[PATCH v1 08/12] target/riscv: Handle KVM_EXIT_RISCV_SBI exit

[Philippe Mathieu-Daudé]

Hi,

On 11/20/21 08:46, Yifei Jiang wrote:
> Use char-fe to handle console sbi call, which implement early
> console io while apply 'earlycon=sbi' into kernel parameters.
> 
> Signed-off-by: Yifei Jiang <jiangyifei at huawei.com>
> Signed-off-by: Mingwang Li <limingwang at huawei.com>
> ---
>  target/riscv/kvm.c                 | 42 ++++++++++++++++-
>  target/riscv/sbi_ecall_interface.h | 72 ++++++++++++++++++++++++++++++
>  2 files changed, 113 insertions(+), 1 deletion(-)
>  create mode 100644 target/riscv/sbi_ecall_interface.h
> 
> diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
> index 8da2648d1a..6d419ba02e 100644
> --- a/target/riscv/kvm.c
> +++ b/target/riscv/kvm.c
> @@ -38,6 +38,8 @@
>  #include "qemu/log.h"
>  #include "hw/loader.h"
>  #include "kvm_riscv.h"
> +#include "sbi_ecall_interface.h"
> +#include "chardev/char-fe.h"
>  
>  static uint64_t kvm_riscv_reg_id(CPURISCVState *env, uint64_t type, uint64_t idx)
>  {
> @@ -440,9 +442,47 @@ bool kvm_arch_stop_on_emulation_error(CPUState *cs)
>      return true;
>  }
>  
> +static int kvm_riscv_handle_sbi(struct kvm_run *run)
> +{
> +    int ret = 0;
> +    unsigned char ch;
> +    switch (run->riscv_sbi.extension_id) {
> +    case SBI_EXT_0_1_CONSOLE_PUTCHAR:
> +        ch = run->riscv_sbi.args[0];
> +        qemu_chr_fe_write(serial_hd(0)->be, &ch, sizeof(ch));
> +        break;
> +    case SBI_EXT_0_1_CONSOLE_GETCHAR:
> +        ret = qemu_chr_fe_read_all(serial_hd(0)->be, &ch, sizeof(ch));
> +        if (ret == sizeof(ch)) {
> +            run->riscv_sbi.args[0] = ch;
> +        } else {
> +            run->riscv_sbi.args[0] = -1;
> +        }
> +        break;

Shouldn't this code use the Semihosting Console API from
"semihosting/console.h" instead?