Re: [PATCH 4/4] m68k: add Virtual M68k Machine

["Philippe Mathieu-Daudé" <f4bug@amsat.org>]

On 10/13/20 5:51 PM, Laurent Vivier wrote:
> The machine is based on Goldfish interfaces defined by Google
> for Android simulator. It uses Goldfish-rtc (timer and RTC),
> Goldfish-pic (PIC) and Goldfish-tty (for serial port and early tty).
> 
> The machine is created with 128 virtio-mmio bus, and they can
> be used to use serial console, GPU, disk, NIC, HID, ...
> 
> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
> ---
>   default-configs/devices/m68k-softmmu.mak      |   1 +
>   .../standard-headers/asm-m68k/bootinfo-virt.h |  17 +
>   hw/m68k/virt.c                                | 296 ++++++++++++++++++
>   MAINTAINERS                                   |   9 +
>   hw/m68k/Kconfig                               |   8 +
>   hw/m68k/meson.build                           |   1 +
>   6 files changed, 332 insertions(+)
>   create mode 100644 include/standard-headers/asm-m68k/bootinfo-virt.h
>   create mode 100644 hw/m68k/virt.c
> 
> diff --git a/default-configs/devices/m68k-softmmu.mak b/default-configs/devices/m68k-softmmu.mak
> index 6629fd2aa330..7f8619e42786 100644
> --- a/default-configs/devices/m68k-softmmu.mak
> +++ b/default-configs/devices/m68k-softmmu.mak
> @@ -8,3 +8,4 @@ CONFIG_AN5206=y
>   CONFIG_MCF5208=y
>   CONFIG_NEXTCUBE=y
>   CONFIG_Q800=y
> +CONFIG_M68K_VIRT=y
> diff --git a/include/standard-headers/asm-m68k/bootinfo-virt.h b/include/standard-headers/asm-m68k/bootinfo-virt.h
> new file mode 100644
> index 000000000000..b3d90a601513
> --- /dev/null
> +++ b/include/standard-headers/asm-m68k/bootinfo-virt.h
> @@ -0,0 +1,17 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +/*
> +** asm/bootinfo-virt.h -- Virtual-m68k-specific boot information definitions
> +*/
> +
> +#ifndef _UAPI_ASM_M68K_BOOTINFO_VIRT_H
> +#define _UAPI_ASM_M68K_BOOTINFO_VIRT_H
> +
> +#define BI_VIRT_QEMU_VERSION	0x8000
> +#define BI_VIRT_GF_PIC_BASE	0x8001
> +#define BI_VIRT_GF_RTC_BASE	0x8002
> +#define BI_VIRT_GF_TTY_BASE	0x8003
> +#define BI_VIRT_VIRTIO_BASE	0x8004
> +
> +#define VIRT_BOOTI_VERSION	MK_BI_VERSION(2, 0)
> +
> +#endif /* _UAPI_ASM_M68K_BOOTINFO_MAC_H */
> diff --git a/hw/m68k/virt.c b/hw/m68k/virt.c
> new file mode 100644
> index 000000000000..8b89373dafdb
> --- /dev/null
> +++ b/hw/m68k/virt.c
> @@ -0,0 +1,296 @@
> +/*
> + * SPDX-License-Identifer: GPL-2.0-or-later
> + *
> + * QEMU Vitual M68K Machine
> + *
> + * (c) 2020 Laurent Vivier <laurent@vivier.eu>
> + *
> + */
> +
> +#include "qemu/osdep.h"
> +#include "qemu/units.h"
> +#include "qemu-common.h"
> +#include "sysemu/sysemu.h"
> +#include "cpu.h"
> +#include "hw/hw.h"
> +#include "hw/boards.h"
> +#include "hw/irq.h"
> +#include "hw/qdev-properties.h"
> +#include "elf.h"
