reduce default SWIOTLB size when no PCI devs are used #514
Conversation
Linux inside HVM will allocate 64MB for bouncing DMA (SWIOTLB) by default. If no real PCI device is assigned, that's way too much, and wastes over 15% of VM's initial memory. With real PCI devices, it's usually too much too, but it's very device specific, so don't risk breaking it. In other cases, reduce default to 4MB. Note PVH domain will not allocate SWIOTLB anyway, as no PCI devices are there at all. This difference contributes to the VM start time, so reducing SWIOTLB should also improve that part. QubesOS/qubes-issues#6174
After fixing cyclic import, qmemman is now imported in tests too and expects "xid" property to be set on a running VM.
Set the permission only to the 'memory/meminfo' key (needs to be created first), not the whole 'memory' dir. And do it only if memory balancing is enabled. This avoids VM potentially messing with other keys (like static-max), or reporting meminfo when not expected to.
The old (multiline) meminfo format was used before R4.0. We can drop it now.
OpenQA test summaryComplete test suite and dependencies: https://openqa.qubes-os.org/tests/overview?distri=qubesos&version=4.2&build=2023011805-4.2&flavor=pull-requests New failures, excluding unstableCompared to: https://openqa.qubes-os.org/tests/overview?distri=qubesos&version=4.2&build=2022121202-4.2&flavor=update
Failed tests15 failures
Fixed failuresCompared to: https://openqa.qubes-os.org/tests/55523#dependencies 56 fixed
Unstable tests |
Linux inside HVM will allocate 64MB for bouncing DMA (SWIOTLB) by default.
If no real PCI device is assigned, that's way too much, and wastes over 15%
of VM's initial memory. With real PCI devices, it's usually too much too,
but it's very device specific, so don't risk breaking it. In other cases,
reduce default to 4MB.
Note PVH domain will not allocate SWIOTLB anyway, as no PCI devices are
there at all. This difference contributes to the VM start time, so reducing
SWIOTLB should also improve that part.
QubesOS/qubes-issues#6174
Also, include few fixes from #506, to have them merged independently