Support virtio entropy device

[sbutz]

In virtualized deployments seed DRNG from entropy provided by host.

Tbh this driver is of limited use, but was good exercise to get started with virtio.

Arch	mmio	pci
x86_64	✅	✅
aarch64	✅	✅
riscv64	✅	❌ - pci will be added with #2550

Blocked by integration of rust-osdev/virtio-spec-rs#24 and new release of virtio-spec-rs.

[github-actions]

Benchmark Results

Details

Benchmark	Current: 9a3240a	Previous: 2e23902	Performance Ratio
startup_benchmark Build Time	81.91 s	80.34 s	1.02 ❗
startup_benchmark File Size	0.77 MB	0.80 MB	0.96 ❗
Startup Time - 1 core	0.76 s (±0.02 s)	0.75 s (±0.02 s)	1.02
Startup Time - 2 cores	0.76 s (±0.02 s)	0.74 s (±0.02 s)	1.03
Startup Time - 4 cores	0.76 s (±0.03 s)	0.74 s (±0.02 s)	1.02
multithreaded_benchmark Build Time	84.55 s	82.11 s	1.03 ❗
multithreaded_benchmark File Size	0.87 MB	0.86 MB	1.02 ❗
Multithreaded Pi Efficiency - 2 Threads	88.99 % (±6.57 %)	85.89 % (±6.61 %)	1.04
Multithreaded Pi Efficiency - 4 Threads	43.87 % (±2.36 %)	43.43 % (±2.56 %)	1.01
Multithreaded Pi Efficiency - 8 Threads	25.58 % (±1.49 %)	25.76 % (±1.53 %)	0.99
micro_benchmarks Build Time	83.24 s	80.40 s	1.04 ❗
micro_benchmarks File Size	0.88 MB	0.86 MB	1.02 ❗
Scheduling time - 1 thread	65.98 ticks (±3.41 ticks)	62.65 ticks (±4.06 ticks)	1.05
Scheduling time - 2 threads	36.10 ticks (±4.66 ticks)	34.08 ticks (±4.10 ticks)	1.06
Micro - Time for syscall (getpid)	4.49 ticks (±0.70 ticks)	3.45 ticks (±0.58 ticks)	1.30 ❗
Memcpy speed - (built_in) block size 4096	82626.56 MByte/s (±57054.43 MByte/s)	82448.38 MByte/s (±56997.13 MByte/s)	1.00
Memcpy speed - (built_in) block size 1048576	30140.40 MByte/s (±24338.31 MByte/s)	30585.98 MByte/s (±24707.84 MByte/s)	0.99
Memcpy speed - (built_in) block size 16777216	26203.78 MByte/s (±21686.61 MByte/s)	26340.06 MByte/s (±21720.96 MByte/s)	0.99
Memset speed - (built_in) block size 4096	83106.47 MByte/s (±57369.50 MByte/s)	82292.76 MByte/s (±56891.50 MByte/s)	1.01
Memset speed - (built_in) block size 1048576	30888.32 MByte/s (±24780.12 MByte/s)	31323.85 MByte/s (±25145.86 MByte/s)	0.99
Memset speed - (built_in) block size 16777216	26967.52 MByte/s (±22174.48 MByte/s)	27104.68 MByte/s (±22209.94 MByte/s)	0.99
Memcpy speed - (rust) block size 4096	75097.31 MByte/s (±52391.18 MByte/s)	74097.96 MByte/s (±51811.44 MByte/s)	1.01
Memcpy speed - (rust) block size 1048576	30071.47 MByte/s (±24371.31 MByte/s)	30361.60 MByte/s (±24602.37 MByte/s)	0.99
Memcpy speed - (rust) block size 16777216	27143.07 MByte/s (±22400.28 MByte/s)	27625.34 MByte/s (±22806.88 MByte/s)	0.98
Memset speed - (rust) block size 4096	75772.31 MByte/s (±52845.56 MByte/s)	74373.47 MByte/s (±51976.48 MByte/s)	1.02
Memset speed - (rust) block size 1048576	30816.13 MByte/s (±24804.05 MByte/s)	31110.89 MByte/s (±25033.24 MByte/s)	0.99
Memset speed - (rust) block size 16777216	27911.75 MByte/s (±22877.62 MByte/s)	28386.93 MByte/s (±23265.03 MByte/s)	0.98
alloc_benchmarks Build Time	76.55 s	74.76 s	1.02 ❗
alloc_benchmarks File Size	0.84 MB	0.87 MB	0.97 ❗
Allocations - Allocation success	91.34 %	91.31 %	1.00 ❗
Allocations - Deallocation success	100.00 %	100.00 %	1
Allocations - Pre-fail Allocations	61.54 %	61.44 %	1.00 ❗
Allocations - Average Allocation time	2679.27 Ticks (±705.73 Ticks)	5860.58 Ticks (±98.43 Ticks)	0.46 ❗
Allocations - Average Allocation time (no fail)	3703.72 Ticks (±619.95 Ticks)	6554.81 Ticks (±92.86 Ticks)	0.57 ❗
Allocations - Average Deallocation time	728.74 Ticks (±126.43 Ticks)	1805.01 Ticks (±250.35 Ticks)	0.40 ❗
mutex_benchmark Build Time	80.92 s	79.82 s	1.01 ❗
mutex_benchmark File Size	0.88 MB	0.86 MB	1.02 ❗
Mutex Stress Test Average Time per Iteration - 1 Threads	12.14 ns (±0.40 ns)	12.10 ns (±0.41 ns)	1.00
Mutex Stress Test Average Time per Iteration - 2 Threads	40.82 ns (±2.30 ns)	40.26 ns (±1.68 ns)	1.01

This comment was automatically generated by workflow using github-action-benchmark.

[sbutz]

@mkroening does the new feature virtio-entropy require a new kernel version and a bump in hermit-rs?
The ci tests are added in the last commit. It can be moved to separate PR which can be merged after the next new kernel release and bump in hermit-rs.

[mkroening]

@mkroening does the new feature virtio-entropy require a new kernel version and a bump in hermit-rs? The ci tests are added in the last commit. It can be moved to separate PR which can be merged after the next new kernel release and bump in hermit-rs.

All it should need is the new feature being listed in the hermit-rs wrapper crate's Cargo.toml. A new kernel release or kernel bump in hermit-rs should not be necessary for the kernel CI to pick up the feature. Kernel CI always uses the latest hermit-rs commit. So please open a PR in hermit-rs, adding the feature. That uncontroversial one-line change can be merged immediately to unblock your further work here.

Sorry for the long wait. I have not forgotten this PR and will review it in the next days. :)

Edit: Thanks for keeping this PR up to date and rebasing on #2527, which I had prioritized for review in preparation for this PR.