[PATCH v3 06/12] target/riscv: Support start kernel directly by KVM

Anup Patel anup at brainfault.org
Wed Dec 22 22:04:29 PST 2021


On Thu, Dec 23, 2021 at 11:33 AM Anup Patel <anup at brainfault.org> wrote:
>
> On Mon, Dec 20, 2021 at 6:39 PM Yifei Jiang <jiangyifei at huawei.com> wrote:
> >
> > Get kernel and fdt start address in virt.c, and pass them to KVM
> > when cpu reset. Add kvm_riscv.h to place riscv specific interface.
> >
> > In addition, PLIC is created without M-mode PLIC contexts when KVM
> > is enabled.
> >
> > Signed-off-by: Yifei Jiang <jiangyifei at huawei.com>
> > Signed-off-by: Mingwang Li <limingwang at huawei.com>
> > Reviewed-by: Alistair Francis <alistair.francis at wdc.com>
> > ---
> >  hw/intc/sifive_plic.c    |  8 +++-
> >  hw/riscv/boot.c          | 16 +++++++-
> >  hw/riscv/virt.c          | 87 ++++++++++++++++++++++++++++------------
> >  include/hw/riscv/boot.h  |  1 +
> >  target/riscv/cpu.c       |  8 ++++
> >  target/riscv/cpu.h       |  3 ++
> >  target/riscv/kvm-stub.c  | 25 ++++++++++++
> >  target/riscv/kvm.c       | 14 +++++++
> >  target/riscv/kvm_riscv.h | 24 +++++++++++
> >  target/riscv/meson.build |  2 +-
> >  10 files changed, 159 insertions(+), 29 deletions(-)
> >  create mode 100644 target/riscv/kvm-stub.c
> >  create mode 100644 target/riscv/kvm_riscv.h
> >
> > diff --git a/hw/intc/sifive_plic.c b/hw/intc/sifive_plic.c
> > index 877e76877c..1b2b4cc25e 100644
> > --- a/hw/intc/sifive_plic.c
> > +++ b/hw/intc/sifive_plic.c
> > @@ -30,6 +30,7 @@
> >  #include "target/riscv/cpu.h"
> >  #include "migration/vmstate.h"
> >  #include "hw/irq.h"
> > +#include "sysemu/kvm.h"
> >
> >  #define RISCV_DEBUG_PLIC 0
> >
> > @@ -555,8 +556,11 @@ DeviceState *sifive_plic_create(hwaddr addr, char *hart_config,
> >
> >          qdev_connect_gpio_out(dev, i,
> >                                qdev_get_gpio_in(DEVICE(cpu), IRQ_S_EXT));
> > -        qdev_connect_gpio_out(dev, num_harts + i,
> > -                              qdev_get_gpio_in(DEVICE(cpu), IRQ_M_EXT));
> > +
> > +        if (!kvm_enabled()) {
> > +            qdev_connect_gpio_out(dev, num_harts + i,
> > +                                  qdev_get_gpio_in(DEVICE(cpu), IRQ_M_EXT));
> > +        }
>
> We should have any KVM enabled check in interrupt controller emulators
> instead I suggest to re-write the for-loop in sifive_plic_create() as follows:

Typo correction:
*"We should not have any KVM enabled check in ...."

Regards,
Anup

>
> SiFivePLICState *plic;
>
> (....)
