On Tue, Feb 19, 2019 at 11:25:43AM +0000, Dr. David Alan Gilbert wrote:
> * Yan Zhao (yan.y.zhao@xxxxxxxxx) wrote:
> > If a device has device memory capability, save/load data from device memory
> > in pre-copy and stop-and-copy phases.
> >
> > LOGGING state is set for device memory for dirty page logging:
> > in LOGGING state, get device memory returns whole device memory snapshot;
> > outside LOGGING state, get device memory returns dirty data since last get
> > operation.
> >
> > Usually, device memory is very big, qemu needs to chunk it into several
> > pieces each with size of device memory region.
> >
> > Signed-off-by: Yan Zhao <yan.y.zhao@xxxxxxxxx>
> > Signed-off-by: Kirti Wankhede <kwankhede@xxxxxxxxxx>
> > ---
> > hw/vfio/migration.c | 235 ++++++++++++++++++++++++++++++++++++++++++++++++++--
> > hw/vfio/pci.h | 1 +
> > 2 files changed, 231 insertions(+), 5 deletions(-)
> >
> > diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> > index 16d6395..f1e9309 100644
> > --- a/hw/vfio/migration.c
> > +++ b/hw/vfio/migration.c
> > @@ -203,6 +203,201 @@ static int vfio_load_data_device_config(VFIOPCIDevice *vdev,
> > return 0;
> > }
> >
> > +static int vfio_get_device_memory_size(VFIOPCIDevice *vdev)
> > +{
> > + VFIODevice *vbasedev = &vdev->vbasedev;
> > + VFIORegion *region_ctl =
> > + &vdev->migration->region[VFIO_DEVSTATE_REGION_CTL];
> > + uint64_t len;
> > + int sz;
> > +
> > + sz = sizeof(len);
> > + if (pread(vbasedev->fd, &len, sz,
> > + region_ctl->fd_offset +
> > + offsetof(struct vfio_device_state_ctl, device_memory.size))
> > + != sz) {
> > + error_report("vfio: Failed to get length of device memory");
> > + return -1;
> > + }
> > + vdev->migration->devmem_size = len;
> > + return 0;
> > +}
> > +
> > +static int vfio_set_device_memory_size(VFIOPCIDevice *vdev, uint64_t size)
> > +{
> > + VFIODevice *vbasedev = &vdev->vbasedev;
> > + VFIORegion *region_ctl =
> > + &vdev->migration->region[VFIO_DEVSTATE_REGION_CTL];
> > + int sz;
> > +
> > + sz = sizeof(size);
> > + if (pwrite(vbasedev->fd, &size, sz,
> > + region_ctl->fd_offset +
> > + offsetof(struct vfio_device_state_ctl, device_memory.size))
> > + != sz) {
> > + error_report("vfio: Failed to set length of device comemory");
> > + return -1;
> > + }
> > + vdev->migration->devmem_size = size;
> > + return 0;
> > +}
> > +
> > +static
> > +int vfio_save_data_device_memory_chunk(VFIOPCIDevice *vdev, QEMUFile *f,
> > + uint64_t pos, uint64_t len)
> > +{
> > + VFIODevice *vbasedev = &vdev->vbasedev;
> > + VFIORegion *region_ctl =
> > + &vdev->migration->region[VFIO_DEVSTATE_REGION_CTL];
> > + VFIORegion *region_devmem =
> > + &vdev->migration->region[VFIO_DEVSTATE_REGION_DATA_DEVICE_MEMORY];
> > + void *dest;
> > + uint32_t sz;
> > + uint8_t *buf = NULL;
> > + uint32_t action = VFIO_DEVICE_DATA_ACTION_GET_BUFFER;
> > +
> > + if (len > region_devmem->size) {
> > + return -1;
> > + }
> > +
> > + sz = sizeof(pos);
> > + if (pwrite(vbasedev->fd, &pos, sz,
> > + region_ctl->fd_offset +
> > + offsetof(struct vfio_device_state_ctl, device_memory.pos))
> > + != sz) {
> > + error_report("vfio: Failed to set save buffer pos");
> > + return -1;
> > + }
> > + sz = sizeof(action);
> > + if (pwrite(vbasedev->fd, &action, sz,
> > + region_ctl->fd_offset +
> > + offsetof(struct vfio_device_state_ctl, device_memory.action))
> > + != sz) {
> > + error_report("vfio: Failed to set save buffer action");
> > + return -1;
> > + }
> > +
> > + if (!vfio_device_state_region_mmaped(region_devmem)) {
> > + buf = g_malloc(len);
> > + if (buf == NULL) {
> > + error_report("vfio: Failed to allocate memory for migrate");
> > + return -1;
> > + }
> > + if (pread(vbasedev->fd, buf, len, region_devmem->fd_offset) != len) {
> > + error_report("vfio: error load device memory buffer");
>
> That's forgotten to g_free(buf)
>
Right, I'll correct that.
