diff mbox series

[v7,07/13] vfio: Query and store the maximum number of possible DMA mappings

Message ID 20210224094910.44986-8-david@redhat.com
State New
Headers show
Series virtio-mem: vfio support | expand

Commit Message

David Hildenbrand Feb. 24, 2021, 9:49 a.m. UTC 
Let's query the maximum number of possible DMA mappings by querying the
available mappings when creating the container (before any mappings are
created). We'll use this informaton soon to perform some sanity checks
and warn the user.

Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Auger Eric <eric.auger@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: teawater <teawaterz@linux.alibaba.com>
Cc: Marek Kedzierski <mkedzier@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 hw/vfio/common.c              | 4 ++++
 include/hw/vfio/vfio-common.h | 1 +
 2 files changed, 5 insertions(+)
diff mbox series

Patch

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 5788bf6b6e..2f20075b8c 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -1898,6 +1898,7 @@  static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
     container->fd = fd;
     container->error = NULL;
     container->dirty_pages_supported = false;
+    container->dma_max_mappings = 0;
     QLIST_INIT(&container->giommu_list);
     QLIST_INIT(&container->hostwin_list);
     QLIST_INIT(&container->vrdl_list);
@@ -1929,7 +1930,10 @@  static int vfio_connect_container(VFIOGroup *group, AddressSpace *as,
         vfio_host_win_add(container, 0, (hwaddr)-1, info->iova_pgsizes);
         container->pgsizes = info->iova_pgsizes;
 
+        /* The default in the kernel ("dma_entry_limit") is 65535. */
+        container->dma_max_mappings = 65535;
         if (!ret) {
+            vfio_get_info_dma_avail(info, &container->dma_max_mappings);
             vfio_get_iommu_info_migration(container, info);
         }
         g_free(info);
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 681432213d..8af11b0a76 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -88,6 +88,7 @@  typedef struct VFIOContainer {
     uint64_t dirty_pgsizes;
     uint64_t max_dirty_bitmap_size;
     unsigned long pgsizes;
+    unsigned int dma_max_mappings;
     QLIST_HEAD(, VFIOGuestIOMMU) giommu_list;
     QLIST_HEAD(, VFIOHostDMAWindow) hostwin_list;
     QLIST_HEAD(, VFIOGroup) group_list;