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Re: [Qemu-devel] [PATCH v4 09/13] vfio: Add load state functions to Save
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [PATCH v4 09/13] vfio: Add load state functions to SaveVMHandlers |
Date: |
Fri, 28 Jun 2019 10:18:55 +0100 |
User-agent: |
Mutt/1.12.0 (2019-05-25) |
* Kirti Wankhede (address@hidden) wrote:
> During _RESUMING device state:
> - If Vendor driver defines mappable region, mmap migration region.
> - Load config state.
> - For data packet, till VFIO_MIG_FLAG_END_OF_STATE is not reached
> - read data_size from packet, read buffer of data_size
> - read data_offset from where QEMU should write data.
> if region is mmaped, write data of data_size to mmaped region.
> - write data_size.
> In case of mmapped region, write to data_size indicates kernel
> driver that data is written in staging buffer.
> - if region is trapped, pwrite() data of data_size from data_offset.
> - Repeat above until VFIO_MIG_FLAG_END_OF_STATE.
> - Unmap migration region.
>
> Signed-off-by: Kirti Wankhede <address@hidden>
> Reviewed-by: Neo Jia <address@hidden>
> ---
> hw/vfio/migration.c | 153
> ++++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 153 insertions(+)
>
> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> index 0a2f30872316..e4895f91761d 100644
> --- a/hw/vfio/migration.c
> +++ b/hw/vfio/migration.c
> @@ -212,6 +212,22 @@ static int vfio_save_device_config_state(QEMUFile *f,
> void *opaque)
> return qemu_file_get_error(f);
> }
>
> +static int vfio_load_device_config_state(QEMUFile *f, void *opaque)
> +{
> + VFIODevice *vbasedev = opaque;
> +
> + if (vbasedev->type == VFIO_DEVICE_TYPE_PCI) {
> + vfio_pci_load_config(vbasedev, f);
> + }
> +
> + if (qemu_get_be64(f) != VFIO_MIG_FLAG_END_OF_STATE) {
> + error_report("Wrong end of block while loading device config space");
You might find it useful to print the value in the error.
> + return -EINVAL;
> + }
> +
> + return qemu_file_get_error(f);
> +}
> +
> /* ---------------------------------------------------------------------- */
>
> static int vfio_save_setup(QEMUFile *f, void *opaque)
> @@ -372,12 +388,149 @@ static int vfio_save_complete_precopy(QEMUFile *f,
> void *opaque)
> return ret;
> }
>
> +static int vfio_load_setup(QEMUFile *f, void *opaque)
> +{
> + VFIODevice *vbasedev = opaque;
> + VFIOMigration *migration = vbasedev->migration;
> + int ret = 0;
> +
> + if (migration->region.buffer.mmaps) {
> + ret = vfio_region_mmap(&migration->region.buffer);
> + if (ret) {
> + error_report("Failed to mmap VFIO migration region %d: %s",
> + migration->region.index, strerror(-ret));
> + return ret;
> + }
> + }
> +
> + ret = vfio_migration_set_state(vbasedev, VFIO_DEVICE_STATE_RESUMING);
> + if (ret) {
> + error_report("Failed to set state RESUMING");
> + }
> + return ret;
> +}
> +
> +static int vfio_load_cleanup(void *opaque)
> +{
> + vfio_save_cleanup(opaque);
> + return 0;
> +}
> +
> +static int vfio_load_state(QEMUFile *f, void *opaque, int version_id)
> +{
> + VFIODevice *vbasedev = opaque;
> + VFIOMigration *migration = vbasedev->migration;
> + int ret = 0;
> + uint64_t data, data_size;
> +
> + data = qemu_get_be64(f);
> + while (data != VFIO_MIG_FLAG_END_OF_STATE) {
> + switch (data) {
> + case VFIO_MIG_FLAG_DEV_CONFIG_STATE:
> + {
> + ret = vfio_load_device_config_state(f, opaque);
> + if (ret) {
> + return ret;
> + }
> + break;
> + }
> + case VFIO_MIG_FLAG_DEV_SETUP_STATE:
> + {
> + data = qemu_get_be64(f);
> + if (data == VFIO_MIG_FLAG_END_OF_STATE) {
> + return ret;
> + } else {
> + error_report("SETUP STATE: EOS not found 0x%lx", data);
Please use PRIx64 for uint64_t (I know it's painful, but it's portable).
