diff mbox series

[QEMU,v25,09/17] vfio: Add load state functions to SaveVMHandlers

Message ID 1592684486-18511-10-git-send-email-kwankhede@nvidia.com
State New
Headers show
Series Add migration support for VFIO devices | expand

Commit Message

Kirti Wankhede June 20, 2020, 8:21 p.m. UTC 
Sequence  during _RESUMING device state:
While data for this device is available, repeat below steps:
a. read data_offset from where user application should write data.
b. write data of data_size to migration region from data_offset.
c. write data_size which indicates vendor driver that data is written in
   staging buffer.

For user, data is opaque. User should write data in the same order as
received.

Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
Reviewed-by: Neo Jia <cjia@nvidia.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 hw/vfio/migration.c  | 177 +++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/vfio/trace-events |   3 +
 2 files changed, 180 insertions(+)

Comments

Alex Williamson June 24, 2020, 6:54 p.m. UTC | #1 
On Sun, 21 Jun 2020 01:51:18 +0530
Kirti Wankhede <kwankhede@nvidia.com> wrote:

> Sequence  during _RESUMING device state:
> While data for this device is available, repeat below steps:
> a. read data_offset from where user application should write data.
> b. write data of data_size to migration region from data_offset.
> c. write data_size which indicates vendor driver that data is written in
>    staging buffer.
> 
> For user, data is opaque. User should write data in the same order as
> received.
> 
> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
> Reviewed-by: Neo Jia <cjia@nvidia.com>
> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
>  hw/vfio/migration.c  | 177 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  hw/vfio/trace-events |   3 +
>  2 files changed, 180 insertions(+)
> 
> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> index ef1150c1ff02..faacea5327cb 100644
> --- a/hw/vfio/migration.c
> +++ b/hw/vfio/migration.c
> @@ -302,6 +302,33 @@ 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;
> +    uint64_t data;
> +
> +    if (vbasedev->ops && vbasedev->ops->vfio_load_config) {
> +        int ret;
> +
> +        ret = vbasedev->ops->vfio_load_config(vbasedev, f);
> +        if (ret) {
> +            error_report("%s: Failed to load device config space",
> +                         vbasedev->name);
> +            return ret;
> +        }
> +    }
> +
> +    data = qemu_get_be64(f);
> +    if (data != VFIO_MIG_FLAG_END_OF_STATE) {
> +        error_report("%s: Failed loading device config space, "
> +                     "end flag incorrect 0x%"PRIx64, vbasedev->name, data);
> +        return -EINVAL;
> +    }
> +
> +    trace_vfio_load_device_config_state(vbasedev->name);
> +    return qemu_file_get_error(f);
> +}
> +
>  /* ---------------------------------------------------------------------- */
>  
>  static int vfio_save_setup(QEMUFile *f, void *opaque)
> @@ -472,12 +499,162 @@ 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.mmaps) {
> +        ret = vfio_region_mmap(&migration->region);
> +        if (ret) {
> +            error_report("%s: Failed to mmap VFIO migration region %d: %s",
> +                         vbasedev->name, migration->region.nr,
> +                         strerror(-ret));
> +            return ret;


Not fatal.


> +        }
> +    }
> +
> +    ret = vfio_migration_set_state(vbasedev, ~VFIO_DEVICE_STATE_MASK,
> +                                   VFIO_DEVICE_STATE_RESUMING);
> +    if (ret) {
> +        error_report("%s: Failed to set state RESUMING", vbasedev->name);
> +    }
> +    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) {
> +
> +        trace_vfio_load_state(vbasedev->name, data);
> +
> +        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("%s: SETUP STATE: EOS not found 0x%"PRIx64,
> +                             vbasedev->name, data);
> +                return -EINVAL;

This is essentially just a compatibility failure, right?  For instance
some future version of QEMU might include additional data between these
markers that we don't understand and therefore we fail the migration.
Thanks,

