[libvirt] [PATCH for-4.0 v2] virtio: Provide version-specific variants of virtio PCI devices
Cornelia Huck
cohuck at redhat.com
Thu Nov 15 11:21:55 UTC 2018
On Wed, 14 Nov 2018 21:38:31 -0200
Eduardo Habkost <ehabkost at redhat.com> wrote:
> diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
> index 813082b0d7..1d2a11504f 100644
> --- a/hw/virtio/virtio-pci.h
> +++ b/hw/virtio/virtio-pci.h
(...)
> +/**
> + * VirtioPCIDeviceTypeInfo:
> + *
> + * Template for virtio PCI device types. See virtio_pci_types_register()
> + * for details.
> + */
> +typedef struct VirtioPCIDeviceTypeInfo {
> + /* Prefix for the class names */
> + const char *name_prefix;
<bikeshed>Maybe call this the vpci_name instead? It's not really a
prefix in the way I would usually use the term, but rather a type name
with a possible suffix tacked onto it.</bikeshed>
> + /* Parent type. If NULL, TYPE_VIRTIO_PCI is used */
> + const char *parent;
> + /* If modern_only is true, only <name_prefix> type will be registered */
> + bool modern_only;
> +
> + /* Same as TypeInfo fields: */
> + size_t instance_size;
> + void (*instance_init)(Object *obj);
> + void (*class_init)(ObjectClass *klass, void *data);
> +} VirtioPCIDeviceTypeInfo;
> +
> +/*
> + * Register virtio-pci types. Each virtio-pci device type will be available
> + * in 3 flavors:
> + * - <prefix>-transitional: modern device supporting legacy drivers
> + * - Supports Conventional PCI buses only
> + * - <prefix>-non-transitional: modern-only
> + * - Supports Conventional PCI and PCI Express buses
> + * - <prefix>: virtio version configurable, legacy driver support
> + * automatically selected when device is plugged
> + * _ This was the only flavor supported until QEMU 3.1
s/_/-/
s/until/up to/ ?
> + * - Supports Conventional PCI and PCI Express buses
> + *
> + * All the types above will inherit from "<prefix>-base", so generic
> + * code can use "<prefix>-base" on type casts.
> + *
> + * We need a separate "<prefix>-base" type instead of making all types inherit
> + * from <prefix> for two reasons:
> + * 1) <prefix> will implement INTERFACE_PCIE_DEVICE, but
> + * <prefix>-transitional won't.
> + * 2) <prefix> will have the "disable-legacy" and "disable-modern" properties,
> + * <prefix>-transitional and <prefix>-non-transitional won't.
<bikeshed>I'd formulate this rather as "x implements/has something, y
and z do not", as the code actually does that (and does not just intend
to do so :)</bikeshed>
> + */
> +void virtio_pci_types_register(const VirtioPCIDeviceTypeInfo *t);
> +
> #endif
(...)
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index a954799267..0fa248d68c 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
(...)
> +static void virtio_pci_1_0_instance_init(Object *obj)
Ditch the _0? I don't expect this to change the name when virtio 1.1
arrives.
> +{
> + VirtIOPCIProxy *proxy = VIRTIO_PCI(obj);
> +
> + proxy->disable_legacy = ON_OFF_AUTO_ON;
> + proxy->disable_modern = false;
> +}
(...)
After a quick look, this seems fine; have not actually tried to run it
yet.
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