>
> plic = SIFIVE_PLIC(dev);
> for (i = 0; i < plic->num_addrs; i++) {
>     CPUState *cpu = qemu_get_cpu(plic->addr_config[i].hartid);
>
>    if (plic->addr_mode[i] == PLICMode_S) {
>        qdev_connect_gpio_out(dev, i,
>             qdev_get_gpio_in(DEVICE(cpu), IRQ_S_EXT));
>    }
>    if (plic->addr_mode[i] == PLICMode_M) {
>         qdev_connect_gpio_out(dev, num_harts + i,
>             qdev_get_gpio_in(DEVICE(cpu), IRQ_M_EXT));
>     }
> }
>
> >      }
> >
> >      return dev;
> > diff --git a/hw/riscv/boot.c b/hw/riscv/boot.c
> > index 519fa455a1..ccff662d89 100644
> > --- a/hw/riscv/boot.c
> > +++ b/hw/riscv/boot.c
> > @@ -30,6 +30,7 @@
> >  #include "elf.h"
> >  #include "sysemu/device_tree.h"
> >  #include "sysemu/qtest.h"
> > +#include "sysemu/kvm.h"
> >
> >  #include <libfdt.h>
> >
> > @@ -51,7 +52,9 @@ char *riscv_plic_hart_config_string(int hart_count)
> >          CPUState *cs = qemu_get_cpu(i);
> >          CPURISCVState *env = &RISCV_CPU(cs)->env;
> >
> > -        if (riscv_has_ext(env, RVS)) {
> > +        if (kvm_enabled()) {
> > +            vals[i] = "S";
> > +        } else if (riscv_has_ext(env, RVS)) {
> >              vals[i] = "MS";
> >          } else {
> >              vals[i] = "M";
> > @@ -317,3 +320,14 @@ void riscv_setup_rom_reset_vec(MachineState *machine, RISCVHartArrayState *harts
> >
> >      return;
> >  }
> > +
> > +void riscv_setup_direct_kernel(hwaddr kernel_addr, hwaddr fdt_addr)
> > +{
> > +    CPUState *cs;
> > +
> > +    for (cs = first_cpu; cs; cs = CPU_NEXT(cs)) {
> > +        RISCVCPU *riscv_cpu = RISCV_CPU(cs);
> > +        riscv_cpu->env.kernel_addr = kernel_addr;
> > +        riscv_cpu->env.fdt_addr = fdt_addr;
> > +    }
> > +}
> > diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> > index 3af074148e..cc1a03f284 100644
> > --- a/hw/riscv/virt.c
> > +++ b/hw/riscv/virt.c
> > @@ -38,6 +38,7 @@
> >  #include "chardev/char.h"
> >  #include "sysemu/device_tree.h"
> >  #include "sysemu/sysemu.h"
> > +#include "sysemu/kvm.h"
> >  #include "hw/pci/pci.h"
> >  #include "hw/pci-host/gpex.h"
> >  #include "hw/display/ramfb.h"
> > @@ -50,7 +51,11 @@ static const MemMapEntry virt_memmap[] = {
> >      [VIRT_CLINT] =       {  0x2000000,       0x10000 },
> >      [VIRT_ACLINT_SSWI] = {  0x2F00000,        0x4000 },
> >      [VIRT_PCIE_PIO] =    {  0x3000000,       0x10000 },
> > +#if defined(CONFIG_KVM)
> > +    [VIRT_PLIC] =        {  0xc000000, VIRT_PLIC_SIZE(VIRT_CPUS_MAX * 1) },
> > +#else
> >      [VIRT_PLIC] =        {  0xc000000, VIRT_PLIC_SIZE(VIRT_CPUS_MAX * 2) },
> > +#endif
>
> Please drop this change because the same QEMU binary should be
> usable with and without KVM enabled.
>
> >      [VIRT_UART0] =       { 0x10000000,         0x100 },
> >      [VIRT_VIRTIO] =      { 0x10001000,        0x1000 },
> >      [VIRT_FW_CFG] =      { 0x10100000,          0x18 },
> > @@ -372,13 +377,22 @@ static void create_fdt_socket_plic(RISCVVirtState *s,
> >          "sifive,plic-1.0.0", "riscv,plic0"
> >      };
> >
> > -    plic_cells = g_new0(uint32_t, s->soc[socket].num_harts * 4);
> > +    if (kvm_enabled()) {
> > +        plic_cells = g_new0(uint32_t, s->soc[socket].num_harts * 2);
> > +    } else {
> > +        plic_cells = g_new0(uint32_t, s->soc[socket].num_harts * 4);
> > +    }
> >
> >      for (cpu = 0; cpu < s->soc[socket].num_harts; cpu++) {
> > -        plic_cells[cpu * 4 + 0] = cpu_to_be32(intc_phandles[cpu]);
> > -        plic_cells[cpu * 4 + 1] = cpu_to_be32(IRQ_M_EXT);
> > -        plic_cells[cpu * 4 + 2] = cpu_to_be32(intc_phandles[cpu]);
> > -        plic_cells[cpu * 4 + 3] = cpu_to_be32(IRQ_S_EXT);
> > +        if (kvm_enabled()) {
> > +            plic_cells[cpu * 2 + 0] = cpu_to_be32(intc_phandles[cpu]);
