[SeaBIOS] [PATCH 05/18] virtio: add version 1.0 structs and #defines
Kevin O'Connor
kevin at koconnor.net
Mon Jun 29 15:19:34 CEST 2015
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
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