vfio: Don't issue full 2^64 unmap

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>
This commit is contained in:
Jean-Philippe Brucker 2020-10-30 19:05:10 +01:00 committed by Michael S. Tsirkin
parent 5c3cfe33f4
commit 1b296c3def
1 changed files with 11 additions and 0 deletions

View File

@ -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", "