> > + return -1;
> > + }
> > + qemu_put_be64(f, len);
> > + qemu_put_be64(f, pos);
> > + qemu_put_buffer(f, buf, len);
> > + g_free(buf);
> > + } else {
> > + dest = region_devmem->mmaps[0].mmap;
> > + qemu_put_be64(f, len);
> > + qemu_put_be64(f, pos);
> > + qemu_put_buffer(f, dest, len);
> > + }
> > + return 0;
> > +}
> > +
> > +static int vfio_save_data_device_memory(VFIOPCIDevice *vdev, QEMUFile *f)
> > +{
> > + VFIORegion *region_devmem =
> > + &vdev->migration->region[VFIO_DEVSTATE_REGION_DATA_DEVICE_MEMORY];
> > + uint64_t total_len = vdev->migration->devmem_size;
> > + uint64_t pos = 0;
> > +
> > + qemu_put_be64(f, total_len);
> > + while (pos < total_len) {
> > + uint64_t len = region_devmem->size;
> > +
> > + if (pos + len >= total_len) {
> > + len = total_len - pos;
> > + }
> > + if (vfio_save_data_device_memory_chunk(vdev, f, pos, len)) {
> > + return -1;
> > + }
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static
> > +int vfio_load_data_device_memory_chunk(VFIOPCIDevice *vdev, QEMUFile *f,
> > + uint64_t pos, uint64_t len)
> > +{
> > + VFIODevice *vbasedev = &vdev->vbasedev;
> > + VFIORegion *region_ctl =
> > + &vdev->migration->region[VFIO_DEVSTATE_REGION_CTL];
> > + VFIORegion *region_devmem =
> > + &vdev->migration->region[VFIO_DEVSTATE_REGION_DATA_DEVICE_MEMORY];
> > +
> > + void *dest;
> > + uint32_t sz;
> > + uint8_t *buf = NULL;
> > + uint32_t action = VFIO_DEVICE_DATA_ACTION_SET_BUFFER;
> > +
> > + if (len > region_devmem->size) {
> > + return -1;
> > + }
> > +
> > + sz = sizeof(pos);
> > + if (pwrite(vbasedev->fd, &pos, sz,
> > + region_ctl->fd_offset +
> > + offsetof(struct vfio_device_state_ctl, device_memory.pos))
> > + != sz) {
> > + error_report("vfio: Failed to set device memory buffer pos");
> > + return -1;
> > + }
> > + if (!vfio_device_state_region_mmaped(region_devmem)) {
> > + buf = g_malloc(len);
> > + if (buf == NULL) {
> > + error_report("vfio: Failed to allocate memory for migrate");
> > + return -1;
> > + }
> > + qemu_get_buffer(f, buf, len);
> > + if (pwrite(vbasedev->fd, buf, len,
> > + region_devmem->fd_offset) != len) {
> > + error_report("vfio: Failed to load devie memory buffer");
>
> Again, failed to free buf
>
Right, I'll correct that.
> > + return -1;
> > + }
> > + g_free(buf);
> > + } else {
> > + dest = region_devmem->mmaps[0].mmap;
> > + qemu_get_buffer(f, dest, len);
> > + }
>
> You might want to use qemu_file_get_error(f) before writing the data
> to the device, to check for the case of a read error on the migration
> stream that happened somewhere in the pevious qemu_get's
>
ok.
> > + sz = sizeof(action);
> > + if (pwrite(vbasedev->fd, &action, sz,
> > + region_ctl->fd_offset +
> > + offsetof(struct vfio_device_state_ctl, device_memory.action))
> > + != sz) {
> > + error_report("vfio: Failed to set load device memory buffer action");
> > + return -1;
> > + }
> > +
> > + return 0;
> > +
> > +}
> > +
> > +static int vfio_load_data_device_memory(VFIOPCIDevice *vdev,
> > + QEMUFile *f, uint64_t total_len)
> > +{
> > + uint64_t pos = 0, len = 0;
> > +
> > + vfio_set_device_memory_size(vdev, total_len);
> > +
> > + while (pos + len < total_len) {
> > + len = qemu_get_be64(f);
> > + pos = qemu_get_be64(f);
>
> Please check len/pos - always assume that the migration stream could
> be (maliciously or accidentally) corrupt.
>
ok.
