GSI Allocator: free GSIs when they are no longer used#74
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amphi merged 3 commits intocyberus-technology:gardenlinuxfrom Feb 11, 2026
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GSI Allocator: free GSIs when they are no longer used#74amphi merged 3 commits intocyberus-technology:gardenlinuxfrom
amphi merged 3 commits intocyberus-technology:gardenlinuxfrom
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I think a bitmap is trivial enough to keep the functionality in the module itself |
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I think we can leave this as is, good design! Please address the remaining remarks
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The old implementation used a u32 to allocate new GSIs. The counter increased every time a new GSI was allocated, and freeing GSIs was not possible. Thus, Cloud Hypervisor could run out of GSIs and panic. This new implementation can also free GSIs. Please note that this commit only replaces the old mechanism, the next commit will introduce a mechanism to free used GSIs. While I was here I also propagated the errors that the allocator may throw where necessary. On-behalf-of: SAP sebastian.eydam@sap.com Signed-off-by: Sebastian Eydam <sebastian.eydam@cyberus-technology.de>
These changes free GSIs when they are no longer used. That way we won't exhaust the available GSIs anymore when attaching and detaching devices. On-behalf-of: SAP sebastian.eydam@sap.com Signed-off-by: Sebastian Eydam <sebastian.eydam@cyberus-technology.de>
On-behalf-of: SAP sebastian.eydam@sap.com Signed-off-by: Sebastian Eydam <sebastian.eydam@cyberus-technology.de>
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This PR changes the
GsiAllocatorto enable it to free GSIs when they are no longer used. To do that, it replaces theu32that was used to track used GSIs with a simple bitmap. If you know a good bitmap crate that I should use, please tell me.While I was here, I also made sure that errors from the allocator a propagated. I also used the bitmap for the IRQs of the
GsiAllocator, just because it made it easier for me to propagate useful errors.I am not completely sure whether I free the GSIs at all necessary places.