> + return -EINVAL;
> + }
> + break;
> + }
> + case VFIO_MIG_FLAG_DEV_DATA_STATE:
> + {
> + VFIORegion *region = &migration->region.buffer;
> + void *buf = NULL;
> + bool buffer_mmaped = false;
> + uint64_t data_offset = 0;
> +
> + data_size = qemu_get_be64(f);
> + if (data_size == 0) {
> + break;
> + }
> +
> + ret = pread(vbasedev->fd, &data_offset, sizeof(data_offset),
> + region->fd_offset +
> + offsetof(struct vfio_device_migration_info,
> + data_offset));
> + if (ret != sizeof(data_offset)) {
> + error_report("Failed to get migration buffer data offset %d",
> + ret);
> + return -EINVAL;
> + }
> +
> + if (region->mmaps) {
> + int i;
> +
> + for (i = 0; i < region->nr_mmaps; i++) {
> + if (region->mmaps[i].mmap &&
> + (data_offset >= region->mmaps[i].offset) &&
> + (data_offset < region->mmaps[i].offset +
> + region->mmaps[i].size)) {
> + buf = region->mmaps[i].mmap + (data_offset -
> +
> region->mmaps[i].offset);
What checks that the read data_size fits in the region?
[Treat the incoming stream as broken/malicious until proven otherwise]
> + buffer_mmaped = true;
> + break;
> + }
> + }
I think you had some code like this on the save side? Perhaps a
'find_region' helper would be good?
> + }
> +
> + if (!buffer_mmaped) {
> + buf = g_malloc0(data_size);
> + }
Given that data_size could be quite large, you might want to use
g_try_malloc0 and check the return value; especially since 'data_size'
is read from the stream.
> + qemu_get_buffer(f, buf, data_size);
> +
> + ret = pwrite(vbasedev->fd, &data_size, sizeof(data_size),
> + region->fd_offset +
> + offsetof(struct vfio_device_migration_info,
> data_size));
> + if (ret != sizeof(data_size)) {
> + error_report("Failed to set migration buffer data size %d",
> + ret);
> + return -EINVAL;
> + }
> +
> + if (!buffer_mmaped) {
> + ret = pwrite(vbasedev->fd, buf, data_size,
> + region->fd_offset + data_offset);
> + g_free(buf);
> +
> + if (ret != data_size) {
> + error_report("Failed to set migration buffer %d", ret);
> + return -EINVAL;
> + }
> + }
> + break;
> + }
> + }
> +
> + ret = qemu_file_get_error(f);
> + if (ret) {
> + return ret;
> + }
> + data = qemu_get_be64(f);
> + }
> +
> + return ret;
> +}
> +
> static SaveVMHandlers savevm_vfio_handlers = {
> .save_setup = vfio_save_setup,
> .save_cleanup = vfio_save_cleanup,
> .save_live_pending = vfio_save_pending,
> .save_live_iterate = vfio_save_iterate,
> .save_live_complete_precopy = vfio_save_complete_precopy,
> + .load_setup = vfio_load_setup,
> + .load_cleanup = vfio_load_cleanup,
> + .load_state = vfio_load_state,
> };
>
> /* ---------------------------------------------------------------------- */
> --
> 2.7.0
>
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK
- Re: [Qemu-devel] [PATCH v4 08/13] vfio: Add save state functions to SaveVMHandlers, (continued)
- Re: [Qemu-devel] [PATCH v4 08/13] vfio: Add save state functions to SaveVMHandlers, Kirti Wankhede, 2019/06/21
- Re: [Qemu-devel] [PATCH v4 08/13] vfio: Add save state functions to SaveVMHandlers, Alex Williamson, 2019/06/21
- Re: [Qemu-devel] [PATCH v4 08/13] vfio: Add save state functions to SaveVMHandlers, Kirti Wankhede, 2019/06/21
- Re: [Qemu-devel] [PATCH v4 08/13] vfio: Add save state functions to SaveVMHandlers, Alex Williamson, 2019/06/21
- Re: [Qemu-devel] [PATCH v4 08/13] vfio: Add save state functions to SaveVMHandlers, Kirti Wankhede, 2019/06/24
Re: [Qemu-devel] [PATCH v4 08/13] vfio: Add save state functions to SaveVMHandlers, Yan Zhao, 2019/06/20
Re: [Qemu-devel] [PATCH v4 08/13] vfio: Add save state functions to SaveVMHandlers, Dr. David Alan Gilbert, 2019/06/28
[Qemu-devel] [PATCH v4 09/13] vfio: Add load state functions to SaveVMHandlers, Kirti Wankhede, 2019/06/20
- Re: [Qemu-devel] [PATCH v4 09/13] vfio: Add load state functions to SaveVMHandlers,
Dr. David Alan Gilbert <=
[Qemu-devel] [PATCH v4 10/13] vfio: Add function to get dirty page list, Kirti Wankhede, 2019/06/20
[Qemu-devel] [PATCH v4 11/13] vfio: Add vfio_listerner_log_sync to mark dirty pages, Kirti Wankhede, 2019/06/20
[Qemu-devel] [PATCH v4 12/13] vfio: Make vfio-pci device migration capable., Kirti Wankhede, 2019/06/20
[Qemu-devel] [PATCH v4 13/13] vfio: Add trace events in migration code path, Kirti Wankhede, 2019/06/20
Re: [Qemu-devel] [PATCH v4 00/13] Add migration support for VFIO device, Yan Zhao, 2019/06/20