Alex

> +            }
> +            break;
> +        }
> +        case VFIO_MIG_FLAG_DEV_DATA_STATE:
> +        {
> +            VFIORegion *region = &migration->region;
> +            uint64_t data_offset = 0, size;
> +
> +            data_size = 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("%s:Failed to get migration buffer data offset %d",
> +                             vbasedev->name, ret);
> +                return -EINVAL;
> +            }
> +
> +            trace_vfio_load_state_device_data(vbasedev->name, data_offset,
> +                                              data_size);
> +
> +            while (size) {
> +                void *buf = NULL;
> +                uint64_t sec_size;
> +                bool buffer_mmaped;
> +
> +                buf = get_data_section_size(region, data_offset, size,
> +                                            &sec_size);
> +
> +                buffer_mmaped = (buf != NULL);
> +
> +                if (!buffer_mmaped) {
> +                    buf = g_try_malloc(sec_size);
> +                    if (!buf) {
> +                        error_report("%s: Error allocating buffer ", __func__);
> +                        return -ENOMEM;
> +                    }
> +                }
> +
> +                qemu_get_buffer(f, buf, sec_size);
> +
> +                if (!buffer_mmaped) {
> +                    ret = pwrite(vbasedev->fd, buf, sec_size,
> +                                 region->fd_offset + data_offset);
> +                    g_free(buf);
> +
> +                    if (ret != sec_size) {
> +                        error_report("%s: Failed to set migration buffer %d",
> +                                vbasedev->name, ret);
> +                        return -EINVAL;
> +                    }
> +                }
> +                size -= sec_size;
> +                data_offset += sec_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("%s: Failed to set migration buffer data size %d",
> +                             vbasedev->name, ret);
> +                return -EINVAL;
> +            }
> +            break;
> +        }
> +
> +        default:
> +            error_report("%s: Unknown tag 0x%"PRIx64, vbasedev->name, data);
> +            return -EINVAL;
> +        }
> +
> +        data = qemu_get_be64(f);
> +        ret = qemu_file_get_error(f);
> +        if (ret) {
> +            return ret;
> +        }
> +    }
> +
> +    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,
>  };
>  
>  /* ---------------------------------------------------------------------- */
> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> index 9a1c5e17d97f..4a4bd3ba9a2a 100644
> --- a/hw/vfio/trace-events
> +++ b/hw/vfio/trace-events
> @@ -157,3 +157,6 @@ vfio_save_device_config_state(const char *name) " (%s)"
>  vfio_save_pending(const char *name, uint64_t precopy, uint64_t postcopy, uint64_t compatible) " (%s) precopy 0x%"PRIx64" postcopy 0x%"PRIx64" compatible 0x%"PRIx64
>  vfio_save_iterate(const char *name, int data_size) " (%s) data_size %d"
>  vfio_save_complete_precopy(const char *name) " (%s)"
> +vfio_load_device_config_state(const char *name) " (%s)"
> +vfio_load_state(const char *name, uint64_t data) " (%s) data 0x%"PRIx64
> +vfio_load_state_device_data(const char *name, uint64_t data_offset, uint64_t data_size) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64
Kirti Wankhede June 25, 2020, 2:16 p.m. UTC | #2 
On 6/25/2020 12:24 AM, Alex Williamson wrote:
> On Sun, 21 Jun 2020 01:51:18 +0530
> Kirti Wankhede <kwankhede@nvidia.com> wrote:
> 
>> Sequence  during _RESUMING device state:
>> While data for this device is available, repeat below steps:
>> a. read data_offset from where user application should write data.
>> b. write data of data_size to migration region from data_offset.
>> c. write data_size which indicates vendor driver that data is written in
>>     staging buffer.
>>
>> For user, data is opaque. User should write data in the same order as
>> received.
>>
>> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
>> Reviewed-by: Neo Jia <cjia@nvidia.com>
>> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>> ---
>>   hw/vfio/migration.c  | 177 +++++++++++++++++++++++++++++++++++++++++++++++++++
>>   hw/vfio/trace-events |   3 +
>>   2 files changed, 180 insertions(+)
>>
>> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
>> index ef1150c1ff02..faacea5327cb 100644
>> --- a/hw/vfio/migration.c
>> +++ b/hw/vfio/migration.c
>> @@ -302,6 +302,33 @@ 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;
>> +    uint64_t data;
>> +
>> +    if (vbasedev->ops && vbasedev->ops->vfio_load_config) {
>> +        int ret;
>> +
>> +        ret = vbasedev->ops->vfio_load_config(vbasedev, f);
>> +        if (ret) {
>> +            error_report("%s: Failed to load device config space",
>> +                         vbasedev->name);
>> +            return ret;
>> +        }
>> +    }
>> +
>> +    data = qemu_get_be64(f);
>> +    if (data != VFIO_MIG_FLAG_END_OF_STATE) {
>> +        error_report("%s: Failed loading device config space, "
>> +                     "end flag incorrect 0x%"PRIx64, vbasedev->name, data);
>> +        return -EINVAL;
>> +    }
>> +
>> +    trace_vfio_load_device_config_state(vbasedev->name);
>> +    return qemu_file_get_error(f);
>> +}
>> +
>>   /* ---------------------------------------------------------------------- */
>>   
>>   static int vfio_save_setup(QEMUFile *f, void *opaque)
>> @@ -472,12 +499,162 @@ 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.mmaps) {
>> +        ret = vfio_region_mmap(&migration->region);
>> +        if (ret) {
>> +            error_report("%s: Failed to mmap VFIO migration region %d: %s",
>> +                         vbasedev->name, migration->region.nr,
>> +                         strerror(-ret));
>> +            return ret;
> 
> 
> Not fatal.
>

