[PULL 22/28] vfio: add unmap_all flag to DMA unmap callback

["Cédric Le Goater" <clg@redhat.com>]

From: John Levon <john.levon@nutanix.com>

We'll use this parameter shortly; this just adds the plumbing.

Signed-off-by: John Levon <john.levon@nutanix.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250507152020.1254632-9-john.levon@nutanix.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
 include/hw/vfio/vfio-container-base.h | 15 +++++++++++++--
 hw/vfio/container-base.c              |  4 ++--
 hw/vfio/container.c                   |  8 ++++++--
 hw/vfio/iommufd.c                     |  6 +++++-
 hw/vfio/listener.c                    |  8 ++++----
 5 files changed, 30 insertions(+), 11 deletions(-)

diff --git a/include/hw/vfio/vfio-container-base.h b/include/hw/vfio/vfio-container-base.h
index 5527e027220ac05f82d2a9beaf8b921e26597271..59f07d26e8226916c9c58eac07cb494552097138 100644
--- a/include/hw/vfio/vfio-container-base.h
+++ b/include/hw/vfio/vfio-container-base.h
@@ -81,7 +81,7 @@ int vfio_container_dma_map(VFIOContainerBase *bcontainer,
                            void *vaddr, bool readonly);
 int vfio_container_dma_unmap(VFIOContainerBase *bcontainer,
                              hwaddr iova, ram_addr_t size,
-                             IOMMUTLBEntry *iotlb);
+                             IOMMUTLBEntry *iotlb, bool unmap_all);
 bool vfio_container_add_section_window(VFIOContainerBase *bcontainer,
                                        MemoryRegionSection *section,
                                        Error **errp);
@@ -120,9 +120,20 @@ struct VFIOIOMMUClass {
     int (*dma_map)(const VFIOContainerBase *bcontainer,
                    hwaddr iova, ram_addr_t size,
                    void *vaddr, bool readonly);
+    /**
+     * @dma_unmap
+     *
+     * Unmap an address range from the container.
+     *
+     * @bcontainer: #VFIOContainerBase to use for unmap
+     * @iova: start address to unmap
+     * @size: size of the range to unmap
+     * @iotlb: The IOMMU TLB mapping entry (or NULL)
+     * @unmap_all: if set, unmap the entire address space
+     */
     int (*dma_unmap)(const VFIOContainerBase *bcontainer,
                      hwaddr iova, ram_addr_t size,
-                     IOMMUTLBEntry *iotlb);
+                     IOMMUTLBEntry *iotlb, bool unmap_all);
     bool (*attach_device)(const char *name, VFIODevice *vbasedev,
                           AddressSpace *as, Error **errp);
     void (*detach_device)(VFIODevice *vbasedev);
diff --git a/hw/vfio/container-base.c b/hw/vfio/container-base.c
index 09340fd97a074c9a3b56c686e7a750530bed619f..3ff473a45c2db779a54f3d8e77079d4a1601eb36 100644
--- a/hw/vfio/container-base.c
+++ b/hw/vfio/container-base.c
@@ -85,12 +85,12 @@ int vfio_container_dma_map(VFIOContainerBase *bcontainer,
 
 int vfio_container_dma_unmap(VFIOContainerBase *bcontainer,
                              hwaddr iova, ram_addr_t size,
-                             IOMMUTLBEntry *iotlb)
+                             IOMMUTLBEntry *iotlb, bool unmap_all)
 {
     VFIOIOMMUClass *vioc = VFIO_IOMMU_GET_CLASS(bcontainer);
 
     g_assert(vioc->dma_unmap);
-    return vioc->dma_unmap(bcontainer, iova, size, iotlb);
+    return vioc->dma_unmap(bcontainer, iova, size, iotlb, unmap_all);
 }
 
 bool vfio_container_add_section_window(VFIOContainerBase *bcontainer,
diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index cf23aa799f61da58da09411ca6213a753a7f4794..d5f4e66f1c4146c2eb6a2ce209c74c4d391c27ce 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -124,7 +124,7 @@ unmap_exit:
  */
 static int vfio_legacy_dma_unmap(const VFIOContainerBase *bcontainer,
                                  hwaddr iova, ram_addr_t size,
-                                 IOMMUTLBEntry *iotlb)
+                                 IOMMUTLBEntry *iotlb, bool unmap_all)
 {
     const VFIOContainer *container = container_of(bcontainer, VFIOContainer,
                                                   bcontainer);
@@ -138,6 +138,10 @@ static int vfio_legacy_dma_unmap(const VFIOContainerBase *bcontainer,
     int ret;
     Error *local_err = NULL;
 
