On 13.07.21 16:28, Jan Beulich wrote:
On 13.07.2021 16:23, Juergen Gross wrote:On 13.07.21 16:19, Julien Grall wrote:On 13/07/2021 15:14, Jan Beulich wrote:And I don't think it should be named XC_PAGE_*, but rather XEN_PAGE_*.Even that doesn't seem right to me, at least in principle. There shouldn't be a build time setting when it may vary at runtime. IOW on Arm I think a runtime query to the hypervisor would be needed instead.Yes, we want to be able to use the same userspace/OS without rebuilding to a specific hypervisor page size.This define is used for accessing data of other domains. See the define for XEN_PAGE_SIZE in xen/include/public/io/ring.h So it should be a constant (minimal) page size for all hypervisors and guests of an architecture.But that's only because of limitations baked into ring.h. For example, a grant shouldn't be (address,attributes), but (address,order,attributes). A frontend running in an OS with 16k page size could then still announce a single ring "page", and a backend running in an OS with 4k page size would still have no trouble mapping that ring. (The other way around would of course get more interesting.)
Right. The current interfaces don't provide this ability. For those the minimal size is "the right thing" IMO. Juergen
OpenPGP_0xB0DE9DD628BF132F.asc
Description: OpenPGP public key
OpenPGP_signature
Description: OpenPGP digital signature
