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| author | Steve Sistare <steven.sistare@oracle.com> | 2025-07-02 14:58:56 -0700 |
|---|---|---|
| committer | Cédric Le Goater <clg@redhat.com> | 2025-07-03 13:42:28 +0200 |
| commit | 6ff4cccd13155e718e630fe16a72d3cc9decde3b (patch) | |
| tree | 7ea6fb44d7a0ba6bdc9fabc00c16137990707405 /backends | |
| parent | 5c066c4be2328c46f03e9166ea720b13bf68ea5d (diff) | |
| download | focaccia-qemu-6ff4cccd13155e718e630fe16a72d3cc9decde3b.tar.gz focaccia-qemu-6ff4cccd13155e718e630fe16a72d3cc9decde3b.zip | |
iommufd: preserve DMA mappings
During cpr-transfer load in new QEMU, the vfio_memory_listener causes spurious calls to map and unmap DMA regions, as devices are created and the address space is built. This memory was already already mapped by the device in old QEMU, so suppress the map and unmap callbacks during incoming CPR. Signed-off-by: Steve Sistare <steven.sistare@oracle.com> Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com> Link: https://lore.kernel.org/qemu-devel/1751493538-202042-20-git-send-email-steven.sistare@oracle.com Signed-off-by: Cédric Le Goater <clg@redhat.com>
Diffstat (limited to 'backends')
| -rw-r--r-- | backends/iommufd.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/backends/iommufd.c b/backends/iommufd.c index e0917923bf..2a33c7ab0b 100644 --- a/backends/iommufd.c +++ b/backends/iommufd.c @@ -245,6 +245,10 @@ int iommufd_backend_map_file_dma(IOMMUFDBackend *be, uint32_t ioas_id, .length = size, }; + if (cpr_is_incoming()) { + return 0; + } + if (!readonly) { map.flags |= IOMMU_IOAS_MAP_WRITEABLE; } @@ -274,6 +278,10 @@ int iommufd_backend_unmap_dma(IOMMUFDBackend *be, uint32_t ioas_id, .length = size, }; + if (cpr_is_incoming()) { + return 0; + } + ret = ioctl(fd, IOMMU_IOAS_UNMAP, &unmap); /* * IOMMUFD takes mapping as some kind of object, unmapping |