Re: [Qemu-devel] [PATCH] virtio: Introduce virtio-testdev

[Anup Patel]

Hi Andrew,

On Mon, Oct 14, 2013 at 9:29 PM, Andrew Jones <address@hidden> wrote:
> This is a virtio version of hw/misc/debugexit and should evolve into a
> virtio version of pc-testdev. pc-testdev uses the PC's ISA bus, whereas
> this testdev can be plugged into a virtio-mmio transport, which is
> needed for kvm-unit-tests/arm. virtio-testdev uses the virtio device
> config space as a communication channel, and implements an RTAS-like
> protocol through it allowing guests to execute commands. Only three
> commands are currently implemented;
> 1) VERSION: for version compatibility checks
> 2) CLEAR:   set all the config space back to zero
> 3) EXIT:    exit() from qemu with a status code

How about adding RESET command to reset the VM?

Regards,
Anup

>
> Note, the protocol also requires all data passing through the config
> space to be in little-endian.
>
> See [1] for an example of a driver for this device.
>
> [1] 
> https://github.com/rhdrjones/kvm-unit-tests/blob/ff8df5378ffccfbdf25fe79241837e61eb2258e1/lib/virtio-testdev.c
>
> Signed-off-by: Andrew Jones <address@hidden>
> ---
>  default-configs/arm-softmmu.mak |   2 +
>  hw/virtio/Makefile.objs         |   1 +
>  hw/virtio/virtio-testdev.c      | 117 
> ++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 120 insertions(+)
>  create mode 100644 hw/virtio/virtio-testdev.c
>
> diff --git a/default-configs/arm-softmmu.mak b/default-configs/arm-softmmu.mak
> index ac0815d66310f..56f8086e61974 100644
> --- a/default-configs/arm-softmmu.mak
> +++ b/default-configs/arm-softmmu.mak
> @@ -80,3 +80,5 @@ CONFIG_VERSATILE_PCI=y
>  CONFIG_VERSATILE_I2C=y
>
>  CONFIG_SDHCI=y
> +
> +CONFIG_VIRTIO_TESTDEV=y
> diff --git a/hw/virtio/Makefile.objs b/hw/virtio/Makefile.objs
> index 1ba53d9cc316c..b3d16d522f54b 100644
> --- a/hw/virtio/Makefile.objs
> +++ b/hw/virtio/Makefile.objs
> @@ -3,6 +3,7 @@ common-obj-$(CONFIG_VIRTIO_PCI) += virtio-pci.o
>  common-obj-y += virtio-bus.o
>  common-obj-y += virtio-mmio.o
>  common-obj-$(CONFIG_VIRTIO_BLK_DATA_PLANE) += dataplane/
> +common-obj-$(CONFIG_VIRTIO_TESTDEV) += virtio-testdev.o
>
>  obj-y += virtio.o virtio-balloon.o
>  obj-$(CONFIG_LINUX) += vhost.o
> diff --git a/hw/virtio/virtio-testdev.c b/hw/virtio/virtio-testdev.c
> new file mode 100644
> index 0000000000000..d6852d563702e
> --- /dev/null
> +++ b/hw/virtio/virtio-testdev.c
> @@ -0,0 +1,117 @@
> +#include "hw/virtio/virtio-bus.h"
> +
> +#define VIRTIO_ID_TESTDEV 0xffff
> +
> +#define TYPE_VIRTIO_TESTDEV "virtio-testdev"
> +#define VIRTIO_TESTDEV(obj) \
> +        OBJECT_CHECK(VirtIOTestdev, (obj), TYPE_VIRTIO_TESTDEV)
> +
> +#define TESTDEV_MAJOR_VER 1
> +#define TESTDEV_MINOR_VER 1
> +
> +#define CONFIG_SIZE 0x100
> +
> +enum {
> +    VERSION = 1,
> +    CLEAR,
> +    EXIT,
> +};
> +
> +enum { TOKEN, NARGS, NRETS, ARG1, ARG2, ARG3, ARG4, };
> +
