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

Re: [Xen-devel] [PULL 1/7] exec: Limit translation limiting in address_space_translate to xen

On 7 May 2014 16:22, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote:
> Fixing Xen to not truncate is not possible because of the Xen mapcache,
> unless of course QEMU is changed to avoid the mapcache completely on 64-bit
> hosts.  I'm not sure if that makes sense from the Xen point of view.
> Regarding fixing callers, a known one is virtio-scsi which is a bug and on
> my todo list.  But another is VFIO, which cannot accept truncation if the
> IOMMU page size is greater than TARGET_PAGE_SIZE.

The API can't simultaneously allow the implementation to truncate
and guarantee to the caller that we don't truncate, so one of these
has to change, surely?

Otherwise we would need to provide some sort of flag for
truncation-unacceptable so that incompatible combinations
fail nicely rather than silently doing weird stuff, I guess.

-- PMM

Xen-devel mailing list



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