask,
+ uint32_t value)
+{
+ VFIOMigration *migration = vbasedev->migration;
+ VFIORegion *region = &migration->region;
+ off_t dev_state_off = region->fd_offset +
+ VFIO_MIG_STRUCT_OFFSET(device_state);
+ uint32_t device_state;
+ int ret;
+
+ ret = vfio_mig_read(vbasedev, &device_state, sizeof(device_state),
+ dev_state_off);
+ if (ret < 0) {
+ return ret;
+ }
+
+ device_state = (device_state & mask) | value;
+
+ if (!VFIO_DEVICE_STATE_VALID(device_state)) {
+ return -EINVAL;
+ }
+
+ ret = vfio_mig_write(vbasedev, &device_state, sizeof(device_state),
+ dev_state_off);
+ if (ret < 0) {
+ int rret;
+
+ rret = vfio_mig_read(vbasedev, &device_state, sizeof(device_state),
+ dev_state_off);
+
+ if ((rret < 0) || (VFIO_DEVICE_STATE_IS_ERROR(device_state))) {
+ hw_error("%s: Device in error state 0x%x", vbasedev->name,
+ device_state);
+ return rret ? rret : -EIO;
+ }
+ return ret;
+ }
+
+ migration->device_state = device_state;
+ trace_vfio_migration_set_state(vbasedev->name, device_state);
+ return 0;
+}
+
+static void vfio_vmstate_change(void *opaque, int running, RunState state)
+{
+ VFIODevice *vbasedev = opaque;
+ VFIOMigration *migration = vbasedev->migration;
+ uint32_t value, mask;
+ int ret;
+
+ if ((vbasedev->migration->vm_running == running)) {
+ return;
+ }
+
+ if (running) {
+ /*
+ * Here device state can have one of _SAVING, _RESUMING or _STOP bit.
+ * Transition from _SAVING to _RUNNING can happen if there is migration
+ * failure, in that case clear _SAVING bit.
+ * Transition from _RESUMING to _RUNNING occurs during resuming
+ * phase, in that case clear _RESUMING bit.
+ * In both the above cases, set _RUNNING bit.
+ */
+ mask = ~VFIO_DEVICE_STATE_MASK;
+ value = VFIO_DEVICE_STATE_RUNNING;
+ } else {
+ /*
+ * Here device state could be either _RUNNING or _SAVING|_RUNNING.
Reset
+ * _RUNNING bit
+ */
+ mask = ~VFIO_DEVICE_STATE_RUNNING;
+ value = 0;
+ }
+
+ ret = vfio_migration_set_state(vbasedev, mask, value);
+ if (ret) {
+ /*
+ * Migration should be aborted in this case, but vm_state_notify()
+ * currently does not support reporting failures.
+ */
+ error_report("%s: Failed to set device state 0x%x", vbasedev->name,
+ (migration->device_state & mask) | value);
+ qemu_file_set_error(migrate_get_current()->to_dst_file, ret);
+ }
+ vbasedev->migration->vm_running = running;
+ trace_vfio_vmstate_change(vbasedev->name, running, RunState_str(state),
+ (migration->device_state & mask) | value);
+}
static void vfio_migration_region_exit(VFIODevice *vbasedev)
{
@@ -71,6 +223,8 @@ static int vfio_migration_init(VFIODevice *vbasedev,
}
vbasedev->migration = migration;
+ migration->vm_state = qemu_add_vm_change_state_handler(vfio_vmstate_change,
+ vbasedev);
return 0;
err:
@@ -118,6 +272,10 @@ add_blocker:
void vfio_migration_finalize(VFIODevice *vbasedev)
{
+ if (vbasedev->migration->vm_state) {
+ qemu_del_vm_change_state_handler(vbasedev->migration->vm_state);
+ }
