risc-v启动arceos乱码

[451846939]

步骤：

make PLATFORM=riscv64-qemu-virt SMP=1 A=examples/helloworld

使用的是上面make build出来的helloworld_riscv64-qemu-virt.bin文件

修改配置./configs/vms/arceos-riscv64.toml 中的 kernel_path = "helloworld_riscv64-qemu-virt.bin" 没有其它修改

启动risc-v的arceos （使用的是当前最新的主分支）

make ACCEL=n ARCH=riscv64 LOG=info VM_CONFIGS=configs/vms/arceos-riscv64.toml APP_FEATURES=fs run

输出如下:

    _         __     ___
   / \   __  _\ \   / (_)___  ___  _ __
  / _ \  \ \/ /\ \ / /| / __|/ _ \| '__|
 / ___ \  >  <  \ V / | \__ \ (_) | |
/_/   \_\/_/\_\  \_/  |_|___/\___/|_|


by AxVisor Team

[  0.184800 0:2 axvisor:20] Starting virtualization...
[  0.185147 0:2 axvisor:21] Hardware support: true
[  0.185973 0:4 axvisor::vmm::timer:101] Initing HV Timer...
[  0.186243 0:4 axvisor::hal:117] Hardware virtualization support enabled on core 0
[  0.198929 0:2 axvisor::vmm::config:33] Creating VM[1] "arceos"
[  0.199446 0:2 axvm::vm:114] Setting up memory region: [0x80000000~0x84000000] READ | WRITE | EXECUTE | USER
[  0.205202 0:2 axvm::vm:157] Setting up passthrough device memory region: [0xc000000~0xc210000] -> [0xc000000~0xc210000]
[  0.205813 0:2 axvm::vm:157] Setting up passthrough device memory region: [0x10000000~0x10001000] -> [0x10000000~0x10001000]
[  0.206304 0:2 axvm::vm:193] VM[1] created
[  0.206604 0:2 axvm::vm:208] VM[1] vcpus set up
[  0.206844 0:2 axvisor::vmm::config:40] VM[1] created success, loading images...
[  0.207105 0:2 axvisor::vmm::images::fs:102] Loading VM images from filesystem
[  0.216543 0:2 axvisor::vmm:35] Setting up vcpus...
[  0.217084 0:2 axvisor::vmm::vcpus:219] Initializing VM[1]'s 1 vcpus
[  0.217376 0:2 axvisor::vmm::vcpus:250] Spawning task for VM[1] VCpu[0]
[  0.217825 0:2 axvisor::vmm::vcpus:262] VCpu task Task(5, "VM[1]-VCpu[0]") created cpumask: [0, ]
[  0.218260 0:2 axvisor::vmm:43] VMM starting, booting VMs...
[  0.218537 0:2 axvm::vm:275] Booting VM[1]
[  0.218758 0:2 axvisor::vmm:49] VM[1] boot success
[  0.219020 0:2 axvisor::vmm:60] a VM exited, current running VM count: 1
[  0.219516 0:5 axvisor::vmm::vcpus:283] VM[1] VCpu[0] waiting for running
[  0.219808 0:5 axvisor::vmm::vcpus:286] VM[1] VCpu[0] running...
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[lkdWind]

我也有类似的情况，请问你的qemu版本是多少，我的是9.2.3

[451846939]

我也有类似的情况，请问你的qemu版本是多少，我的是9.2.3

我也是9.2.3

[451846939]

[ 1.540452 0:5 riscv_vcpu::vcpu:180] vmexit_handler: Exception(VirtualSupervisorEnvCall), sepc: 0xffffffc08020221a, stval: 0x0
[ 1.540728 0:5 riscv_vcpu::vcpu:197] sbi_call: eid 0x4442434e ('DBCN') fid 0x0 param [14, 2149601648, 0, 14, 274877906944, 0]
添加了一些日志发现调用的是DBCN
这是相关规范
https://github.com/riscv-non-isa/riscv-sbi-doc/blob/master/src/ext-debug-console.adoc