> +#include "hw/loader.h"
> +#include "ui/console.h"
> +#include "exec/address-spaces.h"
> +#include "hw/sysbus.h"
> +#include "standard-headers/asm-m68k/bootinfo.h"
> +#include "standard-headers/asm-m68k/bootinfo-virt.h"
> +#include "bootinfo.h"
> +#include "net/net.h"
> +#include "qapi/error.h"
> +#include "sysemu/qtest.h"
> +#include "sysemu/runstate.h"
> +#include "sysemu/reset.h"
> +
> +#include "hw/char/goldfish_tty.h"
> +#include "hw/rtc/goldfish_rtc.h"
> +#include "hw/intc/goldfish_pic.h"
> +#include "hw/virtio/virtio-mmio.h"
> +#include "hw/virtio/virtio-blk.h"
> +
> +/*
> + * 6 goldfish-pic for CPU IRQ #1 to IRQ #6
> + * CPU IRQ #1 -> PIC #1
> + *               IRQ #1 to IRQ #31 -> unused
> + *               IRQ #32 -> goldfish-tty
> + * CPU IRQ #2 -> PIC #2
> + *               IRQ #1 to IRQ #32 -> virtio-mmio from 1 to 32
> + * CPU IRQ #3 -> PIC #3
> + *               IRQ #1 to IRQ #32 -> virtio-mmio from 33 to 64
> + * CPU IRQ #4 -> PIC #4
> + *               IRQ #1 to IRQ #32 -> virtio-mmio from 65 to 96
> + * CPU IRQ #5 -> PIC #5
> + *               IRQ #1 to IRQ #32 -> virtio-mmio from 97 to 128
> + * CPU IRQ #6 -> PIC #5
> + *               IRQ #1 -> goldfish-rtc
> + *               IRQ #2 to IRQ #32 -> unused
> + * CPU IRQ #7 -> NMI
> + */
> +
> +#define PIC_IRQ_BASE(num)     (8 + (num - 1) * 32)
> +#define PIC_IRQ(num, irq)     (PIC_IRQ_BASE(num) + irq - 1)
> +#define PIC_GPIO(pic_irq)     (qdev_get_gpio_in(pic_dev[(pic_irq - 8) / 32], \
> +                                                (pic_irq - 8) % 32))
> +
> +#define VIRT_GF_PIC_MMIO_BASE 0xff000000     /* MMIO: 0xff000000 - 0xff005fff */
> +#define VIRT_GF_PIC_IRQ_BASE  1              /* IRQ: #1 -> #6 */
> +
> +/* 1 goldfish-rtc (and timer) */
> +#define VIRT_GF_RTC_MMIO_BASE 0xff006000     /* MMIO: 0xff006000 - 0xff006fff */
> +#define VIRT_GF_RTC_IRQ_BASE  PIC_IRQ(6, 1)  /* PIC: #6, IRQ: #1 */
> +
> +/* 1 goldfish-tty */
> +#define VIRT_GF_TTY_MMIO_BASE 0xff007000     /* MMIO: 0xff007000 - 0xff007000 */
> +#define VIRT_GF_TTY_IRQ_BASE  PIC_IRQ(1, 32) /* PIC: #1, IRQ: #32 */
> +/*
> + * virtio-mmio size is 0x200 bytes
> + * we use 4 goldfish-pic to attach them,
> + * we can attach 32 virtio devices / goldfish-pic
> + * -> we can manage 32 * 4 = 128 virtio devices
> + */
> +#define VIRT_VIRTIO_MMIO_BASE 0xff010000     /* MMIO: 0xff010000 - 0xff01ffff */
> +#define VIRT_VIRTIO_IRQ_BASE  PIC_IRQ(2, 1)  /* PIC: 2, 3, 4, 5, IRQ: ALL */
> +
> +/*
> + * The GLUE (General Logic Unit) is an Apple custom integrated circuit chip
> + * that performs a variety of functions (RAM management, clock generation, ...).
> + * The GLUE chip receives interrupt requests from various devices,
> + * assign priority to each, and asserts one or more interrupt line to the
> + * CPU.

