Re: [Qemu-devel] [Xen-devel] [PATCH 1/1] xen-hvm.c: Add support for Xen access to vmport

[Ian Campbell]

On Wed, 2014-10-01 at 10:20 +0100, Stefano Stabellini wrote:
> I wonder if we could send both ioreqs at once from Xen and back from
> QEMU. Or maybe append the registers to IOREQ_TYPE_VMWARE_PORT, changing
> the size of ioreq_t only for this ioreq type.

Random idea: Why new add a IOREQ_TYPE_FULL_STATE which would be issued
for these ports and let qemu decode the fact that it is vmware
internally? That might be a more generically useful interface in the
future?

WRT to fitting all the register state in the current sized request, you
could declare that this new thing takes multiple slots.

Also, I may be wrong, but I thought most IOREQs were synchronous so only
one slot was ever used? The buffered ioreq stuff has a separate ring (or
uses a different part of the page, or something). I might be talking
nonsense here though ;-)

Ian.