diff mbox series

[for-8.2,v2,6/6] vfio/migration: Allow migration of multiple P2P supporting devices

Message ID 20230731102521.15335-7-avihaih@nvidia.com
State New
Headers show
Series vfio/migration: Add P2P support for VFIO migration | expand

Commit Message

Avihai Horon July 31, 2023, 10:25 a.m. UTC 
Now that P2P support has been added to VFIO migration, allow migration
of multiple devices if all of them support P2P migration.

Single device migration is allowed regardless of P2P migration support.

Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
---
 hw/vfio/common.c | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

Comments

Cédric Le Goater Aug. 1, 2023, 12:03 p.m. UTC | #1 
On 7/31/23 12:25, Avihai Horon wrote:
> Now that P2P support has been added to VFIO migration, allow migration
> of multiple devices if all of them support P2P migration.
> 
> Single device migration is allowed regardless of P2P migration support.
> 
> Signed-off-by: Avihai Horon <avihaih@nvidia.com>
> Signed-off-by: Joao Martins <joao.m.martins@oracle.com>


Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.


> ---
>   hw/vfio/common.c | 26 ++++++++++++++++++--------
>   1 file changed, 18 insertions(+), 8 deletions(-)
> 
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 7c3d636025..8a8d074e18 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -363,21 +363,31 @@ bool vfio_mig_active(void)
>   
>   static Error *multiple_devices_migration_blocker;
>   
> -static unsigned int vfio_migratable_device_num(void)
> +/*
> + * Multiple devices migration is allowed only if all devices support P2P
> + * migration. Single device migration is allowed regardless of P2P migration
> + * support.
> + */
> +static bool vfio_multiple_devices_migration_is_supported(void)
>   {
>       VFIOGroup *group;
>       VFIODevice *vbasedev;
>       unsigned int device_num = 0;
> +    bool all_support_p2p = true;
>   
>       QLIST_FOREACH(group, &vfio_group_list, next) {
>           QLIST_FOREACH(vbasedev, &group->device_list, next) {
>               if (vbasedev->migration) {
>                   device_num++;
> +
> +                if (!(vbasedev->migration->mig_flags & VFIO_MIGRATION_P2P)) {
> +                    all_support_p2p = false;
> +                }
>               }
>           }
>       }
>   
> -    return device_num;
> +    return all_support_p2p || device_num <= 1;
>   }
>   
>   int vfio_block_multiple_devices_migration(VFIODevice *vbasedev, Error **errp)
> @@ -385,19 +395,19 @@ int vfio_block_multiple_devices_migration(VFIODevice *vbasedev, Error **errp)
>       int ret;
>   
>       if (multiple_devices_migration_blocker ||
> -        vfio_migratable_device_num() <= 1) {
> +        vfio_multiple_devices_migration_is_supported()) {
>           return 0;
>       }
>   
>       if (vbasedev->enable_migration == ON_OFF_AUTO_ON) {
> -        error_setg(errp, "Migration is currently not supported with multiple "
> -                         "VFIO devices");
> +        error_setg(errp, "Multiple VFIO devices migration is supported only if "
> +                         "all of them support P2P migration");
>           return -EINVAL;
>       }
>   
>       error_setg(&multiple_devices_migration_blocker,
> -               "Migration is currently not supported with multiple "
> -               "VFIO devices");
> +               "Multiple VFIO devices migration is supported only if all of "
> +               "them support P2P migration");
>       ret = migrate_add_blocker(multiple_devices_migration_blocker, errp);
>       if (ret < 0) {
>           error_free(multiple_devices_migration_blocker);
> @@ -410,7 +420,7 @@ int vfio_block_multiple_devices_migration(VFIODevice *vbasedev, Error **errp)
>   void vfio_unblock_multiple_devices_migration(void)
>   {
>       if (!multiple_devices_migration_blocker ||
> -        vfio_migratable_device_num() > 1) {
> +        !vfio_multiple_devices_migration_is_supported()) {
>           return;
>       }
>
diff mbox series

Patch

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 7c3d636025..8a8d074e18 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -363,21 +363,31 @@  bool vfio_mig_active(void)
 
 static Error *multiple_devices_migration_blocker;
 
-static unsigned int vfio_migratable_device_num(void)
+/*
+ * Multiple devices migration is allowed only if all devices support P2P
+ * migration. Single device migration is allowed regardless of P2P migration
+ * support.
+ */
+static bool vfio_multiple_devices_migration_is_supported(void)
 {
     VFIOGroup *group;
     VFIODevice *vbasedev;
     unsigned int device_num = 0;
+    bool all_support_p2p = true;
 
     QLIST_FOREACH(group, &vfio_group_list, next) {
         QLIST_FOREACH(vbasedev, &group->device_list, next) {
             if (vbasedev->migration) {
                 device_num++;
+
+                if (!(vbasedev->migration->mig_flags & VFIO_MIGRATION_P2P)) {
+                    all_support_p2p = false;
+                }
             }
         }
     }
 
-    return device_num;
+    return all_support_p2p || device_num <= 1;
 }
 
 int vfio_block_multiple_devices_migration(VFIODevice *vbasedev, Error **errp)
@@ -385,19 +395,19 @@  int vfio_block_multiple_devices_migration(VFIODevice *vbasedev, Error **errp)
     int ret;
 
     if (multiple_devices_migration_blocker ||
-        vfio_migratable_device_num() <= 1) {
+        vfio_multiple_devices_migration_is_supported()) {
         return 0;
     }
 
     if (vbasedev->enable_migration == ON_OFF_AUTO_ON) {
-        error_setg(errp, "Migration is currently not supported with multiple "
-                         "VFIO devices");
+        error_setg(errp, "Multiple VFIO devices migration is supported only if "
+                         "all of them support P2P migration");
         return -EINVAL;
     }
 
     error_setg(&multiple_devices_migration_blocker,
-               "Migration is currently not supported with multiple "
-               "VFIO devices");
+               "Multiple VFIO devices migration is supported only if all of "
+               "them support P2P migration");
     ret = migrate_add_blocker(multiple_devices_migration_blocker, errp);
     if (ret < 0) {
         error_free(multiple_devices_migration_blocker);
@@ -410,7 +420,7 @@  int vfio_block_multiple_devices_migration(VFIODevice *vbasedev, Error **errp)
 void vfio_unblock_multiple_devices_migration(void)
 {
     if (!multiple_devices_migration_blocker ||
-        vfio_migratable_device_num() > 1) {
+        !vfio_multiple_devices_migration_is_supported()) {
         return;
     }