On 10/16/13 19:29, Olivier Martin wrote:
> This protocol introduces an abstraction to access the VirtIo
> Configuration and Device spaces.
> The registers in these spaces are located at a different offset and have
> a different width whether the transport layer is either PCI or MMIO. This
> protocol would also allow to support VirtIo PCI devices with MSI-X
> capability in a transparent way (Device space is at a different offset
> when a PCIe device has MSI-X capability).
>
> Contributed-under: TianoCore Contribution Agreement 1.0
> Signed-off-by: Olivier Martin <[email protected]>
> ---
> OvmfPkg/Include/Protocol/VirtioDevice.h | 376
> +++++++++++++++++++++++++++++++
> OvmfPkg/OvmfPkg.dec | 1 +
> 2 files changed, 377 insertions(+), 0 deletions(-)
> create mode 100644 OvmfPkg/Include/Protocol/VirtioDevice.h
I compared this patch agains v3 03/10. I think it's good. One note:
> +// VirtIo Specification Revision: Major[31:24].Minor[23:16].Revision[15:0
> +#define VIRTIO_SPEC_REVISION(major,minor,revision) \
> + ((((major) & 0xFF) << 24) | (((minor) & 0xFF) << 16) | ((revision) &
> 0xFFFF))
and
> +struct _VIRTIO_DEVICE_PROTOCOL {
> + /// VirtIo Specification Revision encoded with VIRTIO_SPEC_REVISION()
> + UINT32 Revision;
First, if (major >= 0x80), then VIRTIO_SPEC_REVISION() invokes undefined
behavior (the shifted value cannot be represented in a signed int).
Second, I'm uncertain if tying the protocol revision number to the
virtio spec version number is going to be useful. I have no use cases in
mind right now, so I can't decide either way.
Third, the Revision field should have been UINT64 I guess -- just
because other protocols' revision fields seem to be UINT64. Anyway, 32
bits should be plenty for compatible extensions.
None of the above warrants more churn right now, so
Reviewed-by: Laszlo Ersek <[email protected]>
Thanks!
Laszlo
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