From: Steve Sistare <steven.sistare@oracle.com>

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>
---
 include/system/iommufd.h |  3 +++
 backends/iommufd.c       | 34 ++++++++++++++++++++++++++++++++++
 backends/trace-events    |  1 +
 3 files changed, 38 insertions(+)

diff --git a/include/system/iommufd.h b/include/system/iommufd.h
index 283861b92432a1297e3e7465bdf86c3816393dcc..2d24d93d17e280bce53030a52588bd91425e03ea 100644
--- a/include/system/iommufd.h
+++ b/include/system/iommufd.h
@@ -43,6 +43,9 @@ void iommufd_backend_disconnect(IOMMUFDBackend *be);
 bool iommufd_backend_alloc_ioas(IOMMUFDBackend *be, uint32_t *ioas_id,
                                 Error **errp);
 void iommufd_backend_free_id(IOMMUFDBackend *be, uint32_t id);
+int iommufd_backend_map_file_dma(IOMMUFDBackend *be, uint32_t ioas_id,
+                                 hwaddr iova, ram_addr_t size, int fd,
+                                 unsigned long start, bool readonly);
 int iommufd_backend_map_dma(IOMMUFDBackend *be, uint32_t ioas_id, hwaddr iova,
                             ram_addr_t size, void *vaddr, bool readonly);
 int iommufd_backend_unmap_dma(IOMMUFDBackend *be, uint32_t ioas_id,
diff --git a/backends/iommufd.c b/backends/iommufd.c
index c2c47abf7ed533c0512b89e58605b6b20ac103e8..3a2ecc7f5ba67699249ae1ad632fc8a45e9b53d3 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)
 {
diff --git a/backends/trace-events b/backends/trace-events
index 7278214ea51144b7d7b36d64908567c9467036e8..e5f3e70cd1ba7eb532c8f763b12460ef8f552245 100644
--- a/backends/trace-events
+++ b/backends/trace-events
@@ -11,6 +11,7 @@ iommufd_backend_connect(int fd, bool owned, uint32_t users) "fd=%d owned=%d user
 iommufd_backend_disconnect(int fd, uint32_t users) "fd=%d users=%d"
 iommu_backend_set_fd(int fd) "pre-opened /dev/iommu fd=%d"
 iommufd_backend_map_dma(int iommufd, uint32_t ioas, uint64_t iova, uint64_t size, void *vaddr, bool readonly, int ret) " iommufd=%d ioas=%d iova=0x%"PRIx64" size=0x%"PRIx64" addr=%p readonly=%d (%d)"
+iommufd_backend_map_file_dma(int iommufd, uint32_t ioas, uint64_t iova, uint64_t size, int fd, unsigned long start, bool readonly, int ret) " iommufd=%d ioas=%d iova=0x%"PRIx64" size=0x%"PRIx64" fd=%d start=%ld readonly=%d (%d)"
 iommufd_backend_unmap_dma_non_exist(int iommufd, uint32_t ioas, uint64_t iova, uint64_t size, int ret) " Unmap nonexistent mapping: iommufd=%d ioas=%d iova=0x%"PRIx64" size=0x%"PRIx64" (%d)"
 iommufd_backend_unmap_dma(int iommufd, uint32_t ioas, uint64_t iova, uint64_t size, int ret) " iommufd=%d ioas=%d iova=0x%"PRIx64" size=0x%"PRIx64" (%d)"
 iommufd_backend_alloc_ioas(int iommufd, uint32_t ioas) " iommufd=%d ioas=%d"
-- 
2.50.0