Re: [Qemu-devel] [PATCH for 4.1 v3 6/6] riscv: Add a generic spike machine

[Igor Mammedov <imammedo@redhat.com>]

On Wed, 10 Apr 2019 23:11:00 +0000
Alistair Francis <Alistair.Francis@wdc.com> wrote:

> Add a generic spike machine (not tied to a version) and deprecate the
> spike mahines that are tied to a specific version. As we can now specify
> the CPU via the command line we no londer need specific versions of the
> spike machines.
> 
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

For cpu and initial RAM related parts:

Acked-by: Igor Mammedov <imammedo@redhat.com>

a couple of questions below.
> ---
>  hw/riscv/spike.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 105 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/riscv/spike.c b/hw/riscv/spike.c
> index 2a000a5800..9d3f7cec4d 100644
> --- a/hw/riscv/spike.c
> +++ b/hw/riscv/spike.c
> @@ -39,6 +39,7 @@
>  #include "chardev/char.h"
>  #include "sysemu/arch_init.h"
>  #include "sysemu/device_tree.h"
> +#include "sysemu/qtest.h"
>  #include "exec/address-spaces.h"
>  #include "elf.h"
>  
> @@ -160,7 +161,89 @@ static void create_fdt(SpikeState *s, const struct MemmapEntry *memmap,
>          qemu_fdt_add_subnode(fdt, "/chosen");
>          qemu_fdt_setprop_string(fdt, "/chosen", "bootargs", cmdline);
>      }
> - }
> +}
> +
> +static void spike_board_init(MachineState *machine)
> +{
> +    const struct MemmapEntry *memmap = spike_memmap;
> +
> +    SpikeState *s = g_new0(SpikeState, 1);
> +    MemoryRegion *system_memory = get_system_memory();
> +    MemoryRegion *main_mem = g_new(MemoryRegion, 1);
> +    MemoryRegion *mask_rom = g_new(MemoryRegion, 1);
> +    int i;
> +
> +    /* Initialize SOC */
> +    object_initialize_child(OBJECT(machine), "soc", &s->soc, sizeof(s->soc),
> +                            TYPE_RISCV_HART_ARRAY, &error_abort, NULL);
> +    object_property_set_str(OBJECT(&s->soc), machine->cpu_type, "cpu-type",
> +                            &error_abort);
> +    object_property_set_int(OBJECT(&s->soc), smp_cpus, "num-harts",
> +                            &error_abort);
> +    object_property_set_bool(OBJECT(&s->soc), true, "realized",
> +                            &error_abort);
> +
> +    /* register system main memory (actual RAM) */
> +    memory_region_init_ram(main_mem, NULL, "riscv.spike.ram",
> +                           machine->ram_size, &error_fatal);
do you really care about migration? if not then _nomigrate flavor would
be more suitable.

> +    memory_region_add_subregion(system_memory, memmap[SPIKE_DRAM].base,
> +        main_mem);
> +
> +    /* create device tree */
> +    create_fdt(s, memmap, machine->ram_size, machine->kernel_cmdline);
> +
> +    /* boot rom */
> +    memory_region_init_rom(mask_rom, NULL, "riscv.spike.mrom",
> +                           memmap[SPIKE_MROM].size, &error_fatal);
> +    memory_region_add_subregion(system_memory, memmap[SPIKE_MROM].base,
> +                                mask_rom);
> +
> +    if (machine->kernel_filename) {
> +        load_kernel(machine->kernel_filename);
> +    }
> +
> +    /* reset vector */
> +    uint32_t reset_vec[8] = {
> +        0x00000297,                  /* 1:  auipc  t0, %pcrel_hi(dtb) */
> +        0x02028593,                  /*     addi   a1, t0, %pcrel_lo(1b) */
> +        0xf1402573,                  /*     csrr   a0, mhartid  */
> +#if defined(TARGET_RISCV32)
> +        0x0182a283,                  /*     lw     t0, 24(t0) */
> +#elif defined(TARGET_RISCV64)
> +        0x0182b283,                  /*     ld     t0, 24(t0) */
> +#endif
> +        0x00028067,                  /*     jr     t0 */
> +        0x00000000,
> +        memmap[SPIKE_DRAM].base,     /* start: .dword DRAM_BASE */
> +        0x00000000,
> +                                     /* dtb: */
> +    };
> +
> +    /* copy in the reset vector in little_endian byte order */
> +    for (i = 0; i < sizeof(reset_vec) >> 2; i++) {
> +        reset_vec[i] = cpu_to_le32(reset_vec[i]);
> +    }
> +    rom_add_blob_fixed_as("mrom.reset", reset_vec, sizeof(reset_vec),
> +                          memmap[SPIKE_MROM].base, &address_space_memory);
> +
> +    /* copy in the device tree */
> +    if (fdt_pack(s->fdt) || fdt_totalsize(s->fdt) >
> +            memmap[SPIKE_MROM].size - sizeof(reset_vec)) {
> +        error_report("not enough space to store device-tree");
> +        exit(1);
> +    }
> +    qemu_fdt_dumpdtb(s->fdt, fdt_totalsize(s->fdt));
> +    rom_add_blob_fixed_as("mrom.fdt", s->fdt, fdt_totalsize(s->fdt),
> +                          memmap[SPIKE_MROM].base + sizeof(reset_vec),
> +                          &address_space_memory);
> +
> +    /* initialize HTIF using symbols found in load_kernel */
> +    htif_mm_init(system_memory, mask_rom, &s->soc.harts[0].env, serial_hd(0));
> +
> +    /* Core Local Interruptor (timer and IPI) */
> +    sifive_clint_create(memmap[SPIKE_CLINT].base, memmap[SPIKE_CLINT].size,
> +        smp_cpus, SIFIVE_SIP_BASE, SIFIVE_TIMECMP_BASE, SIFIVE_TIME_BASE);
> +}
>  
>  static void spike_v1_10_0_board_init(MachineState *machine)
>  {
> @@ -172,6 +255,12 @@ static void spike_v1_10_0_board_init(MachineState *machine)
>      MemoryRegion *mask_rom = g_new(MemoryRegion, 1);
>      int i;
>  
> +    if (!qtest_enabled()) {
> +        info_report("The Spike v1.10.0 machine has been depreceated. "
> +                    "Please use the deneric spike machine and specify the ISA "
> +                    "versions using -cpu.");
> +    }
Did you mean deprecated in sense that machines will be removed in 2 releases
according to QEMU's deprecation policy?

> +
>      /* Initialize SOC */
>      object_initialize_child(OBJECT(machine), "soc", &s->soc, sizeof(s->soc),
>                              TYPE_RISCV_HART_ARRAY, &error_abort, NULL);
> @@ -254,6 +343,12 @@ static void spike_v1_09_1_board_init(MachineState *machine)
>      MemoryRegion *mask_rom = g_new(MemoryRegion, 1);
>      int i;
>  
> +    if (!qtest_enabled()) {
> +        info_report("The Spike v1.09.1 machine has been depreceated. "
> +                    "Please use the deneric spike machine and specify the ISA "
> +                    "versions using -cpu.");
> +    }
> +
>      /* Initialize SOC */
>      object_initialize_child(OBJECT(machine), "soc", &s->soc, sizeof(s->soc),
>                              TYPE_RISCV_HART_ARRAY, &error_abort, NULL);
> @@ -359,8 +454,17 @@ static void spike_v1_10_0_machine_init(MachineClass *mc)
>      mc->desc = "RISC-V Spike Board (Privileged ISA v1.10)";
>      mc->init = spike_v1_10_0_board_init;
>      mc->max_cpus = 1;
> +}
> +
> +static void spike_machine_init(MachineClass *mc)
> +{
> +    mc->desc = "RISC-V Spike Board";
> +    mc->init = spike_board_init;
> +    mc->max_cpus = 1;
>      mc->is_default = 1;
> +    mc->default_cpu_type = SPIKE_V1_10_0_CPU;
>  }
>  
>  DEFINE_MACHINE("spike_v1.9.1", spike_v1_09_1_machine_init)
>  DEFINE_MACHINE("spike_v1.10", spike_v1_10_0_machine_init)
> +DEFINE_MACHINE("spike", spike_machine_init)