> > +            plic_cells[cpu * 2 + 1] = cpu_to_be32(IRQ_S_EXT);
> > +        } else {
> > +            plic_cells[cpu * 4 + 0] = cpu_to_be32(intc_phandles[cpu]);
> > +            plic_cells[cpu * 4 + 1] = cpu_to_be32(IRQ_M_EXT);
> > +            plic_cells[cpu * 4 + 2] = cpu_to_be32(intc_phandles[cpu]);
> > +            plic_cells[cpu * 4 + 3] = cpu_to_be32(IRQ_S_EXT);
> > +        }
> >      }
> >
> >      plic_phandles[socket] = (*phandle)++;
> > @@ -436,10 +450,12 @@ static void create_fdt_sockets(RISCVVirtState *s, const MemMapEntry *memmap,
> >
> >          create_fdt_socket_memory(s, memmap, socket);
> >
> > -        if (s->have_aclint) {
> > -            create_fdt_socket_aclint(s, memmap, socket, intc_phandles);
> > -        } else {
> > -            create_fdt_socket_clint(s, memmap, socket, intc_phandles);
> > +        if (!kvm_enabled()) {
> > +            if (s->have_aclint) {
> > +                create_fdt_socket_aclint(s, memmap, socket, intc_phandles);
> > +            } else {
> > +                create_fdt_socket_clint(s, memmap, socket, intc_phandles);
> > +            }
> >          }
> >
> >          create_fdt_socket_plic(s, memmap, socket, phandle,
> > @@ -801,23 +817,25 @@ static void virt_machine_init(MachineState *machine)
> >                                  hart_count, &error_abort);
> >          sysbus_realize(SYS_BUS_DEVICE(&s->soc[i]), &error_abort);
> >
> > -        /* Per-socket CLINT */
> > -        riscv_aclint_swi_create(
> > -            memmap[VIRT_CLINT].base + i * memmap[VIRT_CLINT].size,
> > -            base_hartid, hart_count, false);
> > -        riscv_aclint_mtimer_create(
> > -            memmap[VIRT_CLINT].base + i * memmap[VIRT_CLINT].size +
> > -                RISCV_ACLINT_SWI_SIZE,
> > -            RISCV_ACLINT_DEFAULT_MTIMER_SIZE, base_hartid, hart_count,
> > -            RISCV_ACLINT_DEFAULT_MTIMECMP, RISCV_ACLINT_DEFAULT_MTIME,
> > -            RISCV_ACLINT_DEFAULT_TIMEBASE_FREQ, true);
> > -
> > -        /* Per-socket ACLINT SSWI */
> > -        if (s->have_aclint) {
> > +        if (!kvm_enabled()) {
> > +            /* Per-socket CLINT */
> >              riscv_aclint_swi_create(
> > -                memmap[VIRT_ACLINT_SSWI].base +
> > -                    i * memmap[VIRT_ACLINT_SSWI].size,
> > -                base_hartid, hart_count, true);
> > +                memmap[VIRT_CLINT].base + i * memmap[VIRT_CLINT].size,
> > +                base_hartid, hart_count, false);
> > +            riscv_aclint_mtimer_create(
> > +                memmap[VIRT_CLINT].base + i * memmap[VIRT_CLINT].size +
> > +                    RISCV_ACLINT_SWI_SIZE,
> > +                RISCV_ACLINT_DEFAULT_MTIMER_SIZE, base_hartid, hart_count,
> > +                RISCV_ACLINT_DEFAULT_MTIMECMP, RISCV_ACLINT_DEFAULT_MTIME,
> > +                RISCV_ACLINT_DEFAULT_TIMEBASE_FREQ, true);
> > +
> > +            /* Per-socket ACLINT SSWI */
> > +            if (s->have_aclint) {
> > +                riscv_aclint_swi_create(
> > +                    memmap[VIRT_ACLINT_SSWI].base +
> > +                        i * memmap[VIRT_ACLINT_SSWI].size,
> > +                    base_hartid, hart_count, true);
> > +            }
> >          }
> >
> >          /* Per-socket PLIC hart topology configuration string */
> > @@ -884,6 +902,16 @@ static void virt_machine_init(MachineState *machine)
> >      memory_region_add_subregion(system_memory, memmap[VIRT_MROM].base,
> >                                  mask_rom);
> >
> > +    /*
> > +     * Only direct boot kernel is currently supported for KVM VM,
> > +     * so the "-bios" parameter is ignored and treated like "-bios none"
> > +     * when KVM is enabled.
> > +     */
> > +    if (kvm_enabled()) {
> > +        g_free(machine->firmware);
> > +        machine->firmware = g_strdup("none");
> > +    }
> > +
> >      if (riscv_is_32bit(&s->soc[0])) {
> >          firmware_end_addr = riscv_find_and_load_firmware(machine,
> >                                      RISCV32_BIOS_BIN, start_addr, NULL);
> > @@ -941,6 +969,15 @@ static void virt_machine_init(MachineState *machine)
> >                                virt_memmap[VIRT_MROM].size, kernel_entry,
> >                                fdt_load_addr, machine->fdt);
> >
> > +    /*
> > +     * Only direct boot kernel is currently supported for KVM VM,
> > +     * So here setup kernel start address and fdt address.
> > +     * TODO:Support firmware loading and integrate to TCG start
> > +     */
> > +    if (kvm_enabled()) {
> > +        riscv_setup_direct_kernel(kernel_entry, fdt_load_addr);
> > +    }
> > +
> >      /* SiFive Test MMIO device */
> >      sifive_test_create(memmap[VIRT_TEST].base);
> >
> > diff --git a/include/hw/riscv/boot.h b/include/hw/riscv/boot.h
> > index baff11dd8a..5834c234aa 100644
> > --- a/include/hw/riscv/boot.h
> > +++ b/include/hw/riscv/boot.h
> > @@ -58,5 +58,6 @@ void riscv_rom_copy_firmware_info(MachineState *machine, hwaddr rom_base,
> >                                    hwaddr rom_size,
> >                                    uint32_t reset_vec_size,
> >                                    uint64_t kernel_entry);
> > +void riscv_setup_direct_kernel(hwaddr kernel_addr, hwaddr fdt_addr);
> >
> >  #endif /* RISCV_BOOT_H */
> > diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c
> > index f812998123..1c944872a3 100644
> > --- a/target/riscv/cpu.c
> > +++ b/target/riscv/cpu.c
> > @@ -29,6 +29,8 @@
> >  #include "hw/qdev-properties.h"
> >  #include "migration/vmstate.h"
> >  #include "fpu/softfloat-helpers.h"
> > +#include "sysemu/kvm.h"
> > +#include "kvm_riscv.h"
> >
> >  /* RISC-V CPU definitions */
> >
> > @@ -380,6 +382,12 @@ static void riscv_cpu_reset(DeviceState *dev)
> >      cs->exception_index = RISCV_EXCP_NONE;
> >      env->load_res = -1;
> >      set_default_nan_mode(1, &env->fp_status);
> > +
> > +#ifndef CONFIG_USER_ONLY
> > +    if (kvm_enabled()) {
> > +        kvm_riscv_reset_vcpu(cpu);
> > +    }
> > +#endif
> >  }
> >
> >  static void riscv_cpu_disas_set_info(CPUState *s, disassemble_info *info)
> > diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h
> > index 0760c0af93..2807eb1bcb 100644
> > --- a/target/riscv/cpu.h
> > +++ b/target/riscv/cpu.h
> > @@ -255,6 +255,9 @@ struct CPURISCVState {
> >
> >      /* Fields from here on are preserved across CPU reset. */
> >      QEMUTimer *timer; /* Internal timer */
> > +
> > +    hwaddr kernel_addr;
> > +    hwaddr fdt_addr;
> >  };
> >
> >  OBJECT_DECLARE_TYPE(RISCVCPU, RISCVCPUClass,
> > diff --git a/target/riscv/kvm-stub.c b/target/riscv/kvm-stub.c
> > new file mode 100644
> > index 0000000000..39b96fe3f4
> > --- /dev/null
> > +++ b/target/riscv/kvm-stub.c
> > @@ -0,0 +1,25 @@
> > +/*
> > + * QEMU KVM RISC-V specific function stubs
> > + *
> > + * Copyright (c) 2020 Huawei Technologies Co., Ltd
> > + *
> > + * This program is free software; you can redistribute it and/or modify it
> > + * under the terms and conditions of the GNU General Public License,
> > + * version 2 or later, as published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope it will be useful, but WITHOUT
> > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> > + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> > + * more details.
> > + *
> > + * You should have received a copy of the GNU General Public License along with
> > + * this program.  If not, see <http://www.gnu.org/licenses/>.
> > + */
> > +#include "qemu/osdep.h"
> > +#include "cpu.h"
> > +#include "kvm_riscv.h"
> > +
> > +void kvm_riscv_reset_vcpu(RISCVCPU *cpu)
> > +{
> > +    abort();
> > +}
> > diff --git a/target/riscv/kvm.c b/target/riscv/kvm.c
> > index e695b91dc7..db6d8a5b6e 100644
> > --- a/target/riscv/kvm.c
> > +++ b/target/riscv/kvm.c
> > @@ -37,6 +37,7 @@
> >  #include "hw/irq.h"
> >  #include "qemu/log.h"
> >  #include "hw/loader.h"
> > +#include "kvm_riscv.h"
> >
> >  static uint64_t kvm_riscv_reg_id(CPURISCVState *env, uint64_t type, uint64_t idx)
> >  {
> > @@ -369,6 +370,19 @@ int kvm_arch_handle_exit(CPUState *cs, struct kvm_run *run)
> >      return 0;
> >  }
> >
> > +void kvm_riscv_reset_vcpu(RISCVCPU *cpu)
> > +{
> > +    CPURISCVState *env = &cpu->env;
> > +
> > +    if (!kvm_enabled()) {
> > +        return;
> > +    }
> > +    env->pc = cpu->env.kernel_addr;
> > +    env->gpr[10] = kvm_arch_vcpu_id(CPU(cpu)); /* a0 */
> > +    env->gpr[11] = cpu->env.fdt_addr;          /* a1 */
> > +    env->satp = 0;
> > +}
> > +
> >  bool kvm_arch_cpu_check_are_resettable(void)
> >  {
> >      return true;
> > diff --git a/target/riscv/kvm_riscv.h b/target/riscv/kvm_riscv.h
> > new file mode 100644
> > index 0000000000..f38c82bf59
> > --- /dev/null
> > +++ b/target/riscv/kvm_riscv.h
> > @@ -0,0 +1,24 @@
> > +/*
> > + * QEMU KVM support -- RISC-V specific functions.
> > + *
> > + * Copyright (c) 2020 Huawei Technologies Co., Ltd
> > + *
> > + * This program is free software; you can redistribute it and/or modify it
> > + * under the terms and conditions of the GNU General Public License,
> > + * version 2 or later, as published by the Free Software Foundation.
> > + *
> > + * This program is distributed in the hope it will be useful, but WITHOUT
> > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> > + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> > + * more details.
> > + *
> > + * You should have received a copy of the GNU General Public License along with
> > + * this program.  If not, see <http://www.gnu.org/licenses/>.
> > + */
> > +
> > +#ifndef QEMU_KVM_RISCV_H
> > +#define QEMU_KVM_RISCV_H
> > +
> > +void kvm_riscv_reset_vcpu(RISCVCPU *cpu);
> > +
> > +#endif
> > diff --git a/target/riscv/meson.build b/target/riscv/meson.build
> > index 2faf08a941..fe41cc5805 100644
> > --- a/target/riscv/meson.build
> > +++ b/target/riscv/meson.build
> > @@ -19,7 +19,7 @@ riscv_ss.add(files(
> >    'bitmanip_helper.c',
> >    'translate.c',
> >  ))
> > -riscv_ss.add(when: 'CONFIG_KVM', if_true: files('kvm.c'))
> > +riscv_ss.add(when: 'CONFIG_KVM', if_true: files('kvm.c'), if_false: files('kvm-stub.c'))
> >
> >  riscv_softmmu_ss = ss.source_set()
> >  riscv_softmmu_ss.add(files(
> > --
> > 2.19.1
> >
>
> Regards,
> Anup



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