vmbus_server: always notify that the connection is modified when disconnecting #1809
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SvenGroot
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Pull Request Overview
This PR fixes a bug where the VMBus server would not properly notify connection modifications during disconnection when all channels were already reset. The issue caused memory corruption in Linux during hibernate resume operations due to monitor pages not being properly cleaned up.
Key Changes
- Always invoke
notify_disconnect()when disconnecting, even if all channels are already reset - Extracted
notify_disconnect()method to consolidate disconnection notification logic - Added comprehensive tests for disconnect scenarios including channels with/without open channels and forced disconnects
Co-authored-by: Copilot <[email protected]>
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…onnecting (microsoft#1809) This change fixes an issue where, if all channels are already reset when a disconnect happens, the server would not invoke `Notifier::modify_connection`. This means that the state such as the interrupt page and monitor pages is not reset, and in the case of OpenHCL the relay is not notified of the disconnect (which can leave host state intact, including monitor pages if MNF is handled by the host). This caused an issue where Linux would occasionally crash during resume from hibernate. When resuming, Linux makes two connections, first to read the memory image, and then to resume normal operations, both using MNF. When the first connection unloads, the overlay pages for the monitor pages were not removed until the reconnect, leading to memory corruption when Linux proceeds to use these pages as normal memory. This change also adds some tests ensuring the notifier is invoked for an unload with open channels, without open channels, and a forced disconnect when a new InitiateContact message is received. --------- Co-authored-by: Copilot <[email protected]>
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…onnecting (#1812) This change fixes an issue where, if all channels are already reset when a disconnect happens, the server would not invoke `Notifier::modify_connection`. This means that the state such as the interrupt page and monitor pages is not reset, and in the case of OpenHCL the relay is not notified of the disconnect (which can leave host state intact, including monitor pages if MNF is handled by the host). This caused an issue where Linux would occasionally crash during resume from hibernate. When resuming, Linux makes two connections, first to read the memory image, and then to resume normal operations, both using MNF. When the first connection unloads, the overlay pages for the monitor pages were not removed until the reconnect, leading to memory corruption when Linux proceeds to use these pages as normal memory. This change also adds some tests ensuring the notifier is invoked for an unload with open channels, without open channels, and a forced disconnect when a new InitiateContact message is received. Cherry-picked from #1809 --------- Co-authored-by: Copilot <[email protected]>
|
Backported to release/2411 in #1812 |
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SvenGroot
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…onnecting (microsoft#1809) This change fixes an issue where, if all channels are already reset when a disconnect happens, the server would not invoke `Notifier::modify_connection`. This means that the state such as the interrupt page and monitor pages is not reset, and in the case of OpenHCL the relay is not notified of the disconnect (which can leave host state intact, including monitor pages if MNF is handled by the host). This caused an issue where Linux would occasionally crash during resume from hibernate. When resuming, Linux makes two connections, first to read the memory image, and then to resume normal operations, both using MNF. When the first connection unloads, the overlay pages for the monitor pages were not removed until the reconnect, leading to memory corruption when Linux proceeds to use these pages as normal memory. This change also adds some tests ensuring the notifier is invoked for an unload with open channels, without open channels, and a forced disconnect when a new InitiateContact message is received. --------- Co-authored-by: Copilot <[email protected]>
benhillis
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that referenced
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…onnecting (#1817) This change fixes an issue where, if all channels are already reset when a disconnect happens, the server would not invoke `Notifier::modify_connection`. This means that the state such as the interrupt page and monitor pages is not reset, and in the case of OpenHCL the relay is not notified of the disconnect (which can leave host state intact, including monitor pages if MNF is handled by the host). This caused an issue where Linux would occasionally crash during resume from hibernate. When resuming, Linux makes two connections, first to read the memory image, and then to resume normal operations, both using MNF. When the first connection unloads, the overlay pages for the monitor pages were not removed until the reconnect, leading to memory corruption when Linux proceeds to use these pages as normal memory. This change also adds some tests ensuring the notifier is invoked for an unload with open channels, without open channels, and a forced disconnect when a new InitiateContact message is received. Cherry-picked from #1809 Co-authored-by: Copilot <[email protected]>
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Backported to release/2505 in #1817 |
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This change fixes an issue where, if all channels are already reset when a disconnect happens, the server would not invoke
Notifier::modify_connection. This means that the state such as the interrupt page and monitor pages is not reset, and in the case of OpenHCL the relay is not notified of the disconnect (which can leave host state intact, including monitor pages if MNF is handled by the host).This caused an issue where Linux would occasionally crash during resume from hibernate. When resuming, Linux makes two connections, first to read the memory image, and then to resume normal operations, both using MNF. When the first connection unloads, the overlay pages for the monitor pages were not removed until the reconnect, leading to memory corruption when Linux proceeds to use these pages as normal memory.
This change also adds some tests ensuring the notifier is invoked for an unload with open channels, without open channels, and a forced disconnect when a new InitiateContact message is received.