diff mbox series

[PULL,v3,22/31] vfio: Don't issue full 2^64 unmap

Message ID 20201104184040.285057-23-mst@redhat.com
State New
Headers show
Series [PULL,v3,01/31] pc: comment style fixup | expand

Commit Message

Michael S. Tsirkin Nov. 4, 2020, 6:42 p.m. UTC 
From: Jean-Philippe Brucker <jean-philippe@linaro.org>


IOMMUs may declare memory regions spanning from 0 to UINT64_MAX. When
attempting to deal with such region, vfio_listener_region_del() passes a
size of 2^64 to int128_get64() which throws an assertion failure.  Even
ignoring this, the VFIO_IOMMU_DMA_MAP ioctl cannot handle this size
since the size field is 64-bit. Split the request in two.

Acked-by: Alex Williamson <alex.williamson@redhat.com>

Reviewed-by: Eric Auger <eric.auger@redhat.com>

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

Message-Id: <20201030180510.747225-11-jean-philippe@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

---
 hw/vfio/common.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

-- 
MST
diff mbox series

Patch

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 35895b18a6..c1fdbf17f2 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -950,6 +950,17 @@  static void vfio_listener_region_del(MemoryListener *listener,
     }
 
     if (try_unmap) {
+        if (int128_eq(llsize, int128_2_64())) {
+            /* The unmap ioctl doesn't accept a full 64-bit span. */
+            llsize = int128_rshift(llsize, 1);
+            ret = vfio_dma_unmap(container, iova, int128_get64(llsize), NULL);
+            if (ret) {
+                error_report("vfio_dma_unmap(%p, 0x%"HWADDR_PRIx", "
+                             "0x%"HWADDR_PRIx") = %d (%m)",
+                             container, iova, int128_get64(llsize), ret);
+            }
+            iova += int128_get64(llsize);
+        }
         ret = vfio_dma_unmap(container, iova, int128_get64(llsize), NULL);
         if (ret) {
             error_report("vfio_dma_unmap(%p, 0x%"HWADDR_PRIx", "