InvalidInput for http server on qemu

[m4b]

I don't know if this is the right repo to post an issue, but, was playing around with hermit, copied the the simple http_server demo to a rust template, did best I could to copy qemu instructions, built the loader, and ran:

qemu-system-x86_64 -smp 1 -m 256M -device isa-debug-exit,iobase=0xf4,iosize=0x04 -kernel hermit-loader-x86_64 -initrd target/x86_64-unknown-hermit/debug/http_server -display none -serial stdio -netdev user,id=u1,hostfwd=tcp::9975-:9975 -device rtl8139,netdev=u1 --enable-kvm -cpu host
[LOADER][INFO] Loader: [0x100000 - 0x121058]
[LOADER][INFO] Found Multiboot information at 0x9500
[LOADER][WARN] Mapping 1 4KiB pages from 0x9000..0xa000 to 0x9000..0xa000
[LOADER][INFO] Found an ELF module at [0x123000 - 0x1982f68]
[LOADER][INFO] Module length: 0x185ff68
[LOADER][WARN] Mapping 4KiB pages starting from 0x123000 to frames 0x123000..0x200000
[LOADER][WARN] Mapping 2MiB pages starting from 0x200000 to frames 0x200000..0x1a00000
[LOADER][INFO] Parsing kernel from ELF at 0x123000..0x1982f68 (len = 0x185ff68 B / 25558888 B)
[LOADER][INFO] Found Hermit version 0.10.0
[LOADER][WARN] Mapping 2 2MiB pages from 0x1a00000..0x1e00000 to 0x1a00000..0x1e00000
[LOADER][INFO] Loading kernel to 0x1a00000..0x1d3f404 (len = 0x33f404 B / 3404804 B)
[LOADER][INFO] TLS is at 0x1d09a80..0x1d09b18 (len =  0x98 B / 152 B)
[LOADER][WARN] Mapping 8 4KiB pages from 0xa000..0x12000 to 0xa000..0x12000
[LOADER][INFO] boot_info = BootInfo {
    hardware_info: HardwareInfo {
        phys_addr_range: 0x0..0x0,
        serial_port_base: Some(
            0x3f8,
        ),
        device_tree: Some(
            0x120550,
        ),
    },
    load_info: LoadInfo {
        kernel_image_addr_range: 0x1a00000..0x1d3f404,
        tls_info: Some(
            TlsInfo {
                start: 0x1d09a80,
                filesz: 0x21,
                memsz: 0x98,
                align: 0x8,
            },
        ),
    },
    platform_info: Multiboot {
        command_line: Some(
            "hermit-loader-x86_64 ",
        ),
        multiboot_info_addr: 0x9500,
    },
}
[LOADER][INFO] Entering kernel at 0x1bed82c, stack at 0xa000, raw_boot_info at 0x11f008
[0][INFO] Welcome to Hermit 0.10.0
[0][INFO] Kernel starts at 0x1a00000
[0][INFO] FDT:
 / {
    compatible = "hermit,multiboot"
    #address-cells = <0x2>
    #size-cells = <0x2>

    memory@0 {
        device_type = "memory"
        reg = <0x0 0x9fc00>
    };

    memory@100000 {
        device_type = "memory"
        reg = <0x100000 0xfee0000>
    };

    chosen {
        bootargs = [104, 101, 114, 109, 105, 116, 45, 108, 111, 97, 100, 101, 114, 45, 120, 56, 54, 95, 54, 52, 32, 0]
    };
};