调用链路是handle_ecall->_rustsbi_console 具体实现可以看下面

#[doc(hidden)]
#[inline(always)]
pub fn _rustsbi_console<T: crate::Console>(
    console: &T,
    param: [usize; 6],
    function: usize,
) -> SbiRet {
    let [param0, param1, param2] = [param[0], param[1], param[2]];
    match function {
        spec::dbcn::CONSOLE_WRITE => {
            let bytes = Physical::new(param0, param1, param2);
            console.write(bytes)
        }
        spec::dbcn::CONSOLE_READ => {
            let bytes = Physical::new(param0, param1, param2);
            console.read(bytes)
        }
        spec::dbcn::CONSOLE_WRITE_BYTE => console.write_byte((param0 & 0xFF) as u8),
        _ => SbiRet::not_supported(),
    }
}
#[derive(Debug, Clone)]
pub struct Forward;

impl Console for Forward {
    #[inline]
    fn write(&self, bytes: Physical<&[u8]>) -> SbiRet {
        match () {
            #[cfg(feature = "forward")]
            () => sbi_rt::console_write(bytes),
            #[cfg(not(feature = "forward"))]
            () => {
                let _ = bytes;
                unimplemented!()
            }
        }
    }

    #[inline]
    fn read(&self, bytes: Physical<&mut [u8]>) -> SbiRet {
        match () {
            #[cfg(feature = "forward")]
            () => sbi_rt::console_read(bytes),
            #[cfg(not(feature = "forward"))]
            () => {
                let _ = bytes;
                unimplemented!()
            }
        }
    }

    #[inline]
    fn write_byte(&self, byte: u8) -> SbiRet {
        match () {
            #[cfg(feature = "forward")]
            () => sbi_rt::console_write_byte(byte),
            #[cfg(not(feature = "forward"))]
            () => {
                let _ = byte;
                unimplemented!()
            }
        }
    }
}

#[inline]
pub fn console_write(bytes: Physical<&[u8]>) -> SbiRet {
    sbi_call_3(
        EID_DBCN,
        CONSOLE_WRITE,
        bytes.num_bytes(),
        bytes.phys_addr_lo(),
        bytes.phys_addr_hi(),
    )
}

#[inline(always)]
pub(crate) fn sbi_call_3(eid: usize, fid: usize, arg0: usize, arg1: usize, arg2: usize) -> SbiRet {
    let (error, value);
    unsafe {
        core::arch::asm!(
            "ecall",
            in("a7") eid,
            in("a6") fid,
            inlateout("a0") arg0 => error,
            inlateout("a1") arg1 => value,
            in("a2") arg2,
        );
    }
    SbiRet { error, value }
}

此时拿到的 param[0], param[1], param[2]，其实是 guest 传进来的 “guest physical address” 相关参数

•param[0]: num_bytes
•param[1]: base_addr_lo
•param[2]: base_addr_hi

但在 Hypervisor 这里，这个物理地址应该是属于 guest 地址空间的，并不是hypervisor 直接可访问的 host 虚拟地址

在inject_interrupt分支里找到了以下mem_extable.S
可以直接使用

unsafe extern "C" {=
    fn _copy_from_guest(dst: *mut u8, guest_paddr: *const u8, len: usize) -> usize;
    fn _copy_to_guest(dst: *mut u8, src: *const u8, len: usize) -> usize;
}

大概代码修复方式如下

            FID_CONSOLE_WRITE => {
                let num_bytes = param[0];
                let base_lo = param[1];
                let base_hi = param[2];
                let gpa = ((base_hi as u64) << 32) | (base_lo as u64);
                if num_bytes == 0 {
                    self.set_gpr_from_gpr_index(GprIndex::A0, 0);
                    self.set_gpr_from_gpr_index(GprIndex::A1, 0);
                    self.advance_pc(4);
                    return Ok(AxVCpuExitReason::Nothing);
                }
                let mut buf = vec![0u8; num_bytes as usize];
                let copied = unsafe { _copy_from_guest(buf.as_mut_ptr(), gpa as *const u8, buf.len()) };
                if copied == buf.len() {
                    uart_write(&buf);
                    self.set_gpr_from_gpr_index(GprIndex::A0, 0);
                } else {
                    self.set_gpr_from_gpr_index(GprIndex::A0, -1i64 as usize);
                }
                self.set_gpr_from_gpr_index(GprIndex::A1, 0);
                self.advance_pc(4);
                return Ok(AxVCpuExitReason::Nothing);
            }

[451846939]

目前uart_write 的实现是用的log::info打印

log::info!("{}", alloc::string::String::from_utf8_lossy(&buf));

等uart_write实现后我会提pr解决