As discussed on 07/17 patch of this series, it should fall back to 
read/write, right?

> 
>> +        }
>> +    }
>> +
>> +    ret = vfio_migration_set_state(vbasedev, ~VFIO_DEVICE_STATE_MASK,
>> +                                   VFIO_DEVICE_STATE_RESUMING);
>> +    if (ret) {
>> +        error_report("%s: Failed to set state RESUMING", vbasedev->name);
>> +    }
>> +    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) {
>> +
>> +        trace_vfio_load_state(vbasedev->name, data);
>> +
>> +        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("%s: SETUP STATE: EOS not found 0x%"PRIx64,
>> +                             vbasedev->name, data);
>> +                return -EINVAL;
> 
> This is essentially just a compatibility failure, right?  For instance
> some future version of QEMU might include additional data between these
> markers that we don't understand and therefore we fail the migration.
> 

Yes.

Thanks,
Kirti

Thanks,
> 
> Alex
> 
>> +            }
>> +            break;
>> +        }
>> +        case VFIO_MIG_FLAG_DEV_DATA_STATE:
>> +        {
>> +            VFIORegion *region = &migration->region;
>> +            uint64_t data_offset = 0, size;
>> +
>> +            data_size = 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("%s:Failed to get migration buffer data offset %d",
>> +                             vbasedev->name, ret);
>> +                return -EINVAL;
>> +            }
>> +
>> +            trace_vfio_load_state_device_data(vbasedev->name, data_offset,
>> +                                              data_size);
>> +
>> +            while (size) {
>> +                void *buf = NULL;
>> +                uint64_t sec_size;
>> +                bool buffer_mmaped;
>> +
>> +                buf = get_data_section_size(region, data_offset, size,
>> +                                            &sec_size);
>> +
>> +                buffer_mmaped = (buf != NULL);
>> +
>> +                if (!buffer_mmaped) {
>> +                    buf = g_try_malloc(sec_size);
>> +                    if (!buf) {
>> +                        error_report("%s: Error allocating buffer ", __func__);
>> +                        return -ENOMEM;
>> +                    }
>> +                }
>> +
>> +                qemu_get_buffer(f, buf, sec_size);
>> +
>> +                if (!buffer_mmaped) {
>> +                    ret = pwrite(vbasedev->fd, buf, sec_size,
>> +                                 region->fd_offset + data_offset);
>> +                    g_free(buf);
>> +
>> +                    if (ret != sec_size) {
>> +                        error_report("%s: Failed to set migration buffer %d",
>> +                                vbasedev->name, ret);
>> +                        return -EINVAL;
>> +                    }
>> +                }
>> +                size -= sec_size;
>> +                data_offset += sec_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("%s: Failed to set migration buffer data size %d",
>> +                             vbasedev->name, ret);
>> +                return -EINVAL;
>> +            }
>> +            break;
>> +        }
>> +
>> +        default:
>> +            error_report("%s: Unknown tag 0x%"PRIx64, vbasedev->name, data);
>> +            return -EINVAL;
>> +        }
>> +
>> +        data = qemu_get_be64(f);
>> +        ret = qemu_file_get_error(f);
>> +        if (ret) {
>> +            return ret;
>> +        }
>> +    }
>> +
>> +    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,
>>   };
>>   
>>   /* ---------------------------------------------------------------------- */
>> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
>> index 9a1c5e17d97f..4a4bd3ba9a2a 100644
>> --- a/hw/vfio/trace-events
>> +++ b/hw/vfio/trace-events
>> @@ -157,3 +157,6 @@ vfio_save_device_config_state(const char *name) " (%s)"
>>   vfio_save_pending(const char *name, uint64_t precopy, uint64_t postcopy, uint64_t compatible) " (%s) precopy 0x%"PRIx64" postcopy 0x%"PRIx64" compatible 0x%"PRIx64
>>   vfio_save_iterate(const char *name, int data_size) " (%s) data_size %d"
>>   vfio_save_complete_precopy(const char *name) " (%s)"
>> +vfio_load_device_config_state(const char *name) " (%s)"
>> +vfio_load_state(const char *name, uint64_t data) " (%s) data 0x%"PRIx64
>> +vfio_load_state_device_data(const char *name, uint64_t data_offset, uint64_t data_size) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64
>
Alex Williamson June 25, 2020, 2:57 p.m. UTC | #3 
On Thu, 25 Jun 2020 19:46:22 +0530
Kirti Wankhede <kwankhede@nvidia.com> wrote:

> On 6/25/2020 12:24 AM, Alex Williamson wrote:
> > On Sun, 21 Jun 2020 01:51:18 +0530
> > Kirti Wankhede <kwankhede@nvidia.com> wrote:
> >   
> >> Sequence  during _RESUMING device state:
> >> While data for this device is available, repeat below steps:
> >> a. read data_offset from where user application should write data.
> >> b. write data of data_size to migration region from data_offset.
> >> c. write data_size which indicates vendor driver that data is written in
> >>     staging buffer.
> >>
> >> For user, data is opaque. User should write data in the same order as
> >> received.
> >>
> >> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
> >> Reviewed-by: Neo Jia <cjia@nvidia.com>
> >> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> >> ---
> >>   hw/vfio/migration.c  | 177 +++++++++++++++++++++++++++++++++++++++++++++++++++
> >>   hw/vfio/trace-events |   3 +
> >>   2 files changed, 180 insertions(+)
> >>
> >> diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> >> index ef1150c1ff02..faacea5327cb 100644
> >> --- a/hw/vfio/migration.c
> >> +++ b/hw/vfio/migration.c
> >> @@ -302,6 +302,33 @@ 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;
> >> +    uint64_t data;
> >> +
> >> +    if (vbasedev->ops && vbasedev->ops->vfio_load_config) {
> >> +        int ret;
> >> +
> >> +        ret = vbasedev->ops->vfio_load_config(vbasedev, f);
> >> +        if (ret) {
> >> +            error_report("%s: Failed to load device config space",
> >> +                         vbasedev->name);
> >> +            return ret;
> >> +        }
> >> +    }
> >> +
> >> +    data = qemu_get_be64(f);
> >> +    if (data != VFIO_MIG_FLAG_END_OF_STATE) {
> >> +        error_report("%s: Failed loading device config space, "
> >> +                     "end flag incorrect 0x%"PRIx64, vbasedev->name, data);
> >> +        return -EINVAL;
> >> +    }
> >> +
> >> +    trace_vfio_load_device_config_state(vbasedev->name);
> >> +    return qemu_file_get_error(f);
> >> +}
> >> +
> >>   /* ---------------------------------------------------------------------- */
> >>   
> >>   static int vfio_save_setup(QEMUFile *f, void *opaque)
> >> @@ -472,12 +499,162 @@ 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.mmaps) {
> >> +        ret = vfio_region_mmap(&migration->region);
> >> +        if (ret) {
> >> +            error_report("%s: Failed to mmap VFIO migration region %d: %s",
> >> +                         vbasedev->name, migration->region.nr,
> >> +                         strerror(-ret));
> >> +            return ret;  
> > 
> > 
> > Not fatal.
> >  
> 
> As discussed on 07/17 patch of this series, it should fall back to 
> read/write, right?

