[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: hypercalls with 64-bit results

On 17.06.21 10:00, Jan Beulich wrote:
On 17.06.2021 06:55, Juergen Gross wrote:
On 16.06.21 18:04, Jan Beulich wrote:
Since hypercalls from the tool stack are based on ioctl(), and since
ioctl() has a return type of "int", I'm afraid there's no way we can
deal with this by adjusting function return types in the libraries.
Instead we appear to need either a new privcmd ioctl or new XENMEM_*
subops (for those cases where potentially large values get returned).

I think we can just use a multicall in libxc to wrap the affected

Hmm, we might, if we're happy for these to then not work in HVM domains
(PVH Dom0, which still is experimental only, or PVH/HVM DomU-s using
the libraries for some purpose), or if we finally wire up multicalls in
the HVM case (there ought to be a reason why they aren't, but I have no
idea what that is).

Me neither, especially as on Arm they are supported.

And TBH: PVH Dom0 without multicalls might be hard anyway.


Attachment: OpenPGP_0xB0DE9DD628BF132F.asc
Description: OpenPGP public key

Attachment: OpenPGP_signature
Description: OpenPGP digital signature



Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.