[PATCH V3 39/42] vfio/iommufd: reconstruct hwpt

[Steve Sistare <steven.sistare@oracle.com>]

Save the hwpt_id in vmstate.  In realize, skip its allocation from
iommufd_cdev_attach -> iommufd_cdev_attach_container ->
iommufd_cdev_autodomains_get.

Rebuild userland structures to hold hwpt_id by calling
iommufd_cdev_rebuild_hwpt at post load time.  This depends on hw_caps, which
was restored by the post_load call to vfio_device_hiod_create_and_realize.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
---
 hw/vfio/cpr-iommufd.c      |  7 +++++++
 hw/vfio/iommufd.c          | 24 ++++++++++++++++++++++--
 hw/vfio/trace-events       |  1 +
 hw/vfio/vfio-iommufd.h     |  3 +++
 include/hw/vfio/vfio-cpr.h |  1 +
 5 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/hw/vfio/cpr-iommufd.c b/hw/vfio/cpr-iommufd.c
index 24cdf10..6d3f4e0 100644
--- a/hw/vfio/cpr-iommufd.c
+++ b/hw/vfio/cpr-iommufd.c
@@ -110,6 +110,12 @@ static int vfio_device_post_load(void *opaque, int version_id)
         error_report_err(err);
         return false;
     }
+    if (!vbasedev->mdev) {
+        VFIOIOMMUFDContainer *container = container_of(vbasedev->bcontainer,
+                                                       VFIOIOMMUFDContainer,
+                                                       bcontainer);
+        iommufd_cdev_rebuild_hwpt(vbasedev, container);
+    }
     return true;
 }
 
@@ -121,6 +127,7 @@ static const VMStateDescription vfio_device_vmstate = {
     .needed = cpr_needed_for_reuse,
     .fields = (VMStateField[]) {
         VMSTATE_INT32(devid, VFIODevice),
+        VMSTATE_UINT32(cpr.hwpt_id, VFIODevice),
         VMSTATE_END_OF_LIST()
     }
 };
diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index d980684..ec79c83 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -318,6 +318,7 @@ static bool iommufd_cdev_detach_ioas_hwpt(VFIODevice *vbasedev, Error **errp)
 static void iommufd_cdev_use_hwpt(VFIODevice *vbasedev, VFIOIOASHwpt *hwpt)
 {
     vbasedev->hwpt = hwpt;
+    vbasedev->cpr.hwpt_id = hwpt->hwpt_id;
     vbasedev->iommu_dirty_tracking = iommufd_hwpt_dirty_tracking(hwpt);
     QLIST_INSERT_HEAD(&hwpt->device_list, vbasedev, hwpt_next);
 }
@@ -373,6 +374,23 @@ static bool iommufd_cdev_make_hwpt(VFIODevice *vbasedev,
     return true;
 }
 
+void iommufd_cdev_rebuild_hwpt(VFIODevice *vbasedev,
+                               VFIOIOMMUFDContainer *container)
+{
+    VFIOIOASHwpt *hwpt;
+    int hwpt_id = vbasedev->cpr.hwpt_id;
+
+    trace_iommufd_cdev_rebuild_hwpt(container->be->fd, hwpt_id);
+
+    QLIST_FOREACH(hwpt, &container->hwpt_list, next) {
+        if (hwpt->hwpt_id == hwpt_id) {
+            iommufd_cdev_use_hwpt(vbasedev, hwpt);
+            return;
+        }
+    }
+    iommufd_cdev_make_hwpt(vbasedev, container, hwpt_id, false, NULL);
+}
+
 static bool iommufd_cdev_autodomains_get(VFIODevice *vbasedev,
                                          VFIOIOMMUFDContainer *container,
                                          Error **errp)
@@ -567,7 +585,8 @@ static bool iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
             vbasedev->iommufd != container->be) {
             continue;
         }
-        if (!iommufd_cdev_attach_container(vbasedev, container, &err)) {
+        if (!vbasedev->cpr.reused &&
+            !iommufd_cdev_attach_container(vbasedev, container, &err)) {
             const char *msg = error_get_pretty(err);
 
             trace_iommufd_cdev_fail_attach_existing_container(msg);
@@ -605,7 +624,8 @@ skip_ioas_alloc:
     bcontainer = &container->bcontainer;
     vfio_address_space_insert(space, bcontainer);
 
-    if (!iommufd_cdev_attach_container(vbasedev, container, errp)) {
+    if (!vbasedev->cpr.reused &&
+        !iommufd_cdev_attach_container(vbasedev, container, errp)) {
         goto err_attach_container;
     }
 
diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
index e90ec9b..4955264 100644
--- a/hw/vfio/trace-events
+++ b/hw/vfio/trace-events
@@ -190,6 +190,7 @@ iommufd_cdev_connect_and_bind(int iommufd, const char *name, int devfd, int devi
 iommufd_cdev_getfd(const char *dev, int devfd) " %s (fd=%d)"
 iommufd_cdev_attach_ioas_hwpt(int iommufd, const char *name, int devfd, int id) " [iommufd=%d] Successfully attached device %s (%d) to id=%d"
 iommufd_cdev_detach_ioas_hwpt(int iommufd, const char *name) " [iommufd=%d] Successfully detached %s"
+iommufd_cdev_rebuild_hwpt(int iommufd, int hwpt_id) " [iommufd=%d] hwpt %d"
 iommufd_cdev_fail_attach_existing_container(const char *msg) " %s"
 iommufd_cdev_alloc_ioas(int iommufd, int ioas_id) " [iommufd=%d] new IOMMUFD container with ioasid=%d"
 iommufd_cdev_device_info(char *name, int devfd, int num_irqs, int num_regions, int flags) " %s (%d) num_irqs=%d num_regions=%d flags=%d"
diff --git a/hw/vfio/vfio-iommufd.h b/hw/vfio/vfio-iommufd.h
index 148ce89..78af0d8 100644
--- a/hw/vfio/vfio-iommufd.h
+++ b/hw/vfio/vfio-iommufd.h
@@ -38,4 +38,7 @@ OBJECT_DECLARE_SIMPLE_TYPE(VFIOIOMMUFDContainer, VFIO_IOMMU_IOMMUFD);
 bool iommufd_cdev_get_info_iova_range(VFIOIOMMUFDContainer *container,
                                       uint32_t ioas_id, Error **errp);
 
+void iommufd_cdev_rebuild_hwpt(VFIODevice *vbasedev,
+                               VFIOIOMMUFDContainer *container);
+
 #endif /* HW_VFIO_VFIO_IOMMUFD_H */
diff --git a/include/hw/vfio/vfio-cpr.h b/include/hw/vfio/vfio-cpr.h
index 1379b20..b98c247 100644
--- a/include/hw/vfio/vfio-cpr.h
+++ b/include/hw/vfio/vfio-cpr.h
@@ -24,6 +24,7 @@ typedef struct VFIODeviceCPR {
     bool reused;
     Error *mdev_blocker;
     Error *id_blocker;
+    uint32_t hwpt_id;
 } VFIODeviceCPR;
 
 struct VFIOContainer;
-- 
1.8.3.1