Yes, it's worth an error_report() but not a migration abort imo.
Thanks,

Alex

> >> +        }
> >> +    }
> >> +
> >> +    ret = vfio_migration_set_state(vbasedev, ~VFIO_DEVICE_STATE_MASK,
> >> +                                   VFIO_DEVICE_STATE_RESUMING);
> >> +    if (ret) {
> >> +        error_report("%s: Failed to set state RESUMING", vbasedev->name);
> >> +    }
> >> +    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) {
> >> +
> >> +        trace_vfio_load_state(vbasedev->name, data);
> >> +
> >> +        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("%s: SETUP STATE: EOS not found 0x%"PRIx64,
> >> +                             vbasedev->name, data);
> >> +                return -EINVAL;  
> > 
> > This is essentially just a compatibility failure, right?  For instance
> > some future version of QEMU might include additional data between these
> > markers that we don't understand and therefore we fail the migration.
> >   
> 
> Yes.
> 
> Thanks,
> Kirti
> 
> Thanks,
> > 
> > Alex
> >   
> >> +            }
> >> +            break;
> >> +        }
> >> +        case VFIO_MIG_FLAG_DEV_DATA_STATE:
> >> +        {
> >> +            VFIORegion *region = &migration->region;
> >> +            uint64_t data_offset = 0, size;
> >> +
> >> +            data_size = 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("%s:Failed to get migration buffer data offset %d",
> >> +                             vbasedev->name, ret);
> >> +                return -EINVAL;
> >> +            }
> >> +
> >> +            trace_vfio_load_state_device_data(vbasedev->name, data_offset,
> >> +                                              data_size);
> >> +
> >> +            while (size) {
> >> +                void *buf = NULL;
> >> +                uint64_t sec_size;
> >> +                bool buffer_mmaped;
> >> +
> >> +                buf = get_data_section_size(region, data_offset, size,
> >> +                                            &sec_size);
> >> +
> >> +                buffer_mmaped = (buf != NULL);
> >> +
> >> +                if (!buffer_mmaped) {
> >> +                    buf = g_try_malloc(sec_size);
> >> +                    if (!buf) {
> >> +                        error_report("%s: Error allocating buffer ", __func__);
> >> +                        return -ENOMEM;
> >> +                    }
> >> +                }
> >> +
> >> +                qemu_get_buffer(f, buf, sec_size);
> >> +
> >> +                if (!buffer_mmaped) {
> >> +                    ret = pwrite(vbasedev->fd, buf, sec_size,
> >> +                                 region->fd_offset + data_offset);
> >> +                    g_free(buf);
> >> +
> >> +                    if (ret != sec_size) {
> >> +                        error_report("%s: Failed to set migration buffer %d",
> >> +                                vbasedev->name, ret);
> >> +                        return -EINVAL;
> >> +                    }
> >> +                }
> >> +                size -= sec_size;
> >> +                data_offset += sec_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("%s: Failed to set migration buffer data size %d",
> >> +                             vbasedev->name, ret);
> >> +                return -EINVAL;
> >> +            }
> >> +            break;
> >> +        }
> >> +
> >> +        default:
> >> +            error_report("%s: Unknown tag 0x%"PRIx64, vbasedev->name, data);
> >> +            return -EINVAL;
> >> +        }
> >> +
> >> +        data = qemu_get_be64(f);
> >> +        ret = qemu_file_get_error(f);
> >> +        if (ret) {
> >> +            return ret;
> >> +        }
> >> +    }
> >> +
> >> +    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,
> >>   };
> >>   
> >>   /* ---------------------------------------------------------------------- */
> >> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> >> index 9a1c5e17d97f..4a4bd3ba9a2a 100644
> >> --- a/hw/vfio/trace-events
> >> +++ b/hw/vfio/trace-events
> >> @@ -157,3 +157,6 @@ vfio_save_device_config_state(const char *name) " (%s)"
