backends/iommufd: iommufd_backend_map_file_dma

Define iommufd_backend_map_file_dma to implement IOMMU_IOAS_MAP_FILE.
This will be called as a substitute for iommufd_backend_map_dma, so
the error conditions for BARs are copied as-is from that function.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Link: https://lore.kernel.org/qemu-devel/1751493538-202042-6-git-send-email-steven.sistare@oracle.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/backends/iommufd.c b/backends/iommufd.c
index c2c47abf7e..3a2ecc7f5b 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -172,6 +172,40 @@ int iommufd_backend_map_dma(IOMMUFDBackend *be, uint32_t ioas_id, hwaddr iova,
     return ret;
 }
 
+int iommufd_backend_map_file_dma(IOMMUFDBackend *be, uint32_t ioas_id,
+                                 hwaddr iova, ram_addr_t size,
+                                 int mfd, unsigned long start, bool readonly)
+{
+    int ret, fd = be->fd;
+    struct iommu_ioas_map_file map = {
+        .size = sizeof(map),
+        .flags = IOMMU_IOAS_MAP_READABLE |
+                 IOMMU_IOAS_MAP_FIXED_IOVA,
+        .ioas_id = ioas_id,
+        .fd = mfd,
+        .start = start,
+        .iova = iova,
+        .length = size,
+    };
+
+    if (!readonly) {
+        map.flags |= IOMMU_IOAS_MAP_WRITEABLE;
+    }
+
+    ret = ioctl(fd, IOMMU_IOAS_MAP_FILE, &map);
+    trace_iommufd_backend_map_file_dma(fd, ioas_id, iova, size, mfd, start,
+                                       readonly, ret);
+    if (ret) {
+        ret = -errno;
+
+        /* TODO: Not support mapping hardware PCI BAR region for now. */
+        if (errno == EFAULT) {
+            warn_report("IOMMU_IOAS_MAP_FILE failed: %m, PCI BAR?");
+        }
+    }
+    return ret;
+}
+
 int iommufd_backend_unmap_dma(IOMMUFDBackend *be, uint32_t ioas_id,
                               hwaddr iova, ram_addr_t size)
 {