vfio/iommufd: Implement VFIOIOMMUClass::query_dirty_bitmap support

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>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>

1 files changed, 29 insertions, 0 deletions

diff --git a/backends/iommufd.c b/backends/iommufd.c
index b978835038..9bc466a89c 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -261,6 +261,35 @@ bool iommufd_backend_set_dirty_tracking(IOMMUFDBackend *be,
     return true;
 }
 
+bool 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,
+                                      Error **errp)
+{
+    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 ? errno : 0);
+    if (ret) {
+        error_setg_errno(errp, errno,
+                         "IOMMU_HWPT_GET_DIRTY_BITMAP (iova: 0x%"HWADDR_PRIx
+                         " size: 0x"RAM_ADDR_FMT") failed", iova, size);
+        return false;
+    }
+
+    return true;
+}
+
 bool iommufd_backend_get_device_info(IOMMUFDBackend *be, uint32_t devid,
                                      uint32_t *type, void *data, uint32_t len,
                                      uint64_t *caps, Error **errp)