> >>   vfio_save_pending(const char *name, uint64_t precopy, uint64_t postcopy, uint64_t compatible) " (%s) precopy 0x%"PRIx64" postcopy 0x%"PRIx64" compatible 0x%"PRIx64
> >>   vfio_save_iterate(const char *name, int data_size) " (%s) data_size %d"
> >>   vfio_save_complete_precopy(const char *name) " (%s)"
> >> +vfio_load_device_config_state(const char *name) " (%s)"
> >> +vfio_load_state(const char *name, uint64_t data) " (%s) data 0x%"PRIx64
> >> +vfio_load_state_device_data(const char *name, uint64_t data_offset, uint64_t data_size) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64  
> >   
>
Dr. David Alan Gilbert June 26, 2020, 2:54 p.m. UTC | #4 
* Alex Williamson (alex.williamson@redhat.com) wrote:
> On Sun, 21 Jun 2020 01:51:18 +0530
> Kirti Wankhede <kwankhede@nvidia.com> wrote:
> 
> > Sequence  during _RESUMING device state:
> > While data for this device is available, repeat below steps:
> > a. read data_offset from where user application should write data.
> > b. write data of data_size to migration region from data_offset.
> > c. write data_size which indicates vendor driver that data is written in
> >    staging buffer.
> > 
> > For user, data is opaque. User should write data in the same order as
> > received.
> > 
> > Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
> > Reviewed-by: Neo Jia <cjia@nvidia.com>
> > Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> > ---
> >  hw/vfio/migration.c  | 177 +++++++++++++++++++++++++++++++++++++++++++++++++++
> >  hw/vfio/trace-events |   3 +
> >  2 files changed, 180 insertions(+)
> > 
> > diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
> > index ef1150c1ff02..faacea5327cb 100644
> > --- a/hw/vfio/migration.c
> > +++ b/hw/vfio/migration.c
> > @@ -302,6 +302,33 @@ 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;
> > +    uint64_t data;
> > +
> > +    if (vbasedev->ops && vbasedev->ops->vfio_load_config) {
> > +        int ret;
> > +
> > +        ret = vbasedev->ops->vfio_load_config(vbasedev, f);
> > +        if (ret) {
> > +            error_report("%s: Failed to load device config space",
> > +                         vbasedev->name);
> > +            return ret;
> > +        }
> > +    }
> > +
> > +    data = qemu_get_be64(f);
> > +    if (data != VFIO_MIG_FLAG_END_OF_STATE) {
> > +        error_report("%s: Failed loading device config space, "
> > +                     "end flag incorrect 0x%"PRIx64, vbasedev->name, data);
> > +        return -EINVAL;
> > +    }
> > +
> > +    trace_vfio_load_device_config_state(vbasedev->name);
> > +    return qemu_file_get_error(f);
> > +}
> > +
> >  /* ---------------------------------------------------------------------- */
> >  
> >  static int vfio_save_setup(QEMUFile *f, void *opaque)
> > @@ -472,12 +499,162 @@ 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.mmaps) {
> > +        ret = vfio_region_mmap(&migration->region);
> > +        if (ret) {
> > +            error_report("%s: Failed to mmap VFIO migration region %d: %s",
> > +                         vbasedev->name, migration->region.nr,
> > +                         strerror(-ret));
> > +            return ret;
> 
> 
> Not fatal.
> 
> 
> > +        }
> > +    }
> > +
> > +    ret = vfio_migration_set_state(vbasedev, ~VFIO_DEVICE_STATE_MASK,
> > +                                   VFIO_DEVICE_STATE_RESUMING);
> > +    if (ret) {
> > +        error_report("%s: Failed to set state RESUMING", vbasedev->name);
> > +    }
> > +    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) {
> > +
> > +        trace_vfio_load_state(vbasedev->name, data);
> > +
> > +        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("%s: SETUP STATE: EOS not found 0x%"PRIx64,
> > +                             vbasedev->name, data);
> > +                return -EINVAL;
> 
> This is essentially just a compatibility failure, right?  For instance
> some future version of QEMU might include additional data between these
> markers that we don't understand and therefore we fail the migration.

Or any other screwup in data layout;  we've found having a canary at the
end of state is quite useful for when we screwup for one reason or
another.

