[PATCH v3 06/10] vfio/iommufd: Implement VFIOIOMMUClass::set_dirty_tracking support

[Joao Martins]

ioctl(iommufd, IOMMU_HWPT_SET_DIRTY_TRACKING, arg) is the UAPI that
enables or disables dirty page tracking. It is used if the hwpt
has been created with dirty tracking supported domain (stored in
hwpt::flags) and it is called on the whole list of iommu domains
it is are tracking. On failure it rolls it back.

The checking of hwpt::flags is introduced here as a second user
and thus consolidate such check into a helper function
iommufd_hwpt_dirty_tracking().

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
---
 include/sysemu/iommufd.h |  3 +++
 backends/iommufd.c       | 20 ++++++++++++++++++
 hw/vfio/iommufd.c        | 45 +++++++++++++++++++++++++++++++++++++++-
 backends/trace-events    |  1 +
 4 files changed, 68 insertions(+), 1 deletion(-)

diff --git a/include/sysemu/iommufd.h b/include/sysemu/iommufd.h
index 35a8cec9780f..1470377f55ba 100644
--- a/include/sysemu/iommufd.h
+++ b/include/sysemu/iommufd.h
@@ -54,6 +54,9 @@ int iommufd_backend_alloc_hwpt(IOMMUFDBackend *be, uint32_t 
dev_id,
                                uint32_t pt_id, uint32_t flags,
                                uint32_t data_type, uint32_t data_len,
                                void *data_ptr, uint32_t *out_hwpt);
+int iommufd_backend_set_dirty_tracking(IOMMUFDBackend *be, uint32_t hwpt_id,
+                                       bool start);
 
 #define TYPE_HOST_IOMMU_DEVICE_IOMMUFD TYPE_HOST_IOMMU_DEVICE "-iommufd"
+
 #endif
diff --git a/backends/iommufd.c b/backends/iommufd.c
index f5f73eaf4a1a..69daabc27473 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -237,6 +237,26 @@ int iommufd_backend_alloc_hwpt(IOMMUFDBackend *be, 
uint32_t dev_id,
     return ret;
 }
 
+int iommufd_backend_set_dirty_tracking(IOMMUFDBackend *be, uint32_t hwpt_id,
+                                       bool start)
+{
+    int ret;
+    struct iommu_hwpt_set_dirty_tracking set_dirty = {
+            .size = sizeof(set_dirty),
+            .hwpt_id = hwpt_id,
+            .flags = !start ? 0 : IOMMU_HWPT_DIRTY_TRACKING_ENABLE,
+    };
+
+    ret = ioctl(be->fd, IOMMU_HWPT_SET_DIRTY_TRACKING, &set_dirty);
+    trace_iommufd_backend_set_dirty(be->fd, hwpt_id, start, ret);
+    if (ret) {
+        ret = -errno;
+        error_report("IOMMU_HWPT_SET_DIRTY_TRACKING failed: %s",
+                     strerror(errno));
+    }
+    return ret;
+}
+
 bool iommufd_backend_get_device_info(IOMMUFDBackend *be, uint32_t devid,
                                      uint32_t *type, void *data, uint32_t len,
                                      uint64_t *caps, Error **errp)
diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index 1b5b46d28ed6..158a98cb3b12 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -110,6 +110,48 @@ static void iommufd_cdev_unbind_and_disconnect(VFIODevice 
*vbasedev)
     iommufd_backend_disconnect(vbasedev->iommufd);
 }
 
+static bool iommufd_hwpt_dirty_tracking(VFIOIOASHwpt *hwpt)
+{
+    return hwpt->hwpt_flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING;
+}
+
+static int iommufd_set_dirty_page_tracking(const VFIOContainerBase *bcontainer,
+                                           bool start, Error **errp)
+{
+    const VFIOIOMMUFDContainer *container =
+        container_of(bcontainer, VFIOIOMMUFDContainer, bcontainer);
+    int ret;
+    VFIOIOASHwpt *hwpt;
+
+    QLIST_FOREACH(hwpt, &container->hwpt_list, next) {
+        if (!iommufd_hwpt_dirty_tracking(hwpt)) {
+            continue;
+        }
+
+        ret = iommufd_backend_set_dirty_tracking(container->be,
+                                                 hwpt->hwpt_id, start);
+        if (ret) {
+            ret = -errno;
+            error_setg_errno(errp, errno,
+                             "Failed to start dirty tracking on hwpt_id %u",
+                             hwpt->hwpt_id);
+            goto err;
+        }
+    }
+
+    return 0;
+
+err:
+    QLIST_FOREACH(hwpt, &container->hwpt_list, next) {
+        if (!iommufd_hwpt_dirty_tracking(hwpt)) {
+            continue;
+        }
+        iommufd_backend_set_dirty_tracking(container->be,
+                                           hwpt->hwpt_id, !start);
+    }
+    return ret;
+}
+
 static int iommufd_cdev_getfd(const char *sysfs_path, Error **errp)
 {
     ERRP_GUARD();
@@ -292,7 +334,7 @@ static bool iommufd_cdev_autodomains_get(VFIODevice 
*vbasedev,
     QLIST_INSERT_HEAD(&hwpt->device_list, vbasedev, hwpt_next);
     QLIST_INSERT_HEAD(&container->hwpt_list, hwpt, next);
     container->bcontainer.dirty_pages_supported |=
-                              (flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING);
+                              iommufd_hwpt_dirty_tracking(hwpt);
     return true;
 }
 
@@ -734,6 +776,7 @@ static void vfio_iommu_iommufd_class_init(ObjectClass 
*klass, void *data)
     vioc->attach_device = iommufd_cdev_attach;
     vioc->detach_device = iommufd_cdev_detach;
     vioc->pci_hot_reset = iommufd_cdev_pci_hot_reset;
+    vioc->set_dirty_page_tracking = iommufd_set_dirty_page_tracking;
 };
 
 static bool hiod_iommufd_vfio_realize(HostIOMMUDevice *hiod, void *opaque,
diff --git a/backends/trace-events b/backends/trace-events
index 4d8ac02fe7d6..28aca3b859d4 100644
--- a/backends/trace-events
+++ b/backends/trace-events
@@ -16,3 +16,4 @@ iommufd_backend_unmap_dma(int iommufd, uint32_t ioas, 
uint64_t iova, uint64_t si
 iommufd_backend_alloc_ioas(int iommufd, uint32_t ioas) " iommufd=%d ioas=%d"
 iommufd_backend_alloc_hwpt(int iommufd, uint32_t dev_id, uint32_t pt_id, 
uint32_t flags, uint32_t hwpt_type, uint32_t len, uint64_t data_ptr, uint32_t 
out_hwpt_id, int ret) " iommufd=%d dev_id=%u pt_id=%u flags=0x%x hwpt_type=%u 
len=%u data_ptr=0x%"PRIx64" out_hwpt=%u (%d)"
 iommufd_backend_free_id(int iommufd, uint32_t id, int ret) " iommufd=%d id=%d 
(%d)"
+iommufd_backend_set_dirty(int iommufd, uint32_t hwpt_id, bool start, int ret) 
" iommufd=%d hwpt=%u enable=%d (%d)"
-- 
2.17.2