[PATCH RFCv2 4/8] 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 called on the whole list of iommu domains it is are tracking,
and on failure it rolls it back.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
---
 backends/iommufd.c       | 19 +++++++++++++++++++
 backends/trace-events    |  1 +
 hw/vfio/common.c         |  7 ++++++-
 hw/vfio/iommufd.c        | 28 ++++++++++++++++++++++++++++
 include/sysemu/iommufd.h |  3 +++
 5 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/backends/iommufd.c b/backends/iommufd.c
index 2970135af4b9..954de61c2da0 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -240,6 +240,25 @@ int iommufd_backend_alloc_hwpt(int iommufd, uint32_t 
dev_id,
     return !ret ? 0 : -errno;
 }
 
+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) {
+        error_report("IOMMU_HWPT_SET_DIRTY_TRACKING failed: %s",
+                     strerror(errno));
+    }
+    return !ret ? 0 : -errno;
+}
+
 static const TypeInfo iommufd_backend_info = {
     .name = TYPE_IOMMUFD_BACKEND,
     .parent = TYPE_OBJECT,
diff --git a/backends/trace-events b/backends/trace-events
index f83a276a4253..feba2baca5f7 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_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_alloc_ioas(int iommufd, uint32_t ioas, int ret) " iommufd=%d 
ioas=%d (%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=%d enable=%d (%d)"
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index d8fc7077f839..a940c0b6ede8 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -190,7 +190,7 @@ static bool 
vfio_devices_all_dirty_tracking(VFIOContainerBase *bcontainer)
     QLIST_FOREACH(vbasedev, &bcontainer->device_list, container_next) {
         VFIOMigration *migration = vbasedev->migration;
 
-        if (!migration) {
+        if (!migration && !vbasedev->iommufd_dev.iommufd) {
             return false;
         }
 
@@ -199,6 +199,11 @@ static bool 
vfio_devices_all_dirty_tracking(VFIOContainerBase *bcontainer)
              vfio_device_state_is_precopy(vbasedev))) {
             return false;
         }
+
+        if (vbasedev->iommufd_dev.iommufd &&
+            !bcontainer->dirty_pages_supported) {
+            return false;
+        }
     }
     return true;
 }
diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index edacb6d72748..361e659288fd 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -25,6 +25,7 @@
 #include "qemu/cutils.h"
 #include "qemu/chardev_open.h"
 #include "pci.h"
+#include "migration/migration.h"
 
 static int iommufd_cdev_map(const VFIOContainerBase *bcontainer, hwaddr iova,
                             ram_addr_t size, void *vaddr, bool readonly)
@@ -115,6 +116,32 @@ static void iommufd_cdev_unbind_and_disconnect(VFIODevice 
*vbasedev)
     iommufd_backend_disconnect(vbasedev->iommufd_dev.iommufd);
 }
 
+static int iommufd_set_dirty_page_tracking(const VFIOContainerBase *bcontainer,
+                                           bool start)
+{
+    const VFIOIOMMUFDContainer *container =
+        container_of(bcontainer, VFIOIOMMUFDContainer, bcontainer);
+    int ret;
+    VFIOIOASHwpt *hwpt;
+
+    QLIST_FOREACH(hwpt, &container->hwpt_list, next) {
+        ret = iommufd_backend_set_dirty_tracking(container->be,
+                                                 hwpt->hwpt_id, start);
+        if (ret) {
+            goto err;
+        }
+    }
+
+    return 0;
+
+err:
+    QLIST_FOREACH(hwpt, &container->hwpt_list, next) {
+        iommufd_backend_set_dirty_tracking(container->be,
+                                           hwpt->hwpt_id, !start);
+    }
+    return ret;
+}
+
 static int iommufd_cdev_getfd(const char *sysfs_path, Error **errp)
 {
     long int ret = -ENOTTY;
@@ -737,6 +764,7 @@ static void vfio_iommu_iommufd_class_init(ObjectClass 
*klass, void *data)
     vioc->detach_device = iommufd_cdev_detach;
     vioc->pci_hot_reset = iommufd_cdev_pci_hot_reset;
     vioc->host_iommu_device_init = vfio_cdev_host_iommu_device_init;
+    vioc->set_dirty_page_tracking = iommufd_set_dirty_page_tracking;
 };
 
 static const TypeInfo types[] = {
diff --git a/include/sysemu/iommufd.h b/include/sysemu/iommufd.h
index 1966b75caae2..562c189dd92c 100644
--- a/include/sysemu/iommufd.h
+++ b/include/sysemu/iommufd.h
@@ -53,4 +53,7 @@ int iommufd_backend_alloc_hwpt(int iommufd, 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);
+
 #endif
-- 
2.39.3