[0][INFO] BSS starts at 0x1d3e440
[0][INFO] tls_info = Some(
    TlsInfo {
        start: 0x1d09a80,
        filesz: 0x21,
        memsz: 0x98,
        align: 0x8,
    },
)
[0][INFO] Total memory size: 225 MiB
[0][INFO] Kernel region: 0x1a00000..0x1e00000
[0][INFO] Minimum memory size: 34
[0][INFO] Heap: size 170 MB, start address 0x1e00000
[0][INFO] Heap is located at 0x1e00000..0xc800000 (0 Bytes unmapped)
[0][INFO] Physical memory free list:
         0xc800000..         0xffe0000 (len =          0x37e0000, pages =            14304)
[0][INFO] Virtual memory free list:
         0xc800000..    0x800000000000 (len =     0x7ffff3800000, pages =      34359687168)
[0][INFO] bootargs = hermit-loader-x86_64
[0][INFO]
[0][INFO] ========================== CPU INFORMATION ===========================
[0][INFO] Model:                   11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz
[0][INFO] Frequency:               2800 MHz (from CpuId Tsc Info)
[0][INFO] SpeedStep Technology:    Not Available
[0][INFO] Features:                MMX SSE SSE2 SSE3 SSSE3 SSE4.1 SSE4.2 AVX AESNI RDRAND FMA MOVBE MCE FXSR XSAVE VMX RDTSCP CLFLUSH TSC-DEADLINE X2APIC HYPERVISOR AVX2 AVX512F AVX512DQ AVX512IFMA AVX512CD AVX512BW AVX512VL BMI1 BMI2 PKU FSGSBASE RDSEED
[0][INFO] Physical Address Width:  39 bits
[0][INFO] Linear Address Width:    48 bits
[0][INFO] Supports 1GiB Pages:     Yes
[0][INFO] ======================================================================
[0][INFO]
[0][INFO] Hermit booted on 2025-08-12 4:45:26.789751 +00:00:00
[0][INFO] Found MP config at 0xf66f0
[0][INFO] System uses Multiprocessing Specification 1.4
[0][INFO] MP features 1: 0
[0][INFO] Virtual-Wire mode implemented
[0][INFO] Found IOAPIC at 0x0xfec00000
[0][INFO] IOAPIC v17 has 24 entries
[0][INFO]
[0][INFO] ===================== MULTIPROCESSOR INFORMATION =====================
[0][INFO] APIC in use:             x2APIC
[0][INFO] Initialized CPUs:        1
[0][INFO] ======================================================================
[0][INFO]
[0][INFO] Compiled with PCI support
[0][INFO]
[0][INFO] ======================== PCI BUS INFORMATION =========================
[0][INFO] 00:00 Unknown Class [0600]: Unknown Vendor Unknown Device [8086:1237]
[0][INFO] 00:01 Unknown Class [0601]: Unknown Vendor Unknown Device [8086:7000]
[0][INFO] 00:02 Unknown Class [0300]: Unknown Vendor Unknown Device [1234:1111], BAR0 Memory32 { address: 0xFD000000, size: 0x1000000, prefetchable: true }, BAR2 Memory32 { address: 0xFEBD0000, size: 0x1000, prefetchable: false }
[0][INFO] 00:03 Unknown Class [0200]: Unknown Vendor Unknown Device [10EC:8139], IRQ 11, BAR0 IO { port: 0xC000 }, BAR1 Memory32 { address: 0xFEBD1000, size: 0x100, prefetchable: false }
[0][INFO] ======================================================================
[0][INFO]
[0][INFO] Hermit is running on common system!
[0][INFO] Try to initialize network!
[0][INFO] Try to initialize uhyve filesystem
[0][INFO] Jumping into application

thread 'main' panicked at src/main.rs:15:58:
called `Result::unwrap()` on an `Err` value: Kind(InvalidInput)
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Number of interrupts
[0][FPU]: 1
exit status -1

line 15 is just copied from the simple http server example:

#[cfg(target_os = "hermit")]
use hermit as _;

fn handle_request(request: tiny_http::Request) {
    eprintln!("{request:?}");

    let now_utc = time::OffsetDateTime::now_utc();
    let text = format!("Hello from Hermit! 🦀\nThe current date and time in UTC is {now_utc}.");
    let response = tiny_http::Response::from_string(text);

    request.respond(response).unwrap();
}

fn main() {
    let server = tiny_http::Server::http("0.0.0.0:9975").unwrap();
    eprintln!("Now listening on port 9975");

    for request in server.incoming_requests() {
        handle_request(request);

        if cfg!(feature = "ci") {
            break;
        }
    }
}

did I mess up the QEMU command somehow or?

