[virtio-mem] Dynamic slots and performance tests #5490
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Codecov Report❌ Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## feature/virtio-mem #5490 +/- ##
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+ Coverage 83.23% 83.31% +0.07%
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Files 276 276
Lines 28666 28839 +173
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+ Hits 23861 24028 +167
- Misses 4805 4811 +6
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kalyazin
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Oct 27, 2025
Add a slot_cnt parameter to next_kvm_slot. This will be used to allocate multiple slots for a slotted hotpluggable region. Signed-off-by: Riccardo Mancini <[email protected]>
To avoid boilerplate code in multiple places, let's just define it once and use it everywhere. Signed-off-by: Riccardo Mancini <[email protected]>
In preparation to adding support for multiple memory slots, refactor the mincore_bitmap function to accept a pointer and length rather than an entire memory region object. Signed-off-by: Riccardo Mancini <[email protected]>
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kalyazin
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Oct 28, 2025
ShadowCurse
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Nov 4, 2025
A single GuestMemoryRegion can be split into multiple KVM slots. This is used for Hotplug type regions where we can dynamically remove access to the region from the guest. Signed-off-by: Riccardo Mancini <[email protected]>
Dynamically plug/unplug KVM slots when any/all of the blocks are plugged/unplugged. This prevents the guest from accessing unplugged memory. However, this doesn't yet prevent the device emulation from accessing the slots. Signed-off-by: Riccardo Mancini <[email protected]>
Add a performance test that measures the latency to hot(un)plug different amounts of memory. Signed-off-by: Riccardo Mancini <[email protected]>
Add the memory hotplug tests to buildkite. Signed-off-by: Riccardo Mancini <[email protected]>
This prevents the device emulation to be tricked into accessing unplugged memory ranges. If a malicious driver tries to do so, the VMM will crash with a memory error. Signed-off-by: Riccardo Mancini <[email protected]>
These two functions were doing a similar thing. Let's extend the build_from_snapshot to support uffd and drop the newly introduced clone_vm. Signed-off-by: Riccardo Mancini <[email protected]>
Extend the tests to also check that everything works with diff snapshots (dirty page tracking and mincore). Signed-off-by: Riccardo Mancini <[email protected]>
Add a test that verifies that incremental snapshots work as expected. Each generation will plug more memory and verify that the contents in memory from previous generations are persisted. Signed-off-by: Riccardo Mancini <[email protected]>
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ShadowCurse
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Nov 7, 2025
kalyazin
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Nov 7, 2025
Manciukic
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Changes
mprotectto protect unplugged slots from the VMM device emulation.Reason
virtio-mem feature work.
License Acceptance
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CONTRIBUTING.md.PR Checklist
tools/devtool checkbuild --allto verify that the PR passesbuild checks on all supported architectures.
tools/devtool checkstyleto verify that the PR passes theautomated style checks.
how they are solving the problem in a clear and encompassing way.
in the PR.
CHANGELOG.md.Runbook for Firecracker API changes.
integration tests.
TODO.rust-vmm.