Does your virt machine really requires a GLUE? Or only another
cascaded PIC?

> + */
> +
> +typedef struct {
> +    M68kCPU *cpu;
> +    uint8_t ipr;
> +} GLUEState;
> +
> +static void GLUE_set_irq(void *opaque, int irq, int level)
> +{
> +    GLUEState *s = opaque;
> +    int i;
> +
> +    if (level) {
> +        s->ipr |= 1 << irq;
> +    } else {
> +        s->ipr &= ~(1 << irq);
> +    }
> +
> +    for (i = 7; i >= 0; i--) {
> +        if ((s->ipr >> i) & 1) {
> +            m68k_set_irq_level(s->cpu, i + 1, i + 25);
> +            return;
> +        }
> +    }
> +    m68k_set_irq_level(s->cpu, 0, 0);
> +}
> +
> +static void main_cpu_reset(void *opaque)
> +{
> +    M68kCPU *cpu = opaque;
> +    CPUState *cs = CPU(cpu);
> +
> +    cpu_reset(cs);
> +    cpu->env.aregs[7] = ldl_phys(cs->as, 0);
> +    cpu->env.pc = ldl_phys(cs->as, 4);
> +}
> +
> +static void virt_init(MachineState *machine)
> +{
> +    M68kCPU *cpu = NULL;
> +    int32_t kernel_size;
> +    uint64_t elf_entry;
> +    ram_addr_t initrd_base;
> +    int32_t initrd_size;
> +    ram_addr_t ram_size = machine->ram_size;
> +    const char *kernel_filename = machine->kernel_filename;
> +    const char *initrd_filename = machine->initrd_filename;
> +    const char *kernel_cmdline = machine->kernel_cmdline;
> +    hwaddr parameters_base;
> +    DeviceState *dev;
> +    DeviceState *pic_dev[7];
> +    GLUEState *irq;
> +    qemu_irq *cpu_pic;
> +    SysBusDevice *sysbus;
> +    hwaddr io_base;
> +    int i;
> +
> +
> +    if (ram_size > 3399672 * KiB) {
> +        /*
> +         * The physical memory can be up to 4 GiB - 16 MiB, but linux
> +         * kernel crashes after this limit (~ 3.2 GiB)
> +         */
> +        error_report("Too much memory for this machine: %" PRId64 " KiB, "
> +                     "maximum 3399672 KiB", ram_size / KiB);
> +        exit(1);
> +    }
> +
> +    /* init CPUs */
> +    cpu = M68K_CPU(cpu_create(machine->cpu_type));

Due to BOOTINFO1(..., BI_CPUTYPE, CPU_68040) below, don't you
need to check machine->cpu_type == M68K_CPU_TYPE_NAME("m68040")?