Dave

> Thanks,
> 
> Alex
> 
> > +            }
> > +            break;
> > +        }
> > +        case VFIO_MIG_FLAG_DEV_DATA_STATE:
> > +        {
> > +            VFIORegion *region = &migration->region;
> > +            uint64_t data_offset = 0, size;
> > +
> > +            data_size = 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("%s:Failed to get migration buffer data offset %d",
> > +                             vbasedev->name, ret);
> > +                return -EINVAL;
> > +            }
> > +
> > +            trace_vfio_load_state_device_data(vbasedev->name, data_offset,
> > +                                              data_size);
> > +
> > +            while (size) {
> > +                void *buf = NULL;
> > +                uint64_t sec_size;
> > +                bool buffer_mmaped;
> > +
> > +                buf = get_data_section_size(region, data_offset, size,
> > +                                            &sec_size);
> > +
> > +                buffer_mmaped = (buf != NULL);
> > +
> > +                if (!buffer_mmaped) {
> > +                    buf = g_try_malloc(sec_size);
> > +                    if (!buf) {
> > +                        error_report("%s: Error allocating buffer ", __func__);
> > +                        return -ENOMEM;
> > +                    }
> > +                }
> > +
> > +                qemu_get_buffer(f, buf, sec_size);
> > +
> > +                if (!buffer_mmaped) {
> > +                    ret = pwrite(vbasedev->fd, buf, sec_size,
> > +                                 region->fd_offset + data_offset);
> > +                    g_free(buf);
> > +
> > +                    if (ret != sec_size) {
> > +                        error_report("%s: Failed to set migration buffer %d",
> > +                                vbasedev->name, ret);
> > +                        return -EINVAL;
> > +                    }
> > +                }
> > +                size -= sec_size;
> > +                data_offset += sec_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("%s: Failed to set migration buffer data size %d",
> > +                             vbasedev->name, ret);
> > +                return -EINVAL;
> > +            }
> > +            break;
> > +        }
> > +
> > +        default:
> > +            error_report("%s: Unknown tag 0x%"PRIx64, vbasedev->name, data);
> > +            return -EINVAL;
> > +        }
> > +
> > +        data = qemu_get_be64(f);
> > +        ret = qemu_file_get_error(f);
> > +        if (ret) {
> > +            return ret;
> > +        }
> > +    }
> > +
> > +    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,
> >  };
> >  
> >  /* ---------------------------------------------------------------------- */
> > diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> > index 9a1c5e17d97f..4a4bd3ba9a2a 100644
> > --- a/hw/vfio/trace-events
> > +++ b/hw/vfio/trace-events
> > @@ -157,3 +157,6 @@ vfio_save_device_config_state(const char *name) " (%s)"
> >  vfio_save_pending(const char *name, uint64_t precopy, uint64_t postcopy, uint64_t compatible) " (%s) precopy 0x%"PRIx64" postcopy 0x%"PRIx64" compatible 0x%"PRIx64
> >  vfio_save_iterate(const char *name, int data_size) " (%s) data_size %d"
> >  vfio_save_complete_precopy(const char *name) " (%s)"
> > +vfio_load_device_config_state(const char *name) " (%s)"
> > +vfio_load_state(const char *name, uint64_t data) " (%s) data 0x%"PRIx64
> > +vfio_load_state_device_data(const char *name, uint64_t data_offset, uint64_t data_size) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
diff mbox series

Patch

diff --git a/hw/vfio/migration.c b/hw/vfio/migration.c
index ef1150c1ff02..faacea5327cb 100644
--- a/hw/vfio/migration.c
+++ b/hw/vfio/migration.c
@@ -302,6 +302,33 @@  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;
+    uint64_t data;
+
+    if (vbasedev->ops && vbasedev->ops->vfio_load_config) {
+        int ret;
+
+        ret = vbasedev->ops->vfio_load_config(vbasedev, f);
+        if (ret) {
+            error_report("%s: Failed to load device config space",
+                         vbasedev->name);
+            return ret;
+        }
+    }
+
+    data = qemu_get_be64(f);
+    if (data != VFIO_MIG_FLAG_END_OF_STATE) {
+        error_report("%s: Failed loading device config space, "
+                     "end flag incorrect 0x%"PRIx64, vbasedev->name, data);
+        return -EINVAL;
+    }
+
+    trace_vfio_load_device_config_state(vbasedev->name);
+    return qemu_file_get_error(f);
+}
+
 /* ---------------------------------------------------------------------- */
 