> +#define RET1(nargs) (ARG1 + (nargs) + 0)
> +#define RET2(nargs) (ARG1 + (nargs) + 1)
> +#define RET3(nargs) (ARG1 + (nargs) + 2)
> +#define RET4(nargs) (ARG1 + (nargs) + 3)
> +
> +#define calc_len(nargs, nrets) ((3 + (nargs) + (nrets)) * 4)
> +
> +typedef struct VirtIOTestdev {
> +    VirtIODevice parent_obj;
> +    uint8_t config[CONFIG_SIZE];
> +    size_t len; /* currently used bytes */
> +} VirtIOTestdev;
> +
> +static void virtio_testdev_get_config(VirtIODevice *vdev, uint8_t 
> *config_data)
> +{
> +    VirtIOTestdev *dev = VIRTIO_TESTDEV(vdev);
> +    memcpy(config_data, &dev->config[0], dev->len);
> +}
> +
> +static void virtio_testdev_set_config(VirtIODevice *vdev,
> +                                      const uint8_t *config_data)
> +{
> +    VirtIOTestdev *dev = VIRTIO_TESTDEV(vdev);
> +    uint32_t *c32 = (uint32_t *)&dev->config[0];
> +    uint32_t token, nargs, nrets;
> +
> +    memcpy(c32, config_data, 32); /* assume write is in first 32 bytes,
> +                                     we can grab more later, if needed */
> +    token = le32_to_cpu(c32[TOKEN]);
> +    nargs = le32_to_cpu(c32[NARGS]);
> +    nrets = le32_to_cpu(c32[NRETS]);
> +
> +    if (!token) {
> +        return;
> +    }
> +
> +    switch (token) {
> +    case VERSION:
> +        c32[RET1(nargs)] =
> +            cpu_to_le32((TESTDEV_MAJOR_VER << 16) | TESTDEV_MINOR_VER);
> +        break;
> +    case CLEAR:
> +        memset(c32, 0, CONFIG_SIZE);
> +        break;
> +    case EXIT:
> +        exit((le32_to_cpu(c32[ARG1]) << 1) | 1);
> +    default:
> +        break;
> +    }
> +
> +    c32[TOKEN] = 0;
> +    dev->len = calc_len(nargs, nrets);
> +}
> +
> +static uint32_t virtio_testdev_get_features(VirtIODevice *vdev, uint32_t f)
> +{
> +    return f;
> +}
> +
> +static int virtio_testdev_init(VirtIODevice *vdev)
> +{
> +    virtio_init(vdev, "virtio-testdev", VIRTIO_ID_TESTDEV, CONFIG_SIZE);
> +    return 0;
> +}
> +
> +static int virtio_testdev_exit(DeviceState *qdev)
> +{
> +    virtio_cleanup(VIRTIO_DEVICE(qdev));
> +    return 0;
> +}
> +
> +static void virtio_testdev_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    VirtioDeviceClass *vdc = VIRTIO_DEVICE_CLASS(klass);
> +    dc->exit = virtio_testdev_exit;
> +    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
> +    vdc->init = virtio_testdev_init;
> +    vdc->get_config = virtio_testdev_get_config;
> +    vdc->set_config = virtio_testdev_set_config;
> +    vdc->get_features = virtio_testdev_get_features;
> +}
> +
> +static const TypeInfo virtio_testdev_info = {
> +    .name = TYPE_VIRTIO_TESTDEV,
> +    .parent = TYPE_VIRTIO_DEVICE,
> +    .instance_size = sizeof(VirtIOTestdev),
> +    .class_init = virtio_testdev_class_init,
> +};
> +
> +static void virtio_register_types(void)
> +{
> +    type_register_static(&virtio_testdev_info);
> +}
> +
> +type_init(virtio_register_types)
> --
> 1.8.3.1
>
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