Re: [Qemu-devel] [PATCH 08/11] Add S390x virtio machine description

[Aurelien Jarno <aurelien@aurel32.net>]

On Thu, Nov 26, 2009 at 02:23:17PM +0100, Alexander Graf wrote:
> In order to use the new S390x virtio bus we just introduced, we also
> need a machine description that sets up the machine according to our
> PV specification.
> 
> Let's add that machine description and be happy!

Please find the comments below.

> Signed-off-by: Alexander Graf <agraf@suse.de>
> 
> ---
> 
> v4 -> v5
> 
>  - disable early console
> ---
>  Makefile.target  |    2 +-
>  hw/s390-virtio.c |  240 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 241 insertions(+), 1 deletions(-)
>  create mode 100644 hw/s390-virtio.c
> 
> diff --git a/Makefile.target b/Makefile.target
> index 1619c23..9460c56 100644
> --- a/Makefile.target
> +++ b/Makefile.target
> @@ -296,7 +296,7 @@ obj-sh4-y += ide/core.o ide/mmio.o
>  obj-m68k-y = an5206.o mcf5206.o mcf_uart.o mcf_intc.o mcf5208.o mcf_fec.o
>  obj-m68k-y += m68k-semi.o dummy_m68k.o
>  
> -obj-s390x-y = s390-virtio-bus.o
> +obj-s390x-y = s390-virtio-bus.o s390-virtio.o 
>  
>  main.o vl.o: QEMU_CFLAGS+=$(GPROF_CFLAGS)
>  
> diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c
> new file mode 100644
> index 0000000..a501e34
> --- /dev/null
> +++ b/hw/s390-virtio.c
> @@ -0,0 +1,240 @@
> +/*
> + * QEMU S390 virtio target
> + *
> + * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2 of the License, or (at your option) any later version.
> + *
> + * This library is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include "hw.h"
> +#include "block.h"
> +#include "sysemu.h"
> +#include "net.h"
> +#include "boards.h"
> +#include "monitor.h"
> +#include "loader.h"
> +#include "elf.h"
> +#include "hw/virtio.h"
> +#include "hw/virtio-console.h"
> +#include "hw/sysbus.h"
> +#include "kvm.h"
> +
> +#include "hw/s390-virtio-bus.h"
> +
> +//#define DEBUG_S390
> +
> +#ifdef DEBUG_S390
> +#define dprintf(fmt, ...) \
> +    do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
> +#else
> +#define dprintf(fmt, ...) \
> +    do { } while (0)
> +#endif
> +
> +#define KVM_S390_VIRTIO_NOTIFY          0
> +#define KVM_S390_VIRTIO_RESET           1
> +#define KVM_S390_VIRTIO_SET_STATUS      2
> +
> +#define KERN_IMAGE_START                0x010000UL
> +#define KERN_PARM_AREA                  0x010480UL
> +#define INITRD_START                    0x800000UL
> +#define INITRD_PARM_START               0x010408UL
> +#define INITRD_PARM_SIZE                0x010410UL
> +#define PARMFILE_START                  0x001000UL
> +
> +#define MAX_BLK_DEVS                    10
> +
> +static VirtIOS390Bus *s390_bus;
> +static CPUState **ipi_states;
> +
> +void irq_info(Monitor *mon);
> +void pic_info(Monitor *mon);
> +
> +void irq_info(Monitor *mon)
> +{
> +}
> +
> +void pic_info(Monitor *mon)
> +{
> +}
> +
> +CPUState *s390_cpu_addr2state(uint16_t cpu_addr)
> +{
> +    if (cpu_addr >= smp_cpus)
> +        return NULL;

coding style.

> +
> +    return ipi_states[cpu_addr];
> +}
> +
> +int s390_virtio_hypercall(CPUState *env)
> +{
> +    int r = 0, i;
> +    target_ulong mem = env->regs[2];
> +
> +    dprintf("KVM hypercall: %ld\n", env->regs[1]);
> +    switch (env->regs[1]) {
> +    case KVM_S390_VIRTIO_NOTIFY:
> +        if (mem > ram_size) {
> +            VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
> +                                                               mem, &i);
> +            if (dev) {
> +                virtio_queue_notify(dev->vdev, i);
> +            } else {
> +                r = -EINVAL;
> +            }
> +        } else {
> +            /* Early printk */
> +        }
> +        break;
> +    case KVM_S390_VIRTIO_RESET:
> +    {
> +        /* Virtio_reset resets the internal addresses, so we'd have to sync
> +           them up again. We don't want to reallicate a vring though, so let's

                                              ^^^^^ typo

> +           just not reset. */
> +        /* virtio_reset(dev->vdev); */
> +        break;
> +    }
> +    case KVM_S390_VIRTIO_SET_STATUS:
> +    {
> +        VirtIOS390Device *dev;
> +
> +        dev = s390_virtio_bus_find_mem(s390_bus, mem);
> +        if (dev)
> +            s390_virtio_device_update_status(dev);
> +        else
> +            r = -EINVAL;

coding style.

> +        break;
> +    }
> +    default:
> +        r = -EINVAL;
> +        break;
> +    }
> +
> +    env->regs[2] = r;
> +    return 0;
> +}
> +
> +/* PC hardware initialisation */
> +static void s390_init(ram_addr_t _ram_size,
> +                      const char *boot_device,
> +                      const char *kernel_filename,
> +                      const char *kernel_cmdline,
> +                      const char *initrd_filename,
> +                      const char *cpu_model)
> +{
> +    CPUState *env = NULL;
> +    ram_addr_t ram_addr, ram_size = _ram_size;
> +    ram_addr_t kernel_size = 0;
> +    ram_addr_t initrd_offset;
> +    ram_addr_t initrd_size = 0;
> +    int i;
> +
> +    /* get a BUS */
> +    s390_bus = s390_virtio_bus_init(&ram_size);
> +
> +    /* allocate RAM */
> +    ram_addr = qemu_ram_alloc(ram_size);
> +    cpu_register_physical_memory(0, ram_size, ram_addr);
> +
> +    /* init CPUs */
> +    if (cpu_model == NULL) {
> +        cpu_model = "host";
> +    }
> +
> +    ipi_states = qemu_malloc(sizeof(CPUState *) * smp_cpus);
> +
> +    for (i = 0; i < smp_cpus; i++) {
> +        env = cpu_init(cpu_model);
> +        ipi_states[smp_cpus - (i + 1)] = env;
> +        env->halted = 1;
> +        env->exception_index = EXCP_HLT;
> +    }
> +
> +    env->halted = 0;
> +    env->exception_index = 0;
> +
> +    if (kernel_filename) {
> +        kernel_size = load_image(kernel_filename, qemu_get_ram_ptr(0));
> +

You should probably use load_image_targphys() instead to reload the
kernel on reset.

> +        if (lduw_phys(KERN_IMAGE_START) != 0x0dd0) {
> +            fprintf(stderr, "Specified image is not an s390 boot image\n");
> +            exit(1);
> +        }
> +
> +        cpu_synchronize_state(env);
> +        env->psw.addr = KERN_IMAGE_START;
> +        env->psw.mask = 0x0000000180000000UL;

Shouldn't it be done by registering a reset handler, so that this value
are restored on reset?

> +    }
> +
> +    if (initrd_filename) {
> +        initrd_offset = INITRD_START;
> +        while (kernel_size + 0x100000 > initrd_offset)
> +            initrd_offset += 0x100000;

coding style.

> +        initrd_size = load_image(initrd_filename, qemu_get_ram_ptr(initrd_offset));
> +

Same as for the kernel.

> +        stq_phys(INITRD_PARM_START, initrd_offset);
> +        stq_phys(INITRD_PARM_SIZE, initrd_size);

The same way, it should probably be added with rom_add_blob_fixed().

> +    }
> +
> +    if (kernel_cmdline) {
> +        cpu_physical_memory_rw(KERN_PARM_AREA, (uint8_t *)kernel_cmdline,
> +                               strlen(kernel_cmdline), 1);

and here with pstrcpy_targphys().

> +    }
> +
> +    /* Create VirtIO console */
> +    qdev_init_nofail(qdev_create((BusState *)s390_bus, "virtio-console-s390"));
> +
> +    /* Create VirtIO network adapters */
> +    for(i = 0; i < nb_nics; i++) {
> +        NICInfo *nd = &nd_table[i];
> +        DeviceState *dev;
> +
> +        if (!nd->model)
> +            nd->model = (char*)"virtio";

What happens if someone request a nice that is not virtio? It should
probably fail.

> +        dev = qdev_create((BusState *)s390_bus, "virtio-net-s390");
> +        qdev_set_nic_properties(dev, nd);
> +        qdev_init_nofail(dev);
> +    }
> +
> +    /* Create VirtIO disk drives */
> +    for(i = 0; i < MAX_BLK_DEVS; i++) {
> +        DriveInfo *dinfo;
> +        DeviceState *dev;
> +
> +        dinfo = drive_get(IF_IDE, 0, i);
> +        if (!dinfo)
> +            continue;
> +
> +        dev = qdev_create((BusState *)s390_bus, "virtio-blk-s390");
> +        qdev_prop_set_drive(dev, "drive", dinfo);
> +        qdev_init_nofail(dev);
> +    }
> +}
> +
> +static QEMUMachine s390_machine = {
> +    .name = "s390-virtio",
> +    .alias = "s390",
> +    .desc = "VirtIO based S390 machine",
> +    .init = s390_init,
> +    .max_cpus = 255,
> +    .is_default = 1,
> +};
> +
> +static void s390_machine_init(void)
> +{
> +    qemu_register_machine(&s390_machine);
> +}
> +
> +machine_init(s390_machine_init);
> -- 
> 1.6.0.2
> 
> 
> 
> 

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
aurelien@aurel32.net                 http://www.aurel32.net