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Bug
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Resolution: Unresolved
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Major
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None
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rhel-10.1
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No
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Important
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rhel-virt-core-live-migration
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None
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False
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False
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None
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Red Hat Enterprise Linux
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None
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None
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Automated
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Unspecified
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Unspecified
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Unspecified
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Unspecified
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None
What were you trying to do that didn't work?
Postcopy-preempt migration with Numa pinned and Hugepage pinned guest--file backend.
Sometimes postcopy would switch to postcopy-paused status, and get error description: Channel error: Input/output error
Please provide the package NVR for which bug is seen:
hosts info: kernel-6.12.0-105.el10.x86_64 && qemu-img-10.0.0-7.el10.x86_64 or qemu-img-10.0.0-9.el10.x86_64
How reproducible:
1/30
Steps to reproduce
1.Configure hugepage on hosts
2.Boot a guest with hugepage memdev and numa on src host
...
-m 4096 \
-object '
{"qom-type":"memory-backend-file","id":"ram-node0","prealloc":true,"mem-path":"/mnt/kvm_hugepage","size":2147483648}
' \
-object '
{"qom-type":"memory-backend-file","id":"ram-node1","prealloc":true,"mem-path":"/mnt/kvm_hugepage","size":2147483648,"host-nodes":[0],"policy":"bind"}
' \
-numa node,nodeid=0,cpus=0-1,memdev=ram-node0 \
-numa node,nodeid=1,cpus=2-3,memdev=ram-node1 \
...
3.Boot a guest on dst host with appending "-incoming defer" qemu command
4.enable postcopy, postcopy-preempt and do migration
5.switch to postcopy in the 1st iteration
Expected results
After step 5, postcopy migration succeeds.
Actual results
After step 5,
2025-08-20-17:05:40: Host(10.72.136.82) Sending qmp command :
{"execute": "query-migrate", "id": "BCMtZlsg"}
2025-08-20-17:05:40: Host(10.72.136.82) Responding qmp command: {"return": {"expected-downtime": 300, "status": "active", "setup-time": 21, "total-time": 1016, "ram": {"total": 4316536832, "postcopy-requests": 0, "dirty-sync-count": 1, "multifd-bytes": 0, "pages-per-second": 28800, "downtime-bytes": 0, "page-size": 4096, "remaining": 4180688896, "postcopy-bytes": 0, "mbps": 945.5616, "transferred": 117186305, "dirty-sync-missed-zero-copy": 0, "precopy-bytes": 117313128, "duplicate": 4590, "dirty-pages-rate": 0, "normal-bytes": 117043200, "normal": 28575}}, "id": "BCMtZlsg"}
2025-08-20-17:05:40: Host(10.72.136.82) Sending qmp command :
{"execute": "query-migrate", "id": "IH3AHcTl"}
2025-08-20-17:05:41: Host(10.72.136.82) Responding qmp command: {"return": {"expected-downtime": 300, "status": "device", "setup-time": 21, "total-time": 1027, "ram": {"total": 4316536832, "postcopy-requests": 0, "dirty-sync-count": 2, "multifd-bytes": 0, "pages-per-second": 28800, "downtime-bytes": 0, "page-size": 4096, "remaining": 4238942208, "postcopy-bytes": 0, "mbps": 945.5616, "transferred": 117786062, "dirty-sync-missed-zero-copy": 0, "precopy-bytes": 117785088, "duplicate": 4590, "dirty-pages-rate": 449, "normal-bytes": 117514240, "normal": 28690}}, "id": "IH3AHcTl"}
2025-08-20-17:05:41: Host(10.72.136.82) Sending qmp command :
{"execute": "query-migrate", "id": "FuwUioQV"}
2025-08-20-17:05:41: Host(10.72.136.82) Responding qmp command: {"return": {"status": "postcopy-active", "setup-time": 21, "downtime": 14, "total-time": 2025, "ram": {"total": 4316536832, "postcopy-requests": 47, "dirty-sync-count": 2, "multifd-bytes": 0, "pages-per-second": 29370, "downtime-bytes": 0, "page-size": 4096, "remaining": 3534827520, "postcopy-bytes": 110630169, "mbps": 940.02429629629637, "transferred": 228775077, "dirty-sync-missed-zero-copy": 0, "precopy-bytes": 117785088, "duplicate": 149854, "dirty-pages-rate": 449, "normal-bytes": 226623488, "normal": 55328}}, "id": "FuwUioQV"}
2025-08-20-17:05:41: Host(10.72.136.82) Sending qmp command :
{"execute": "query-migrate", "id": "VmN72vWb"}
2025-08-20-17:05:41: Host(10.72.136.82) Responding qmp command: {"return": {"status": "postcopy-active", "setup-time": 21, "downtime": 14, "total-time": 2029, "ram": {"total": 4316536832, "postcopy-requests": 51, "dirty-sync-count": 2, "multifd-bytes": 0, "pages-per-second": 29370, "downtime-bytes": 0, "page-size": 4096, "remaining": 3532337152, "postcopy-bytes": 113125401, "mbps": 940.02429629629637, "transferred": 231270309, "dirty-sync-missed-zero-copy": 0, "precopy-bytes": 117785088, "duplicate": 149854, "dirty-pages-rate": 449, "normal-bytes": 229113856, "normal": 55936}}, "id": "VmN72vWb"}
2025-08-20-17:05:46: Host(10.72.136.82) Sending qmp command :
{"execute": "query-migrate", "id": "MUuDT4b7"}
2025-08-20-17:05:46: Host(10.72.136.82) Responding qmp command: {"return": {"status": "postcopy-active", "setup-time": 21, "downtime": 14, "total-time": 7034, "ram": {"total": 4316536832, "postcopy-requests": 366, "dirty-sync-count": 2, "multifd-bytes": 0, "pages-per-second": 28636, "downtime-bytes": 0, "page-size": 4096, "remaining": 2905362432, "postcopy-bytes": 698709404, "mbps": 931.96893854748612, "transferred": 816739410, "dirty-sync-missed-zero-copy": 0, "precopy-bytes": 117785088, "duplicate": 160261, "dirty-pages-rate": 449, "normal-bytes": 813461504, "normal": 198599}}, "id": "MUuDT4b7"}
2025-08-20-17:05:51: Host(10.72.136.82) Sending qmp command :
{"execute": "query-migrate", "id": "DGzA9qtU"}
2025-08-20-17:05:51: Host(10.72.136.82) Responding qmp command: {"return": {"status": "postcopy-paused", "setup-time": 21, "error-desc": "Channel error: Input/output error", "downtime": 14, "total-time": 12039, "ram": {"total": 4316536832, "postcopy-requests": 593, "dirty-sync-count": 2, "multifd-bytes": 0, "pages-per-second": 29291, "downtime-bytes": 0, "page-size": 4096, "remaining": 2411724800, "postcopy-bytes": 1156825761, "mbps": 944.80573134328358, "transferred": 1274178607, "dirty-sync-missed-zero-copy": 0, "precopy-bytes": 117785088, "duplicate": 169172, "dirty-pages-rate": 449, "normal-bytes": 1270603776, "normal": 310206}}, "id": "DGzA9qtU"}