 static int vfio_save_setup(QEMUFile *f, void *opaque)
@@ -472,12 +499,162 @@  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.mmaps) {
+        ret = vfio_region_mmap(&migration->region);
+        if (ret) {
+            error_report("%s: Failed to mmap VFIO migration region %d: %s",
+                         vbasedev->name, migration->region.nr,
+                         strerror(-ret));
+            return ret;
+        }
+    }
+
+    ret = vfio_migration_set_state(vbasedev, ~VFIO_DEVICE_STATE_MASK,
+                                   VFIO_DEVICE_STATE_RESUMING);
+    if (ret) {
+        error_report("%s: Failed to set state RESUMING", vbasedev->name);
+    }
+    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) {
+
+        trace_vfio_load_state(vbasedev->name, data);
+
+        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("%s: SETUP STATE: EOS not found 0x%"PRIx64,
+                             vbasedev->name, data);
+                return -EINVAL;
+            }
+            break;
+        }
+        case VFIO_MIG_FLAG_DEV_DATA_STATE:
+        {
+            VFIORegion *region = &migration->region;
+            uint64_t data_offset = 0, size;
+
+            data_size = 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("%s:Failed to get migration buffer data offset %d",
+                             vbasedev->name, ret);
+                return -EINVAL;
+            }
+
+            trace_vfio_load_state_device_data(vbasedev->name, data_offset,
+                                              data_size);
+
+            while (size) {
+                void *buf = NULL;
+                uint64_t sec_size;
+                bool buffer_mmaped;
+
+                buf = get_data_section_size(region, data_offset, size,
+                                            &sec_size);
+
+                buffer_mmaped = (buf != NULL);
+
+                if (!buffer_mmaped) {
+                    buf = g_try_malloc(sec_size);
+                    if (!buf) {
+                        error_report("%s: Error allocating buffer ", __func__);
+                        return -ENOMEM;
+                    }
+                }
+
+                qemu_get_buffer(f, buf, sec_size);
+
+                if (!buffer_mmaped) {
+                    ret = pwrite(vbasedev->fd, buf, sec_size,
+                                 region->fd_offset + data_offset);
+                    g_free(buf);
+
+                    if (ret != sec_size) {
+                        error_report("%s: Failed to set migration buffer %d",
+                                vbasedev->name, ret);
+                        return -EINVAL;
+                    }
+                }
+                size -= sec_size;
+                data_offset += sec_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("%s: Failed to set migration buffer data size %d",
+                             vbasedev->name, ret);
+                return -EINVAL;
+            }
+            break;
+        }
+
+        default:
+            error_report("%s: Unknown tag 0x%"PRIx64, vbasedev->name, data);
+            return -EINVAL;
+        }
+
+        data = qemu_get_be64(f);
+        ret = qemu_file_get_error(f);
+        if (ret) {
+            return ret;
+        }
+    }
+
+    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,
 };
 
 /* ---------------------------------------------------------------------- */
diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
index 9a1c5e17d97f..4a4bd3ba9a2a 100644
--- a/hw/vfio/trace-events
+++ b/hw/vfio/trace-events
@@ -157,3 +157,6 @@  vfio_save_device_config_state(const char *name) " (%s)"
 vfio_save_pending(const char *name, uint64_t precopy, uint64_t postcopy, uint64_t compatible) " (%s) precopy 0x%"PRIx64" postcopy 0x%"PRIx64" compatible 0x%"PRIx64
 vfio_save_iterate(const char *name, int data_size) " (%s) data_size %d"
 vfio_save_complete_precopy(const char *name) " (%s)"
+vfio_load_device_config_state(const char *name) " (%s)"
+vfio_load_state(const char *name, uint64_t data) " (%s) data 0x%"PRIx64
+vfio_load_state_device_data(const char *name, uint64_t data_offset, uint64_t data_size) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64