> +    qemu_register_reset(main_cpu_reset, cpu);
> +
> +    /* RAM */
> +    memory_region_add_subregion(get_system_memory(), 0, machine->ram);
> +
> +    /* IRQ Glue */
> +
> +    irq = g_new0(GLUEState, 1);
> +    irq->cpu = cpu;
> +    cpu_pic = qemu_allocate_irqs(GLUE_set_irq, irq, 8);
> +
> +    /*
> +     * 6 goldfish-pic
> +     *
> +     * map: 0xff000000 - 0xff006fff = 28 KiB
> +     * IRQ: #1 (lower priority) -> #6 (higher priority)
> +     *
> +     */
> +    io_base = VIRT_GF_PIC_MMIO_BASE;
> +    for (i = 0; i < 6; i++) {
> +        pic_dev[i] = qdev_new(TYPE_GOLDFISH_PIC);
> +        sysbus = SYS_BUS_DEVICE(pic_dev[i]);
> +        sysbus_realize_and_unref(sysbus, &error_fatal);
> +
> +        sysbus_mmio_map(sysbus, 0, io_base);
> +        sysbus_connect_irq(sysbus, 0, cpu_pic[i]);
> +
> +        io_base += 0x1000;
> +    }
> +
> +    /* goldfish-rtc */
> +    dev = qdev_new(TYPE_GOLDFISH_RTC);
> +    sysbus = SYS_BUS_DEVICE(dev);
> +    sysbus_realize_and_unref(sysbus, &error_fatal);
> +    sysbus_mmio_map(sysbus, 0, VIRT_GF_RTC_MMIO_BASE);
> +    sysbus_connect_irq(sysbus, 0, PIC_GPIO(VIRT_GF_RTC_IRQ_BASE));
> +
> +    /* goldfish-tty */
> +    dev = qdev_new(TYPE_GOLDFISH_TTY);
> +    sysbus = SYS_BUS_DEVICE(dev);
> +    qdev_prop_set_chr(dev, "chardev", serial_hd(0));
> +    sysbus_realize_and_unref(sysbus, &error_fatal);
> +    sysbus_mmio_map(sysbus, 0, VIRT_GF_TTY_MMIO_BASE);
> +    sysbus_connect_irq(sysbus, 0, PIC_GPIO(VIRT_GF_TTY_IRQ_BASE));
> +
> +    /* virtio-mmio */
> +    io_base = VIRT_VIRTIO_MMIO_BASE;
> +    for (i = 0; i < 128; i++) {
> +        dev = qdev_new(TYPE_VIRTIO_MMIO);
> +        qdev_prop_set_bit(dev, "force-legacy", false);
> +        sysbus = SYS_BUS_DEVICE(dev);
> +        sysbus_realize_and_unref(sysbus, &error_fatal);
> +        sysbus_connect_irq(sysbus, 0, PIC_GPIO(VIRT_VIRTIO_IRQ_BASE + i));
> +        sysbus_mmio_map(sysbus, 0, io_base);
> +        io_base += 0x200;
> +    }
> +
> +    if (kernel_filename) {
> +        CPUState *cs = CPU(cpu);
> +        uint64_t high;
> +
> +        kernel_size = load_elf(kernel_filename, NULL, NULL, NULL,
> +                               &elf_entry, NULL, &high, NULL, 1,
> +                               EM_68K, 0, 0);
> +        if (kernel_size < 0) {
> +            error_report("could not load kernel '%s'", kernel_filename);
> +            exit(1);
> +        }
> +        stl_phys(cs->as, 4, elf_entry); /* reset initial PC */
> +        parameters_base = (high + 1) & ~1;
> +
> +        BOOTINFO1(cs->as, parameters_base, BI_MACHTYPE, MACH_VIRT);
> +        BOOTINFO1(cs->as, parameters_base, BI_FPUTYPE, FPU_68040);
> +        BOOTINFO1(cs->as, parameters_base, BI_MMUTYPE, MMU_68040);
> +        BOOTINFO1(cs->as, parameters_base, BI_CPUTYPE, CPU_68040);

(see machine->cpu_type question earlier).

