[SeaBIOS] [PATCH 05/18] virtio: add version 1.0 structs and #defines

[Kevin O'Connor]

On Mon, Jun 29, 2015 at 10:53:27AM +0200, Gerd Hoffmann wrote:
> Signed-off-by: Gerd Hoffmann <kraxel at redhat.com>
> ---
>  src/hw/virtio-pci.h  | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++
>  src/hw/virtio-ring.h |  5 +++++
>  2 files changed, 64 insertions(+)
> 
> diff --git a/src/hw/virtio-pci.h b/src/hw/virtio-pci.h
> index 3cf0327..e6f9c0b 100644
> --- a/src/hw/virtio-pci.h
> +++ b/src/hw/virtio-pci.h
> @@ -40,6 +40,65 @@
>  /* Virtio ABI version, this must match exactly */
>  #define VIRTIO_PCI_ABI_VERSION          0
>  
> +
> +/* Common configuration */
> +#define VIRTIO_PCI_CAP_COMMON_CFG       1
> +/* Notifications */
> +#define VIRTIO_PCI_CAP_NOTIFY_CFG       2
> +/* ISR access */
> +#define VIRTIO_PCI_CAP_ISR_CFG          3
> +/* Device specific configuration */
> +#define VIRTIO_PCI_CAP_DEVICE_CFG       4
> +/* PCI configuration access */
> +#define VIRTIO_PCI_CAP_PCI_CFG          5
> +
> +/* This is the PCI capability header: */
> +struct virtio_pci_cap {
> +    u8 cap_vndr;          /* Generic PCI field: PCI_CAP_ID_VNDR */
> +    u8 cap_next;          /* Generic PCI field: next ptr. */
> +    u8 cap_len;           /* Generic PCI field: capability length */
> +    u8 cfg_type;          /* Identifies the structure. */
> +    u8 bar;               /* Where to find it. */
> +    u8 padding[3];        /* Pad to full dword. */
> +    u32 offset;           /* Offset within bar. */
> +    u32 length;           /* Length of the structure, in bytes. */
> +};
> +
> +struct virtio_pci_notify_cap {
> +    struct virtio_pci_cap cap;
> +    u32 notify_off_multiplier;   /* Multiplier for queue_notify_off. */
> +};
> +
> +typedef struct virtio_pci_common_cfg {
> +    /* About the whole device. */
> +    u32 device_feature_select;   /* read-write */

If I understand these structs correctly, they don't reside in memory,
but instead represent an interface layout and are used with offsetof()
and sizeof().  If so, I think they should be marked with PACKED.

BTW, it would be nice (but certainly not required) to move these types
of interface definitions to a new virtio header in the std/ directory.

-Kevin