I also have the same error if i run it through uhvye, but my understanding is that probably doesn't work? (would be great if it did :D )

[mkroening]

Thanks for reaching out! :)

Which Hermit features did you enable? I think the issue is that you did not compile Hermit with the correct network driver. For RTL8139, you need to enable hermit/rtl8139. Alternatively, you can enable hermit/virtio-net and use virtio-net on QEMU. The hermit/virtio-net feature is very recent, though, and does not exist outside the Git repo yet. If that feature does not exist, hermit/rtl8139 will disable virtio-net support.

We definitely need to provide clearer error messages during driver initialization.

[m4b]

Ah neat, yea I didn't see that feature. So adding rtl8139 works to get a little further, and the logging on network init looks better, but it still fails with invalid input:

[0][INFO] Found Realtek network device with device id 0x8139
[0][INFO] RTL8139: CR = 0xd, ISR = 0x0, speed = 10 mbps
[0][INFO] RTL8139 use interrupt line 11
[0][INFO] Try to initialize network!
[0][INFO] MAC address 52-54-00-12-34-56
[0][INFO] Configure network interface with address 10.0.5.3/24
[0][INFO] Configure gateway with address 10.0.5.1
[0][INFO] ChecksumCapabilities { ipv4: Both, udp: Both, tcp: Both, icmpv4: Both, icmpv6: Both }
[0][INFO] MTU: 1514 bytes
[0][INFO] Try to initialize uhyve filesystem
[0][INFO] Jumping into application

thread 'main' panicked at src/main.rs:15:58:
called `Result::unwrap()` on an `Err` value: Kind(InvalidInput)

If I understood you correctly, enabling the feature on the crates hermit release should work with uhvye or qemu, and the above is unexpected (it was invoked with qemu command above)?

I tried above with uhvye but it fails, only qemu gets to above (and still has the invalidinput issue).

Lastly, if I don't want that I should enable a virtio feature on a recent git hermit which will work with qemu.

Did I get that right, that this should work on qemu or uhvye with a crates release, but the above is not currently expected?

[m4b]

Ok, so I just I read the advanced section again, and noted it said if don't want to add taps can use dhcpv4 feature to transparently connect, and indeed, I can navigate to http://localhost:9975 and it returns the message:

[    0.874137][0][INFO] Found Realtek network device with device id 0x8139
[    0.917414][0][INFO] RTL8139: CR = 0xd, ISR = 0x0, speed = 10 mbps
[    0.934537][0][INFO] RTL8139 use interrupt line 11
[    0.951458][0][INFO] Try to initialize network!
[    0.968715][0][INFO] MAC address 52-54-00-12-34-56
[    0.986217][0][INFO] ChecksumCapabilities { ipv4: Both, udp: Both, tcp: Both, icmpv4: Both, icmpv6: Both }
[    1.020331][0][INFO] MTU: 1514 bytes
[    0.992521][0][INFO] DHCP lost config!
[    1.009145][0][INFO] DHCP config acquired!
[    1.025347][0][INFO] IP address:      10.0.2.15/24
[    1.041715][0][INFO] Default gateway: 10.0.2.2
[    1.058180][0][INFO] DNS server 0:    10.0.2.3
[    1.075059][0][INFO] Try to initialize uhyve filesystem
[    1.091405][0][INFO] Jumping into application
Now listening on port 9975
Request(GET / from Some(10.0.2.2:33210))

huzzah! Very cool, this is awesome stuff :D

Note, I did have to point at the latest top of tree on hermit, along with updated kernel submodule.

Ideally, it would also be great if I could use that with uhvye too, not sure how involved that is, but it's cool I can see it working with qemu.

I think we can close this issue if you like, as I believe it's resolved by:

1. Updating to 5e12a62bfc538ae91103e0415065f7062bf8938c
2. git submodule update --remote kernel to 11432b0b219d6552c625c30f9667ee4bfd5a4b5b
3. Enable dhcpv4 and rtl8139 features
4. Point hermit in the rust hermit app at the local git version

Note I also had this crash when I Just updated the hermit-rs repo, but forgot to update the kernel submodule, and it crashed with another error about cannot write out fully, but this was fixed once i properly synced the repos, e.g., git submodule update --remote kernel :)

[jounathaen]

Unfortunately, uhyve does not support networking yet hermit-os/uhyve#374
But we are still working on it.