On Tue, Dec 21, 2021 at 3:41 AM Yifei Jiang via <qemu-devel@xxxxxxxxxx> 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@xxxxxxxxxx>
> Signed-off-by: Mingwang Li <limingwang@xxxxxxxxxx>
> Reviewed-by: Anup Patel <anup.patel@xxxxxxx>
> ---
> target/riscv/kvm.c | 43 +++++++++++++++++-
> target/riscv/sbi_ecall_interface.h | 72 ++++++++++++++++++++++++++++++
> 2 files changed, 114 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 0027f11f45..4d08669c81 100644
> --- a/target/riscv/kvm.c
> +++ b/target/riscv/kvm.c
> @@ -38,6 +38,9 @@
> #include "qemu/log.h"
> #include "hw/loader.h"
> #include "kvm_riscv.h"
> +#include "sbi_ecall_interface.h"
> +#include "chardev/char-fe.h"
> +#include "semihosting/console.h"
>
> static uint64_t kvm_riscv_reg_id(CPURISCVState *env, uint64_t type, uint64_t idx)
> {
> @@ -365,9 +368,47 @@ bool kvm_arch_stop_on_emulation_error(CPUState *cs)
> return true;
> }
>
> +static int kvm_riscv_handle_sbi(CPUState *cs, 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_semihosting_log_out((const char *)&ch, sizeof(ch));
Hmmm... We print to the semihosting
> + break;
> + case SBI_EXT_0_1_CONSOLE_GETCHAR:
> + ret = qemu_chr_fe_read_all(serial_hd(0)->be, &ch, sizeof(ch));
but then read from the first serial device.
That seems a little strange. Would it be better to just print to serial as well?
Alistair
> + if (ret == sizeof(ch)) {
> + run->riscv_sbi.args[0] = ch;
> + } else {
> + run->riscv_sbi.args[0] = -1;
> + }
> + break;
> + default:
> + qemu_log_mask(LOG_UNIMP,
> + "%s: un-handled SBI EXIT, specific reasons is %lu\n",
> + __func__, run->riscv_sbi.extension_id);
> + ret = -1;
> + break;
> + }
> + return ret;
> +}
> +
> int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
> {
> - return 0;
> + int ret = 0;
> + switch (run->exit_reason) {
> + case KVM_EXIT_RISCV_SBI:
> + ret = kvm_riscv_handle_sbi(cs, run);
> + break;
> + default:
> + qemu_log_mask(LOG_UNIMP, "%s: un-handled exit reason %d\n",
> + __func__, run->exit_reason);
> + ret = -1;
> + break;
> + }
> + return ret;
> }
>
> void kvm_riscv_reset_vcpu(RISCVCPU *cpu)
> diff --git a/target/riscv/sbi_ecall_interface.h b/target/riscv/sbi_ecall_interface.h
> new file mode 100644
> index 0000000000..fb1a3fa8f2
> --- /dev/null
> +++ b/target/riscv/sbi_ecall_interface.h
> @@ -0,0 +1,72 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2019 Western Digital Corporation or its affiliates.
> + *
> + * Authors:
> + * Anup Patel <anup.patel@xxxxxxx>
> + */
> +
> +#ifndef __SBI_ECALL_INTERFACE_H__
> +#define __SBI_ECALL_INTERFACE_H__
> +
> +/* clang-format off */
> +
> +/* SBI Extension IDs */
> +#define SBI_EXT_0_1_SET_TIMER 0x0
> +#define SBI_EXT_0_1_CONSOLE_PUTCHAR 0x1
> +#define SBI_EXT_0_1_CONSOLE_GETCHAR 0x2
> +#define SBI_EXT_0_1_CLEAR_IPI 0x3
> +#define SBI_EXT_0_1_SEND_IPI 0x4
> +#define SBI_EXT_0_1_REMOTE_FENCE_I 0x5
> +#define SBI_EXT_0_1_REMOTE_SFENCE_VMA 0x6
> +#define SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID 0x7
> +#define SBI_EXT_0_1_SHUTDOWN 0x8
> +#define SBI_EXT_BASE 0x10
> +#define SBI_EXT_TIME 0x54494D45
> +#define SBI_EXT_IPI 0x735049
> +#define SBI_EXT_RFENCE 0x52464E43
> +#define SBI_EXT_HSM 0x48534D
> +
> +/* SBI function IDs for BASE extension*/
> +#define SBI_EXT_BASE_GET_SPEC_VERSION 0x0
> +#define SBI_EXT_BASE_GET_IMP_ID 0x1
> +#define SBI_EXT_BASE_GET_IMP_VERSION 0x2
> +#define SBI_EXT_BASE_PROBE_EXT 0x3
> +#define SBI_EXT_BASE_GET_MVENDORID 0x4
> +#define SBI_EXT_BASE_GET_MARCHID 0x5
> +#define SBI_EXT_BASE_GET_MIMPID 0x6
> +
> +/* SBI function IDs for TIME extension*/
> +#define SBI_EXT_TIME_SET_TIMER 0x0
> +
> +/* SBI function IDs for IPI extension*/
> +#define SBI_EXT_IPI_SEND_IPI 0x0
> +
> +/* SBI function IDs for RFENCE extension*/
> +#define SBI_EXT_RFENCE_REMOTE_FENCE_I 0x0
> +#define SBI_EXT_RFENCE_REMOTE_SFENCE_VMA 0x1
> +#define SBI_EXT_RFENCE_REMOTE_SFENCE_VMA_ASID 0x2
> +#define SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA 0x3
> +#define SBI_EXT_RFENCE_REMOTE_HFENCE_GVMA_VMID 0x4
> +#define SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA 0x5
> +#define SBI_EXT_RFENCE_REMOTE_HFENCE_VVMA_ASID 0x6
> +
> +/* SBI function IDs for HSM extension */
> +#define SBI_EXT_HSM_HART_START 0x0
> +#define SBI_EXT_HSM_HART_STOP 0x1
> +#define SBI_EXT_HSM_HART_GET_STATUS 0x2
> +
> +#define SBI_HSM_HART_STATUS_STARTED 0x0
> +#define SBI_HSM_HART_STATUS_STOPPED 0x1
> +#define SBI_HSM_HART_STATUS_START_PENDING 0x2
> +#define SBI_HSM_HART_STATUS_STOP_PENDING 0x3
> +
> +#define SBI_SPEC_VERSION_MAJOR_OFFSET 24
> +#define SBI_SPEC_VERSION_MAJOR_MASK 0x7f
> +#define SBI_SPEC_VERSION_MINOR_MASK 0xffffff
> +#define SBI_EXT_VENDOR_START 0x09000000
> +#define SBI_EXT_VENDOR_END 0x09FFFFFF
> +/* clang-format on */
> +
> +#endif
> --
> 2.19.1
>
>
