[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH] virtio: Mark virtio-device as non-user-creatabl
From: |
Eduardo Habkost |
Subject: |
Re: [Qemu-devel] [PATCH] virtio: Mark virtio-device as non-user-creatable |
Date: |
Wed, 2 Aug 2017 10:10:21 -0300 |
User-agent: |
Mutt/1.8.0 (2017-02-23) |
On Tue, Aug 01, 2017 at 08:01:55PM -0300, Eduardo Habkost wrote:
> TYPE_VIRTIO_DEVICE devices are already not usable with -device
> and device_add, but they are reported as user-creatable on
> "-device help" and through monitor interfaces.
>
> Mark them as not user-creatable to avoid confusing users, and to
> allow automated testing (e.g. scripts/device-crash-test) to skip
> them.
>
> Before this patch, device-crash-test will try to test
> virtio-device devices with all machine-types:
>
> $ time ./scripts/device-crash-test -D virtio-device -v
> ./x86_64-softmmu/qemu-system-x86_64
> [...]
> INFO: Total: 1088 test cases
> INFO: Skipped 408 test cases
>
> real 0m49.775s
>
> After this patch, the script won't try to test virtio-device
> devices:
>
> $ time ./scripts/device-crash-test -D virtio-device -v
> ./x86_64-softmmu/qemu-system-x86_64
> INFO: Total: 0 test cases
>
> real 0m0.092s
>
> Signed-off-by: Eduardo Habkost <address@hidden>
> ---
> hw/virtio/virtio.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 464947f..c4bdb94 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -2653,6 +2653,17 @@ static void virtio_device_class_init(ObjectClass
> *klass, void *data)
> dc->unrealize = virtio_device_unrealize;
> dc->bus_type = TYPE_VIRTIO_BUS;
> dc->props = virtio_properties;
> + /*
> + * Reason:
> + * - TYPE_VIRTIO_DEVICE devices are not visible to guests
> + * unless they are created and controlled by transport-specific
> + * devices (virtio-pci, virtio-mmio, and virtio-ccw).
> + * - A TYPE_VIRTIO_BUS bus is never available for plugging
> + * using -device/device_add, as virtio-bus buses are
> + * created on the fly and immediately populated by the
> + * transport-specific devices' realize methods.
> + */
Oops, I just found out that this is not true on virtio-mmio:
unused virtio-mmio-bus buses are available for plugging when
virtio-mmio devices are created.
So at least on arm, there are virtio-bus buses where
virtio-device devices can be plugged by users, and this patch is
incorrect.
> + dc->user_creatable = false;
> vdc->start_ioeventfd = virtio_device_start_ioeventfd_impl;
> vdc->stop_ioeventfd = virtio_device_stop_ioeventfd_impl;
>
> --
> 2.9.4
>
--
Eduardo