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| author | Thanos Makatos <thanos.makatos@nutanix.com> | 2020-02-25 11:31:45 -0500 |
|---|---|---|
| committer | Thanos <tmakatos@gmail.com> | 2020-02-28 11:06:47 +0000 |
| commit | 4af9ad8d3428d49ff0a7d668441d47eb5b7be89a (patch) | |
| tree | 80ae3f24dce60db4a24fc591a9fce4f1af098da4 /kmod | |
| parent | c563455c4bc76bd8b3635545d2c38cff3a57db81 (diff) | |
| download | libvfio-user-4af9ad8d3428d49ff0a7d668441d47eb5b7be89a.zip libvfio-user-4af9ad8d3428d49ff0a7d668441d47eb5b7be89a.tar.gz libvfio-user-4af9ad8d3428d49ff0a7d668441d47eb5b7be89a.tar.bz2 | |
ignore non-existent DMA regions when unmapping
The problem of not receiving a DMA unmap looks like it will be solved by having
VFIO send us the DMA unmap even if we haven't called vfio_pin_pages, so instead
of failing for regions we haven't mapped (e.g. non-shared regions) we simply
ignore that operation.
Signed-off-by: Thanos Makatos <thanos.makatos@nutanix.com>
Diffstat (limited to 'kmod')
| -rw-r--r-- | kmod/muser.c | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/kmod/muser.c b/kmod/muser.c index 718c5fa..796b6b1 100644 --- a/kmod/muser.c +++ b/kmod/muser.c @@ -714,9 +714,18 @@ static int muser_iommu_dma_unmap(struct muser_dev *const mudev, mutex_lock(&mudev->dev_lock); dma_map = __find_dma_map(mudev, unmap->iova); if (!dma_map) { + /* + * XXX We no longer use vfio_pin_pages() so VFIO doesn't send + * DMA unmap events at all. We've patched vfio_iommu_type1 to + * send DMA unmap events even if we haven't pinned any of the + * pages of a particular region (e.g. the VMA is not + * shareable), so we have to ignore requests for such regions. + * This behaviormight be temprorary, depending on whether or + * not this solution gets accepted. For more information see: + * https://www.redhat.com/archives/vfio-users/2020-February/msg00016.html. + */ mutex_unlock(&mudev->dev_lock); - muser_dbg("failed to find dma map for iova:%llu\n", unmap->iova); - return -EINVAL; + return 0; } list_del(&dma_map->entry); mutex_unlock(&mudev->dev_lock); |