[PATCH v3 07/10] vfio/iommufd: Implement VFIOIOMMUClass::query_dirty_bitmap support

[Joao Martins]

ioctl(iommufd, IOMMU_HWPT_GET_DIRTY_BITMAP, arg) is the UAPI
that fetches the bitmap that tells what was dirty in an IOVA
range.

A single bitmap is allocated and used across all the hwpts
sharing an IOAS which is then used in log_sync() to set Qemu
global bitmaps.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
---
 include/sysemu/iommufd.h |  3 +++
 backends/iommufd.c       | 26 ++++++++++++++++++++++++++
 hw/vfio/iommufd.c        | 34 ++++++++++++++++++++++++++++++++++
 backends/trace-events    |  1 +
 4 files changed, 64 insertions(+)

diff --git a/include/sysemu/iommufd.h b/include/sysemu/iommufd.h
index 1470377f55ba..223f1ea14e84 100644
--- a/include/sysemu/iommufd.h
+++ b/include/sysemu/iommufd.h
@@ -56,6 +56,9 @@ int iommufd_backend_alloc_hwpt(IOMMUFDBackend *be, uint32_t 
dev_id,
                                void *data_ptr, uint32_t *out_hwpt);
 int iommufd_backend_set_dirty_tracking(IOMMUFDBackend *be, uint32_t hwpt_id,
                                        bool start);
+int iommufd_backend_get_dirty_bitmap(IOMMUFDBackend *be, uint32_t hwpt_id,
+                                     uint64_t iova, ram_addr_t size,
+                                     uint64_t page_size, uint64_t *data);
 
 #define TYPE_HOST_IOMMU_DEVICE_IOMMUFD TYPE_HOST_IOMMU_DEVICE "-iommufd"
 
diff --git a/backends/iommufd.c b/backends/iommufd.c
index 69daabc27473..b2d3bbd7c31b 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -257,6 +257,32 @@ int iommufd_backend_set_dirty_tracking(IOMMUFDBackend *be, 
uint32_t hwpt_id,
     return ret;
 }
 
+int iommufd_backend_get_dirty_bitmap(IOMMUFDBackend *be, uint32_t hwpt_id,
+                                     uint64_t iova, ram_addr_t size,
+                                     uint64_t page_size, uint64_t *data)
+{
+    int ret;
+    struct iommu_hwpt_get_dirty_bitmap get_dirty_bitmap = {
+        .size = sizeof(get_dirty_bitmap),
+        .hwpt_id = hwpt_id,
+        .iova = iova,
+        .length = size,
+        .page_size = page_size,
+        .data = (uintptr_t)data,
+    };
+
+    ret = ioctl(be->fd, IOMMU_HWPT_GET_DIRTY_BITMAP, &get_dirty_bitmap);
+    trace_iommufd_backend_get_dirty_bitmap(be->fd, hwpt_id, iova, size,
+                                           page_size, ret);
+    if (ret) {
+        error_report("IOMMU_HWPT_GET_DIRTY_BITMAP (iova: 0x%"PRIx64
+                     " size: 0x%"PRIx64") failed: %s", iova,
+                     size, strerror(errno));
+    }
+
+    return !ret ? 0 : -errno;
+}
+
 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 158a98cb3b12..9fad47baed9e 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 "exec/ram_addr.h"
 
 static int iommufd_cdev_map(const VFIOContainerBase *bcontainer, hwaddr iova,
                             ram_addr_t size, void *vaddr, bool readonly)
@@ -152,6 +153,38 @@ err:
     return ret;
 }
 
+static int iommufd_query_dirty_bitmap(const VFIOContainerBase *bcontainer,
+                                      VFIOBitmap *vbmap, hwaddr iova,
+                                      hwaddr size, Error **errp)
+{
+    VFIOIOMMUFDContainer *container = container_of(bcontainer,
+                                                   VFIOIOMMUFDContainer,
+                                                   bcontainer);
+    int ret;
+    VFIOIOASHwpt *hwpt;
+    unsigned long page_size;
+
+    page_size = qemu_real_host_page_size();
+    QLIST_FOREACH(hwpt, &container->hwpt_list, next) {
+        if (!iommufd_hwpt_dirty_tracking(hwpt)) {
+            continue;
+        }
+
+        ret = iommufd_backend_get_dirty_bitmap(container->be, hwpt->hwpt_id,
+                                               iova, size, page_size,
+                                               vbmap->bitmap);
+        if (ret) {
+            error_setg_errno(errp, ret,
+                             "Failed to get dirty bitmap report, hwpt_id %u, 
iova: "
+                             "0x%" HWADDR_PRIx ", size: 0x%" HWADDR_PRIx,
+                             hwpt->hwpt_id, iova, size);
+            return ret;
+        }
+    }
+
+    return 0;
+}
+
 static int iommufd_cdev_getfd(const char *sysfs_path, Error **errp)
 {
     ERRP_GUARD();
@@ -777,6 +810,7 @@ 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->set_dirty_page_tracking = iommufd_set_dirty_page_tracking;
+    vioc->query_dirty_bitmap = iommufd_query_dirty_bitmap;
 };
 
 static bool hiod_iommufd_vfio_realize(HostIOMMUDevice *hiod, void *opaque,
diff --git a/backends/trace-events b/backends/trace-events
index 28aca3b859d4..40811a316215 100644
--- a/backends/trace-events
+++ b/backends/trace-events
@@ -17,3 +17,4 @@ 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)"
+iommufd_backend_get_dirty_bitmap(int iommufd, uint32_t hwpt_id, uint64_t iova, 
uint64_t size, uint64_t page_size, int ret) " iommufd=%d hwpt=%u 
iova=0x%"PRIx64" size=0x%"PRIx64" page_size=0x%"PRIx64" (%d)"
-- 
2.17.2