+    if (unmap_all) {
+        return -ENOTSUP;
+    }
+
     if (iotlb && vfio_container_dirty_tracking_is_started(bcontainer)) {
         if (!vfio_container_devices_dirty_tracking_is_supported(bcontainer) &&
             bcontainer->dirty_pages_supported) {
@@ -205,7 +209,7 @@ static int vfio_legacy_dma_map(const VFIOContainerBase *bcontainer, hwaddr iova,
      */
     if (ioctl(container->fd, VFIO_IOMMU_MAP_DMA, &map) == 0 ||
         (errno == EBUSY &&
-         vfio_legacy_dma_unmap(bcontainer, iova, size, NULL) == 0 &&
+         vfio_legacy_dma_unmap(bcontainer, iova, size, NULL, false) == 0 &&
          ioctl(container->fd, VFIO_IOMMU_MAP_DMA, &map) == 0)) {
         return 0;
     }
diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index 62ecb758f1ade0e39efaef2b4001dab91abaa001..6b2764c044135b95c199b5df2f864156817fb6fc 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -46,11 +46,15 @@ static int iommufd_cdev_map(const VFIOContainerBase *bcontainer, hwaddr iova,
 
 static int iommufd_cdev_unmap(const VFIOContainerBase *bcontainer,
                               hwaddr iova, ram_addr_t size,
-                              IOMMUTLBEntry *iotlb)
+                              IOMMUTLBEntry *iotlb, bool unmap_all)
 {
     const VFIOIOMMUFDContainer *container =
         container_of(bcontainer, VFIOIOMMUFDContainer, bcontainer);
 
+    if (unmap_all) {
+        return -ENOTSUP;
+    }
+
     /* TODO: Handle dma_unmap_bitmap with iotlb args (migration) */
     return iommufd_backend_unmap_dma(container->be,
                                      container->ioas_id, iova, size);
diff --git a/hw/vfio/listener.c b/hw/vfio/listener.c
index 6f77e18a7a2f9437d50976eeb9847f99bfe4a739..c5183700dbd859c9a66083f2cb6f74a75a01cc66 100644
--- a/hw/vfio/listener.c
+++ b/hw/vfio/listener.c
@@ -172,7 +172,7 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
         }
     } else {
         ret = vfio_container_dma_unmap(bcontainer, iova,
-                                       iotlb->addr_mask + 1, iotlb);
+                                       iotlb->addr_mask + 1, iotlb, false);
         if (ret) {
             error_setg(&local_err,
                        "vfio_container_dma_unmap(%p, 0x%"HWADDR_PRIx", "
@@ -201,7 +201,7 @@ static void vfio_ram_discard_notify_discard(RamDiscardListener *rdl,
     int ret;
 
     /* Unmap with a single call. */
-    ret = vfio_container_dma_unmap(bcontainer, iova, size , NULL);
+    ret = vfio_container_dma_unmap(bcontainer, iova, size , NULL, false);
     if (ret) {
         error_report("%s: vfio_container_dma_unmap() failed: %s", __func__,
                      strerror(-ret));
@@ -638,7 +638,7 @@ static void vfio_listener_region_del(MemoryListener *listener,
             /* The unmap ioctl doesn't accept a full 64-bit span. */
             llsize = int128_rshift(llsize, 1);
             ret = vfio_container_dma_unmap(bcontainer, iova,
-                                           int128_get64(llsize), NULL);
+                                           int128_get64(llsize), NULL, false);
             if (ret) {
                 error_report("vfio_container_dma_unmap(%p, 0x%"HWADDR_PRIx", "
                              "0x%"HWADDR_PRIx") = %d (%s)",
@@ -648,7 +648,7 @@ static void vfio_listener_region_del(MemoryListener *listener,
             iova += int128_get64(llsize);
         }
         ret = vfio_container_dma_unmap(bcontainer, iova,
-                                       int128_get64(llsize), NULL);
+                                       int128_get64(llsize), NULL, false);
         if (ret) {
             error_report("vfio_container_dma_unmap(%p, 0x%"HWADDR_PRIx", "
                          "0x%"HWADDR_PRIx") = %d (%s)",
-- 
2.49.0