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Panic example UFFD handlers on receiving POLLHUP.

Reason

If Firecracker process disconnects from the socket, the UFFD handler receives a POLLHUP epoll event. We would like to handle it explicitly to get more precise data when debugging.

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  • This functionality cannot be added in rust-vmm.

If Firecracker process disconnects from the socket, the UFFD handler
receives a POLLHUP epoll event.  We would like to handle it explicitly
to get more precise data when debugging.

Signed-off-by: Nikita Kalyazin <[email protected]>
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codecov bot commented Mar 26, 2025

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 83.19%. Comparing base (a6c9559) to head (fa2e212).
Report is 10 commits behind head on main.

Additional details and impacted files
@@           Coverage Diff           @@
##             main    #5115   +/-   ##
=======================================
  Coverage   83.19%   83.19%           
=======================================
  Files         249      249           
  Lines       26885    26885           
=======================================
  Hits        22368    22368           
  Misses       4517     4517           
Flag Coverage Δ
5.10-c5n.metal 83.60% <ø> (ø)
5.10-m5n.metal 83.60% <ø> (+<0.01%) ⬆️
5.10-m6a.metal 82.80% <ø> (ø)
5.10-m6g.metal 79.60% <ø> (ø)
5.10-m6i.metal 83.60% <ø> (ø)
5.10-m7a.metal-48xl 82.80% <ø> (?)
5.10-m7g.metal 79.60% <ø> (ø)
6.1-c5n.metal 83.65% <ø> (ø)
6.1-m5n.metal 83.65% <ø> (+<0.01%) ⬆️
6.1-m6a.metal 82.85% <ø> (+<0.01%) ⬆️
6.1-m6g.metal 79.60% <ø> (ø)
6.1-m6i.metal 83.64% <ø> (+<0.01%) ⬆️
6.1-m7a.metal-48xl 82.84% <ø> (?)
6.1-m7g.metal 79.60% <ø> (ø)

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@kalyazin kalyazin marked this pull request as draft March 26, 2025 14:27
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This is not right. In fact we typically receive both EPOLLIN and EPOLLHUP at the same time, because Firecracker closes the connection immediately after sending mappings to the UFFD handler.

@kalyazin kalyazin closed this Mar 26, 2025
@kalyazin kalyazin deleted the pollhup branch March 26, 2025 17:14
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2 participants