The old implementation used an ever monotonically increasing u32 counter
to allocate new GSIs. The counter increased every time a new GSI was
allocated, and freeing GSIs was not possible. Thus, Cloud Hypervisor
can run out of GSIs and panics. This currently happened at the 1024th
GSI [0]. Further, this caused the `KVM_SET_GSI_ROUTING` ioctl to carry
much more payload than needed.
This new implementation uses a bitmap for proper tracking of resources
and can gracefully free GSIs - this is abstracted in type
InterruptAllocator.
Please note that this commit only replaces the old mechanism. The next
commit will introduce freeing used GSIs automatically when an
InterruptRoute is dropped.
While being on this, we also propagate the errors that the allocator may
throw where necessary.
Co-authored-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>
On-behalf-of: Philipp Schuster@sap.com
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
This helps to uncover expensive and needless clones in the code base.
For example, I prevented extensive clones in the snapshot path where
(nested) BTreeMap's have been cloned over and over again. Further,
the lint helps devs to much better reason about the ownership of
parameters.
All of these changes have been done manually with the necessary
caution. A few structs that are cheap to clone are now `copy` so that
this lint won't trigger for them.
I didn't enable the lint so far as it is a massive rabbit hole and
needs much more fixes. Nevertheless, it is very useful.
Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com
Provide implementation for GSI allocator to work on riscv64
architecture, and doc comment for riscv64 as well.
Signed-off-by: Ruoqing He <heruoqing@iscas.ac.cn>
Add a Default implementation that delegates to new, so that clippy
can be removed.
Signed-off-by: Ravi kumar Veeramally <ravikumar.veeramally@intel.com>
Implemented GSI allocator and system allocator for AArch64.
Renamed some layout definitions to align more code between architectures.
Signed-off-by: Michael Zhao <michael.zhao@arm.com>
GSI (Global System Interrupt) is an extension of just a linear array of
IRQs. It takes IOAPICs into account for example.
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
