From: Jean-Philippe Brucker Date: Fri, 30 Oct 2020 18:05:10 +0000 (+0100) Subject: vfio: Don't issue full 2^64 unmap X-Git-Tag: v5.2.0-rc1~15^2~9 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1b296c3def4b9b63d2fdbce6646edd108a3e616c;p=thirdparty%2Fqemu.git 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 Reviewed-by: Eric Auger Signed-off-by: Jean-Philippe Brucker Message-Id: <20201030180510.747225-11-jean-philippe@linaro.org> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- diff --git a/hw/vfio/common.c b/hw/vfio/common.c index 35895b18a6f..c1fdbf17f2e 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", "