> > + vfio_load_data_device_memory_chunk(vdev, f, pos, len);
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +
> > static int vfio_set_dirty_page_bitmap_chunk(VFIOPCIDevice *vdev,
> > uint64_t start_addr, uint64_t page_nr)
> > {
> > @@ -377,6 +572,10 @@ static void vfio_save_live_pending(QEMUFile *f, void *opaque,
> > return;
> > }
> >
> > + /* get dirty data size of device memory */
> > + vfio_get_device_memory_size(vdev);
> > +
> > + *res_precopy_only += vdev->migration->devmem_size;
> > return;
> > }
> >
> > @@ -388,7 +587,9 @@ static int vfio_save_iterate(QEMUFile *f, void *opaque)
> > return 0;
> > }
> >
> > - return 0;
> > + qemu_put_byte(f, VFIO_SAVE_FLAG_DEVMEMORY);
> > + /* get dirty data of device memory */
> > + return vfio_save_data_device_memory(vdev, f);
> > }
> >
> > static void vfio_pci_load_config(VFIOPCIDevice *vdev, QEMUFile *f)
> > @@ -458,6 +659,10 @@ static int vfio_load_state(QEMUFile *f, void *opaque, int version_id)
> > len = qemu_get_be64(f);
> > vfio_load_data_device_config(vdev, f, len);
> > break;
> > + case VFIO_SAVE_FLAG_DEVMEMORY:
> > + len = qemu_get_be64(f);
> > + vfio_load_data_device_memory(vdev, f, len);
> > + break;
> > default:
> > ret = -EINVAL;
> > }
> > @@ -503,6 +708,13 @@ static int vfio_save_complete_precopy(QEMUFile *f, void *opaque)
> > VFIOPCIDevice *vdev = opaque;
> > int rc = 0;
> >
> > + if (vfio_device_data_cap_device_memory(vdev)) {
> > + qemu_put_byte(f, VFIO_SAVE_FLAG_DEVMEMORY | VFIO_SAVE_FLAG_CONTINUE);
> > + /* get dirty data of device memory */
> > + vfio_get_device_memory_size(vdev);
> > + rc = vfio_save_data_device_memory(vdev, f);
> > + }
> > +
> > qemu_put_byte(f, VFIO_SAVE_FLAG_PCI | VFIO_SAVE_FLAG_CONTINUE);
> > vfio_pci_save_config(vdev, f);
> >
> > @@ -515,12 +727,22 @@ static int vfio_save_complete_precopy(QEMUFile *f, void *opaque)
> >
> > static int vfio_save_setup(QEMUFile *f, void *opaque)
> > {
> > + int rc = 0;
> > VFIOPCIDevice *vdev = opaque;
> > - qemu_put_byte(f, VFIO_SAVE_FLAG_SETUP);
> > +
> > + if (vfio_device_data_cap_device_memory(vdev)) {
> > + qemu_put_byte(f, VFIO_SAVE_FLAG_SETUP | VFIO_SAVE_FLAG_CONTINUE);
> > + qemu_put_byte(f, VFIO_SAVE_FLAG_DEVMEMORY);
> > + /* get whole snapshot of device memory */
> > + vfio_get_device_memory_size(vdev);
> > + rc = vfio_save_data_device_memory(vdev, f);
> > + } else {
> > + qemu_put_byte(f, VFIO_SAVE_FLAG_SETUP);
> > + }
> >
> > vfio_set_device_state(vdev, VFIO_DEVICE_STATE_RUNNING |
> > VFIO_DEVICE_STATE_LOGGING);
> > - return 0;
> > + return rc;
> > }
> >
> > static int vfio_load_setup(QEMUFile *f, void *opaque)
> > @@ -576,8 +798,11 @@ int vfio_migration_init(VFIOPCIDevice *vdev, Error **errp)
> > goto error;
> > }
> >
> > - if (vfio_device_data_cap_device_memory(vdev)) {
> > - error_report("No suppport of data cap device memory Yet");
> > + if (vfio_device_data_cap_device_memory(vdev) &&
> > + vfio_device_state_region_setup(vdev,
> > + &vdev->migration->region[VFIO_DEVSTATE_REGION_DATA_DEVICE_MEMORY],
> > + VFIO_REGION_SUBTYPE_DEVICE_STATE_DATA_MEMORY,
> > + "device-state-data-device-memory")) {
> > goto error;
> > }
> >
> > diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
> > index 4b7b1bb..a2cc64b 100644
> > --- a/hw/vfio/pci.h
> > +++ b/hw/vfio/pci.h
> > @@ -69,6 +69,7 @@ typedef struct VFIOMigration {
> > uint32_t data_caps;
> > uint32_t device_state;
> > uint64_t devconfig_size;
> > + uint64_t devmem_size;
> > VMChangeStateEntry *vm_state;
> > } VFIOMigration;
> >
> > --
> > 2.7.4
> >
> --
> Dr. David Alan Gilbert / dgilbert@xxxxxxxxxx / Manchester, UK
> _______________________________________________
> intel-gvt-dev mailing list
> intel-gvt-dev@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev
