Re: [Qemu-devel] [PATCH 8/8] s390: Add new channel I/O based virtio transport.

[Alexander Graf]

On 07.12.2012, at 13:50, Cornelia Huck wrote:

> Add a new virtio transport that uses channel commands to perform
> virtio operations.
> 
> Add a new machine type s390-ccw that uses this virtio-ccw transport
> and make it the default machine for s390.
> 
> Signed-off-by: Cornelia Huck <address@hidden>
> ---
> hw/s390-virtio.c       | 149 ++++++--
> hw/s390x/Makefile.objs |   1 +
> hw/s390x/virtio-ccw.c  | 909 +++++++++++++++++++++++++++++++++++++++++++++++++
> hw/s390x/virtio-ccw.h  |  81 +++++
> trace-events           |   4 +
> 5 files changed, 1124 insertions(+), 20 deletions(-)
> create mode 100644 hw/s390x/virtio-ccw.c
> create mode 100644 hw/s390x/virtio-ccw.h
> 
> diff --git a/hw/s390-virtio.c b/hw/s390-virtio.c
> index 9e1afb2..f29ff74 100644
> --- a/hw/s390-virtio.c
> +++ b/hw/s390-virtio.c
> @@ -33,6 +33,8 @@
> 
> #include "hw/s390-virtio-bus.h"
> #include "hw/s390x/sclp.h"
> +#include "hw/s390x/css.h"
> +#include "hw/s390x/virtio-ccw.h"
> 
> //#define DEBUG_S390
> 
> @@ -47,6 +49,7 @@
> #define KVM_S390_VIRTIO_NOTIFY          0
> #define KVM_S390_VIRTIO_RESET           1
> #define KVM_S390_VIRTIO_SET_STATUS      2
> +#define KVM_S390_VIRTIO_CCW_NOTIFY      3
> 
> #define KERN_IMAGE_START                0x010000UL
> #define KERN_PARM_AREA                  0x010480UL
> @@ -63,6 +66,7 @@
> 
> static VirtIOS390Bus *s390_bus;
> static S390CPU **ipi_states;
> +VirtioCcwBus *ccw_bus;
> 
> S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
> {
> @@ -76,15 +80,21 @@ S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
> int s390_virtio_hypercall(CPUS390XState *env, uint64_t mem, uint64_t 
> hypercall)
> {
>     int r = 0, i;
> +    int cssid, ssid, schid, m;
> +    SubchDev *sch;
> 
>     dprintf("KVM hypercall: %ld\n", hypercall);
>     switch (hypercall) {
>     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);
> +            if (s390_bus) {
> +                VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus,
> +                                                                   mem, &i);
> +                if (dev) {
> +                    virtio_queue_notify(dev->vdev, i);
> +                } else {
> +                    r = -EINVAL;
> +                }
>             } else {
>                 r = -EINVAL;
>             }
> @@ -93,28 +103,49 @@ int s390_virtio_hypercall(CPUS390XState *env, uint64_t 
> mem, uint64_t hypercall)
>         }
>         break;
>     case KVM_S390_VIRTIO_RESET:
> -    {
> -        VirtIOS390Device *dev;
> -
> -        dev = s390_virtio_bus_find_mem(s390_bus, mem);
> -        virtio_reset(dev->vdev);
> -        stb_phys(dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0);
> -        s390_virtio_device_sync(dev);
> -        s390_virtio_reset_idx(dev);
> +        if (s390_bus) {
> +            VirtIOS390Device *dev;
> +
> +            dev = s390_virtio_bus_find_mem(s390_bus, mem);
> +            virtio_reset(dev->vdev);
> +            stb_phys(dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0);
> +            s390_virtio_device_sync(dev);
> +            s390_virtio_reset_idx(dev);
> +        } else {
> +            r = -EINVAL;
> +        }
>         break;
> -    }
>     case KVM_S390_VIRTIO_SET_STATUS:
> -    {
> -        VirtIOS390Device *dev;
> +        if (s390_bus) {
> +            VirtIOS390Device *dev;
> 
> -        dev = s390_virtio_bus_find_mem(s390_bus, mem);
> -        if (dev) {
> -            s390_virtio_device_update_status(dev);
> +            dev = s390_virtio_bus_find_mem(s390_bus, mem);
> +            if (dev) {
> +                s390_virtio_device_update_status(dev);
> +            } else {
> +                r = -EINVAL;
> +            }
>         } else {
>             r = -EINVAL;
>         }
>         break;
> -    }
> +    case KVM_S390_VIRTIO_CCW_NOTIFY:
> +        if (ccw_bus) {
> +            if (ioinst_disassemble_sch_ident(env->regs[2], &m, &cssid, &ssid,
> +                                             &schid)) {
> +                r = -EINVAL;
> +            } else {
> +                sch = css_find_subch(m, cssid, ssid, schid);
> +                if (sch && css_subch_visible(sch)) {
> +                    virtio_queue_notify(virtio_ccw_get_vdev(sch), 
> env->regs[3]);
> +                } else {
> +                    r = -EINVAL;
> +                }
> +            }
> +         } else {
> +             r = -EINVAL;
> +         }
> +         break;
>     default:
>         r = -EINVAL;
>         break;
> @@ -370,7 +401,6 @@ static QEMUMachine s390_machine = {
>     .no_sdcard = 1,
>     .use_virtcon = 1,
>     .max_cpus = 255,
> -    .is_default = 1,
> };
> 
> static void s390_machine_init(void)
> @@ -379,3 +409,82 @@ static void s390_machine_init(void)
> }
> 
> machine_init(s390_machine_init);
> +
> +static void ccw_init(QEMUMachineInitArgs *args)
> +{
> +    ram_addr_t my_ram_size = args->ram_size;
> +    ram_addr_t ram_size = args->ram_size;
> +    const char *cpu_model = args->cpu_model;
> +    const char *kernel_filename = args->kernel_filename;
> +    const char *kernel_cmdline = args->kernel_cmdline;
> +    const char *initrd_filename = args->initrd_filename;
> +    CPUS390XState *env = NULL;
> +    MemoryRegion *sysmem = get_system_memory();
> +    MemoryRegion *ram = g_new(MemoryRegion, 1);
> +    int shift = 0;
> +    uint8_t *storage_keys;
> +    int ret;
> +
> +    /* s390x ram size detection needs a 16bit multiplier + an increment. So
> +       guests > 64GB can be specified in 2MB steps etc. */
> +    while ((my_ram_size >> (20 + shift)) > 65535) {
> +        shift++;
> +    }
> +    my_ram_size = my_ram_size >> (20 + shift) << (20 + shift);
> +
> +    /* lets propagate the changed ram size into the global variable. */
> +    ram_size = my_ram_size;
> +
> +    /* get a BUS */
> +    ccw_bus = virtio_ccw_bus_init();
> +    s390_sclp_init();
> +
> +    /* allocate RAM */
> +    memory_region_init_ram(ram, "s390.ram", my_ram_size);
> +    vmstate_register_ram_global(ram);
> +    memory_region_add_subregion(sysmem, 0, ram);
> +
> +    /* allocate storage keys */
> +    storage_keys = g_malloc0(my_ram_size / TARGET_PAGE_SIZE);
> +
> +    /* init CPUs */
> +    env = s390_init_cpus(cpu_model, storage_keys);
> +
> +    kvm_s390_enable_css_support(env);
> +
> +    /*
> +     * Create virtual css and set it as default so that non mcss-e
> +     * enabled guests only see virtio devices.
> +     */
> +    ret = css_create_css_image(VIRTUAL_CSSID, true);
> +    assert(ret == 0);
> +
> +
> +    s390_set_up_kernel(env, kernel_filename, kernel_cmdline, 
> initrd_filename);
> +
> +    /* Create VirtIO network adapters */
> +    s390_create_virtio_net((BusState *)ccw_bus, "virtio-net-ccw");
> +
> +}
> +
> +static QEMUMachine ccw_machine = {
> +    .name = "s390-ccw-virtio",
> +    .alias = "s390-ccw",
> +    .desc = "VirtIO-ccw based S390 machine",
> +    .init = ccw_init,
> +    .no_cdrom = 1,
> +    .no_floppy = 1,
> +    .no_serial = 1,
> +    .no_parallel = 1,
> +    .no_sdcard = 1,
> +    .use_virtcon = 1,

The ccw machine should use the ASCII console as default.


Alex