> +        BOOTINFO2(cs->as, parameters_base, BI_MEMCHUNK, 0, ram_size);
> +
> +        BOOTINFO1(cs->as, parameters_base, BI_VIRT_QEMU_VERSION,
> +                  ((QEMU_VERSION_MAJOR << 24) | (QEMU_VERSION_MICRO << 16) |
> +                   (QEMU_VERSION_MINOR << 8)));
> +        BOOTINFO2(cs->as, parameters_base, BI_VIRT_GF_PIC_BASE,
> +                  VIRT_GF_PIC_MMIO_BASE, VIRT_GF_PIC_IRQ_BASE);
> +        BOOTINFO2(cs->as, parameters_base, BI_VIRT_GF_RTC_BASE,
> +                  VIRT_GF_RTC_MMIO_BASE, VIRT_GF_RTC_IRQ_BASE);
> +        BOOTINFO2(cs->as, parameters_base, BI_VIRT_GF_TTY_BASE,
> +                  VIRT_GF_TTY_MMIO_BASE, VIRT_GF_TTY_IRQ_BASE);
> +        BOOTINFO2(cs->as, parameters_base, BI_VIRT_VIRTIO_BASE,
> +                  VIRT_VIRTIO_MMIO_BASE, VIRT_VIRTIO_IRQ_BASE);
> +
> +        if (kernel_cmdline) {
> +            BOOTINFOSTR(cs->as, parameters_base, BI_COMMAND_LINE,
> +                        kernel_cmdline);
> +        }
> +
> +        /* load initrd */
> +        if (initrd_filename) {
> +            initrd_size = get_image_size(initrd_filename);
> +            if (initrd_size < 0) {
> +                error_report("could not load initial ram disk '%s'",
> +                             initrd_filename);
> +                exit(1);
> +            }
> +
> +            initrd_base = (ram_size - initrd_size) & TARGET_PAGE_MASK;
> +            load_image_targphys(initrd_filename, initrd_base,
> +                                ram_size - initrd_base);
> +            BOOTINFO2(cs->as, parameters_base, BI_RAMDISK, initrd_base,
> +                      initrd_size);
> +        } else {
> +            initrd_base = 0;
> +            initrd_size = 0;
> +        }
> +        BOOTINFO0(cs->as, parameters_base, BI_LAST);
> +    }
> +}
> +
> +static void virt_machine_class_init(ObjectClass *oc, void *data)
> +{
> +    MachineClass *mc = MACHINE_CLASS(oc);
> +    mc->desc = "M68k Virtual Machine";
> +    mc->init = virt_init;
> +    mc->default_cpu_type = M68K_CPU_TYPE_NAME("m68040");
> +    mc->max_cpus = 1;
> +    mc->block_default_type = IF_SCSI;
> +    mc->default_ram_id = "m68k_virt.ram";
> +}
> +
> +static const TypeInfo virt_machine_typeinfo = {
> +    .name       = MACHINE_TYPE_NAME("virt"),
> +    .parent     = TYPE_MACHINE,
> +    .class_init = virt_machine_class_init,
> +};
> +
> +static void virt_machine_register_types(void)
> +{
> +    type_register_static(&virt_machine_typeinfo);
> +}
> +
> +type_init(virt_machine_register_types)
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d0962a22e1b4..b08cf4251246 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1101,6 +1101,15 @@ F: include/hw/nubus/*
>   F: include/hw/display/macfb.h
>   F: include/hw/block/swim.h
>   
> +virt

Maybe "m68k virt".

> +M: Laurent Vivier <laurent@vivier.eu>
> +S: Maintained
> +F: hw/m68k/virt.c
> +F: hw/char/goldfish_tty.c
> +F: hw/intc/goldfish_pic.c
> +F: include/hw/char/goldfish_tty.h
> +F: include/hw/intc/goldfish_pic.h
> +
>   MicroBlaze Machines
>   -------------------
>   petalogix_s3adsp1800
> diff --git a/hw/m68k/Kconfig b/hw/m68k/Kconfig
> index c757e7dfa48b..f4b3b115270e 100644
> --- a/hw/m68k/Kconfig
> +++ b/hw/m68k/Kconfig
> @@ -22,3 +22,11 @@ config Q800
>       select ESCC
>       select ESP
>       select DP8393X
> +
> +config M68K_VIRT
> +    bool
> +    select GOLDFISH_PIC
> +    select GOLDFISH_TTY
> +    select GOLDFISH_RTC
> +    select VIRTIO
> +    select VIRTIO_MMIO
> diff --git a/hw/m68k/meson.build b/hw/m68k/meson.build
> index ca0044c652d3..31248641d301 100644
> --- a/hw/m68k/meson.build
> +++ b/hw/m68k/meson.build
> @@ -3,5 +3,6 @@ m68k_ss.add(when: 'CONFIG_AN5206', if_true: files('an5206.c', 'mcf5206.c'))
>   m68k_ss.add(when: 'CONFIG_MCF5208', if_true: files('mcf5208.c', 'mcf_intc.c'))
>   m68k_ss.add(when: 'CONFIG_NEXTCUBE', if_true: files('next-kbd.c', 'next-cube.c'))
>   m68k_ss.add(when: 'CONFIG_Q800', if_true: files('q800.c'))
> +m68k_ss.add(when: 'CONFIG_M68K_VIRT', if_true: files('virt.c'))
>   
>   hw_arch += {'m68k': m68k_ss}
>