[RFC V1 12/12] vfio: mdev blocker

[Steve Sistare]

Block CPR if the container has any mdevs (mediated devices).  CPR is not
supported for legacy containers and mdevs.  It will be supported for iommufd
containers with mdevs in a future patch.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 hw/vfio/pci.c                         | 10 ++++++++++
 include/hw/vfio/vfio-common.h         |  1 +
 include/hw/vfio/vfio-container-base.h |  2 ++
 3 files changed, 13 insertions(+)

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index b5e7592..872b07c 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3100,6 +3100,13 @@ static void vfio_realize(PCIDevice *pdev, Error **errp)
     is_mdev = subsys && (strcmp(subsys, "/sys/bus/mdev") == 0);
     free(subsys);
 
+    vbasedev->is_mdev = is_mdev;
+    if (is_mdev && !vbasedev->bcontainer->n_mdev++) {
+        error_setg(&vbasedev->bcontainer->cpr_mdev_blocker,
+                   "CPR does not support vfio mdev");
+        migrate_add_blocker_modes(&vbasedev->bcontainer->cpr_mdev_blocker,
+                                  &error_fatal, MIG_MODE_CPR_EXEC, -1);
+    }
     trace_vfio_mdev(vbasedev->name, is_mdev);
 
     if (vbasedev->ram_block_discard_allowed && !is_mdev) {
@@ -3387,6 +3394,9 @@ static void vfio_exitfn(PCIDevice *pdev)
     vfio_teardown_msi(vdev);
     vfio_pci_disable_rp_atomics(vdev);
     vfio_bars_exit(vdev);
+    if (vbasedev->is_mdev && !--vbasedev->bcontainer->n_mdev) {
+        migrate_del_blocker(&vbasedev->bcontainer->cpr_mdev_blocker);
+    }
     vfio_migration_exit(vbasedev);
     pci_device_unset_iommu_device(pdev);
 }
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 8aa02d4..342c40f 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -133,6 +133,7 @@ typedef struct VFIODevice {
     OnOffAuto pre_copy_dirty_page_tracking;
     bool dirty_pages_supported;
     bool dirty_tracking;
+    bool is_mdev;
     HostIOMMUDevice *hiod;
     int devid;
     IOMMUFDBackend *iommufd;
diff --git a/include/hw/vfio/vfio-container-base.h 
b/include/hw/vfio/vfio-container-base.h
index f8b7b26..e29cbb8 100644
--- a/include/hw/vfio/vfio-container-base.h
+++ b/include/hw/vfio/vfio-container-base.h
@@ -45,6 +45,7 @@ typedef struct VFIOContainerBase {
     uint64_t max_dirty_bitmap_size;
     unsigned long pgsizes;
     unsigned int dma_max_mappings;
+    unsigned int n_mdev;
     bool dirty_pages_supported;
     QLIST_HEAD(, VFIOGuestIOMMU) giommu_list;
     QLIST_HEAD(, VFIORamDiscardListener) vrdl_list;
@@ -54,6 +55,7 @@ typedef struct VFIOContainerBase {
     NotifierWithReturn cpr_reboot_notifier;
     NotifierWithReturn cpr_exec_notifier;
     Error *cpr_blocker;
+    Error *cpr_mdev_blocker;
 } VFIOContainerBase;
 
 typedef struct VFIOGuestIOMMU {
-- 
1.8.3.1