[PATCH RFC v6 08/12] target/riscv: Handle KVM_EXIT_RISCV_SBI exit
Jiangyifei
jiangyifei at huawei.com
Fri Aug 20 02:23:09 PDT 2021
> -----Original Message-----
> From: Qemu-riscv
> [mailto:qemu-riscv-bounces+jiangyifei=huawei.com at nongnu.org] On Behalf Of
> Alistair Francis
> Sent: Thursday, August 19, 2021 2:14 PM
> To: Jiangyifei <jiangyifei at huawei.com>
> Cc: Anup Patel <anup.patel at wdc.com>; open list:RISC-V
> <qemu-riscv at nongnu.org>; open list:Overall <kvm at vger.kernel.org>;
> limingwang (A) <limingwang at huawei.com>; libvir-list at redhat.com; Bin Meng
> <bin.meng at windriver.com>; qemu-devel at nongnu.org Developers
> <qemu-devel at nongnu.org>; Alistair Francis <Alistair.Francis at wdc.com>;
> kvm-riscv at lists.infradead.org; Wanghaibin (D)
> <wanghaibin.wang at huawei.com>; Fanliang (EulerOS) <fanliang at huawei.com>;
> Palmer Dabbelt <palmer at dabbelt.com>; Wubin (H) <wu.wubin at huawei.com>
> Subject: Re: [PATCH RFC v6 08/12] target/riscv: Handle KVM_EXIT_RISCV_SBI
> exit
>
> On Tue, Aug 17, 2021 at 1:25 PM Yifei Jiang <jiangyifei at huawei.com> 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
> > bc9cb5d8f9..a68f31c2f3 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) { @@ -435,9 +437,47 @@ 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;
>
> These have been deprecated (see
> https://github.com/riscv/riscv-sbi-doc/blob/master/riscv-sbi.adoc#4-legacy-ext
> ensions-eids-0x00---0x0f),
> is it even worth supporting them?
>
Yes. The legacy console SBI functions (sbi_console_getchar() and sbi_console_putchar())
are expected to be deprecated.
However, the linux kernel still uses these sbi call interfaces, so they are retained here.
If the linux kernel doesn't use these interfaces, we will remove them.
Yifei
> > + 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(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 at wdc.com>
> > + */
> > +
> > +#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
> >
> >
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